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-rw-r--r--src/asm2wasm.cpp1006
-rw-r--r--src/optimizer-shared.cpp121
-rw-r--r--src/optimizer.cpp3851
-rw-r--r--src/optimizer.h119
-rw-r--r--src/parser.cpp144
-rw-r--r--src/parser.h900
-rw-r--r--src/simple_ast.cpp255
-rw-r--r--src/simple_ast.h1518
-rw-r--r--src/wasm.h818
9 files changed, 8732 insertions, 0 deletions
diff --git a/src/asm2wasm.cpp b/src/asm2wasm.cpp
new file mode 100644
index 000000000..c7be912b8
--- /dev/null
+++ b/src/asm2wasm.cpp
@@ -0,0 +1,1006 @@
+
+#include "simple_ast.h"
+#include "wasm.h"
+#include "optimizer.h"
+
+#include "optimizer-shared.cpp"
+
+using namespace cashew;
+using namespace wasm;
+
+// Utilities
+
+IString GLOBAL("global"), NAN_("NaN"), INFINITY_("Infinity"),
+ TOPMOST("topmost"),
+ INT8ARRAY("Int8Array"),
+ INT16ARRAY("Int16Array"),
+ INT32ARRAY("Int32Array"),
+ UINT8ARRAY("Uint8Array"),
+ UINT16ARRAY("Uint16Array"),
+ UINT32ARRAY("Uint32Array"),
+ FLOAT32ARRAY("Float32Array"),
+ FLOAT64ARRAY("Float64Array"),
+ IMPOSSIBLE_CONTINUE("impossible-continue"),
+ MATH("Math"),
+ IMUL("imul");
+
+
+static void abort_on(std::string why) {
+ std::cerr << why << '\n';
+ abort();
+}
+static void abort_on(std::string why, int x) {
+ std::cerr << why << ' ' << x << '\n';
+ abort();
+}
+static void abort_on(std::string why, Ref element) {
+ std::cerr << why << ' ';
+ element->stringify(std::cerr);
+ std::cerr << '\n';
+ abort();
+}
+static void abort_on(std::string why, IString element) {
+ std::cerr << why << ' ' << element.str << '\n';
+ abort();
+}
+
+// useful when we need to see our parent, in an expression stack
+struct AstStackHelper {
+ static std::vector<Ref> astStack;
+ AstStackHelper(Ref curr) {
+ astStack.push_back(curr);
+ }
+ ~AstStackHelper() {
+ astStack.pop_back();
+ }
+ Ref getParent() {
+ assert(astStack.size() >= 2);
+ return astStack[astStack.size()-2];
+ }
+};
+
+std::vector<Ref> AstStackHelper::astStack;
+
+//
+// Asm2WasmModule - converts an asm.js module into WebAssembly
+//
+
+class Asm2WasmModule : public wasm::Module {
+ wasm::Arena allocator;
+
+ // globals
+
+ unsigned nextGlobal; // next place to put a global
+ unsigned maxGlobal; // highest address we can put a global
+ struct MappedGlobal {
+ unsigned address;
+ BasicType type;
+ bool import; // if true, this is an import - we should read the value, not just set a zero
+ MappedGlobal() : address(0), type(none), import(false) {}
+ MappedGlobal(unsigned address, BasicType type, bool import) : address(address), type(type), import(import) {}
+ };
+ std::map<IString, MappedGlobal> mappedGlobals;
+
+ void allocateGlobal(IString name, BasicType type, bool import) {
+ assert(mappedGlobals.find(name) == mappedGlobals.end());
+ mappedGlobals.emplace(name, MappedGlobal(nextGlobal, type, import));
+ nextGlobal += 8;
+ assert(nextGlobal < maxGlobal);
+ }
+
+ struct View {
+ unsigned bytes;
+ bool integer, signed_;
+ View() : bytes(0) {}
+ View(unsigned bytes, bool integer, bool signed_) : bytes(bytes), integer(integer), signed_(signed_) {}
+ };
+
+ std::map<IString, View> views; // name (e.g. HEAP8) => view info
+ IString Math_imul; // imported name of Math.imul
+
+ // function types. we fill in this information as we see
+ // uses, in the first pass
+
+ std::map<IString, FunctionType> importedFunctionTypes;
+
+ void noteImportedFunctionCall(Ref ast, Ref parent, AsmData *asmData) {
+ assert(ast[0] == CALL && ast[1][0] == NAME);
+ IString importName = ast[1][1]->getIString();
+ FunctionType type;
+ type.name = IString((std::string("type$") + importName.str).c_str(), false); // TODO: make a list of such types
+ type.result = detectWasmType(parent, asmData);
+ Ref args = ast[2];
+ for (unsigned i = 0; i < args->size(); i++) {
+ type.params.push_back(detectWasmType(args[i], asmData));
+ }
+ // if we already saw this signature, verify it's the same (or else handle that)
+ if (importedFunctionTypes.find(importName) != importedFunctionTypes.end()) {
+ FunctionType& previous = importedFunctionTypes[importName];
+#if 0
+ std::cout << "compare " << importName.str << "\nfirst: ";
+ type.print(std::cout, 0);
+ std::cout << "\nsecond: ";
+ previous.print(std::cout, 0) << ".\n";
+#endif
+ if (type != previous) {
+ // merge it in. we'll add on extra 0 parameters for ones not actually used, etc.
+ for (size_t i = 0; i < type.params.size(); i++) {
+ if (previous.params.size() > i) {
+ if (previous.params[i] == none) {
+ previous.params[i] = type.params[i]; // use a more concrete type
+ } else {
+ previous.params.push_back(type.params[i]); // add a new param
+ }
+ }
+ }
+ if (previous.result == none) {
+ previous.result = type.result; // use a more concrete type
+ }
+ }
+ } else {
+ importedFunctionTypes[importName] = type;
+ }
+ }
+
+ char getSigFromType(BasicType type) {
+ switch (type) {
+ case i32: return 'i';
+ case f64: return 'd';
+ case none: return 'v';
+ default: abort();
+ }
+ }
+
+ FunctionType *getFunctionType(Ref parent, ExpressionList& operands) {
+ // generate signature
+ BasicType result = detectWasmType(parent, nullptr);
+ std::string str = "FUNCSIG$";
+ str += getSigFromType(result);
+ for (auto operand : operands) {
+ str += getSigFromType(operand->type);
+ }
+ IString sig(str.c_str(), false);
+ if (functionTypes.find(sig) == functionTypes.end()) {
+ // add new type
+ auto type = allocator.alloc<FunctionType>();
+ type->name = sig;
+ type->result = result;
+ for (auto operand : operands) {
+ type->params.push_back(operand->type);
+ }
+ functionTypes[sig] = type;
+ assert(functionTypes.find(sig) != functionTypes.end());
+ }
+ return functionTypes[sig];
+ }
+
+public:
+ Asm2WasmModule() : nextGlobal(8), maxGlobal(1000) {}
+ void processAsm(Ref ast);
+
+private:
+ BasicType asmToWasmType(AsmType asmType) {
+ switch (asmType) {
+ case ASM_INT: return BasicType::i32;
+ case ASM_DOUBLE: return BasicType::f64;
+ case ASM_NONE: return BasicType::none;
+ default: abort_on("confused detectWasmType", asmType);
+ }
+ }
+
+ BasicType detectWasmType(Ref ast, AsmData *data) {
+ return asmToWasmType(detectType(ast, data));
+ }
+
+ bool isInteger(double num) {
+ return fmod(num, 1) == 0 && double(int(num)) == num;
+ }
+ bool isInteger(Ref ast) {
+ return ast[0] == NUM && isInteger(ast[1]->getNumber());
+ }
+
+ bool isUnsignedCoercion(Ref ast) { // TODO: use detectSign?
+ if (ast[0] == BINARY && ast[1] == TRSHIFT) return true;
+ return false;
+ }
+
+ // an asm.js binary op can either be a binary or a relational in wasm
+ bool parseAsmBinaryOp(IString op, Ref left, Ref right, BinaryOp &binary, RelationalOp &relational, AsmData *asmData) {
+ if (op == PLUS) { binary = BinaryOp::Add; return true; }
+ if (op == MINUS) { binary = BinaryOp::Sub; return true; }
+ if (op == MUL) { binary = BinaryOp::Mul; return true; }
+ if (op == AND) { binary = BinaryOp::And; return true; }
+ if (op == OR) { binary = BinaryOp::Or; return true; }
+ if (op == XOR) { binary = BinaryOp::Xor; return true; }
+ if (op == LSHIFT) { binary = BinaryOp::Shl; return true; }
+ if (op == RSHIFT) { binary = BinaryOp::ShrS; return true; }
+ if (op == TRSHIFT) { binary = BinaryOp::ShrU; return true; }
+ if (op == EQ) { relational = RelationalOp::Eq; return false; }
+ if (op == NE) { relational = RelationalOp::Ne; return false; }
+ BasicType leftType = detectWasmType(left, asmData);
+#if 0
+ std::cout << "CHECK\n";
+ left->stringify(std::cout);
+ std::cout << " => ";
+ printBasicType(std::cout, leftType);
+ std::cout << '\n';
+ right->stringify(std::cout);
+ std::cout << " => ";
+ printBasicType(std::cout, detectWasmType(right, asmData));
+#endif
+ bool isInteger = leftType == BasicType::i32;
+ bool isUnsigned = isUnsignedCoercion(left) || isUnsignedCoercion(right);
+ if (op == DIV) {
+ if (isInteger) {
+ { binary = isUnsigned ? BinaryOp::DivU : BinaryOp::DivS; return true; }
+ }
+ { binary = BinaryOp::Div; return true; }
+ }
+ if (op == MOD) {
+ if (isInteger) {
+ { binary = isUnsigned ? BinaryOp::RemU : BinaryOp::RemS; return true; }
+ }
+ abort_on("non-integer rem");
+ }
+ if (op == GE) {
+ if (isInteger) {
+ { relational = isUnsigned ? RelationalOp::GeU : RelationalOp::GeS; return false; }
+ }
+ { relational = RelationalOp::Ge; return false; }
+ }
+ if (op == GT) {
+ if (isInteger) {
+ { relational = isUnsigned ? RelationalOp::GtU : RelationalOp::GtS; return false; }
+ }
+ { relational = RelationalOp::Gt; return false; }
+ }
+ if (op == LE) {
+ if (isInteger) {
+ { relational = isUnsigned ? RelationalOp::LeU : RelationalOp::LeS; return false; }
+ }
+ { relational = RelationalOp::Le; return false; }
+ }
+ if (op == LT) {
+ if (isInteger) {
+ { relational = isUnsigned ? RelationalOp::LtU : RelationalOp::LtS; return false; }
+ }
+ { relational = RelationalOp::Lt; return false; }
+ }
+ abort_on("bad wasm binary op", op);
+ }
+
+ unsigned bytesToShift(unsigned bytes) {
+ switch (bytes) {
+ case 1: return 0;
+ case 2: return 1;
+ case 4: return 2;
+ case 8: return 3;
+ default: abort();
+ }
+ }
+
+ // function table null thunks are always named b\d+
+ bool isNullThunk(IString name) {
+ const char *str = name.str;
+ if (*str != 'b') return false;
+ str++;
+ while (1) {
+ if (*str < '0' || *str > '9') return false;
+ str++;
+ if (*str == 0) break;
+ }
+ return true;
+ }
+
+ wasm::Arena tempAllocator;
+
+ std::map<unsigned, Ref> tempNums;
+
+ Literal getLiteral(Ref ast) {
+ if (ast[0] == NUM) {
+ return Literal((int32_t)ast[1]->getInteger());
+ } else if (ast[0] == UNARY_PREFIX) {
+ assert(ast[1] == MINUS && ast[2][0] == NUM);
+ return Literal((int32_t)-ast[2][1]->getInteger());
+ }
+ abort();
+ }
+
+ Function* processFunction(Ref ast);
+};
+
+void Asm2WasmModule::processAsm(Ref ast) {
+ assert(ast[0] == TOPLEVEL);
+ Ref asmFunction = ast[1][0];
+ assert(asmFunction[0] == DEFUN);
+ Ref body = asmFunction[3];
+ assert(body[0][0] == STAT && body[0][1][0] == STRING && body[0][1][1]->getIString() == IString("use asm"));
+
+ auto addImport = [&](IString name, Ref imported, BasicType type) {
+ assert(imported[0] == DOT);
+ Ref module = imported[1];
+ if (module[0] == DOT) {
+ // we can have (global.Math).floor; skip the 'Math'
+ assert(module[1][0] == NAME);
+ if (module[2] == MATH && imported[2] == IMUL) {
+ assert(Math_imul.isNull());
+ Math_imul = name;
+ return;
+ }
+ module = module[1];
+ }
+ assert(module[0] == NAME);
+ Import import;
+ import.name = name;
+ import.module = module[1]->getIString();
+ import.base = imported[2]->getIString();
+ // special-case some asm builtins
+ if (import.module == GLOBAL && (import.base == NAN_ || import.base == INFINITY_)) {
+ type = BasicType::f64;
+ }
+ if (type != BasicType::none) {
+ // wasm has no imported constants, so allocate a global, and we need to write the value into that
+ allocateGlobal(name, type, true);
+ } else {
+ imports.emplace(name, import);
+ }
+ };
+
+ // first pass - do almost everything, but function imports
+
+ for (unsigned i = 1; i < body->size(); i++) {
+ Ref curr = body[i];
+ if (curr[0] == VAR) {
+ // import, global, or table
+ for (unsigned j = 0; j < curr[1]->size(); j++) {
+ Ref pair = curr[1][j];
+ IString name = pair[0]->getIString();
+ Ref value = pair[1];
+ if (value[0] == NUM) {
+ // global int
+ assert(value[1]->getNumber() == 0);
+ allocateGlobal(name, BasicType::i32, false);
+ } else if (value[0] == BINARY) {
+ // int import
+ assert(value[1] == OR && value[3][0] == NUM && value[3][1]->getNumber() == 0);
+ Ref import = value[2]; // env.what
+ addImport(name, import, BasicType::i32);
+ } else if (value[0] == UNARY_PREFIX) {
+ // double import or global
+ assert(value[1] == PLUS);
+ Ref import = value[2];
+ if (import[0] == NUM) {
+ // global
+ assert(import[1]->getNumber() == 0);
+ allocateGlobal(name, BasicType::f64, false);
+ } else {
+ // import
+ addImport(name, import, BasicType::f64);
+ }
+ } else if (value[0] == DOT) {
+ // function import
+ addImport(name, value, BasicType::none);
+ } else if (value[0] == NEW) {
+ // ignore imports of typed arrays, but note the names of the arrays
+ value = value[1];
+ assert(value[0] == CALL);
+ Ref constructor = value[1];
+ assert(constructor[0] == DOT); // global.*Array
+ IString heap = constructor[2]->getIString();
+ unsigned bytes;
+ bool integer, signed_;
+ if (heap == INT8ARRAY) {
+ bytes = 1; integer = true; signed_ = true;
+ } else if (heap == INT16ARRAY) {
+ bytes = 2; integer = true; signed_ = true;
+ } else if (heap == INT32ARRAY) {
+ bytes = 4; integer = true; signed_ = true;
+ } else if (heap == UINT8ARRAY) {
+ bytes = 1; integer = true; signed_ = false;
+ } else if (heap == UINT16ARRAY) {
+ bytes = 2; integer = true; signed_ = false;
+ } else if (heap == UINT32ARRAY) {
+ bytes = 4; integer = true; signed_ = false;
+ } else if (heap == FLOAT32ARRAY) {
+ bytes = 4; integer = false; signed_ = true;
+ } else if (heap == FLOAT64ARRAY) {
+ bytes = 8; integer = false; signed_ = true;
+ }
+ assert(views.find(name) == views.end());
+ views.emplace(name, View(bytes, integer, signed_));
+ } else if (value[0] == ARRAY) {
+ // function table. we "merge" them, so e.g. [foo, b1] , [b2, bar] => [foo, bar] , assuming b* are the aborting thunks
+ // TODO: we can drop some b*s at the end of the table
+ Ref contents = value[1];
+ for (unsigned k = 0; k < contents->size(); k++) {
+ IString curr = contents[k][1]->getIString();
+ if (table.vars.size() <= k) {
+ table.vars.push_back(curr);
+ } else {
+ if (isNullThunk(table.vars[k])) {
+ table.vars[k] = curr;
+ } else {
+ assert(isNullThunk(curr) && "cannot have aliasing function pointers");
+ }
+ }
+ }
+ } else {
+ abort_on("invalid var element", pair);
+ }
+ }
+ } else if (curr[0] == DEFUN) {
+ // function
+ functions.push_back(processFunction(curr));
+ } else if (curr[0] == RETURN) {
+ // exports
+ Ref object = curr[1];
+ Ref contents = curr[1][1];
+ for (unsigned k = 0; k < contents->size(); k++) {
+ Ref pair = contents[k];
+ IString key = pair[0]->getIString();
+ Ref value = pair[1];
+ assert(value[0] == NAME);
+ Export export_;
+ export_.name = key;
+ export_.value = value[1]->getIString();
+ exports.push_back(export_);
+ }
+ }
+ }
+
+ // second pass - function imports
+
+ std::vector<IString> toErase;
+
+ for (auto& pair : imports) {
+ IString name = pair.first;
+ Import& import = pair.second;
+ if (importedFunctionTypes.find(name) != importedFunctionTypes.end()) {
+ import.type = importedFunctionTypes[name];
+ } else {
+ // never actually used
+ toErase.push_back(name);
+ }
+ }
+
+ for (auto curr : toErase) {
+ imports.erase(curr);
+ }
+
+ // cleanups
+
+ tempAllocator.clear();
+}
+
+Function* Asm2WasmModule::processFunction(Ref ast) {
+ auto function = allocator.alloc<Function>();
+ function->name = ast[1]->getIString();
+ Ref params = ast[2];
+ Ref body = ast[3];
+
+ unsigned nextId = 0;
+ auto getNextId = [&nextId](std::string prefix) {
+ return IString((prefix + '$' + std::to_string(nextId++)).c_str(), false);
+ };
+
+ // given an asm.js label, returns the wasm label for breaks or continues
+ auto getBreakLabelName = [](IString label) {
+ return IString((std::string("label$break$") + label.str).c_str(), false);
+ };
+ auto getContinueLabelName = [](IString label) {
+ return IString((std::string("label$continue$") + label.str).c_str(), false);
+ };
+
+ IStringSet functionVariables; // params or locals
+
+ IString parentLabel; // set in LABEL, then read in WHILE/DO
+ std::vector<IString> breakStack; // where a break will go
+ std::vector<IString> continueStack; // where a continue will go
+
+ AsmData asmData; // need to know var and param types, for asm type detection
+
+ for (unsigned i = 0; i < params->size(); i++) {
+ Ref curr = body[i];
+ assert(curr[0] == STAT);
+ curr = curr[1];
+ assert(curr[0] == ASSIGN && curr[2][0] == NAME);
+ IString name = curr[2][1]->getIString();
+ AsmType asmType = detectType(curr[3]);
+ function->params.emplace_back(name, asmToWasmType(asmType));
+ functionVariables.insert(name);
+ asmData.addParam(name, asmType);
+ }
+ unsigned start = params->size();
+ while (start < body->size() && body[start][0] == VAR) {
+ Ref curr = body[start];
+ for (unsigned j = 0; j < curr[1]->size(); j++) {
+ Ref pair = curr[1][j];
+ IString name = pair[0]->getIString();
+ AsmType asmType = detectType(pair[1], nullptr, true);
+ function->locals.emplace_back(name, asmToWasmType(asmType));
+ functionVariables.insert(name);
+ asmData.addVar(name, asmType);
+ }
+ start++;
+ }
+
+ bool seenReturn = false; // function->result is updated if we see a return
+ bool needTopmost = false; // we label the topmost b lock if we need one for a return
+ // processors
+ std::function<Expression* (Ref, unsigned)> processStatements;
+ std::function<Expression* (Ref, unsigned)> processUnshifted;
+
+ bool debug = !!getenv("ASM2WASM_DEBUG") && getenv("ASM2WASM_DEBUG")[0] != '0';
+
+ std::function<Expression* (Ref)> process = [&](Ref ast) -> Expression* {
+ AstStackHelper astStackHelper(ast); // TODO: only create one when we need it?
+ if (debug) {
+ std::cout << "at: ";
+ ast->stringify(std::cout);
+ std::cout << '\n';
+ }
+ IString what = ast[0]->getIString();
+ if (what == STAT) {
+ return process(ast[1]); // and drop return value, if any
+ } else if (what == ASSIGN) {
+ if (ast[2][0] == NAME) {
+ IString name = ast[2][1]->getIString();
+ if (functionVariables.has(name)) {
+ auto ret = allocator.alloc<SetLocal>();
+ ret->id = ast[2][1]->getIString();
+ ret->value = process(ast[3]);
+ ret->type = ret->value->type;
+ return ret;
+ }
+ // global var, do a store to memory
+ assert(mappedGlobals.find(name) != mappedGlobals.end());
+ MappedGlobal global = mappedGlobals[name];
+ auto ret = allocator.alloc<Store>();
+ ret->bytes = getBasicTypeSize(global.type);
+ ret->float_ = isFloat(global.type);
+ ret->offset = 0;
+ ret->align = ret->bytes;
+ auto ptr = allocator.alloc<Const>();
+ ptr->value.type = BasicType::i32; // XXX for wasm64, need 64
+ ptr->value.i32 = global.address;
+ ret->ptr = ptr;
+ ret->value = process(ast[3]);
+ ret->type = global.type;
+ return ret;
+ } else if (ast[2][0] == SUB) {
+ Ref target = ast[2];
+ assert(target[1][0] == NAME);
+ IString heap = target[1][1]->getIString();
+ assert(views.find(heap) != views.end());
+ View& view = views[heap];
+ auto ret = allocator.alloc<Store>();
+ ret->bytes = view.bytes;
+ ret->float_ = !view.integer;
+ ret->offset = 0;
+ ret->align = view.bytes;
+ ret->ptr = processUnshifted(target[2], view.bytes);
+ ret->value = process(ast[3]);
+ ret->type = ret->value->type;
+ return ret;
+ }
+ abort_on("confusing assign", ast);
+ } else if (what == BINARY) {
+ if (ast[1] == OR && ast[3][0] == NUM && ast[3][1]->getNumber() == 0) {
+ auto ret = process(ast[2]); // just look through the ()|0 coercion
+ ret->type = BasicType::i32; // we add it here for e.g. call coercions
+ return ret;
+ }
+ BinaryOp binary;
+ RelationalOp relational;
+ bool isBinary = parseAsmBinaryOp(ast[1]->getIString(), ast[2], ast[3], binary, relational, &asmData);
+ if (isBinary) {
+ auto ret = allocator.alloc<Binary>();
+ ret->op = binary;
+ ret->left = process(ast[2]);
+ ret->right = process(ast[3]);
+ ret->type = ret->left->type;
+ return ret;
+ } else {
+ auto ret = allocator.alloc<Compare>();
+ ret->op = relational;
+ ret->left = process(ast[2]);
+ ret->right = process(ast[3]);
+ return ret;
+ }
+ } else if (what == NUM) {
+ auto ret = allocator.alloc<Const>();
+ double num = ast[1]->getNumber();
+ if (isInteger(num)) {
+ ret->value.type = BasicType::i32;
+ ret->value.i32 = num;
+ } else {
+ ret->value.type = BasicType::f64;
+ ret->value.f64 = num;
+ }
+ ret->type = ret->value.type;
+ return ret;
+ } else if (what == NAME) {
+ IString name = ast[1]->getIString();
+ if (functionVariables.has(name)) {
+ // var in scope
+ auto ret = allocator.alloc<GetLocal>();
+ ret->id = name;
+ ret->type = asmToWasmType(asmData.getType(name));
+ return ret;
+ }
+ // global var, do a load from memory
+ assert(mappedGlobals.find(name) != mappedGlobals.end());
+ MappedGlobal global = mappedGlobals[name];
+ auto ret = allocator.alloc<Load>();
+ ret->bytes = getBasicTypeSize(global.type);
+ ret->signed_ = true; // but doesn't matter
+ ret->float_ = isFloat(global.type);
+ ret->offset = 0;
+ ret->align = ret->bytes;
+ auto ptr = allocator.alloc<Const>();
+ ptr->value.type = BasicType::i32; // XXX for wasm64, need 64
+ ptr->value.i32 = global.address;
+ ret->ptr = ptr;
+ ret->type = global.type;
+ return ret;
+ } else if (what == SUB) {
+ Ref target = ast[1];
+ assert(target[0] == NAME);
+ IString heap = target[1]->getIString();
+ assert(views.find(heap) != views.end());
+ View& view = views[heap];
+ auto ret = allocator.alloc<Load>();
+ ret->bytes = view.bytes;
+ ret->signed_ = view.signed_;
+ ret->float_ = !view.integer;
+ ret->offset = 0;
+ ret->align = view.bytes;
+ ret->ptr = processUnshifted(ast[2], view.bytes);
+ ret->type = getBasicType(view.bytes, !view.integer);
+ return ret;
+ } else if (what == UNARY_PREFIX) {
+ if (ast[1] == PLUS) {
+ if (ast[2][0] == NUM) {
+ auto ret = allocator.alloc<Const>();
+ ret->value.type = BasicType::f64;
+ ret->value.f64 = ast[2][1]->getNumber();
+ ret->type = ret->value.type;
+ return ret;
+ }
+ AsmType childType = detectType(ast[2], &asmData);
+ if (childType == ASM_INT) {
+ auto ret = allocator.alloc<Convert>();
+ ret->op = isUnsignedCoercion(ast[2]) ? ConvertUInt32 : ConvertSInt32;
+ ret->value = process(ast[2]);
+ ret->type = BasicType::i32;
+ return ret;
+ }
+ assert(childType == ASM_NONE); // e.g. a coercion on a call
+ auto ret = process(ast[2]); // just look through the +() coercion
+ ret->type = BasicType::f64; // we add it here for e.g. call coercions
+ return ret;
+ } else if (ast[1] == MINUS) {
+ if (ast[2][0] == NUM) {
+ auto ret = allocator.alloc<Const>();
+ ret->value = getLiteral(ast);
+ ret->type = ret->value.type;
+ return ret;
+ }
+ AsmType asmType = detectType(ast[2], &asmData);
+ if (asmType == ASM_INT) {
+ // wasm has no unary negation for int, so do 0-
+ auto ret = allocator.alloc<Binary>();
+ ret->op = Sub;
+ ret->left = allocator.alloc<Const>()->set(Literal((int32_t)0));
+ ret->right = process(ast[2]);
+ ret->type = BasicType::i32;
+ return ret;
+ }
+ assert(asmType == ASM_DOUBLE);
+ auto ret = allocator.alloc<Unary>();
+ ret->op = Neg;
+ ret->value = process(ast[2]);
+ ret->type = BasicType::f64;
+ return ret;
+ } else if (ast[1] == B_NOT) {
+ // ~, might be ~~ as a coercion or just a not
+ if (ast[2][0] == UNARY_PREFIX && ast[2][1] == B_NOT) {
+ auto ret = allocator.alloc<Convert>();
+ ret->op = TruncSFloat64; // equivalent to U, except for error handling, which asm.js doesn't have anyhow
+ ret->value = process(ast[2][2]);
+ ret->type = BasicType::i32;
+ return ret;
+ }
+ // no bitwise unary not, so do xor with -1
+ auto ret = allocator.alloc<Binary>();
+ ret->op = Xor;
+ ret->left = process(ast[2]);
+ ret->right = allocator.alloc<Const>()->set(Literal(int32_t(-1)));
+ ret->type = BasicType::i32;
+ return ret;
+ } else if (ast[1] == L_NOT) {
+ // no logical unary not, so do == 0
+ auto ret = allocator.alloc<Compare>();
+ ret->op = Eq;
+ ret->left = process(ast[2]);
+ ret->right = allocator.alloc<Const>()->set(Literal(0));
+ return ret;
+ }
+ abort_on("bad unary", ast);
+ } else if (what == IF) {
+ auto ret = allocator.alloc<If>();
+ ret->condition = process(ast[1]);
+ ret->ifTrue = process(ast[2]);
+ ret->ifFalse = !!ast[3] ? process(ast[3]) : nullptr;
+ return ret;
+ } else if (what == CALL) {
+ if (ast[1][0] == NAME) {
+ IString name = ast[1][1]->getIString();
+ if (name == Math_imul) {
+ auto ret = allocator.alloc<Binary>();
+ ret->op = Mul;
+ ret->left = process(ast[2][0]);
+ ret->right = process(ast[2][1]);
+ ret->type = BasicType::i32;
+ return ret;
+ }
+ Call* ret;
+ if (imports.find(name) != imports.end()) {
+ ret = allocator.alloc<CallImport>();
+ noteImportedFunctionCall(ast, astStackHelper.getParent(), &asmData);
+ } else {
+ ret = allocator.alloc<Call>();
+ }
+ ret->target = name;
+ Ref args = ast[2];
+ for (unsigned i = 0; i < args->size(); i++) {
+ ret->operands.push_back(process(args[i]));
+ }
+ return ret;
+ }
+ // function pointers
+ auto ret = allocator.alloc<CallIndirect>();
+ Ref target = ast[1];
+ assert(target[0] == SUB && target[1][0] == NAME && target[2][0] == BINARY && target[2][1] == AND && target[2][3][0] == NUM); // FUNCTION_TABLE[(expr) & mask]
+ ret->target = process(target[2][2]);
+ Ref args = ast[2];
+ for (unsigned i = 0; i < args->size(); i++) {
+ ret->operands.push_back(process(args[i]));
+ }
+ ret->type = getFunctionType(astStackHelper.getParent(), ret->operands);
+ return ret;
+ } else if (what == RETURN) {
+ BasicType type = !!ast[1] ? detectWasmType(ast[1], &asmData) : none;
+ if (seenReturn) {
+ assert(function->result == type);
+ } else {
+ function->result = type;
+ }
+ // wasm has no return, so we just break on the topmost block
+ needTopmost = true;
+ auto ret = allocator.alloc<Break>();
+ ret->var = TOPMOST;
+ ret->condition = nullptr;
+ ret->value = !!ast[1] ? process(ast[1]) : nullptr;
+ return ret;
+ } else if (what == BLOCK) {
+ return processStatements(ast[1], 0);
+ } else if (what == BREAK) {
+ auto ret = allocator.alloc<Break>();
+ assert(breakStack.size() > 0);
+ ret->var = !!ast[1] ? getBreakLabelName(ast[1]->getIString()) : breakStack.back();
+ ret->condition = nullptr;
+ ret->value = nullptr;
+ return ret;
+ } else if (what == CONTINUE) {
+ auto ret = allocator.alloc<Break>();
+ assert(continueStack.size() > 0);
+ ret->var = !!ast[1] ? getContinueLabelName(ast[1]->getIString()) : continueStack.back();
+ ret->condition = nullptr;
+ ret->value = nullptr;
+ return ret;
+ } else if (what == WHILE) {
+ bool forever = ast[1][0] == NUM && ast[1][1]->getInteger() == 1;
+ auto ret = allocator.alloc<Loop>();
+ IString out, in;
+ if (!parentLabel.isNull()) {
+ out = getBreakLabelName(parentLabel);
+ in = getContinueLabelName(parentLabel);
+ parentLabel = IString();
+ } else {
+ out = getNextId("while-out");
+ in = getNextId("while-in");
+ }
+ ret->out = out;
+ ret->in = in;
+ breakStack.push_back(out);
+ continueStack.push_back(in);
+ if (forever) {
+ ret->body = process(ast[2]);
+ } else {
+ Break *continueWhile = allocator.alloc<Break>();
+ continueWhile->var = in;
+ continueWhile->condition = process(ast[1]);
+ continueWhile->value = nullptr;
+ auto body = allocator.alloc<Block>();
+ body->list.push_back(continueWhile);
+ body->list.push_back(process(ast[2]));
+ ret->body = body;
+ }
+ continueStack.pop_back();
+ breakStack.pop_back();
+ return ret;
+ } else if (what == DO) {
+ if (ast[1][0] == NUM && ast[1][1]->getNumber() == 0) {
+ // one-time loop
+ auto block = allocator.alloc<Block>();
+ IString stop;
+ if (!parentLabel.isNull()) {
+ stop = getBreakLabelName(parentLabel);
+ parentLabel = IString();
+ } else {
+ stop = getNextId("do-once");
+ }
+ block->var = stop;
+ breakStack.push_back(stop);
+ continueStack.push_back(IMPOSSIBLE_CONTINUE);
+ block->list.push_back(process(ast[2]));
+ continueStack.pop_back();
+ breakStack.pop_back();
+ return block;
+ }
+ // general do-while loop
+ auto ret = allocator.alloc<Loop>();
+ IString out, in;
+ if (!parentLabel.isNull()) {
+ out = getBreakLabelName(parentLabel);
+ in = getContinueLabelName(parentLabel);
+ parentLabel = IString();
+ } else {
+ out = getNextId("do-out");
+ in = getNextId("do-in");
+ }
+ ret->out = out;
+ ret->in = in;
+ breakStack.push_back(out);
+ continueStack.push_back(in);
+ ret->body = process(ast[2]);
+ continueStack.pop_back();
+ breakStack.pop_back();
+ Break *continueIf = allocator.alloc<Break>();
+ continueIf->var = in;
+ continueIf->condition = process(ast[1]);
+ continueIf->value = nullptr;
+ if (Block *block = dynamic_cast<Block*>(ret->body)) {
+ block->list.push_back(continueIf);
+ } else {
+ auto newBody = allocator.alloc<Block>();
+ newBody->list.push_back(ret->body);
+ newBody->list.push_back(continueIf);
+ ret->body = newBody;
+ }
+ return ret;
+ } else if (what == LABEL) {
+ parentLabel = ast[1]->getIString();
+ return process(ast[2]);
+ } else if (what == CONDITIONAL) {
+ auto ret = allocator.alloc<If>();
+ ret->condition = process(ast[1]);
+ ret->ifTrue = process(ast[2]);
+ ret->ifFalse = process(ast[3]);
+ return ret;
+ } else if (what == SEQ) {
+ auto ret = allocator.alloc<Block>();
+ ret->list.push_back(process(ast[1]));
+ ret->list.push_back(process(ast[2]));
+ return ret;
+ } else if (what == SWITCH) {
+ IString name = getNextId("switch");
+ breakStack.push_back(name);
+ auto ret = allocator.alloc<Switch>();
+ ret->var = name;
+ ret->value = process(ast[1]);
+ Ref cases = ast[2];
+ for (unsigned i = 0; i < cases->size(); i++) {
+ Ref curr = cases[i];
+ Ref condition = curr[0];
+ Ref body = curr[1];
+ if (condition->isNull()) {
+ ret->default_ = processStatements(body, 0);
+ } else {
+ assert(condition[0] == NUM || condition[0] == UNARY_PREFIX);
+ Switch::Case case_;
+ case_.value = getLiteral(condition);
+ case_.body = processStatements(body, 0);
+ case_.fallthru = false; // XXX we assume no fallthru, ever
+ ret->cases.push_back(case_);
+ }
+ }
+ breakStack.pop_back();
+ return ret;
+ }
+ abort_on("confusing expression", ast);
+ };
+
+ // given HEAP32[addr >> 2], we need an absolute address, and would like to remove that shift.
+ // if there is a shift, we can just look through it, etc.
+ processUnshifted = [&](Ref ptr, unsigned bytes) {
+ unsigned shifts = bytesToShift(bytes);
+ if (ptr[0] == BINARY && ptr[1] == RSHIFT && ptr[3][0] == NUM && ptr[3][1]->getInteger() == shifts) {
+ return process(ptr[2]); // look through it
+ } else if (ptr[0] == NUM) {
+ // constant, apply a shift (e.g. HEAP32[1] is address 4)
+ unsigned addr = ptr[1]->getInteger();
+ unsigned shifted = addr << shifts;
+ auto ret = allocator.alloc<Const>();
+ ret->value.type = BasicType::i32;
+ ret->value.i32 = shifted;
+ return (Expression*)ret;
+ }
+ abort_on("bad processUnshifted", ptr);
+ };
+
+ processStatements = [&](Ref ast, unsigned from) {
+ auto block = allocator.alloc<Block>();
+ for (unsigned i = from; i < ast->size(); i++) {
+ block->list.push_back(process(ast[i]));
+ }
+ return block;
+ };
+ // body
+ function->body = processStatements(body, start);
+ if (needTopmost) {
+ Block* topmost = dynamic_cast<Block*>(function->body);
+ assert(topmost);
+ topmost->var = TOPMOST;
+ }
+ // cleanups/checks
+ assert(breakStack.size() == 0 && continueStack.size() == 0);
+
+ return function;
+}
+
+int main(int argc, char **argv) {
+ char *infile = argv[1];
+
+ printf("loading '%s'...\n", infile);
+ FILE *f = fopen(argv[1], "r");
+ assert(f);
+ fseek(f, 0, SEEK_END);
+ int size = ftell(f);
+ char *input = new char[size+1];
+ rewind(f);
+ int num = fread(input, 1, size, f);
+ // On Windows, ftell() gives the byte position (\r\n counts as two bytes), but when
+ // reading, fread() returns the number of characters read (\r\n is read as one char \n, and counted as one),
+ // so return value of fread can be less than size reported by ftell, and that is normal.
+ assert((num > 0 || size == 0) && num <= size);
+ fclose(f);
+ input[num] = 0;
+
+ /*
+ // Separate asm modules look like
+ //
+ // Module["asm"] = (function(global, env, buffer) {
+ //
+ // , we can remove the part until the function.
+ */
+
+ printf("parsing...\n");
+ cashew::Parser<Ref, ValueBuilder> builder;
+ Ref asmjs = builder.parseToplevel(input);
+
+ //asmjs->stringify(std::cout);
+ //std::cout << '\n';
+
+ printf("wasming...\n");
+ Asm2WasmModule wasm;
+ wasm.processAsm(asmjs);
+
+ printf("printing...\n");
+ wasm.print(std::cout);
+
+ printf("done.\n");
+ printf("TODO: get memory for globals, and clear it to zero; and read values for imports\n");
+}
+
diff --git a/src/optimizer-shared.cpp b/src/optimizer-shared.cpp
new file mode 100644
index 000000000..9072d6c48
--- /dev/null
+++ b/src/optimizer-shared.cpp
@@ -0,0 +1,121 @@
+
+IString ASM_FLOAT_ZERO;
+
+IString SIMD_INT8X16_CHECK("SIMD_Int8x16_check"),
+ SIMD_INT16X8_CHECK("SIMD_Int16x8_check"),
+ SIMD_INT32X4_CHECK("SIMD_Int32x4_check"),
+ SIMD_FLOAT32X4_CHECK("SIMD_Float32x4_check"),
+ SIMD_FLOAT64X2_CHECK("SIMD_Float64x2_check");
+
+bool isInteger(double x) {
+ return fmod(x, 1) == 0;
+}
+
+bool isInteger32(double x) {
+ return isInteger(x) && (x == (int32_t)x || x == (uint32_t)x);
+}
+
+int parseInt(const char *str) {
+ int ret = *str - '0';
+ while (*(++str)) {
+ ret *= 10;
+ ret += *str - '0';
+ }
+ return ret;
+}
+
+HeapInfo parseHeap(const char *name) {
+ HeapInfo ret;
+ if (name[0] != 'H' || name[1] != 'E' || name[2] != 'A' || name[3] != 'P') {
+ ret.valid = false;
+ return ret;
+ }
+ ret.valid = true;
+ ret.unsign = name[4] == 'U';
+ ret.floaty = name[4] == 'F';
+ ret.bits = parseInt(name + (ret.unsign || ret.floaty ? 5 : 4));
+ ret.type = !ret.floaty ? ASM_INT : (ret.bits == 64 ? ASM_DOUBLE : ASM_FLOAT);
+ return ret;
+}
+
+AsmType detectType(Ref node, AsmData *asmData, bool inVarDef) {
+ switch (node[0]->getCString()[0]) {
+ case 'n': {
+ if (node[0] == NUM) {
+ if (!isInteger(node[1]->getNumber())) return ASM_DOUBLE;
+ return ASM_INT;
+ } else if (node[0] == NAME) {
+ if (asmData) {
+ AsmType ret = asmData->getType(node[1]->getCString());
+ if (ret != ASM_NONE) return ret;
+ }
+ if (!inVarDef) {
+ if (node[1] == INF || node[1] == NaN) return ASM_DOUBLE;
+ if (node[1] == TEMP_RET0) return ASM_INT;
+ return ASM_NONE;
+ }
+ // We are in a variable definition, where Math_fround(0) optimized into a global constant becomes f0 = Math_fround(0)
+ if (ASM_FLOAT_ZERO.isNull()) ASM_FLOAT_ZERO = node[1]->getIString();
+ else assert(node[1] == ASM_FLOAT_ZERO);
+ return ASM_FLOAT;
+ }
+ break;
+ }
+ case 'u': {
+ if (node[0] == UNARY_PREFIX) {
+ switch (node[1]->getCString()[0]) {
+ case '+': return ASM_DOUBLE;
+ case '-': return detectType(node[2], asmData, inVarDef);
+ case '!': case '~': return ASM_INT;
+ }
+ break;
+ }
+ break;
+ }
+ case 'c': {
+ if (node[0] == CALL) {
+ if (node[1][0] == NAME) {
+ IString name = node[1][1]->getIString();
+ if (name == MATH_FROUND) return ASM_FLOAT;
+ else if (name == SIMD_FLOAT32X4 || name == SIMD_FLOAT32X4_CHECK) return ASM_FLOAT32X4;
+ else if (name == SIMD_FLOAT64X2 || name == SIMD_FLOAT64X2_CHECK) return ASM_FLOAT64X2;
+ else if (name == SIMD_INT8X16 || name == SIMD_INT8X16_CHECK) return ASM_INT8X16;
+ else if (name == SIMD_INT16X8 || name == SIMD_INT16X8_CHECK) return ASM_INT16X8;
+ else if (name == SIMD_INT32X4 || name == SIMD_INT32X4_CHECK) return ASM_INT32X4;
+ }
+ return ASM_NONE;
+ } else if (node[0] == CONDITIONAL) {
+ return detectType(node[2], asmData, inVarDef);
+ }
+ break;
+ }
+ case 'b': {
+ if (node[0] == BINARY) {
+ switch (node[1]->getCString()[0]) {
+ case '+': case '-':
+ case '*': case '/': case '%': return detectType(node[2], asmData, inVarDef);
+ case '|': case '&': case '^': case '<': case '>': // handles <<, >>, >>=, <=, >=
+ case '=': case '!': { // handles ==, !=
+ return ASM_INT;
+ }
+ }
+ }
+ break;
+ }
+ case 's': {
+ if (node[0] == SEQ) {
+ return detectType(node[2], asmData, inVarDef);
+ } else if (node[0] == SUB) {
+ assert(node[1][0] == NAME);
+ HeapInfo info = parseHeap(node[1][1]->getCString());
+ if (info.valid) return ASM_NONE;
+ return info.floaty ? ASM_DOUBLE : ASM_INT; // XXX ASM_FLOAT?
+ }
+ break;
+ }
+ }
+ //dump("horrible", node);
+ //assert(0);
+ return ASM_NONE;
+}
+
diff --git a/src/optimizer.cpp b/src/optimizer.cpp
new file mode 100644
index 000000000..d569fb928
--- /dev/null
+++ b/src/optimizer.cpp
@@ -0,0 +1,3851 @@
+#include <cstdint>
+#include <cstdio>
+#include <cmath>
+#include <string>
+#include <algorithm>
+#include <map>
+
+#include "simple_ast.h"
+#include "optimizer.h"
+
+#include "optimizer-shared.cpp"
+
+typedef std::vector<IString> StringVec;
+
+//==================
+// Globals
+//==================
+
+Ref extraInfo;
+
+//==================
+// Infrastructure
+//==================
+
+template<class T, class V>
+int indexOf(T list, V value) {
+ for (size_t i = 0; i < list.size(); i++) {
+ if (list[i] == value) return i;
+ }
+ return -1;
+}
+
+int jsD2I(double x) {
+ return (int)((int64_t)x);
+}
+
+char *strdupe(const char *str) {
+ char *ret = (char *)malloc(strlen(str)+1); // leaked!
+ strcpy(ret, str);
+ return ret;
+}
+
+IString getHeapStr(int x, bool unsign) {
+ switch (x) {
+ case 8: return unsign ? HEAPU8 : HEAP8;
+ case 16: return unsign ? HEAPU16 : HEAP16;
+ case 32: return unsign ? HEAPU32 : HEAP32;
+ }
+ assert(0);
+ return ":(";
+}
+
+Ref deStat(Ref node) {
+ if (node[0] == STAT) return node[1];
+ return node;
+}
+
+Ref getStatements(Ref node) {
+ if (node[0] == DEFUN) {
+ return node[3];
+ } else if (node[0] == BLOCK) {
+ return node->size() > 1 ? node[1] : nullptr;
+ } else {
+ return arena.alloc();
+ }
+}
+
+// Types
+
+AsmType intToAsmType(int type) {
+ if (type >= 0 && type <= ASM_NONE) return (AsmType)type;
+ else {
+ assert(0);
+ return ASM_NONE;
+ }
+}
+
+// forward decls
+Ref makeEmpty();
+bool isEmpty(Ref node);
+Ref makeAsmVarDef(const IString& v, AsmType type);
+Ref makeArray(int size_hint);
+Ref makeBool(bool b);
+Ref makeNum(double x);
+Ref makeName(IString str);
+Ref makeAsmCoercion(Ref node, AsmType type);
+Ref make1(IString type, Ref a);
+Ref make3(IString type, Ref a, Ref b, Ref c);
+
+AsmData::AsmData(Ref f) {
+ func = f;
+
+ // process initial params
+ Ref stats = func[3];
+ size_t i = 0;
+ while (i < stats->size()) {
+ Ref node = stats[i];
+ if (node[0] != STAT || node[1][0] != ASSIGN || node[1][2][0] != NAME) break;
+ node = node[1];
+ Ref name = node[2][1];
+ int index = func[2]->indexOf(name);
+ if (index < 0) break; // not an assign into a parameter, but a global
+ IString& str = name->getIString();
+ if (locals.count(str) > 0) break; // already done that param, must be starting function body
+ locals[str] = Local(detectType(node[3]), true);
+ params.push_back(str);
+ stats[i] = makeEmpty();
+ i++;
+ }
+ // process initial variable definitions and remove '= 0' etc parts - these
+ // are not actually assignments in asm.js
+ while (i < stats->size()) {
+ Ref node = stats[i];
+ if (node[0] != VAR) break;
+ for (size_t j = 0; j < node[1]->size(); j++) {
+ Ref v = node[1][j];
+ IString& name = v[0]->getIString();
+ Ref value = v[1];
+ if (locals.count(name) == 0) {
+ locals[name] = Local(detectType(value, nullptr, true), false);
+ vars.push_back(name);
+ v->setSize(1); // make an un-assigning var
+ } else {
+ assert(j == 0); // cannot break in the middle
+ goto outside;
+ }
+ }
+ i++;
+ }
+ outside:
+ // look for other var definitions and collect them
+ while (i < stats->size()) {
+ traversePre(stats[i], [&](Ref node) {
+ Ref type = node[0];
+ if (type == VAR) {
+ dump("bad, seeing a var in need of fixing", func);
+ abort(); //, 'should be no vars to fix! ' + func[1] + ' : ' + JSON.stringify(node));
+ }
+ });
+ i++;
+ }
+ // look for final RETURN statement to get return type.
+ Ref retStmt = stats->back();
+ if (!!retStmt && retStmt[0] == RETURN && !!retStmt[1]) {
+ ret = detectType(retStmt[1]);
+ } else {
+ ret = ASM_NONE;
+ }
+}
+
+void AsmData::denormalize() {
+ Ref stats = func[3];
+ // Remove var definitions, if any
+ for (size_t i = 0; i < stats->size(); i++) {
+ if (stats[i][0] == VAR) {
+ stats[i] = makeEmpty();
+ } else {
+ if (!isEmpty(stats[i])) break;
+ }
+ }
+ // calculate variable definitions
+ Ref varDefs = makeArray(vars.size());
+ for (auto v : vars) {
+ varDefs->push_back(makeAsmVarDef(v, locals[v].type));
+ }
+ // each param needs a line; reuse emptyNodes as much as we can
+ size_t numParams = params.size();
+ size_t emptyNodes = 0;
+ while (emptyNodes < stats->size()) {
+ if (!isEmpty(stats[emptyNodes])) break;
+ emptyNodes++;
+ }
+ size_t neededEmptyNodes = numParams + (varDefs->size() ? 1 : 0); // params plus one big var if there are vars
+ if (neededEmptyNodes > emptyNodes) {
+ stats->insert(0, neededEmptyNodes - emptyNodes);
+ } else if (neededEmptyNodes < emptyNodes) {
+ stats->splice(0, emptyNodes - neededEmptyNodes);
+ }
+ // add param coercions
+ int next = 0;
+ for (auto param : func[2]->getArray()) {
+ IString str = param->getIString();
+ assert(locals.count(str) > 0);
+ stats[next++] = make1(STAT, make3(ASSIGN, makeBool(true), makeName(str.c_str()), makeAsmCoercion(makeName(str.c_str()), locals[str].type)));
+ }
+ if (varDefs->size()) {
+ stats[next] = make1(VAR, varDefs);
+ }
+ /*
+ if (inlines->size() > 0) {
+ var i = 0;
+ traverse(func, function(node, type) {
+ if (type == CALL && node[1][0] == NAME && node[1][1] == 'inlinejs') {
+ node[1] = inlines[i++]; // swap back in the body
+ }
+ });
+ }
+ */
+ // ensure that there's a final RETURN statement if needed.
+ if (ret != ASM_NONE) {
+ Ref retStmt = stats->back();
+ if (!retStmt || retStmt[0] != RETURN) {
+ Ref retVal = makeNum(0);
+ if (ret != ASM_INT) {
+ retVal = makeAsmCoercion(retVal, ret);
+ }
+ stats->push_back(make1(RETURN, retVal));
+ }
+ }
+ //printErr('denormalized \n\n' + astToSrc(func) + '\n\n');
+}
+
+// Constructions TODO: share common constructions, and assert they remain frozen
+
+Ref makeArray(int size_hint=0) {
+ return &arena.alloc()->setArray(size_hint);
+}
+
+Ref makeBool(bool b) {
+ return &arena.alloc()->setBool(b);
+}
+
+Ref makeString(const IString& s) {
+ return &arena.alloc()->setString(s);
+}
+
+Ref makeEmpty() {
+ return ValueBuilder::makeToplevel();
+}
+
+Ref makeNum(double x) {
+ return ValueBuilder::makeDouble(x);
+}
+
+Ref makeName(IString str) {
+ return ValueBuilder::makeName(str);
+}
+
+Ref makeBlock() {
+ return ValueBuilder::makeBlock();
+}
+
+Ref make1(IString s1, Ref a) {
+ Ref ret(makeArray(2));
+ ret->push_back(makeString(s1));
+ ret->push_back(a);
+ return ret;
+}
+
+Ref make2(IString s1, IString s2, Ref a) {
+ Ref ret(makeArray(2));
+ ret->push_back(makeString(s1));
+ ret->push_back(makeString(s2));
+ ret->push_back(a);
+ return ret;
+}
+
+Ref make2(IString s1, Ref a, Ref b) {
+ Ref ret(makeArray(3));
+ ret->push_back(makeString(s1));
+ ret->push_back(a);
+ ret->push_back(b);
+ return ret;
+}
+
+Ref make3(IString type, IString a, Ref b, Ref c) {
+ Ref ret(makeArray(4));
+ ret->push_back(makeString(type));
+ ret->push_back(makeString(a));
+ ret->push_back(b);
+ ret->push_back(c);
+ return ret;
+}
+
+Ref make3(IString type, Ref a, Ref b, Ref c) {
+ Ref ret(makeArray(4));
+ ret->push_back(makeString(type));
+ ret->push_back(a);
+ ret->push_back(b);
+ ret->push_back(c);
+ return ret;
+}
+
+Ref makeAsmVarDef(const IString& v, AsmType type) {
+ Ref val;
+ switch (type) {
+ case ASM_INT: val = makeNum(0); break;
+ case ASM_DOUBLE: val = make2(UNARY_PREFIX, PLUS, makeNum(0)); break;
+ case ASM_FLOAT: {
+ if (!ASM_FLOAT_ZERO.isNull()) {
+ val = makeName(ASM_FLOAT_ZERO);
+ } else {
+ val = make2(CALL, makeName(MATH_FROUND), &(makeArray(1))->push_back(makeNum(0)));
+ }
+ break;
+ }
+ case ASM_FLOAT32X4: {
+ val = make2(CALL, makeName(SIMD_FLOAT32X4), &(makeArray(4))->push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)));
+ break;
+ }
+ case ASM_FLOAT64X2: {
+ val = make2(CALL, makeName(SIMD_FLOAT64X2), &(makeArray(2))->push_back(makeNum(0)).push_back(makeNum(0)));
+ break;
+ }
+ case ASM_INT8X16: {
+ val = make2(CALL, makeName(SIMD_INT8X16), &(makeArray(16))->push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)));
+ break;
+ }
+ case ASM_INT16X8: {
+ val = make2(CALL, makeName(SIMD_INT16X8), &(makeArray(8))->push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)));
+ break;
+ }
+ case ASM_INT32X4: {
+ val = make2(CALL, makeName(SIMD_INT32X4), &(makeArray(4))->push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)).push_back(makeNum(0)));
+ break;
+ }
+ default: assert(0);
+ }
+ return make1(v, val);
+}
+
+Ref makeAsmCoercion(Ref node, AsmType type) {
+ switch (type) {
+ case ASM_INT: return make3(BINARY, OR, node, makeNum(0));
+ case ASM_DOUBLE: return make2(UNARY_PREFIX, PLUS, node);
+ case ASM_FLOAT: return make2(CALL, makeName(MATH_FROUND), &(makeArray(1))->push_back(node));
+ case ASM_FLOAT32X4: return make2(CALL, makeName(SIMD_FLOAT32X4_CHECK), &(makeArray(1))->push_back(node));
+ case ASM_FLOAT64X2: return make2(CALL, makeName(SIMD_FLOAT64X2_CHECK), &(makeArray(1))->push_back(node));
+ case ASM_INT8X16: return make2(CALL, makeName(SIMD_INT8X16_CHECK), &(makeArray(1))->push_back(node));
+ case ASM_INT16X8: return make2(CALL, makeName(SIMD_INT16X8_CHECK), &(makeArray(1))->push_back(node));
+ case ASM_INT32X4: return make2(CALL, makeName(SIMD_INT32X4_CHECK), &(makeArray(1))->push_back(node));
+ case ASM_NONE:
+ default: return node; // non-validating code, emit nothing XXX this is dangerous, we should only allow this when we know we are not validating
+ }
+}
+
+// Checks
+
+bool isEmpty(Ref node) {
+ return (node->size() == 2 && node[0] == TOPLEVEL && node[1]->size() == 0) ||
+ (node->size() > 0 && node[0] == BLOCK && (!node[1] || node[1]->size() == 0));
+}
+
+bool commable(Ref node) { // TODO: hashing
+ IString type = node[0]->getIString();
+ if (type == ASSIGN || type == BINARY || type == UNARY_PREFIX || type == NAME || type == NUM || type == CALL || type == SEQ || type == CONDITIONAL || type == SUB) return true;
+ return false;
+}
+
+bool isMathFunc(const char *name) {
+ static const char *Math_ = "Math_";
+ static unsigned size = strlen(Math_);
+ return strncmp(name, Math_, size) == 0;
+}
+
+bool isMathFunc(Ref value) {
+ return value->isString() && isMathFunc(value->getCString());
+}
+
+bool callHasSideEffects(Ref node) { // checks if the call itself (not the args) has side effects (or is not statically known)
+ return !(node[1][0] == NAME && isMathFunc(node[1][1]));
+}
+
+bool hasSideEffects(Ref node) { // this is 99% incomplete!
+ IString type = node[0]->getIString();
+ switch (type[0]) {
+ case 'n':
+ if (type == NUM || type == NAME) return false;
+ break;
+ case 's':
+ if (type == STRING) return false;
+ if (type == SUB) return hasSideEffects(node[1]) || hasSideEffects(node[2]);
+ break;
+ case 'u':
+ if (type == UNARY_PREFIX) return hasSideEffects(node[2]);
+ break;
+ case 'b':
+ if (type == BINARY) return hasSideEffects(node[2]) || hasSideEffects(node[3]);
+ break;
+ case 'c':
+ if (type == CALL) {
+ if (callHasSideEffects(node)) return true;
+ // This is a statically known call, with no side effects. only args can side effect us
+ for (auto arg : node[2]->getArray()) {
+ if (hasSideEffects(arg)) return true;
+ }
+ return false;
+ } else if (type == CONDITIONAL) return hasSideEffects(node[1]) || hasSideEffects(node[2]) || hasSideEffects(node[3]);
+ break;
+ }
+ return true;
+}
+
+// checks if a node has just basic operations, nothing with side effects nor that can notice side effects, which
+// implies we can move it around in the code
+bool triviallySafeToMove(Ref node, AsmData& asmData) {
+ bool ok = true;
+ traversePre(node, [&](Ref node) {
+ Ref type = node[0];
+ if (type == STAT || type == BINARY || type == UNARY_PREFIX || type == ASSIGN || type == NUM) return;
+ else if (type == NAME) {
+ if (!asmData.isLocal(node[1]->getIString())) ok = false;
+ } else if (type == CALL) {
+ if (callHasSideEffects(node)) ok = false;
+ } else {
+ ok = false;
+ }
+ });
+ return ok;
+}
+
+// Transforms
+
+// We often have branchings that are simplified so one end vanishes, and
+// we then get
+// if (!(x < 5))
+// or such. Simplifying these saves space and time.
+Ref simplifyNotCompsDirect(Ref node) {
+ if (node[0] == UNARY_PREFIX && node[1] == L_NOT) {
+ // de-morgan's laws do not work on floats, due to nans >:(
+ if (node[2][0] == BINARY && (detectType(node[2][2]) == ASM_INT && detectType(node[2][3]) == ASM_INT)) {
+ Ref op = node[2][1];
+ switch(op->getCString()[0]) {
+ case '<': {
+ if (op == LT) { op->setString(GE); break; }
+ if (op == LE) { op->setString(GT); break; }
+ return node;
+ }
+ case '>': {
+ if (op == GT) { op->setString(LE); break; }
+ if (op == GE) { op->setString(LT); break; }
+ return node;
+ }
+ case '=': {
+ if (op == EQ) { op->setString(NE); break; }
+ return node;
+ }
+ case '!': {
+ if (op == NE) { op->setString(EQ); break; }
+ return node;
+ }
+ default: return node;
+ }
+ return make3(BINARY, op, node[2][2], node[2][3]);
+ } else if (node[2][0] == UNARY_PREFIX && node[2][1] == L_NOT) {
+ return node[2][2];
+ }
+ }
+ return node;
+}
+
+Ref flipCondition(Ref cond) {
+ return simplifyNotCompsDirect(make2(UNARY_PREFIX, L_NOT, cond));
+}
+
+void safeCopy(Ref target, Ref source) { // safely copy source onto target, even if source is a subnode of target
+ Ref temp = source; // hold on to source
+ *target = *temp;
+}
+
+void clearEmptyNodes(Ref arr) {
+ int skip = 0;
+ for (size_t i = 0; i < arr->size(); i++) {
+ if (skip) {
+ arr[i-skip] = arr[i];
+ }
+ if (isEmpty(deStat(arr[i]))) {
+ skip++;
+ }
+ }
+ if (skip) arr->setSize(arr->size() - skip);
+}
+void clearUselessNodes(Ref arr) {
+ int skip = 0;
+ for (size_t i = 0; i < arr->size(); i++) {
+ Ref curr = arr[i];
+ if (skip) {
+ arr[i-skip] = curr;
+ }
+ if (isEmpty(deStat(curr)) || (curr[0] == STAT && !hasSideEffects(curr[1]))) {
+ skip++;
+ }
+ }
+ if (skip) arr->setSize(arr->size() - skip);
+}
+
+void removeAllEmptySubNodes(Ref ast) {
+ traversePre(ast, [](Ref node) {
+ if (node[0] == DEFUN) {
+ clearEmptyNodes(node[3]);
+ } else if (node[0] == BLOCK && node->size() > 1 && !!node[1]) {
+ clearEmptyNodes(node[1]);
+ } else if (node[0] == SEQ && isEmpty(node[1])) {
+ safeCopy(node, node[2]);
+ }
+ });
+}
+void removeAllUselessSubNodes(Ref ast) {
+ traversePrePost(ast, [](Ref node) {
+ Ref type = node[0];
+ if (type == DEFUN) {
+ clearUselessNodes(node[3]);
+ } else if (type == BLOCK && node->size() > 1 && !!node[1]) {
+ clearUselessNodes(node[1]);
+ } else if (type == SEQ && isEmpty(node[1])) {
+ safeCopy(node, node[2]);
+ }
+ }, [](Ref node) {
+ Ref type = node[0];
+ if (type == IF) {
+ bool empty2 = isEmpty(node[2]), has3 = node->size() == 4 && !!node[3], empty3 = !has3 || isEmpty(node[3]);
+ if (!empty2 && empty3 && has3) { // empty else clauses
+ node->setSize(3);
+ } else if (empty2 && !empty3) { // empty if blocks
+ safeCopy(node, make2(IF, make2(UNARY_PREFIX, L_NOT, node[1]), node[3]));
+ } else if (empty2 && empty3) {
+ if (hasSideEffects(node[1])) {
+ safeCopy(node, make1(STAT, node[1]));
+ } else {
+ safeCopy(node, makeEmpty());
+ }
+ }
+ }
+ });
+}
+
+Ref unVarify(Ref vars) { // transform var x=1, y=2 etc. into (x=1, y=2), i.e., the same assigns, but without a var definition
+ Ref ret = makeArray(1);
+ ret->push_back(makeString(STAT));
+ if (vars->size() == 1) {
+ ret->push_back(make3(ASSIGN, makeBool(true), makeName(vars[0][0]->getIString()), vars[0][1]));
+ } else {
+ ret->push_back(makeArray(vars->size()-1));
+ Ref curr = ret[1];
+ for (size_t i = 0; i+1 < vars->size(); i++) {
+ curr->push_back(makeString(SEQ));
+ curr->push_back(make3(ASSIGN, makeBool(true), makeName(vars[i][0]->getIString()), vars[i][1]));
+ if (i != vars->size()-2) {
+ curr->push_back(makeArray());
+ curr = curr[2];
+ }
+ }
+ curr->push_back(make3(ASSIGN, makeBool(true), makeName(vars->back()[0]->getIString()), vars->back()[1]));
+ }
+ return ret;
+}
+
+// Calculations
+
+int measureCost(Ref ast) {
+ int size = 0;
+ traversePre(ast, [&size](Ref node) {
+ Ref type = node[0];
+ if (type == NUM || type == UNARY_PREFIX) size--;
+ else if (type == BINARY) {
+ if (node[3][0] == NUM && node[3][1]->getNumber() == 0) size--;
+ else if (node[1] == DIV || node[1] == MOD) size += 2;
+ }
+ else if (type == CALL && !callHasSideEffects(node)) size -= 2;
+ else if (type == SUB) size++;
+ size++;
+ });
+ return size;
+}
+
+//==================
+// Params
+//==================
+
+bool preciseF32 = false,
+ receiveJSON = false,
+ emitJSON = false,
+ minifyWhitespace = false,
+ last = false;
+
+//=====================
+// Optimization passes
+//=====================
+
+#define HASES \
+ bool has(const IString& str) { \
+ return count(str) > 0; \
+ } \
+ bool has(Ref node) { \
+ return node->isString() && count(node->getIString()) > 0; \
+ }
+
+class StringSet : public cashew::IStringSet {
+public:
+ StringSet() {}
+ StringSet(const char *str) : IStringSet(str) {}
+
+ HASES
+
+ void dump() {
+ err("===");
+ for (auto str : *this) {
+ errv("%s", str.c_str());
+ }
+ err("===");
+ }
+};
+
+StringSet USEFUL_BINARY_OPS("<< >> | & ^"),
+ COMPARE_OPS("< <= > >= == == != !=="),
+ BITWISE("| & ^"),
+ SAFE_BINARY_OPS("+ -"), // division is unsafe as it creates non-ints in JS; mod is unsafe as signs matter so we can't remove |0's; mul does not nest with +,- in asm
+ COERCION_REQUIRING_OPS("sub unary-prefix"), // ops that in asm must be coerced right away
+ COERCION_REQUIRING_BINARIES("* / %"); // binary ops that in asm must be coerced
+
+StringSet ASSOCIATIVE_BINARIES("+ * | & ^"),
+ CONTROL_FLOW("do while for if switch"),
+ LOOP("do while for"),
+ NAME_OR_NUM("name num"),
+ CONDITION_CHECKERS("if do while switch"),
+ SAFE_TO_DROP_COERCION("unary-prefix name num");
+
+StringSet BREAK_CAPTURERS("do while for switch"),
+ CONTINUE_CAPTURERS("do while for"),
+ FUNCTIONS_THAT_ALWAYS_THROW("abort ___resumeException ___cxa_throw ___cxa_rethrow");
+
+bool isFunctionTable(const char *name) {
+ static const char *functionTable = "FUNCTION_TABLE";
+ static unsigned size = strlen(functionTable);
+ return strncmp(name, functionTable, size) == 0;
+}
+
+bool isFunctionTable(Ref value) {
+ return value->isString() && isFunctionTable(value->getCString());
+}
+
+// Internal utilities
+
+bool canDropCoercion(Ref node) {
+ if (SAFE_TO_DROP_COERCION.has(node[0])) return true;
+ if (node[0] == BINARY) {
+ switch (node[1]->getCString()[0]) {
+ case '>': return node[1] == RSHIFT || node[1] == TRSHIFT;
+ case '<': return node[1] == LSHIFT;
+ case '|': case '^': case '&': return true;
+ }
+ }
+ return false;
+}
+
+Ref simplifyCondition(Ref node) {
+ node = simplifyNotCompsDirect(node);
+ // on integers, if (x == 0) is the same as if (x), and if (x != 0) as if (!x)
+ if (node[0] == BINARY && (node[1] == EQ || node[1] == NE)) {
+ Ref target;
+ if (detectType(node[2]) == ASM_INT && node[3][0] == NUM && node[3][1]->getNumber() == 0) {
+ target = node[2];
+ } else if (detectType(node[3]) == ASM_INT && node[2][0] == NUM && node[2][1]->getNumber() == 0) {
+ target = node[3];
+ }
+ if (!!target) {
+ if (target[0] == BINARY && (target[1] == OR || target[1] == TRSHIFT) && target[3][0] == NUM && target[3][1]->getNumber() == 0 &&
+ canDropCoercion(target[2])) {
+ target = target[2]; // drop the coercion, in a condition it is ok to do if (x)
+ }
+ if (node[1] == EQ) {
+ return make2(UNARY_PREFIX, L_NOT, target);
+ } else {
+ return target;
+ }
+ }
+ }
+ return node;
+}
+
+// Passes
+
+// Eliminator aka Expressionizer
+//
+// The goal of this pass is to eliminate unneeded variables (which represent one of the infinite registers in the LLVM
+// model) and thus to generate complex expressions where possible, for example
+//
+// var x = a(10);
+// var y = HEAP[20];
+// print(x+y);
+//
+// can be transformed into
+//
+// print(a(10)+HEAP[20]);
+//
+// The basic principle is to scan along the code in the order of parsing/execution, and keep a list of tracked
+// variables that are current contenders for elimination. We must untrack when we see something that we cannot
+// cross, for example, a write to memory means we must invalidate variables that depend on reading from
+// memory, since if we change the order then we do not preserve the computation.
+//
+// We rely on some assumptions about emscripten-generated code here, which means we can do a lot more than
+// a general JS optimization can. For example, we assume that SUB nodes (indexing like HEAP[..]) are
+// memory accesses or FUNCTION_TABLE accesses, and in both cases that the symbol cannot be replaced although
+// the contents can. So we assume FUNCTION_TABLE might have its contents changed but not be pointed to
+// a different object, which allows
+//
+// var x = f();
+// FUNCTION_TABLE[x]();
+//
+// to be optimized (f could replace FUNCTION_TABLE, so in general JS eliminating x is not valid).
+//
+// In memSafe mode, we are more careful and assume functions can replace HEAP and FUNCTION_TABLE, which
+// can happen in ALLOW_MEMORY_GROWTH mode
+
+StringSet ELIMINATION_SAFE_NODES("assign call if toplevel do return label switch binary unary-prefix"); // do is checked carefully, however
+StringSet IGNORABLE_ELIMINATOR_SCAN_NODES("num toplevel string break continue dot"); // dot can only be STRING_TABLE.*
+StringSet ABORTING_ELIMINATOR_SCAN_NODES("new object function defun for while array throw"); // we could handle some of these, TODO, but nontrivial (e.g. for while, the condition is hit multiple times after the body)
+StringSet HEAP_NAMES("HEAP8 HEAP16 HEAP32 HEAPU8 HEAPU16 HEAPU32 HEAPF32 HEAPF64");
+
+bool isTempDoublePtrAccess(Ref node) { // these are used in bitcasts; they are not really affecting memory, and should cause no invalidation
+ assert(node[0] == SUB);
+ return (node[2][0] == NAME && node[2][1] == TEMP_DOUBLE_PTR) ||
+ (node[2][0] == BINARY && ((node[2][2][0] == NAME && node[2][2][1] == TEMP_DOUBLE_PTR) ||
+ (node[2][3][0] == NAME && node[2][3][1] == TEMP_DOUBLE_PTR)));
+}
+
+class StringIntMap : public std::unordered_map<IString, int> {
+public:
+ HASES
+};
+
+class StringStringMap : public std::unordered_map<IString, IString> {
+public:
+ HASES
+};
+
+class StringRefMap : public std::unordered_map<IString, Ref> {
+public:
+ HASES
+};
+
+class StringTypeMap : public std::unordered_map<IString, AsmType> {
+public:
+ HASES
+};
+
+void eliminate(Ref ast, bool memSafe) {
+#ifdef PROFILING
+ clock_t tasmdata = 0;
+ clock_t tfnexamine = 0;
+ clock_t tvarcheck = 0;
+ clock_t tstmtelim = 0;
+ clock_t tstmtscan = 0;
+ clock_t tcleanvars = 0;
+ clock_t treconstruct = 0;
+#endif
+
+ // Find variables that have a single use, and if they can be eliminated, do so
+ traverseFunctions(ast, [&](Ref func) {
+
+#ifdef PROFILING
+ clock_t start = clock();
+#endif
+
+ AsmData asmData(func);
+
+#ifdef PROFILING
+ tasmdata += clock() - start;
+ start = clock();
+#endif
+
+ // First, find the potentially eliminatable functions: that have one definition and one use
+
+ StringIntMap definitions;
+ StringIntMap uses;
+ StringIntMap namings;
+ StringRefMap values;
+ StringIntMap varsToRemove; // variables being removed, that we can eliminate all 'var x;' of (this refers to VAR nodes we should remove)
+ // 1 means we should remove it, 2 means we successfully removed it
+ StringSet varsToTryToRemove; // variables that have 0 uses, but have side effects - when we scan we can try to remove them
+
+ // examine body and note locals
+ traversePre(func, [&](Ref node) {
+ Ref type = node[0];
+ if (type == NAME) {
+ IString& name = node[1]->getIString();
+ uses[name]++;
+ namings[name]++;
+ } else if (type == ASSIGN) {
+ Ref target = node[2];
+ if (target[0] == NAME) {
+ IString& name = target[1]->getIString();
+ // values is only used if definitions is 1
+ if (definitions[name]++ == 0) {
+ values[name] = node[3];
+ }
+ assert(node[1]->isBool(true)); // not +=, -= etc., just =
+ uses[name]--; // because the name node will show up by itself in the previous case
+ }
+ }
+ });
+
+#ifdef PROFILING
+ tfnexamine += clock() - start;
+ start = clock();
+#endif
+
+ StringSet potentials; // local variables with 1 definition and 1 use
+ StringSet sideEffectFree; // whether a local variable has no side effects in its definition. Only relevant when there are no uses
+
+ auto unprocessVariable = [&](IString name) {
+ potentials.erase(name);
+ varsToRemove.erase(name);
+ sideEffectFree.erase(name);
+ varsToTryToRemove.erase(name);
+ };
+ std::function<void (IString)> processVariable = [&](IString name) {
+ if (definitions[name] == 1 && uses[name] == 1) {
+ potentials.insert(name);
+ } else if (uses[name] == 0 && definitions[name] <= 1) { // no uses, no def or 1 def (cannot operate on phis, and the llvm optimizer will remove unneeded phis anyhow) (no definition means it is a function parameter, or a local with just |var x;| but no defining assignment)
+ bool sideEffects = false;
+ auto val = values.find(name);
+ Ref value;
+ if (val != values.end()) {
+ value = val->second;
+ // TODO: merge with other side effect code
+ // First, pattern-match
+ // (HEAP32[((tempDoublePtr)>>2)]=((HEAP32[(($_sroa_0_0__idx1)>>2)])|0),HEAP32[(((tempDoublePtr)+(4))>>2)]=((HEAP32[((($_sroa_0_0__idx1)+(4))>>2)])|0),(+(HEAPF64[(tempDoublePtr)>>3])))
+ // which has no side effects and is the special form of converting double to i64.
+ if (!(value[0] == SEQ && value[1][0] == ASSIGN && value[1][2][0] == SUB && value[1][2][2][0] == BINARY && value[1][2][2][1] == RSHIFT &&
+ value[1][2][2][2][0] == NAME && value[1][2][2][2][1] == TEMP_DOUBLE_PTR)) {
+ // If not that, then traverse and scan normally.
+ sideEffects = hasSideEffects(value);
+ }
+ }
+ if (!sideEffects) {
+ varsToRemove[name] = !definitions[name] ? 2 : 1; // remove it normally
+ sideEffectFree.insert(name);
+ // Each time we remove a variable with 0 uses, if its value has no
+ // side effects and vanishes too, then we can remove a use from variables
+ // appearing in it, and possibly eliminate again
+ if (!!value) {
+ traversePre(value, [&](Ref node) {
+ if (node[0] == NAME) {
+ IString name = node[1]->getIString();
+ node[1]->setString(EMPTY); // we can remove this - it will never be shown, and should not be left to confuse us as we traverse
+ if (asmData.isLocal(name)) {
+ uses[name]--; // cannot be infinite recursion since we descend an energy function
+ assert(uses[name] >= 0);
+ unprocessVariable(name);
+ processVariable(name);
+ }
+ } else if (node[0] == CALL) {
+ // no side effects, so this must be a Math.* call or such. We can just ignore it and all children
+ node[0]->setString(NAME);
+ node[1]->setString(EMPTY);
+ }
+ });
+ }
+ } else {
+ varsToTryToRemove.insert(name); // try to remove it later during scanning
+ }
+ }
+ };
+ for (auto name : asmData.locals) {
+ processVariable(name.first);
+ }
+
+#ifdef PROFILING
+ tvarcheck += clock() - start;
+ start = clock();
+#endif
+
+ //printErr('defs: ' + JSON.stringify(definitions));
+ //printErr('uses: ' + JSON.stringify(uses));
+ //printErr('values: ' + JSON.stringify(values));
+ //printErr('locals: ' + JSON.stringify(locals));
+ //printErr('varsToRemove: ' + JSON.stringify(varsToRemove));
+ //printErr('varsToTryToRemove: ' + JSON.stringify(varsToTryToRemove));
+ values.clear();
+ //printErr('potentials: ' + JSON.stringify(potentials));
+ // We can now proceed through the function. In each list of statements, we try to eliminate
+ struct Tracking {
+ bool usesGlobals, usesMemory, hasDeps;
+ Ref defNode;
+ bool doesCall;
+ };
+ class Tracked : public std::unordered_map<IString, Tracking> {
+ public:
+ HASES
+ };
+ Tracked tracked;
+ #define dumpTracked() { errv("tracking %d", tracked.size()); for (auto t : tracked) errv("... %s", t.first.c_str()); }
+ // Although a set would be more appropriate, it would also be slower
+ std::unordered_map<IString, StringVec> depMap;
+
+ bool globalsInvalidated = false; // do not repeat invalidations, until we track something new
+ bool memoryInvalidated = false;
+ bool callsInvalidated = false;
+ auto track = [&](IString name, Ref value, Ref defNode) { // add a potential that has just been defined to the tracked list, we hope to eliminate it
+ Tracking& track = tracked[name];
+ track.usesGlobals = false;
+ track.usesMemory = false;
+ track.hasDeps = false;
+ track.defNode = defNode;
+ track.doesCall = false;
+ bool ignoreName = false; // one-time ignorings of names, as first op in sub and call
+ traversePre(value, [&](Ref node) {
+ Ref type = node[0];
+ if (type == NAME) {
+ if (!ignoreName) {
+ IString depName = node[1]->getIString();
+ if (!asmData.isLocal(depName)) {
+ track.usesGlobals = true;
+ }
+ if (!potentials.has(depName)) { // deps do not matter for potentials - they are defined once, so no complexity
+ depMap[depName].push_back(name);
+ track.hasDeps = true;
+ }
+ } else {
+ ignoreName = false;
+ }
+ } else if (type == SUB) {
+ track.usesMemory = true;
+ ignoreName = true;
+ } else if (type == CALL) {
+ track.usesGlobals = true;
+ track.usesMemory = true;
+ track.doesCall = true;
+ ignoreName = true;
+ } else {
+ ignoreName = false;
+ }
+ });
+ if (track.usesGlobals) globalsInvalidated = false;
+ if (track.usesMemory) memoryInvalidated = false;
+ if (track.doesCall) callsInvalidated = false;
+ };
+
+ // TODO: invalidate using a sequence number for each type (if you were tracked before the last invalidation, you are cancelled). remove for.in loops
+ #define INVALIDATE(what, check) \
+ auto invalidate##what = [&]() { \
+ std::vector<IString> temp; \
+ for (auto t : tracked) { \
+ IString name = t.first; \
+ Tracking& info = tracked[name]; \
+ if (check) { \
+ temp.push_back(name); \
+ } \
+ } \
+ for (size_t i = 0; i < temp.size(); i++) { \
+ tracked.erase(temp[i]); \
+ } \
+ };
+ INVALIDATE(Globals, info.usesGlobals);
+ INVALIDATE(Memory, info.usesMemory);
+ INVALIDATE(Calls, info.doesCall);
+
+ auto invalidateByDep = [&](IString dep) {
+ for (auto name : depMap[dep]) {
+ tracked.erase(name);
+ }
+ depMap.erase(dep);
+ };
+
+ std::function<void (IString name, Ref node)> doEliminate;
+
+ // Generate the sequence of execution. This determines what is executed before what, so we know what can be reordered. Using
+ // that, performs invalidations and eliminations
+ auto scan = [&](Ref node) {
+ bool abort = false;
+ bool allowTracking = true; // false inside an if; also prevents recursing in an if
+ std::function<void (Ref, bool)> traverseInOrder = [&](Ref node, bool ignoreSub) {
+ if (abort) return;
+ Ref type = node[0];
+ if (type == ASSIGN) {
+ Ref target = node[2];
+ Ref value = node[3];
+ bool nameTarget = target[0] == NAME;
+ // If this is an assign to a name, handle it below rather than
+ // traversing and treating as a read
+ if (!nameTarget) {
+ traverseInOrder(target, true); // evaluate left
+ }
+ traverseInOrder(value, false); // evaluate right
+ // do the actual assignment
+ if (nameTarget) {
+ IString name = target[1]->getIString();
+ if (potentials.has(name) && allowTracking) {
+ track(name, node[3], node);
+ } else if (varsToTryToRemove.has(name)) {
+ // replace it in-place
+ safeCopy(node, value);
+ varsToRemove[name] = 2;
+ } else {
+ // expensive check for invalidating specific tracked vars. This list is generally quite short though, because of
+ // how we just eliminate in short spans and abort when control flow happens TODO: history numbers instead
+ invalidateByDep(name); // can happen more than once per dep..
+ if (!asmData.isLocal(name) && !globalsInvalidated) {
+ invalidateGlobals();
+ globalsInvalidated = true;
+ }
+ // if we can track this name (that we assign into), and it has 0 uses and we want to remove its VAR
+ // definition - then remove it right now, there is no later chance
+ if (allowTracking && varsToRemove.has(name) && uses[name] == 0) {
+ track(name, node[3], node);
+ doEliminate(name, node);
+ }
+ }
+ } else if (target[0] == SUB) {
+ if (isTempDoublePtrAccess(target)) {
+ if (!globalsInvalidated) {
+ invalidateGlobals();
+ globalsInvalidated = true;
+ }
+ } else if (!memoryInvalidated) {
+ invalidateMemory();
+ memoryInvalidated = true;
+ }
+ }
+ } else if (type == SUB) {
+ // Only keep track of the global array names in memsafe mode i.e.
+ // when they may change underneath us due to resizing
+ if (node[1][0] != NAME || memSafe) {
+ traverseInOrder(node[1], false); // evaluate inner
+ }
+ traverseInOrder(node[2], false); // evaluate outer
+ // ignoreSub means we are a write (happening later), not a read
+ if (!ignoreSub && !isTempDoublePtrAccess(node)) {
+ // do the memory access
+ if (!callsInvalidated) {
+ invalidateCalls();
+ callsInvalidated = true;
+ }
+ }
+ } else if (type == BINARY) {
+ bool flipped = false;
+ if (ASSOCIATIVE_BINARIES.has(node[1]) && !NAME_OR_NUM.has(node[2][0]) && NAME_OR_NUM.has(node[3][0])) { // TODO recurse here?
+ // associatives like + and * can be reordered in the simple case of one of the sides being a name, since we assume they are all just numbers
+ Ref temp = node[2];
+ node[2] = node[3];
+ node[3] = temp;
+ flipped = true;
+ }
+ traverseInOrder(node[2], false);
+ traverseInOrder(node[3], false);
+ if (flipped && NAME_OR_NUM.has(node[2][0])) { // dunno if we optimized, but safe to flip back - and keeps the code closer to the original and more readable
+ Ref temp = node[2];
+ node[2] = node[3];
+ node[3] = temp;
+ }
+ } else if (type == NAME) {
+ IString name = node[1]->getIString();
+ if (tracked.has(name)) {
+ doEliminate(name, node);
+ } else if (!asmData.isLocal(name) && !callsInvalidated && (memSafe || !HEAP_NAMES.has(name))) { // ignore HEAP8 etc when not memory safe, these are ok to
+ // access, e.g. SIMD_Int32x4_load(HEAP8, ...)
+ invalidateCalls();
+ callsInvalidated = true;
+ }
+ } else if (type == UNARY_PREFIX || type == UNARY_POSTFIX) {
+ traverseInOrder(node[2], false);
+ } else if (IGNORABLE_ELIMINATOR_SCAN_NODES.has(type)) {
+ } else if (type == CALL) {
+ // Named functions never change and are therefore safe to not track
+ if (node[1][0] != NAME) {
+ traverseInOrder(node[1], false);
+ }
+ Ref args = node[2];
+ for (size_t i = 0; i < args->size(); i++) {
+ traverseInOrder(args[i], false);
+ }
+ if (callHasSideEffects(node)) {
+ // these two invalidations will also invalidate calls
+ if (!globalsInvalidated) {
+ invalidateGlobals();
+ globalsInvalidated = true;
+ }
+ if (!memoryInvalidated) {
+ invalidateMemory();
+ memoryInvalidated = true;
+ }
+ }
+ } else if (type == IF) {
+ if (allowTracking) {
+ traverseInOrder(node[1], false); // can eliminate into condition, but nowhere else
+ if (!callsInvalidated) { // invalidate calls, since we cannot eliminate them into an if that may not execute!
+ invalidateCalls();
+ callsInvalidated = true;
+ }
+ allowTracking = false;
+ traverseInOrder(node[2], false); // 2 and 3 could be 'parallel', really..
+ if (!!node[3]) traverseInOrder(node[3], false);
+ allowTracking = true;
+ } else {
+ tracked.clear();
+ }
+ } else if (type == BLOCK) {
+ Ref stats = getStatements(node);
+ if (!!stats) {
+ for (size_t i = 0; i < stats->size(); i++) {
+ traverseInOrder(stats[i], false);
+ }
+ }
+ } else if (type == STAT) {
+ traverseInOrder(node[1], false);
+ } else if (type == LABEL) {
+ traverseInOrder(node[2], false);
+ } else if (type == SEQ) {
+ traverseInOrder(node[1], false);
+ traverseInOrder(node[2], false);
+ } else if (type == DO) {
+ if (node[1][0] == NUM && node[1][1]->getNumber() == 0) { // one-time loop
+ traverseInOrder(node[2], false);
+ } else {
+ tracked.clear();
+ }
+ } else if (type == RETURN) {
+ if (!!node[1]) traverseInOrder(node[1], false);
+ } else if (type == CONDITIONAL) {
+ if (!callsInvalidated) { // invalidate calls, since we cannot eliminate them into a branch of an LLVM select/JS conditional that does not execute
+ invalidateCalls();
+ callsInvalidated = true;
+ }
+ traverseInOrder(node[1], false);
+ traverseInOrder(node[2], false);
+ traverseInOrder(node[3], false);
+ } else if (type == SWITCH) {
+ traverseInOrder(node[1], false);
+ Tracked originalTracked = tracked;
+ Ref cases = node[2];
+ for (size_t i = 0; i < cases->size(); i++) {
+ Ref c = cases[i];
+ assert(c[0]->isNull() || c[0][0] == NUM || (c[0][0] == UNARY_PREFIX && c[0][2][0] == NUM));
+ Ref stats = c[1];
+ for (size_t j = 0; j < stats->size(); j++) {
+ traverseInOrder(stats[j], false);
+ }
+ // We cannot track from one switch case into another if there are external dependencies, undo all new trackings
+ // Otherwise we can track, e.g. a var used in a case before assignment in another case is UB in asm.js, so no need for the assignment
+ // TODO: general framework here, use in if-else as well
+ std::vector<IString> toDelete;
+ for (auto t : tracked) {
+ if (!originalTracked.has(t.first)) {
+ Tracking& info = tracked[t.first];
+ if (info.usesGlobals || info.usesMemory || info.hasDeps) {
+ toDelete.push_back(t.first);
+ }
+ }
+ }
+ for (auto t : toDelete) {
+ tracked.erase(t);
+ }
+ }
+ tracked.clear(); // do not track from inside the switch to outside
+ } else {
+ assert(ABORTING_ELIMINATOR_SCAN_NODES.has(type));
+ tracked.clear();
+ abort = true;
+ }
+ };
+ traverseInOrder(node, false);
+ };
+ //var eliminationLimit = 0; // used to debugging purposes
+ doEliminate = [&](IString name, Ref node) {
+ //if (eliminationLimit == 0) return;
+ //eliminationLimit--;
+ //printErr('elim!!!!! ' + name);
+ // yes, eliminate!
+ varsToRemove[name] = 2; // both assign and var definitions can have other vars we must clean up
+ assert(tracked.has(name));
+ Tracking& info = tracked[name];
+ Ref defNode = info.defNode;
+ assert(!!defNode);
+ if (!sideEffectFree.has(name)) {
+ assert(defNode[0] != VAR);
+ // assign
+ Ref value = defNode[3];
+ // wipe out the assign
+ safeCopy(defNode, makeEmpty());
+ // replace this node in-place
+ safeCopy(node, value);
+ } else {
+ // This has no side effects and no uses, empty it out in-place
+ safeCopy(node, makeEmpty());
+ }
+ tracked.erase(name);
+ };
+ traversePre(func, [&](Ref block) {
+ // Look for statements, including while-switch pattern
+ Ref stats = getStatements(block);
+ if (!stats && (block[0] == WHILE && block[2][0] == SWITCH)) {
+ stats = &(makeArray(1)->push_back(block[2]));
+ }
+ if (!stats) return;
+ tracked.clear();
+ for (size_t i = 0; i < stats->size(); i++) {
+ Ref node = deStat(stats[i]);
+ Ref type = node[0];
+ if (type == RETURN && i+1 < stats->size()) {
+ stats->setSize(i+1); // remove any code after a return
+ }
+ // Check for things that affect elimination
+ if (ELIMINATION_SAFE_NODES.has(type)) {
+#ifdef PROFILING
+ tstmtelim += clock() - start;
+ start = clock();
+#endif
+ scan(node);
+#ifdef PROFILING
+ tstmtscan += clock() - start;
+ start = clock();
+#endif
+ } else if (type == VAR) {
+ continue; // asm normalisation has reduced 'var' to just the names
+ } else {
+ tracked.clear(); // not a var or assign, break all potential elimination so far
+ }
+ }
+ });
+
+#ifdef PROFILING
+ tstmtelim += clock() - start;
+ start = clock();
+#endif
+
+ StringIntMap seenUses;
+ StringStringMap helperReplacements; // for looper-helper optimization
+
+ // clean up vars, and loop variable elimination
+ traversePrePost(func, [&](Ref node) {
+ // pre
+ Ref type = node[0];
+ /*if (type == VAR) {
+ node[1] = node[1].filter(function(pair) { return !varsToRemove[pair[0]] });
+ if (node[1]->size() == 0) {
+ // wipe out an empty |var;|
+ node[0] = TOPLEVEL;
+ node[1] = [];
+ }
+ } else */
+ if (type == ASSIGN && node[1]->isBool(true) && node[2][0] == NAME && node[3][0] == NAME && node[2][1] == node[3][1]) {
+ // elimination led to X = X, which we can just remove
+ safeCopy(node, makeEmpty());
+ }
+ }, [&](Ref node) {
+ // post
+ Ref type = node[0];
+ if (type == NAME) {
+ IString name = node[1]->getIString();
+ if (helperReplacements.has(name)) {
+ node[1]->setString(helperReplacements[name]);
+ return; // no need to track this anymore, we can't loop-optimize more than once
+ }
+ // track how many uses we saw. we need to know when a variable is no longer used (hence we run this in the post)
+ seenUses[name]++;
+ } else if (type == WHILE) {
+ // try to remove loop helper variables specifically
+ Ref stats = node[2][1];
+ Ref last = stats->back();
+ if (!!last && last[0] == IF && last[2][0] == BLOCK && !!last[3] && last[3][0] == BLOCK) {
+ Ref ifTrue = last[2];
+ Ref ifFalse = last[3];
+ clearEmptyNodes(ifTrue[1]);
+ clearEmptyNodes(ifFalse[1]);
+ bool flip = false;
+ if (ifFalse[1]->size() > 0 && !!ifFalse[1][0] && !!ifFalse[1]->back() && ifFalse[1]->back()[0] == BREAK) { // canonicalize break in the if-true
+ Ref temp = ifFalse;
+ ifFalse = ifTrue;
+ ifTrue = temp;
+ flip = true;
+ }
+ if (ifTrue[1]->size() > 0 && !!ifTrue[1][0] && !!ifTrue[1]->back() && ifTrue[1]->back()[0] == BREAK) {
+ Ref assigns = ifFalse[1];
+ clearEmptyNodes(assigns);
+ std::vector<IString> loopers, helpers;
+ for (size_t i = 0; i < assigns->size(); i++) {
+ if (assigns[i][0] == STAT && assigns[i][1][0] == ASSIGN) {
+ Ref assign = assigns[i][1];
+ if (assign[1]->isBool(true) && assign[2][0] == NAME && assign[3][0] == NAME) {
+ IString looper = assign[2][1]->getIString();
+ IString helper = assign[3][1]->getIString();
+ if (definitions[helper] == 1 && seenUses[looper] == namings[looper] &&
+ !helperReplacements.has(helper) && !helperReplacements.has(looper)) {
+ loopers.push_back(looper);
+ helpers.push_back(helper);
+ }
+ }
+ }
+ }
+ // remove loop vars that are used in the rest of the else
+ for (size_t i = 0; i < assigns->size(); i++) {
+ if (assigns[i][0] == STAT && assigns[i][1][0] == ASSIGN) {
+ Ref assign = assigns[i][1];
+ if (!(assign[1]->isBool(true) && assign[2][0] == NAME && assign[3][0] == NAME) || indexOf(loopers, assign[2][1]->getIString()) < 0) {
+ // this is not one of the loop assigns
+ traversePre(assign, [&](Ref node) {
+ if (node[0] == NAME) {
+ int index = indexOf(loopers, node[1]->getIString());
+ if (index < 0) index = indexOf(helpers, node[1]->getIString());
+ if (index >= 0) {
+ loopers.erase(loopers.begin() + index);
+ helpers.erase(helpers.begin() + index);
+ }
+ }
+ });
+ }
+ }
+ }
+ // remove loop vars that are used in the if
+ traversePre(ifTrue, [&](Ref node) {
+ if (node[0] == NAME) {
+ int index = indexOf(loopers, node[1]->getIString());
+ if (index < 0) index = indexOf(helpers, node[1]->getIString());
+ if (index >= 0) {
+ loopers.erase(loopers.begin() + index);
+ helpers.erase(helpers.begin() + index);
+ }
+ }
+ });
+ if (loopers.size() == 0) return;
+ for (size_t l = 0; l < loopers.size(); l++) {
+ IString looper = loopers[l];
+ IString helper = helpers[l];
+ // the remaining issue is whether loopers are used after the assignment to helper and before the last line (where we assign to it)
+ int found = -1;
+ for (int i = (int)stats->size()-2; i >= 0; i--) {
+ Ref curr = stats[i];
+ if (curr[0] == STAT && curr[1][0] == ASSIGN) {
+ Ref currAssign = curr[1];
+ if (currAssign[1]->isBool(true) && currAssign[2][0] == NAME) {
+ IString to = currAssign[2][1]->getIString();
+ if (to == helper) {
+ found = i;
+ break;
+ }
+ }
+ }
+ }
+ if (found < 0) return;
+ // if a loop variable is used after we assigned to the helper, we must save its value and use that.
+ // (note that this can happen due to elimination, if we eliminate an expression containing the
+ // loop var far down, past the assignment!)
+ // first, see if the looper and helpers overlap. Note that we check for this looper, compared to
+ // *ALL* the helpers. Helpers will be replaced by loopers as we eliminate them, potentially
+ // causing conflicts, so any helper is a concern.
+ int firstLooperUsage = -1;
+ int lastLooperUsage = -1;
+ int firstHelperUsage = -1;
+ for (int i = found+1; i < (int)stats->size(); i++) {
+ Ref curr = i < (int)stats->size()-1 ? stats[i] : last[1]; // on the last line, just look in the condition
+ traversePre(curr, [&](Ref node) {
+ if (node[0] == NAME) {
+ if (node[1] == looper) {
+ if (firstLooperUsage < 0) firstLooperUsage = i;
+ lastLooperUsage = i;
+ } else if (indexOf(helpers, node[1]->getIString()) >= 0) {
+ if (firstHelperUsage < 0) firstHelperUsage = i;
+ }
+ }
+ });
+ }
+ if (firstLooperUsage >= 0) {
+ // the looper is used, we cannot simply merge the two variables
+ if ((firstHelperUsage < 0 || firstHelperUsage > lastLooperUsage) && lastLooperUsage+1 < (int)stats->size() && triviallySafeToMove(stats[found], asmData) &&
+ seenUses[helper] == namings[helper]) {
+ // the helper is not used, or it is used after the last use of the looper, so they do not overlap,
+ // and the last looper usage is not on the last line (where we could not append after it), and the
+ // helper is not used outside of the loop.
+ // just move the looper definition to after the looper's last use
+ stats->insert(lastLooperUsage+1, stats[found]);
+ stats->splice(found, 1);
+ } else {
+ // they overlap, we can still proceed with the loop optimization, but we must introduce a
+ // loop temp helper variable
+ IString temp(strdupe((std::string(looper.c_str()) + "$looptemp").c_str()));
+ assert(!asmData.isLocal(temp));
+ for (int i = firstLooperUsage; i <= lastLooperUsage; i++) {
+ Ref curr = i < (int)stats->size()-1 ? stats[i] : last[1]; // on the last line, just look in the condition
+
+ std::function<bool (Ref)> looperToLooptemp = [&](Ref node) {
+ if (node[0] == NAME) {
+ if (node[1] == looper) {
+ node[1]->setString(temp);
+ }
+ } else if (node[0] == ASSIGN && node[2][0] == NAME) {
+ // do not traverse the assignment target, phi assignments to the loop variable must remain
+ traversePrePostConditional(node[3], looperToLooptemp, [](Ref node){});
+ return false;
+ }
+ return true;
+ };
+ traversePrePostConditional(curr, looperToLooptemp, [](Ref node){});
+ }
+ asmData.addVar(temp, asmData.getType(looper));
+ stats->insert(found, make1(STAT, make3(ASSIGN, makeBool(true), makeName(temp), makeName(looper))));
+ }
+ }
+ }
+ for (size_t l = 0; l < helpers.size(); l++) {
+ for (size_t k = 0; k < helpers.size(); k++) {
+ if (l != k && helpers[l] == helpers[k]) return; // it is complicated to handle a shared helper, abort
+ }
+ }
+ // hurrah! this is safe to do
+ for (size_t l = 0; l < loopers.size(); l++) {
+ IString looper = loopers[l];
+ IString helper = helpers[l];
+ varsToRemove[helper] = 2;
+ traversePre(node, [&](Ref node) { // replace all appearances of helper with looper
+ if (node[0] == NAME && node[1] == helper) node[1]->setString(looper);
+ });
+ helperReplacements[helper] = looper; // replace all future appearances of helper with looper
+ helperReplacements[looper] = looper; // avoid any further attempts to optimize looper in this manner (seenUses is wrong anyhow, too)
+ }
+ // simplify the if. we remove the if branch, leaving only the else
+ if (flip) {
+ last[1] = simplifyNotCompsDirect(make2(UNARY_PREFIX, L_NOT, last[1]));
+ Ref temp = last[2];
+ last[2] = last[3];
+ last[3] = temp;
+ }
+ if (loopers.size() == assigns->size()) {
+ last->pop_back();
+ } else {
+ Ref elseStats = getStatements(last[3]);
+ for (size_t i = 0; i < elseStats->size(); i++) {
+ Ref stat = deStat(elseStats[i]);
+ if (stat[0] == ASSIGN && stat[2][0] == NAME) {
+ if (indexOf(loopers, stat[2][1]->getIString()) >= 0) {
+ elseStats[i] = makeEmpty();
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ });
+
+#ifdef PROFILING
+ tcleanvars += clock() - start;
+ start = clock();
+#endif
+
+ for (auto v : varsToRemove) {
+ if (v.second == 2 && asmData.isVar(v.first)) asmData.deleteVar(v.first);
+ }
+
+ asmData.denormalize();
+
+#ifdef PROFILING
+ treconstruct += clock() - start;
+ start = clock();
+#endif
+
+ });
+
+ removeAllEmptySubNodes(ast);
+
+#ifdef PROFILING
+ errv(" EL stages: a:%li fe:%li vc:%li se:%li (ss:%li) cv:%li r:%li",
+ tasmdata, tfnexamine, tvarcheck, tstmtelim, tstmtscan, tcleanvars, treconstruct);
+#endif
+}
+
+void eliminateMemSafe(Ref ast) {
+ eliminate(ast, true);
+}
+
+void simplifyExpressions(Ref ast) {
+ // Simplify common expressions used to perform integer conversion operations
+ // in cases where no conversion is needed.
+ auto simplifyIntegerConversions = [](Ref ast) {
+ traversePre(ast, [](Ref node) {
+ Ref type = node[0];
+ if (type == BINARY && node[1] == RSHIFT && node[3][0] == NUM &&
+ node[2][0] == BINARY && node[2][1] == LSHIFT && node[2][3][0] == NUM && node[3][1]->getNumber() == node[2][3][1]->getNumber()) {
+ // Transform (x&A)<<B>>B to X&A.
+ Ref innerNode = node[2][2];
+ double shifts = node[3][1]->getNumber();
+ if (innerNode[0] == BINARY && innerNode[1] == AND && innerNode[3][0] == NUM) {
+ double mask = innerNode[3][1]->getNumber();
+ if (isInteger32(mask) && isInteger32(shifts) && ((jsD2I(mask) << jsD2I(shifts)) >> jsD2I(shifts)) == jsD2I(mask)) {
+ safeCopy(node, innerNode);
+ return;
+ }
+ }
+ } else if (type == BINARY && BITWISE.has(node[1])) {
+ for (int i = 2; i <= 3; i++) {
+ Ref subNode = node[i];
+ if (subNode[0] == BINARY && subNode[1] == AND && subNode[3][0] == NUM && subNode[3][1]->getNumber() == 1) {
+ // Rewrite (X < Y) & 1 to X < Y , when it is going into a bitwise operator. We could
+ // remove even more (just replace &1 with |0, then subsequent passes could remove the |0)
+ // but v8 issue #2513 means the code would then run very slowly in chrome.
+ Ref input = subNode[2];
+ if (input[0] == BINARY && COMPARE_OPS.has(input[1])) {
+ safeCopy(node[i], input);
+ }
+ }
+ }
+ }
+ });
+ };
+
+ // When there is a bunch of math like (((8+5)|0)+12)|0, only the external |0 is needed, one correction is enough.
+ // At each node, ((X|0)+Y)|0 can be transformed into (X+Y): The inner corrections are not needed
+ // TODO: Is the same is true for 0xff, 0xffff?
+ // Likewise, if we have |0 inside a block that will be >>'d, then the |0 is unnecessary because some
+ // 'useful' mathops already |0 anyhow.
+
+ auto simplifyOps = [](Ref ast) {
+ auto removeMultipleOrZero = [&ast] {
+ bool rerun = true;
+ while (rerun) {
+ rerun = false;
+ std::vector<int> stack;
+ std::function<void (Ref)> process = [&stack, &rerun, &process, &ast](Ref node) {
+ Ref type = node[0];
+ if (type == BINARY && node[1] == OR) {
+ if (node[2][0] == NUM && node[3][0] == NUM) {
+ node[2][1]->setNumber(jsD2I(node[2][1]->getNumber()) | jsD2I(node[3][1]->getNumber()));
+ stack.push_back(0);
+ safeCopy(node, node[2]);
+ return;
+ }
+ bool go = false;
+ if (node[2][0] == NUM && node[2][1]->getNumber() == 0) {
+ // canonicalize order
+ Ref temp = node[3];
+ node[3] = node[2];
+ node[2] = temp;
+ go = true;
+ } else if (node[3][0] == NUM && node[3][1]->getNumber() == 0) {
+ go = true;
+ }
+ if (!go) {
+ stack.push_back(1);
+ return;
+ }
+ // We might be able to remove this correction
+ for (int i = stack.size()-1; i >= 0; i--) {
+ if (stack[i] >= 1) {
+ if (stack.back() < 2 && node[2][0] == CALL) break; // we can only remove multiple |0s on these
+ if (stack.back() < 1 && (COERCION_REQUIRING_OPS.has(node[2][0]) ||
+ (node[2][0] == BINARY && COERCION_REQUIRING_BINARIES.has(node[2][1])))) break; // we can remove |0 or >>2
+ // we will replace ourselves with the non-zero side. Recursively process that node.
+ Ref result = node[2][0] == NUM && node[2][1]->getNumber() == 0 ? node[3] : node[2], other;
+ // replace node in-place
+ safeCopy(node, result);
+ rerun = true;
+ process(result);
+ return;
+ } else if (stack[i] == -1) {
+ break; // Too bad, we can't
+ }
+ }
+ stack.push_back(2); // From here on up, no need for this kind of correction, it's done at the top
+ // (Add this at the end, so it is only added if we did not remove it)
+ } else if (type == BINARY && USEFUL_BINARY_OPS.has(node[1])) {
+ stack.push_back(1);
+ } else if ((type == BINARY && SAFE_BINARY_OPS.has(node[1])) || type == NUM || type == NAME) {
+ stack.push_back(0); // This node is safe in that it does not interfere with this optimization
+ } else if (type == UNARY_PREFIX && node[1] == B_NOT) {
+ stack.push_back(1);
+ } else {
+ stack.push_back(-1); // This node is dangerous! Give up if you see this before you see '1'
+ }
+ };
+
+ traversePrePost(ast, process, [&stack](Ref node) {
+ assert(!stack.empty());
+ stack.pop_back();
+ });
+ }
+ };
+
+ removeMultipleOrZero();
+
+ // & and heap-related optimizations
+
+ bool hasTempDoublePtr = false, rerunOrZeroPass = false;
+
+ traversePrePostConditional(ast, [](Ref node) {
+ // Detect trees which should not
+ // be simplified.
+ if (node[0] == SUB && node[1][0] == NAME && isFunctionTable(node[1][1])) {
+ return false; // do not traverse subchildren here, we should not collapse 55 & 126.
+ }
+ return true;
+ }, [&hasTempDoublePtr, &rerunOrZeroPass](Ref node) {
+ // Simplifications are done now so
+ // that we simplify a node's operands before the node itself. This allows
+ // optimizations to cascade.
+ Ref type = node[0];
+ if (type == NAME) {
+ if (node[1] == TEMP_DOUBLE_PTR) hasTempDoublePtr = true;
+ } else if (type == BINARY && node[1] == AND && node[3][0] == NUM) {
+ if (node[2][0] == NUM) {
+ safeCopy(node, makeNum(jsD2I(node[2][1]->getNumber()) & jsD2I(node[3][1]->getNumber())));
+ return;
+ }
+ Ref input = node[2];
+ double amount = node[3][1]->getNumber();
+ if (input[0] == BINARY && input[1] == AND && input[3][0] == NUM) {
+ // Collapse X & 255 & 1
+ node[3][1]->setNumber(jsD2I(amount) & jsD2I(input[3][1]->getNumber()));
+ node[2] = input[2];
+ } else if (input[0] == SUB && input[1][0] == NAME) {
+ // HEAP8[..] & 255 => HEAPU8[..]
+ HeapInfo hi = parseHeap(input[1][1]->getCString());
+ if (hi.valid) {
+ if (isInteger32(amount) && amount == powl(2, hi.bits)-1) {
+ if (!hi.unsign) {
+ input[1][1]->setString(getHeapStr(hi.bits, true)); // make unsigned
+ }
+ // we cannot return HEAPU8 without a coercion, but at least we do HEAP8 & 255 => HEAPU8 | 0
+ node[1]->setString(OR);
+ node[3][1]->setNumber(0);
+ return;
+ }
+ }
+ } else if (input[0] == BINARY && input[1] == RSHIFT &&
+ input[2][0] == BINARY && input[2][1] == LSHIFT &&
+ input[2][3][0] == NUM && input[3][0] == NUM &&
+ input[2][3][1]->getInteger() == input[3][1]->getInteger() &&
+ (~(0xFFFFFFFFu >> input[3][1]->getInteger()) & jsD2I(amount)) == 0) {
+ // x << 24 >> 24 & 255 => x & 255
+ return safeCopy(node, make3(BINARY, AND, input[2][2], node[3]));
+ }
+ } else if (type == BINARY && node[1] == XOR) {
+ // LLVM represents bitwise not as xor with -1. Translate it back to an actual bitwise not.
+ if (node[3][0] == UNARY_PREFIX && node[3][1] == MINUS && node[3][2][0] == NUM &&
+ node[3][2][1]->getNumber() == 1 &&
+ !(node[2][0] == UNARY_PREFIX && node[2][1] == B_NOT)) { // avoid creating ~~~ which is confusing for asm given the role of ~~
+ safeCopy(node, make2(UNARY_PREFIX, B_NOT, node[2]));
+ return;
+ }
+ } else if (type == BINARY && node[1] == RSHIFT && node[3][0] == NUM &&
+ node[2][0] == BINARY && node[2][1] == LSHIFT && node[2][3][0] == NUM &&
+ node[2][2][0] == SUB && node[2][2][1][0] == NAME) {
+ // collapse HEAPU?8[..] << 24 >> 24 etc. into HEAP8[..] | 0
+ double amount = node[3][1]->getNumber();
+ if (amount == node[2][3][1]->getNumber()) {
+ HeapInfo hi = parseHeap(node[2][2][1][1]->getCString());
+ if (hi.valid && hi.bits == 32 - amount) {
+ node[2][2][1][1]->setString(getHeapStr(hi.bits, false));
+ node[1]->setString(OR);
+ node[2] = node[2][2];
+ node[3][1]->setNumber(0);
+ rerunOrZeroPass = true;
+ return;
+ }
+ }
+ } else if (type == ASSIGN) {
+ // optimizations for assigning into HEAP32 specifically
+ if (node[1]->isBool(true) && node[2][0] == SUB && node[2][1][0] == NAME) {
+ if (node[2][1][1] == HEAP32) {
+ // HEAP32[..] = x | 0 does not need the | 0 (unless it is a mandatory |0 of a call)
+ if (node[3][0] == BINARY && node[3][1] == OR) {
+ if (node[3][2][0] == NUM && node[3][2][1]->getNumber() == 0 && node[3][3][0] != CALL) {
+ node[3] = node[3][3];
+ } else if (node[3][3][0] == NUM && node[3][3][1]->getNumber() == 0 && node[3][2][0] != CALL) {
+ node[3] = node[3][2];
+ }
+ }
+ } else if (node[2][1][1] == HEAP8) {
+ // HEAP8[..] = x & 0xff does not need the & 0xff
+ if (node[3][0] == BINARY && node[3][1] == AND && node[3][3][0] == NUM && node[3][3][1]->getNumber() == 0xff) {
+ node[3] = node[3][2];
+ }
+ } else if (node[2][1][1] == HEAP16) {
+ // HEAP16[..] = x & 0xffff does not need the & 0xffff
+ if (node[3][0] == BINARY && node[3][1] == AND && node[3][3][0] == NUM && node[3][3][1]->getNumber() == 0xffff) {
+ node[3] = node[3][2];
+ }
+ }
+ }
+ Ref value = node[3];
+ if (value[0] == BINARY && value[1] == OR) {
+ // canonicalize order of |0 to end
+ if (value[2][0] == NUM && value[2][1]->getNumber() == 0) {
+ Ref temp = value[2];
+ value[2] = value[3];
+ value[3] = temp;
+ }
+ // if a seq ends in an |0, remove an external |0
+ // note that it is only safe to do this in assigns, like we are doing here (return (x, y|0); is not valid)
+ if (value[2][0] == SEQ && value[2][2][0] == BINARY && USEFUL_BINARY_OPS.has(value[2][2][1])) {
+ node[3] = value[2];
+ }
+ }
+ } else if (type == BINARY && node[1] == RSHIFT && node[2][0] == NUM && node[3][0] == NUM) {
+ // optimize num >> num, in asm we need this since we do not optimize shifts in asm.js
+ node[0]->setString(NUM);
+ node[1]->setNumber(jsD2I(node[2][1]->getNumber()) >> jsD2I(node[3][1]->getNumber()));
+ node->setSize(2);
+ return;
+ } else if (type == BINARY && node[1] == PLUS) {
+ // The most common mathop is addition, e.g. in getelementptr done repeatedly. We can join all of those,
+ // by doing (num+num) ==> newnum.
+ if (node[2][0] == NUM && node[3][0] == NUM) {
+ node[2][1]->setNumber(jsD2I(node[2][1]->getNumber()) + jsD2I(node[3][1]->getNumber()));
+ safeCopy(node, node[2]);
+ return;
+ }
+ }
+ });
+
+ if (rerunOrZeroPass) removeMultipleOrZero();
+
+ if (hasTempDoublePtr) {
+ AsmData asmData(ast);
+ traversePre(ast, [](Ref node) {
+ Ref type = node[0];
+ if (type == ASSIGN) {
+ if (node[1]->isBool(true) && node[2][0] == SUB && node[2][1][0] == NAME && node[2][1][1] == HEAP32) {
+ // remove bitcasts that are now obviously pointless, e.g.
+ // HEAP32[$45 >> 2] = HEAPF32[tempDoublePtr >> 2] = ($14 < $28 ? $14 : $28) - $42, HEAP32[tempDoublePtr >> 2] | 0;
+ Ref value = node[3];
+ if (value[0] == SEQ && value[1][0] == ASSIGN && value[1][2][0] == SUB && value[1][2][1][0] == NAME && value[1][2][1][1] == HEAPF32 &&
+ value[1][2][2][0] == BINARY && value[1][2][2][2][0] == NAME && value[1][2][2][2][1] == TEMP_DOUBLE_PTR) {
+ // transform to HEAPF32[$45 >> 2] = ($14 < $28 ? $14 : $28) - $42;
+ node[2][1][1]->setString(HEAPF32);
+ node[3] = value[1][3];
+ }
+ }
+ } else if (type == SEQ) {
+ // (HEAP32[tempDoublePtr >> 2] = HEAP32[$37 >> 2], +HEAPF32[tempDoublePtr >> 2])
+ // ==>
+ // +HEAPF32[$37 >> 2]
+ if (node[0] == SEQ && node[1][0] == ASSIGN && node[1][2][0] == SUB && node[1][2][1][0] == NAME &&
+ (node[1][2][1][1] == HEAP32 || node[1][2][1][1] == HEAPF32) &&
+ node[1][2][2][0] == BINARY && node[1][2][2][2][0] == NAME && node[1][2][2][2][1] == TEMP_DOUBLE_PTR &&
+ node[1][3][0] == SUB && node[1][3][1][0] == NAME && (node[1][3][1][1] == HEAP32 || node[1][3][1][1] == HEAPF32) &&
+ node[2][0] != SEQ) { // avoid (x, y, z) which can be used for tempDoublePtr on doubles for alignment fixes
+ if (node[1][2][1][1] == HEAP32) {
+ node[1][3][1][1]->setString(HEAPF32);
+ safeCopy(node, makeAsmCoercion(node[1][3], detectType(node[2])));
+ return;
+ } else {
+ node[1][3][1][1]->setString(HEAP32);
+ safeCopy(node, make3(BINARY, OR, node[1][3], makeNum(0)));
+ return;
+ }
+ }
+ }
+ });
+
+ // finally, wipe out remaining ones by finding cases where all assignments to X are bitcasts, and all uses are writes to
+ // the other heap type, then eliminate the bitcast
+ struct BitcastData {
+ int define_HEAP32, define_HEAPF32, use_HEAP32, use_HEAPF32, namings;
+ bool ok;
+ std::vector<Ref> defines, uses;
+
+ BitcastData() : define_HEAP32(0), define_HEAPF32(0), use_HEAP32(0), use_HEAPF32(0), namings(0), ok(false) {}
+ };
+ std::unordered_map<IString, BitcastData> bitcastVars;
+ traversePre(ast, [&bitcastVars](Ref node) {
+ if (node[0] == ASSIGN && node[1]->isBool(true) && node[2][0] == NAME) {
+ Ref value = node[3];
+ if (value[0] == SEQ && value[1][0] == ASSIGN && value[1][2][0] == SUB && value[1][2][1][0] == NAME &&
+ (value[1][2][1][1] == HEAP32 || value[1][2][1][1] == HEAPF32) &&
+ value[1][2][2][0] == BINARY && value[1][2][2][2][0] == NAME && value[1][2][2][2][1] == TEMP_DOUBLE_PTR) {
+ IString name = node[2][1]->getIString();
+ IString heap = value[1][2][1][1]->getIString();
+ if (heap == HEAP32) {
+ bitcastVars[name].define_HEAP32++;
+ } else {
+ assert(heap == HEAPF32);
+ bitcastVars[name].define_HEAPF32++;
+ }
+ bitcastVars[name].defines.push_back(node);
+ bitcastVars[name].ok = true;
+ }
+ }
+ });
+ traversePre(ast, [&bitcastVars](Ref node) {
+ Ref type = node[0];
+ if (type == NAME && bitcastVars[node[1]->getCString()].ok) {
+ bitcastVars[node[1]->getCString()].namings++;
+ } else if (type == ASSIGN && node[1]->isBool(true)) {
+ Ref value = node[3];
+ if (value[0] == NAME) {
+ IString name = value[1]->getIString();
+ if (bitcastVars[name].ok) {
+ Ref target = node[2];
+ if (target[0] == SUB && target[1][0] == NAME && (target[1][1] == HEAP32 || target[1][1] == HEAPF32)) {
+ if (target[1][1] == HEAP32) {
+ bitcastVars[name].use_HEAP32++;
+ } else {
+ bitcastVars[name].use_HEAPF32++;
+ }
+ bitcastVars[name].uses.push_back(node);
+ }
+ }
+ }
+ }
+ });
+ for (auto iter : bitcastVars) {
+ const IString& v = iter.first;
+ BitcastData& info = iter.second;
+ // good variables define only one type, use only one type, have definitions and uses, and define as a different type than they use
+ if (info.define_HEAP32*info.define_HEAPF32 == 0 && info.use_HEAP32*info.use_HEAPF32 == 0 &&
+ info.define_HEAP32+info.define_HEAPF32 > 0 && info.use_HEAP32+info.use_HEAPF32 > 0 &&
+ info.define_HEAP32*info.use_HEAP32 == 0 && info.define_HEAPF32*info.use_HEAPF32 == 0 &&
+ asmData.isLocal(v.c_str()) && info.namings == info.define_HEAP32+info.define_HEAPF32+info.use_HEAP32+info.use_HEAPF32) {
+ IString& correct = info.use_HEAP32 ? HEAPF32 : HEAP32;
+ for (auto define : info.defines) {
+ define[3] = define[3][1][3];
+ if (correct == HEAP32) {
+ define[3] = make3(BINARY, OR, define[3], makeNum(0));
+ } else {
+ assert(correct == HEAPF32);
+ define[3] = makeAsmCoercion(define[3], preciseF32 ? ASM_FLOAT : ASM_DOUBLE);
+ }
+ // do we want a simplifybitops on the new values here?
+ }
+ for (auto use : info.uses) {
+ use[2][1][1]->setString(correct.c_str());
+ }
+ AsmType correctType;
+ switch(asmData.getType(v.c_str())) {
+ case ASM_INT: correctType = preciseF32 ? ASM_FLOAT : ASM_DOUBLE; break;
+ case ASM_FLOAT: case ASM_DOUBLE: correctType = ASM_INT; break;
+ default: assert(0);
+ }
+ asmData.setType(v.c_str(), correctType);
+ }
+ }
+ asmData.denormalize();
+ }
+ };
+
+ std::function<bool (Ref)> emitsBoolean = [&emitsBoolean](Ref node) {
+ Ref type = node[0];
+ if (type == NUM) {
+ return node[1]->getNumber() == 0 || node[1]->getNumber() == 1;
+ }
+ if (type == BINARY) return COMPARE_OPS.has(node[1]);
+ if (type == UNARY_PREFIX) return node[1] == L_NOT;
+ if (type == CONDITIONAL) return emitsBoolean(node[2]) && emitsBoolean(node[3]);
+ return false;
+ };
+
+ // expensive | expensive can be turned into expensive ? 1 : expensive, and
+ // expensive | cheap can be turned into cheap ? 1 : expensive,
+ // so that we can avoid the expensive computation, if it has no side effects.
+ auto conditionalize = [&emitsBoolean](Ref ast) {
+ traversePre(ast, [&emitsBoolean](Ref node) {
+ const int MIN_COST = 7;
+ if (node[0] == BINARY && (node[1] == OR || node[1] == AND) && node[3][0] != NUM && node[2][0] != NUM) {
+ // logical operator on two non-numerical values
+ Ref left = node[2];
+ Ref right = node[3];
+ if (!emitsBoolean(left) || !emitsBoolean(right)) return;
+ bool leftEffects = hasSideEffects(left);
+ bool rightEffects = hasSideEffects(right);
+ if (leftEffects && rightEffects) return; // both must execute
+ // canonicalize with side effects, if any, happening on the left
+ if (rightEffects) {
+ if (measureCost(left) < MIN_COST) return; // avoidable code is too cheap
+ Ref temp = left;
+ left = right;
+ right = temp;
+ } else if (leftEffects) {
+ if (measureCost(right) < MIN_COST) return; // avoidable code is too cheap
+ } else {
+ // no side effects, reorder based on cost estimation
+ int leftCost = measureCost(left);
+ int rightCost = measureCost(right);
+ if (std::max(leftCost, rightCost) < MIN_COST) return; // avoidable code is too cheap
+ // canonicalize with expensive code on the right
+ if (leftCost > rightCost) {
+ Ref temp = left;
+ left = right;
+ right = temp;
+ }
+ }
+ // worth it, perform conditionalization
+ Ref ret;
+ if (node[1] == OR) {
+ ret = make3(CONDITIONAL, left, makeNum(1), right);
+ } else { // &
+ ret = make3(CONDITIONAL, left, right, makeNum(0));
+ }
+ if (left[0] == UNARY_PREFIX && left[1] == L_NOT) {
+ ret[1] = flipCondition(left);
+ Ref temp = ret[2];
+ ret[2] = ret[3];
+ ret[3] = temp;
+ }
+ safeCopy(node, ret);
+ return;
+ }
+ });
+ };
+
+ traverseFunctions(ast, [&](Ref func) {
+ simplifyIntegerConversions(func);
+ simplifyOps(func);
+ traversePre(func, [](Ref node) {
+ Ref ret = simplifyNotCompsDirect(node);
+ if (ret.get() != node.get()) { // if we received a different pointer in return, then we need to copy the new value
+ safeCopy(node, ret);
+ }
+ });
+ conditionalize(func);
+ });
+}
+
+void simplifyIfs(Ref ast) {
+ traverseFunctions(ast, [](Ref func) {
+ bool simplifiedAnElse = false;
+
+ traversePre(func, [&simplifiedAnElse](Ref node) {
+ // simplify if (x) { if (y) { .. } } to if (x ? y : 0) { .. }
+ if (node[0] == IF) {
+ Ref body = node[2];
+ // recurse to handle chains
+ while (body[0] == BLOCK) {
+ Ref stats = body[1];
+ if (stats->size() == 0) break;
+ Ref other = stats->back();
+ if (other[0] != IF) {
+ // our if block does not end with an if. perhaps if have an else we can flip
+ if (node->size() > 3 && !!node[3] && node[3][0] == BLOCK) {
+ stats = node[3][1];
+ if (stats->size() == 0) break;
+ other = stats->back();
+ if (other[0] == IF) {
+ // flip node
+ node[1] = flipCondition(node[1]);
+ node[2] = node[3];
+ node[3] = body;
+ body = node[2];
+ } else break;
+ } else break;
+ }
+ // we can handle elses, but must be fully identical
+ if (!!node[3] || !!other[3]) {
+ if (!node[3]) break;
+ if (!node[3]->deepCompare(other[3])) {
+ // the elses are different, but perhaps if we flipped a condition we can do better
+ if (node[3]->deepCompare(other[2])) {
+ // flip other. note that other may not have had an else! add one if so; we will eliminate such things later
+ if (!other[3]) other[3] = makeBlock();
+ other[1] = flipCondition(other[1]);
+ Ref temp = other[2];
+ other[2] = other[3];
+ other[3] = temp;
+ } else break;
+ }
+ }
+ if (stats->size() > 1) {
+ // try to commaify - turn everything between the ifs into a comma operator inside the second if
+ bool ok = true;
+ for (size_t i = 0; i+1 < stats->size(); i++) {
+ Ref curr = deStat(stats[i]);
+ if (!commable(curr)) ok = false;
+ }
+ if (!ok) break;
+ for (int i = stats->size()-2; i >= 0; i--) {
+ Ref curr = deStat(stats[i]);
+ other[1] = make2(SEQ, curr, other[1]);
+ }
+ Ref temp = makeArray(1);
+ temp->push_back(other);
+ stats = body[1] = temp;
+ }
+ if (stats->size() != 1) break;
+ if (!!node[3]) simplifiedAnElse = true;
+ node[1] = make3(CONDITIONAL, node[1], other[1], makeNum(0));
+ body = node[2] = other[2];
+ }
+ }
+ });
+
+ if (simplifiedAnElse) {
+ // there may be fusing opportunities
+
+ // we can only fuse if we remove all uses of the label. if there are
+ // other ones - if the label check can be reached from elsewhere -
+ // we must leave it
+ bool abort = false;
+
+ std::unordered_map<int, int> labelAssigns;
+
+ traversePre(func, [&labelAssigns, &abort](Ref node) {
+ if (node[0] == ASSIGN && node[2][0] == NAME && node[2][1] == LABEL) {
+ if (node[3][0] == NUM) {
+ int value = node[3][1]->getInteger();
+ labelAssigns[value] = labelAssigns[value] + 1;
+ } else {
+ // label is assigned a dynamic value (like from indirectbr), we cannot do anything
+ abort = true;
+ }
+ }
+ });
+ if (abort) return;
+
+ std::unordered_map<int, int> labelChecks;
+
+ traversePre(func, [&labelChecks, &abort](Ref node) {
+ if (node[0] == BINARY && node[1] == EQ && node[2][0] == BINARY && node[2][1] == OR &&
+ node[2][2][0] == NAME && node[2][2][1] == LABEL) {
+ if (node[3][0] == NUM) {
+ int value = node[3][1]->getInteger();
+ labelChecks[value] = labelChecks[value] + 1;
+ } else {
+ // label is checked vs a dynamic value (like from indirectbr), we cannot do anything
+ abort = true;
+ }
+ }
+ });
+ if (abort) return;
+
+ int inLoop = 0; // when in a loop, we do not emit label = 0; in the relooper as there is no need
+ traversePrePost(func, [&inLoop, &labelAssigns, &labelChecks](Ref node) {
+ if (node[0] == WHILE) inLoop++;
+ Ref stats = getStatements(node);
+ if (!!stats && stats->size() > 0) {
+ for (int i = 0; i < (int)stats->size()-1; i++) {
+ Ref pre = stats[i];
+ Ref post = stats[i+1];
+ if (pre[0] == IF && pre->size() > 3 && !!pre[3] && post[0] == IF && (post->size() <= 3 || !post[3])) {
+ Ref postCond = post[1];
+ if (postCond[0] == BINARY && postCond[1] == EQ &&
+ postCond[2][0] == BINARY && postCond[2][1] == OR &&
+ postCond[2][2][0] == NAME && postCond[2][2][1] == LABEL &&
+ postCond[2][3][0] == NUM && postCond[2][3][1]->getNumber() == 0 &&
+ postCond[3][0] == NUM) {
+ int postValue = postCond[3][1]->getInteger();
+ Ref preElse = pre[3];
+ if (labelAssigns[postValue] == 1 && labelChecks[postValue] == 1 && preElse[0] == BLOCK && preElse->size() >= 2 && preElse[1]->size() == 1) {
+ Ref preStat = preElse[1][0];
+ if (preStat[0] == STAT && preStat[1][0] == ASSIGN &&
+ preStat[1][1]->isBool(true) && preStat[1][2][0] == NAME && preStat[1][2][1] == LABEL &&
+ preStat[1][3][0] == NUM && preStat[1][3][1]->getNumber() == postValue) {
+ // Conditions match, just need to make sure the post clears label
+ if (post[2][0] == BLOCK && post[2]->size() >= 2 && post[2][1]->size() > 0) {
+ Ref postStat = post[2][1][0];
+ bool haveClear =
+ postStat[0] == STAT && postStat[1][0] == ASSIGN &&
+ postStat[1][1]->isBool(true) && postStat[1][2][0] == NAME && postStat[1][2][1] == LABEL &&
+ postStat[1][3][0] == NUM && postStat[1][3][1]->getNumber() == 0;
+ if (!inLoop || haveClear) {
+ // Everything lines up, do it
+ pre[3] = post[2];
+ if (haveClear) pre[3][1]->splice(0, 1); // remove the label clearing
+ stats->splice(i+1, 1); // remove the post entirely
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }, [&inLoop](Ref node) {
+ if (node[0] == WHILE) inLoop--;
+ });
+ assert(inLoop == 0);
+ }
+ });
+}
+
+void optimizeFrounds(Ref ast) {
+ // collapse fround(fround(..)), which can happen due to elimination
+ // also emit f0 instead of fround(0) (except in returns)
+ int inReturn = 0;
+ traversePrePost(ast, [&](Ref node) {
+ if (node[0] == RETURN) {
+ inReturn++;
+ }
+ }, [&](Ref node) {
+ if (node[0] == RETURN) {
+ inReturn--;
+ }
+ if (node[0] == CALL && node[1][0] == NAME && node[1][1] == MATH_FROUND) {
+ Ref arg = node[2][0];
+ if (arg[0] == NUM) {
+ if (!inReturn && arg[1]->getInteger() == 0) {
+ safeCopy(node, makeName(F0));
+ }
+ } else if (arg[0] == CALL && arg[1][0] == NAME && arg[1][1] == MATH_FROUND) {
+ safeCopy(node, arg);
+ }
+ }
+ });
+}
+
+// Very simple 'registerization', coalescing of variables into a smaller number.
+
+const char* getRegPrefix(AsmType type) {
+ switch (type) {
+ case ASM_INT: return "i"; break;
+ case ASM_DOUBLE: return "d"; break;
+ case ASM_FLOAT: return "f"; break;
+ case ASM_FLOAT32X4: return "F4"; break;
+ case ASM_FLOAT64X2: return "F2"; break;
+ case ASM_INT8X16: return "I16"; break;
+ case ASM_INT16X8: return "I8"; break;
+ case ASM_INT32X4: return "I4"; break;
+ case ASM_NONE: return "Z"; break;
+ default: assert(0); // type doesn't have a name yet
+ }
+ return nullptr;
+}
+
+IString getRegName(AsmType type, int num) {
+ const char* str = getRegPrefix(type);
+ const int size = 256;
+ char temp[size];
+ int written = sprintf(temp, "%s%d", str, num);
+ assert(written < size);
+ temp[written] = 0;
+ IString ret;
+ ret.set(temp, false);
+ return ret;
+}
+
+void registerize(Ref ast) {
+ traverseFunctions(ast, [](Ref fun) {
+ AsmData asmData(fun);
+ // Add parameters as a first (fake) var (with assignment), so they get taken into consideration
+ // note: params are special, they can never share a register between them (see later)
+ Ref fake;
+ if (!!fun[2] && fun[2]->size()) {
+ Ref assign = makeNum(0);
+ // TODO: will be an isEmpty here, can reuse it.
+ fun[3]->insert(0, make1(VAR, fun[2]->map([&assign](Ref param) {
+ return &(makeArray(2)->push_back(param).push_back(assign));
+ })));
+ }
+ // Replace all var definitions with assignments; we will add var definitions at the top after we registerize
+ StringSet allVars;
+ traversePre(fun, [&](Ref node) {
+ Ref type = node[0];
+ if (type == VAR) {
+ Ref vars = node[1]->filter([](Ref varr) { return varr->size() > 1; });
+ if (vars->size() >= 1) {
+ safeCopy(node, unVarify(vars));
+ } else {
+ safeCopy(node, makeEmpty());
+ }
+ } else if (type == NAME) {
+ allVars.insert(node[1]->getIString());
+ }
+ });
+ removeAllUselessSubNodes(fun); // vacuum?
+ StringTypeMap regTypes; // reg name -> type
+ auto getNewRegName = [&](int num, IString name) {
+ AsmType type = asmData.getType(name);
+ IString ret = getRegName(type, num);
+ assert(!allVars.has(ret) || asmData.isLocal(ret)); // register must not shadow non-local name
+ regTypes[ret] = type;
+ return ret;
+ };
+ // Find the # of uses of each variable.
+ // While doing so, check if all a variable's uses are dominated in a simple
+ // way by a simple assign, if so, then we can assign its register to it
+ // just for its definition to its last use, and not to the entire toplevel loop,
+ // we call such variables "optimizable"
+ StringIntMap varUses;
+ int level = 1;
+ std::unordered_map<int, StringSet> levelDominations; // level => set of dominated variables XXX vector?
+ StringIntMap varLevels;
+ StringSet possibles;
+ StringSet unoptimizables;
+ auto purgeLevel = [&]() {
+ // Invalidate all dominating on this level, further users make it unoptimizable
+ for (auto name : levelDominations[level]) {
+ varLevels[name] = 0;
+ }
+ levelDominations[level].clear();
+ level--;
+ };
+ std::function<bool (Ref node)> possibilifier = [&](Ref node) {
+ Ref type = node[0];
+ if (type == NAME) {
+ IString name = node[1]->getIString();
+ if (asmData.isLocal(name)) {
+ varUses[name]++;
+ if (possibles.has(name) && !varLevels[name]) unoptimizables.insert(name); // used outside of simple domination
+ }
+ } else if (type == ASSIGN && node[1]->isBool(true)) {
+ if (!!node[2] && node[2][0] == NAME) {
+ IString name = node[2][1]->getIString();
+ // if local and not yet used, this might be optimizable if we dominate
+ // all other uses
+ if (asmData.isLocal(name) && !varUses[name] && !varLevels[name]) {
+ possibles.insert(name);
+ varLevels[name] = level;
+ levelDominations[level].insert(name);
+ }
+ }
+ } else if (CONTROL_FLOW.has(type)) {
+ // recurse children, in the context of a loop
+ if (type == WHILE || type == DO) {
+ traversePrePostConditional(node[1], possibilifier, [](Ref node){});
+ level++;
+ traversePrePostConditional(node[2], possibilifier, [](Ref node){});
+ purgeLevel();
+ } else if (type == FOR) {
+ traversePrePostConditional(node[1], possibilifier, [](Ref node){});
+ for (int i = 2; i <= 4; i++) {
+ level++;
+ traversePrePostConditional(node[i], possibilifier, [](Ref node){});
+ purgeLevel();
+ }
+ } else if (type == IF) {
+ traversePrePostConditional(node[1], possibilifier, [](Ref node){});
+ level++;
+ traversePrePostConditional(node[2], possibilifier, [](Ref node){});
+ purgeLevel();
+ if (node->size() > 3 && !!node[3]) {
+ level++;
+ traversePrePostConditional(node[3], possibilifier, [](Ref node){});
+ purgeLevel();
+ }
+ } else if (type == SWITCH) {
+ traversePrePostConditional(node[1], possibilifier, [](Ref node){});
+ Ref cases = node[2];
+ for (size_t i = 0; i < cases->size(); i++) {
+ level++;
+ traversePrePostConditional(cases[i][1], possibilifier, [](Ref node){});
+ purgeLevel();
+ }
+ } else assert(0);;
+ return false; // prevent recursion into children, which we already did
+ }
+ return true;
+ };
+ traversePrePostConditional(fun, possibilifier, [](Ref node){});
+
+ StringSet optimizables;
+ for (auto possible : possibles) {
+ if (!unoptimizables.has(possible)) optimizables.insert(possible);
+ }
+
+ // Go through the function's code, assigning 'registers'.
+ // The only tricky bit is to keep variables locked on a register through loops,
+ // since they can potentially be returned to. Optimizable variables lock onto
+ // loops that they enter, unoptimizable variables lock in a conservative way
+ // into the topmost loop.
+ // Note that we cannot lock onto a variable in a loop if it was used and free'd
+ // before! (then they could overwrite us in the early part of the loop). For now
+ // we just use a fresh register to make sure we avoid this, but it could be
+ // optimized to check for safe registers (free, and not used in this loop level).
+ StringStringMap varRegs; // maps variables to the register they will use all their life
+ std::vector<StringVec> freeRegsClasses;
+ freeRegsClasses.resize(ASM_NONE);
+ int nextReg = 1;
+ StringVec fullNames;
+ fullNames.push_back(EMPTY); // names start at 1
+ std::vector<StringVec> loopRegs; // for each loop nesting level, the list of bound variables
+ int loops = 0; // 0 is toplevel, 1 is first loop, etc
+ StringSet activeOptimizables;
+ StringIntMap optimizableLoops;
+ StringSet paramRegs; // true if the register is used by a parameter (and so needs no def at start of function; also cannot
+ // be shared with another param, each needs its own)
+ auto decUse = [&](IString name) {
+ if (!varUses[name]) return false; // no uses left, or not a relevant variable
+ if (optimizables.has(name)) activeOptimizables.insert(name);
+ IString reg = varRegs[name];
+ assert(asmData.isLocal(name));
+ StringVec& freeRegs = freeRegsClasses[asmData.getType(name)];
+ if (!reg) {
+ // acquire register
+ if (optimizables.has(name) && freeRegs.size() > 0 &&
+ !(asmData.isParam(name) && paramRegs.has(freeRegs.back()))) { // do not share registers between parameters
+ reg = freeRegs.back();
+ freeRegs.pop_back();
+ } else {
+ assert(fullNames.size() == nextReg);
+ reg = getNewRegName(nextReg++, name);
+ fullNames.push_back(reg);
+ if (asmData.isParam(name)) paramRegs.insert(reg);
+ }
+ varRegs[name] = reg;
+ }
+ varUses[name]--;
+ assert(varUses[name] >= 0);
+ if (varUses[name] == 0) {
+ if (optimizables.has(name)) activeOptimizables.erase(name);
+ // If we are not in a loop, or we are optimizable and not bound to a loop
+ // (we might have been in one but left it), we can free the register now.
+ if (loops == 0 || (optimizables.has(name) && !optimizableLoops.has(name))) {
+ // free register
+ freeRegs.push_back(reg);
+ } else {
+ // when the relevant loop is exited, we will free the register
+ int relevantLoop = optimizables.has(name) ? (optimizableLoops[name] ? optimizableLoops[name] : 1) : 1;
+ if ((int)loopRegs.size() <= relevantLoop+1) loopRegs.resize(relevantLoop+1);
+ loopRegs[relevantLoop].push_back(reg);
+ }
+ }
+ return true;
+ };
+ traversePrePost(fun, [&](Ref node) { // XXX we rely on traversal order being the same as execution order here
+ Ref type = node[0];
+ if (type == NAME) {
+ IString name = node[1]->getIString();
+ if (decUse(name)) {
+ node[1]->setString(varRegs[name]);
+ }
+ } else if (LOOP.has(type)) {
+ loops++;
+ // Active optimizables lock onto this loop, if not locked onto one that encloses this one
+ for (auto name : activeOptimizables) {
+ if (!optimizableLoops[name]) {
+ optimizableLoops[name] = loops;
+ }
+ }
+ }
+ }, [&](Ref node) {
+ Ref type = node[0];
+ if (LOOP.has(type)) {
+ // Free registers that were locked to this loop
+ if ((int)loopRegs.size() > loops && loopRegs[loops].size() > 0) {
+ for (auto loopReg : loopRegs[loops]) {
+ freeRegsClasses[regTypes[loopReg]].push_back(loopReg);
+ }
+ loopRegs[loops].clear();
+ }
+ loops--;
+ }
+ });
+ if (!!fun[2] && fun[2]->size()) {
+ fun[2]->setSize(0); // clear params, we will fill with registers
+ fun[3]->splice(0, 1); // remove fake initial var
+ }
+
+ asmData.locals.clear();
+ asmData.params.clear();
+ asmData.vars.clear();
+ for (int i = 1; i < nextReg; i++) {
+ IString reg = fullNames[i];
+ AsmType type = regTypes[reg];
+ if (!paramRegs.has(reg)) {
+ asmData.addVar(reg, type);
+ } else {
+ asmData.addParam(reg, type);
+ fun[2]->push_back(makeString(reg));
+ }
+ }
+ asmData.denormalize();
+ });
+}
+
+// Assign variables to 'registers', coalescing them onto a smaller number of shared
+// variables.
+//
+// This does the same job as 'registerize' above, but burns a lot more cycles trying
+// to reduce the total number of register variables. Key points about the operation:
+//
+// * we decompose the AST into a flow graph and perform a full liveness
+// analysis, to determine which variables are live at each point.
+//
+// * variables that are live concurrently are assigned to different registers.
+//
+// * variables that are linked via 'x=y' style statements are assigned the same
+// register if possible, so that the redundant assignment can be removed.
+// (e.g. assignments used to pass state around through loops).
+//
+// * any code that cannot be reached through the flow-graph is removed.
+// (e.g. redundant break statements like 'break L123; break;').
+//
+// * any assignments that we can prove are not subsequently used are removed.
+// (e.g. unnecessary assignments to the 'label' variable).
+//
+void registerizeHarder(Ref ast) {
+#ifdef PROFILING
+ clock_t tasmdata = 0;
+ clock_t tflowgraph = 0;
+ clock_t tlabelfix = 0;
+ clock_t tbackflow = 0;
+ clock_t tjuncvaruniqassign = 0;
+ clock_t tjuncvarsort = 0;
+ clock_t tregassign = 0;
+ clock_t tblockproc = 0;
+ clock_t treconstruct = 0;
+#endif
+
+ traverseFunctions(ast, [&](Ref fun) {
+
+#ifdef PROFILING
+ clock_t start = clock();
+#endif
+
+ // Do not try to process non-validating methods, like the heap replacer
+ bool abort = false;
+ traversePre(fun, [&abort](Ref node) {
+ if (node[0] == NEW) abort = true;
+ });
+ if (abort) return;
+
+ AsmData asmData(fun);
+
+#ifdef PROFILING
+ tasmdata += clock() - start;
+ start = clock();
+#endif
+
+ // Utilities for allocating register variables.
+ // We need distinct register pools for each type of variable.
+
+ typedef std::map<int, IString> IntStringMap;
+ std::vector<IntStringMap> allRegsByType;
+ allRegsByType.resize(ASM_NONE+1);
+ int nextReg = 1;
+
+ auto createReg = [&](IString forName) {
+ // Create a new register of type suitable for the given variable name.
+ AsmType type = asmData.getType(forName);
+ IntStringMap& allRegs = allRegsByType[type];
+ int reg = nextReg++;
+ allRegs[reg] = getRegName(type, reg);
+ return reg;
+ };
+
+ // Traverse the tree in execution order and synthesize a basic flow-graph.
+ // It's convenient to build a kind of "dual" graph where the nodes identify
+ // the junctions between blocks at which control-flow may branch, and each
+ // basic block is an edge connecting two such junctions.
+ // For each junction we store:
+ // * set of blocks that originate at the junction
+ // * set of blocks that terminate at the junction
+ // For each block we store:
+ // * a single entry junction
+ // * a single exit junction
+ // * a 'use' and 'kill' set of names for the block
+ // * full sequence of NAME and ASSIGN nodes in the block
+ // * whether each such node appears as part of a larger expression
+ // (and therefore cannot be safely eliminated)
+ // * set of labels that can be used to jump to this block
+
+ struct Junction {
+ int id;
+ std::set<int> inblocks, outblocks;
+ IOrderedStringSet live;
+ Junction(int id_) : id(id_) {}
+ };
+ struct Node {
+ };
+ struct Block {
+ int id, entry, exit;
+ std::set<int> labels;
+ std::vector<Ref> nodes;
+ std::vector<bool> isexpr;
+ StringIntMap use;
+ StringSet kill;
+ StringStringMap link;
+ StringIntMap lastUseLoc;
+ StringIntMap firstDeadLoc;
+ StringIntMap firstKillLoc;
+ StringIntMap lastKillLoc;
+
+ Block() : id(-1), entry(-1), exit(-1) {}
+ };
+ struct ContinueBreak {
+ int co, br;
+ ContinueBreak() : co(-1), br(-1) {}
+ ContinueBreak(int co_, int br_) : co(co_), br(br_) {}
+ };
+ typedef std::unordered_map<IString, ContinueBreak> LabelState;
+
+ std::vector<Junction> junctions;
+ std::vector<Block*> blocks;
+ int currEntryJunction = -1;
+ Block* nextBasicBlock = nullptr;
+ int isInExpr = 0;
+ std::vector<LabelState> activeLabels;
+ activeLabels.resize(1);
+ IString nextLoopLabel;
+
+ const int ENTRY_JUNCTION = 0;
+ const int EXIT_JUNCTION = 1;
+ const int ENTRY_BLOCK = 0;
+
+ auto addJunction = [&]() {
+ // Create a new junction, without inserting it into the graph.
+ // This is useful for e.g. pre-allocating an exit node.
+ int id = junctions.size();
+ junctions.push_back(Junction(id));
+ return id;
+ };
+
+ std::function<int (int, bool)> joinJunction;
+
+ auto markJunction = [&](int id) {
+ // Mark current traversal location as a junction.
+ // This makes a new basic block exiting at this position.
+ if (id < 0) {
+ id = addJunction();
+ }
+ joinJunction(id, true);
+ return id;
+ };
+
+ auto setJunction = [&](int id, bool force) {
+ // Set the next entry junction to the given id.
+ // This can be used to enter at a previously-declared point.
+ // You can't return to a junction with no incoming blocks
+ // unless the 'force' parameter is specified.
+ assert(nextBasicBlock->nodes.size() == 0); // refusing to abandon an in-progress basic block
+ if (force || junctions[id].inblocks.size() > 0) {
+ currEntryJunction = id;
+ } else {
+ currEntryJunction = -1;
+ }
+ };
+
+ joinJunction = [&](int id, bool force) {
+ // Complete the pending basic block by exiting at this position.
+ // This can be used to exit at a previously-declared point.
+ if (currEntryJunction >= 0) {
+ assert(nextBasicBlock);
+ nextBasicBlock->id = blocks.size();
+ nextBasicBlock->entry = currEntryJunction;
+ nextBasicBlock->exit = id;
+ junctions[currEntryJunction].outblocks.insert(nextBasicBlock->id);
+ junctions[id].inblocks.insert(nextBasicBlock->id);
+ blocks.push_back(nextBasicBlock);
+ }
+ nextBasicBlock = new Block();
+ setJunction(id, force);
+ return id;
+ };
+
+ auto pushActiveLabels = [&](int onContinue, int onBreak) {
+ // Push the target junctions for continuing/breaking a loop.
+ // This should be called before traversing into a loop.
+ assert(activeLabels.size() > 0);
+ LabelState& prevLabels = activeLabels.back();
+ LabelState newLabels = prevLabels;
+ newLabels[EMPTY] = ContinueBreak(onContinue, onBreak);
+ if (!!nextLoopLabel) {
+ newLabels[nextLoopLabel] = ContinueBreak(onContinue, onBreak);
+ nextLoopLabel = EMPTY;
+ }
+ // An unlabelled CONTINUE should jump to innermost loop,
+ // ignoring any nested SWITCH statements.
+ if (onContinue < 0 && prevLabels.count(EMPTY) > 0) {
+ newLabels[EMPTY].co = prevLabels[EMPTY].co;
+ }
+ activeLabels.push_back(newLabels);
+ };
+
+ auto popActiveLabels = [&]() {
+ // Pop the target junctions for continuing/breaking a loop.
+ // This should be called after traversing into a loop.
+ activeLabels.pop_back();
+ };
+
+ auto markNonLocalJump = [&](IString type, IString label) {
+ // Complete a block via RETURN, BREAK or CONTINUE.
+ // This joins the targetted junction and then sets the current junction to null.
+ // Any code traversed before we get back to an existing junction is dead code.
+ if (type == RETURN) {
+ joinJunction(EXIT_JUNCTION, false);
+ } else {
+ assert(activeLabels.size() > 0);
+ assert(activeLabels.back().count(label) > 0); // 'jump to unknown label');
+ auto targets = activeLabels.back()[label];
+ if (type == CONTINUE) {
+ joinJunction(targets.co, false);
+ } else if (type == BREAK) {
+ joinJunction(targets.br, false);
+ } else {
+ assert(0); // 'unknown jump node type');
+ }
+ }
+ currEntryJunction = -1;
+ };
+
+ auto addUseNode = [&](Ref node) {
+ // Mark a use of the given name node in the current basic block.
+ assert(node[0] == NAME); // 'not a use node');
+ IString name = node[1]->getIString();
+ if (asmData.isLocal(name)) {
+ nextBasicBlock->nodes.push_back(node);
+ nextBasicBlock->isexpr.push_back(isInExpr != 0);
+ if (nextBasicBlock->kill.count(name) == 0) {
+ nextBasicBlock->use[name] = 1;
+ }
+ }
+ };
+
+ auto addKillNode = [&](Ref node) {
+ // Mark an assignment to the given name node in the current basic block.
+ assert(node[0] == ASSIGN); //, 'not a kill node');
+ assert(node[1]->isBool(true)); // 'not a kill node');
+ assert(node[2][0] == NAME); //, 'not a kill node');
+ IString name = node[2][1]->getIString();
+ if (asmData.isLocal(name)) {
+ nextBasicBlock->nodes.push_back(node);
+ nextBasicBlock->isexpr.push_back(isInExpr != 0);
+ nextBasicBlock->kill.insert(name);
+ }
+ };
+
+ std::function<Ref (Ref)> lookThroughCasts = [&](Ref node) {
+ // Look through value-preserving casts, like "x | 0" => "x"
+ if (node[0] == BINARY && node[1] == OR) {
+ if (node[3][0] == NUM && node[3][1]->getNumber() == 0) {
+ return lookThroughCasts(node[2]);
+ }
+ }
+ return node;
+ };
+
+ auto addBlockLabel = [&](Ref node) {
+ assert(nextBasicBlock->nodes.size() == 0); // 'cant add label to an in-progress basic block')
+ if (node[0] == NUM) {
+ nextBasicBlock->labels.insert(node[1]->getInteger());
+ }
+ };
+
+ auto isTrueNode = [&](Ref node) {
+ // Check if the given node is statically truthy.
+ return (node[0] == NUM && node[1]->getNumber() != 0);
+ };
+
+ auto isFalseNode = [&](Ref node) {
+ // Check if the given node is statically falsy.
+ return (node[0] == NUM && node[1]->getNumber() == 0);
+ };
+
+ std::function<void (Ref)> buildFlowGraph = [&](Ref node) {
+ // Recursive function to build up the flow-graph.
+ // It walks the tree in execution order, calling the above state-management
+ // functions at appropriate points in the traversal.
+ Ref type = node[0];
+
+ // Any code traversed without an active entry junction must be dead,
+ // as the resulting block could never be entered. Let's remove it.
+ if (currEntryJunction < 0 && junctions.size() > 0) {
+ safeCopy(node, makeEmpty());
+ return;
+ }
+
+ // Traverse each node type according to its particular control-flow semantics.
+ // TODO: switchify this
+ if (type == DEFUN) {
+ int jEntry = markJunction(-1);
+ assert(jEntry == ENTRY_JUNCTION);
+ int jExit = addJunction();
+ assert(jExit == EXIT_JUNCTION);
+ for (size_t i = 0; i < node[3]->size(); i++) {
+ buildFlowGraph(node[3][i]);
+ }
+ joinJunction(jExit, false);
+ } else if (type == IF) {
+ isInExpr++;
+ buildFlowGraph(node[1]);
+ isInExpr--;
+ int jEnter = markJunction(-1);
+ int jExit = addJunction();
+ if (!!node[2]) {
+ // Detect and mark "if (label == N) { <labelled block> }".
+ if (node[1][0] == BINARY && node[1][1] == EQ) {
+ Ref lhs = lookThroughCasts(node[1][2]);
+ if (lhs[0] == NAME && lhs[1] == LABEL) {
+ addBlockLabel(lookThroughCasts(node[1][3]));
+ }
+ }
+ buildFlowGraph(node[2]);
+ }
+ joinJunction(jExit, false);
+ setJunction(jEnter, false);
+ if (node->size() > 3 && !!node[3]) {
+ buildFlowGraph(node[3]);
+ }
+ joinJunction(jExit, false);
+ } else if (type == CONDITIONAL) {
+ isInExpr++;
+ // If the conditional has no side-effects, we can treat it as a single
+ // block, which might open up opportunities to remove it entirely.
+ if (!hasSideEffects(node)) {
+ buildFlowGraph(node[1]);
+ if (!!node[2]) {
+ buildFlowGraph(node[2]);
+ }
+ if (!!node[3]) {
+ buildFlowGraph(node[3]);
+ }
+ } else {
+ buildFlowGraph(node[1]);
+ int jEnter = markJunction(-1);
+ int jExit = addJunction();
+ if (!!node[2]) {
+ buildFlowGraph(node[2]);
+ }
+ joinJunction(jExit, false);
+ setJunction(jEnter, false);
+ if (!!node[3]) {
+ buildFlowGraph(node[3]);
+ }
+ joinJunction(jExit, false);
+ }
+ isInExpr--;
+ } else if (type == WHILE) {
+ // Special-case "while (1) {}" to use fewer junctions,
+ // since emscripten generates a lot of these.
+ if (isTrueNode(node[1])) {
+ int jLoop = markJunction(-1);
+ int jExit = addJunction();
+ pushActiveLabels(jLoop, jExit);
+ buildFlowGraph(node[2]);
+ popActiveLabels();
+ joinJunction(jLoop, false);
+ setJunction(jExit, false);
+ } else {
+ int jCond = markJunction(-1);
+ int jLoop = addJunction();
+ int jExit = addJunction();
+ isInExpr++;
+ buildFlowGraph(node[1]);
+ isInExpr--;
+ joinJunction(jLoop, false);
+ pushActiveLabels(jCond, jExit);
+ buildFlowGraph(node[2]);
+ popActiveLabels();
+ joinJunction(jCond, false);
+ // An empty basic-block linking condition exit to loop exit.
+ setJunction(jLoop, false);
+ joinJunction(jExit, false);
+ }
+ } else if (type == DO) {
+ // Special-case "do {} while (1)" and "do {} while (0)" to use
+ // fewer junctions, since emscripten generates a lot of these.
+ if (isFalseNode(node[1])) {
+ int jExit = addJunction();
+ pushActiveLabels(jExit, jExit);
+ buildFlowGraph(node[2]);
+ popActiveLabels();
+ joinJunction(jExit, false);
+ } else if (isTrueNode(node[1])) {
+ int jLoop = markJunction(-1);
+ int jExit = addJunction();
+ pushActiveLabels(jLoop, jExit);
+ buildFlowGraph(node[2]);
+ popActiveLabels();
+ joinJunction(jLoop, false);
+ setJunction(jExit, false);
+ } else {
+ int jLoop = markJunction(-1);
+ int jCond = addJunction();
+ int jCondExit = addJunction();
+ int jExit = addJunction();
+ pushActiveLabels(jCond, jExit);
+ buildFlowGraph(node[2]);
+ popActiveLabels();
+ joinJunction(jCond, false);
+ isInExpr++;
+ buildFlowGraph(node[1]);
+ isInExpr--;
+ joinJunction(jCondExit, false);
+ joinJunction(jLoop, false);
+ setJunction(jCondExit, false);
+ joinJunction(jExit, false);
+ }
+ } else if (type == FOR) {
+ int jTest = addJunction();
+ int jBody = addJunction();
+ int jStep = addJunction();
+ int jExit = addJunction();
+ buildFlowGraph(node[1]);
+ joinJunction(jTest, false);
+ isInExpr++;
+ buildFlowGraph(node[2]);
+ isInExpr--;
+ joinJunction(jBody, false);
+ pushActiveLabels(jStep, jExit);
+ buildFlowGraph(node[4]);
+ popActiveLabels();
+ joinJunction(jStep, false);
+ buildFlowGraph(node[3]);
+ joinJunction(jTest, false);
+ setJunction(jBody, false);
+ joinJunction(jExit, false);
+ } else if (type == LABEL) {
+ assert(BREAK_CAPTURERS.has(node[2][0])); // 'label on non-loop, non-switch statement')
+ nextLoopLabel = node[1]->getIString();
+ buildFlowGraph(node[2]);
+ } else if (type == SWITCH) {
+ // Emscripten generates switch statements of a very limited
+ // form: all case clauses are numeric literals, and all
+ // case bodies end with a (maybe implicit) break. So it's
+ // basically equivalent to a multi-way IF statement.
+ isInExpr++;
+ buildFlowGraph(node[1]);
+ isInExpr--;
+ Ref condition = lookThroughCasts(node[1]);
+ int jCheckExit = markJunction(-1);
+ int jExit = addJunction();
+ pushActiveLabels(-1, jExit);
+ bool hasDefault = false;
+ for (size_t i = 0; i < node[2]->size(); i++) {
+ setJunction(jCheckExit, false);
+ // All case clauses are either 'default' or a numeric literal.
+ if (!node[2][i][0]) {
+ hasDefault = true;
+ } else {
+ // Detect switches dispatching to labelled blocks.
+ if (condition[0] == NAME && condition[1] == LABEL) {
+ addBlockLabel(lookThroughCasts(node[2][i][0]));
+ }
+ }
+ for (size_t j = 0; j < node[2][i][1]->size(); j++) {
+ buildFlowGraph(node[2][i][1][j]);
+ }
+ // Control flow will never actually reach the end of the case body.
+ // If there's live code here, assume it jumps to case exit.
+ if (currEntryJunction >= 0 && nextBasicBlock->nodes.size() > 0) {
+ if (!!node[2][i][0]) {
+ markNonLocalJump(RETURN, EMPTY);
+ } else {
+ joinJunction(jExit, false);
+ }
+ }
+ }
+ // If there was no default case, we also need an empty block
+ // linking straight from the test evaluation to the exit.
+ if (!hasDefault) {
+ setJunction(jCheckExit, false);
+ }
+ joinJunction(jExit, false);
+ popActiveLabels();
+ } else if (type == RETURN) {
+ if (!!node[1]) {
+ isInExpr++;
+ buildFlowGraph(node[1]);
+ isInExpr--;
+ }
+ markNonLocalJump(type->getIString(), EMPTY);
+ } else if (type == BREAK || type == CONTINUE) {
+ markNonLocalJump(type->getIString(), !!node[1] ? node[1]->getIString() : EMPTY);
+ } else if (type == ASSIGN) {
+ isInExpr++;
+ buildFlowGraph(node[3]);
+ isInExpr--;
+ if (node[1]->isBool(true) && node[2][0] == NAME) {
+ addKillNode(node);
+ } else {
+ buildFlowGraph(node[2]);
+ }
+ } else if (type == NAME) {
+ addUseNode(node);
+ } else if (type == BLOCK || type == TOPLEVEL) {
+ if (!!node[1]) {
+ for (size_t i = 0; i < node[1]->size(); i++) {
+ buildFlowGraph(node[1][i]);
+ }
+ }
+ } else if (type == STAT) {
+ buildFlowGraph(node[1]);
+ } else if (type == UNARY_PREFIX || type == UNARY_POSTFIX) {
+ isInExpr++;
+ buildFlowGraph(node[2]);
+ isInExpr--;
+ } else if (type == BINARY) {
+ isInExpr++;
+ buildFlowGraph(node[2]);
+ buildFlowGraph(node[3]);
+ isInExpr--;
+ } else if (type == CALL) {
+ isInExpr++;
+ buildFlowGraph(node[1]);
+ if (!!node[2]) {
+ for (size_t i = 0; i < node[2]->size(); i++) {
+ buildFlowGraph(node[2][i]);
+ }
+ }
+ isInExpr--;
+ // If the call is statically known to throw,
+ // treat it as a jump to function exit.
+ if (!isInExpr && node[1][0] == NAME) {
+ if (FUNCTIONS_THAT_ALWAYS_THROW.has(node[1][1])) {
+ markNonLocalJump(RETURN, EMPTY);
+ }
+ }
+ } else if (type == SEQ || type == SUB) {
+ isInExpr++;
+ buildFlowGraph(node[1]);
+ buildFlowGraph(node[2]);
+ isInExpr--;
+ } else if (type == DOT || type == THROW) {
+ isInExpr++;
+ buildFlowGraph(node[1]);
+ isInExpr--;
+ } else if (type == NUM || type == STRING || type == VAR) {
+ // nada
+ } else {
+ assert(0); // 'unsupported node type: ' + type);
+ }
+ };
+
+ buildFlowGraph(fun);
+
+#ifdef PROFILING
+ tflowgraph += clock() - start;
+ start = clock();
+#endif
+
+ assert(junctions[ENTRY_JUNCTION].inblocks.size() == 0); // 'function entry must have no incoming blocks');
+ assert(junctions[EXIT_JUNCTION].outblocks.size() == 0); // 'function exit must have no outgoing blocks');
+ assert(blocks[ENTRY_BLOCK]->entry == ENTRY_JUNCTION); //, 'block zero must be the initial block');
+
+ // Fix up implicit jumps done by assigning to the LABEL variable.
+ // If a block ends with an assignment to LABEL and there's another block
+ // with that value of LABEL as precondition, we tweak the flow graph so
+ // that the former jumps straight to the later.
+
+ std::map<int, Block*> labelledBlocks;
+ typedef std::pair<Ref, Block*> Jump;
+ std::vector<Jump> labelledJumps;
+
+ for (size_t i = 0; i < blocks.size(); i++) {
+ Block* block = blocks[i];
+ // Does it have any labels as preconditions to its entry?
+ for (auto labelVal : block->labels) {
+ // If there are multiple blocks with the same label, all bets are off.
+ // This seems to happen sometimes for short blocks that end with a return.
+ // TODO: it should be safe to merge the duplicates if they're identical.
+ if (labelledBlocks.count(labelVal) > 0) {
+ labelledBlocks.clear();
+ labelledJumps.clear();
+ goto AFTER_FINDLABELLEDBLOCKS;
+ }
+ labelledBlocks[labelVal] = block;
+ }
+ // Does it assign a specific label value at exit?
+ if (block->kill.has(LABEL)) {
+ Ref finalNode = block->nodes.back();
+ if (finalNode[0] == ASSIGN && finalNode[2][1] == LABEL) {
+ // If labels are computed dynamically then all bets are off.
+ // This can happen due to indirect branching in llvm output.
+ if (finalNode[3][0] != NUM) {
+ labelledBlocks.clear();
+ labelledJumps.clear();
+ goto AFTER_FINDLABELLEDBLOCKS;
+ }
+ labelledJumps.push_back(Jump(finalNode[3][1], block));
+ } else {
+ // If label is assigned a non-zero value elsewhere in the block
+ // then all bets are off. This can happen e.g. due to outlining
+ // saving/restoring label to the stack.
+ for (size_t j = 0; j < block->nodes.size() - 1; j++) {
+ if (block->nodes[j][0] == ASSIGN && block->nodes[j][2][1] == LABEL) {
+ if (block->nodes[j][3][0] != NUM || block->nodes[j][3][1]->getNumber() != 0) {
+ labelledBlocks.clear();
+ labelledJumps.clear();
+ goto AFTER_FINDLABELLEDBLOCKS;
+ }
+ }
+ }
+ }
+ }
+ }
+
+ AFTER_FINDLABELLEDBLOCKS:
+
+ for (auto labelVal : labelledBlocks) {
+ Block* block = labelVal.second;
+ // Disconnect it from the graph, and create a
+ // new junction for jumps targetting this label.
+ junctions[block->entry].outblocks.erase(block->id);
+ block->entry = addJunction();
+ junctions[block->entry].outblocks.insert(block->id);
+ // Add a fake use of LABEL to keep it alive in predecessor.
+ block->use[LABEL] = 1;
+ block->nodes.insert(block->nodes.begin(), makeName(LABEL));
+ block->isexpr.insert(block->isexpr.begin(), 1);
+ }
+ for (size_t i = 0; i < labelledJumps.size(); i++) {
+ auto labelVal = labelledJumps[i].first;
+ auto block = labelledJumps[i].second;
+ Block* targetBlock = labelledBlocks[labelVal->getInteger()];
+ if (targetBlock) {
+ // Redirect its exit to entry of the target block.
+ junctions[block->exit].inblocks.erase(block->id);
+ block->exit = targetBlock->entry;
+ junctions[block->exit].inblocks.insert(block->id);
+ }
+ }
+
+#ifdef PROFILING
+ tlabelfix += clock() - start;
+ start = clock();
+#endif
+
+ // Do a backwards data-flow analysis to determine the set of live
+ // variables at each junction, and to use this information to eliminate
+ // any unused assignments.
+ // We run two nested phases. The inner phase builds the live set for each
+ // junction. The outer phase uses this to try to eliminate redundant
+ // stores in each basic block, which might in turn affect liveness info.
+
+ auto analyzeJunction = [&](Junction& junc) {
+ // Update the live set for this junction.
+ IOrderedStringSet live;
+ for (auto b : junc.outblocks) {
+ Block* block = blocks[b];
+ IOrderedStringSet& liveSucc = junctions[block->exit].live;
+ for (auto name : liveSucc) {
+ if (!block->kill.has(name)) {
+ live.insert(name);
+ }
+ }
+ for (auto name : block->use) {
+ live.insert(name.first);
+ }
+ }
+ junc.live = live;
+ };
+
+ auto analyzeBlock = [&](Block* block) {
+ // Update information about the behaviour of the block.
+ // This includes the standard 'use' and 'kill' information,
+ // plus a 'link' set naming values that flow through from entry
+ // to exit, possibly changing names via simple 'x=y' assignments.
+ // As we go, we eliminate assignments if the variable is not
+ // subsequently used.
+ auto live = junctions[block->exit].live;
+ StringIntMap use;
+ StringSet kill;
+ StringStringMap link;
+ StringIntMap lastUseLoc;
+ StringIntMap firstDeadLoc;
+ StringIntMap firstKillLoc;
+ StringIntMap lastKillLoc;
+ for (auto name : live) {
+ link[name] = name;
+ lastUseLoc[name] = block->nodes.size();
+ firstDeadLoc[name] = block->nodes.size();
+ }
+ for (int j = block->nodes.size() - 1; j >= 0 ; j--) {
+ Ref node = block->nodes[j];
+ if (node[0] == NAME) {
+ IString name = node[1]->getIString();
+ live.insert(name);
+ use[name] = j;
+ if (lastUseLoc.count(name) == 0) {
+ lastUseLoc[name] = j;
+ firstDeadLoc[name] = j;
+ }
+ } else {
+ IString name = node[2][1]->getIString();
+ // We only keep assignments if they will be subsequently used.
+ if (live.has(name)) {
+ kill.insert(name);
+ use.erase(name);
+ live.erase(name);
+ firstDeadLoc[name] = j;
+ firstKillLoc[name] = j;
+ if (lastUseLoc.count(name) == 0) {
+ lastUseLoc[name] = j;
+ }
+ if (lastKillLoc.count(name) == 0) {
+ lastKillLoc[name] = j;
+ }
+ // If it's an "x=y" and "y" is not live, then we can create a
+ // flow-through link from "y" to "x". If not then there's no
+ // flow-through link for "x".
+ if (link.has(name)) {
+ IString oldLink = link[name];
+ link.erase(name);
+ if (node[3][0] == NAME) {
+ if (asmData.isLocal(node[3][1]->getIString())) {
+ link[node[3][1]->getIString()] = oldLink;
+ }
+ }
+ }
+ } else {
+ // The result of this assignment is never used, so delete it.
+ // We may need to keep the RHS for its value or its side-effects.
+ auto removeUnusedNodes = [&](int j, int n) {
+ for (auto pair : lastUseLoc) {
+ pair.second -= n;
+ }
+ for (auto pair : firstKillLoc) {
+ pair.second -= n;
+ }
+ for (auto pair : lastKillLoc) {
+ pair.second -= n;
+ }
+ for (auto pair : firstDeadLoc) {
+ pair.second -= n;
+ }
+ block->nodes.erase(block->nodes.begin() + j, block->nodes.begin() + j + n);
+ block->isexpr.erase(block->isexpr.begin() + j, block->isexpr.begin() + j + n);
+ };
+ if (block->isexpr[j] || hasSideEffects(node[3])) {
+ safeCopy(node, node[3]);
+ removeUnusedNodes(j, 1);
+ } else {
+ int numUsesInExpr = 0;
+ traversePre(node[3], [&](Ref node) {
+ if (node[0] == NAME && asmData.isLocal(node[1]->getIString())) {
+ numUsesInExpr++;
+ }
+ });
+ safeCopy(node, makeEmpty());
+ j = j - numUsesInExpr;
+ removeUnusedNodes(j, 1 + numUsesInExpr);
+ }
+ }
+ }
+ }
+ // XXX efficiency
+ block->use = use;
+ block->kill = kill;
+ block->link = link;
+ block->lastUseLoc = lastUseLoc;
+ block->firstDeadLoc = firstDeadLoc;
+ block->firstKillLoc = firstKillLoc;
+ block->lastKillLoc = lastKillLoc;
+ };
+
+ // Ordered map to work in approximate reverse order of junction appearance
+ std::set<int> jWorkSet;
+ std::set<int> bWorkSet;
+
+ // Be sure to visit every junction at least once.
+ // This avoids missing some vars because we disconnected them
+ // when processing the labelled jumps.
+ for (size_t i = EXIT_JUNCTION; i < junctions.size(); i++) {
+ jWorkSet.insert(i);
+ for (auto b : junctions[i].inblocks) {
+ bWorkSet.insert(b);
+ }
+ }
+ // Exit junction never has any live variable changes to propagate
+ jWorkSet.erase(EXIT_JUNCTION);
+
+ do {
+ // Iterate on just the junctions until we get stable live sets.
+ // The first run of this loop will grow the live sets to their maximal size.
+ // Subsequent runs will shrink them based on eliminated in-block uses.
+ while (jWorkSet.size() > 0) {
+ auto last = jWorkSet.end();
+ --last;
+ Junction& junc = junctions[*last];
+ jWorkSet.erase(last);
+ IOrderedStringSet oldLive = junc.live; // copy it here, to check for changes later
+ analyzeJunction(junc);
+ if (oldLive != junc.live) {
+ // Live set changed, updated predecessor blocks and junctions.
+ for (auto b : junc.inblocks) {
+ bWorkSet.insert(b);
+ jWorkSet.insert(blocks[b]->entry);
+ }
+ }
+ }
+ // Now update the blocks based on the calculated live sets.
+ while (bWorkSet.size() > 0) {
+ auto last = bWorkSet.end();
+ --last;
+ Block* block = blocks[*last];
+ bWorkSet.erase(last);
+ auto oldUse = block->use;
+ analyzeBlock(block);
+ if (oldUse != block->use) {
+ // The use set changed, re-process the entry junction.
+ jWorkSet.insert(block->entry);
+ }
+ }
+ } while (jWorkSet.size() > 0);
+
+#ifdef PROFILING
+ tbackflow += clock() - start;
+ start = clock();
+#endif
+
+ // Insist that all function parameters are alive at function entry.
+ // This ensures they will be assigned independent registers, even
+ // if they happen to be unused.
+
+ for (auto name : asmData.params) {
+ junctions[ENTRY_JUNCTION].live.insert(name);
+ }
+
+ // For variables that are live at one or more junctions, we assign them
+ // a consistent register for the entire scope of the function. Find pairs
+ // of variable that cannot use the same register (the "conflicts") as well
+ // as pairs of variables that we'd like to have share the same register
+ // (the "links").
+
+ struct JuncVar {
+ std::vector<bool> conf;
+ IOrderedStringSet link;
+ std::unordered_set<int> excl;
+ int reg;
+ bool used;
+ JuncVar() : reg(-1), used(false) {}
+ };
+ size_t numLocals = asmData.locals.size();
+ std::unordered_map<IString, size_t> nameToNum;
+ std::vector<IString> numToName;
+ nameToNum.reserve(numLocals);
+ numToName.reserve(numLocals);
+ for (auto kv : asmData.locals) {
+ nameToNum[kv.first] = numToName.size();
+ numToName.push_back(kv.first);
+ }
+
+ std::vector<JuncVar> juncVars(numLocals);
+ for (Junction& junc : junctions) {
+ for (IString name : junc.live) {
+ JuncVar& jVar = juncVars[nameToNum[name]];
+ jVar.used = true;
+ jVar.conf.assign(numLocals, false);
+ }
+ }
+ std::map<IString, std::vector<Block*>> possibleBlockConflictsMap;
+ std::vector<std::pair<size_t, std::vector<Block*>>> possibleBlockConflicts;
+ std::unordered_map<IString, std::vector<Block*>> possibleBlockLinks;
+ possibleBlockConflicts.reserve(numLocals);
+ possibleBlockLinks.reserve(numLocals);
+
+ for (Junction& junc : junctions) {
+ // Pre-compute the possible conflicts and links for each block rather
+ // than checking potentially impossible options for each var
+ possibleBlockConflictsMap.clear();
+ possibleBlockConflicts.clear();
+ possibleBlockLinks.clear();
+ for (auto b : junc.outblocks) {
+ Block* block = blocks[b];
+ Junction& jSucc = junctions[block->exit];
+ for (auto name : jSucc.live) {
+ possibleBlockConflictsMap[name].push_back(block);
+ }
+ for (auto name_linkname : block->link) {
+ if (name_linkname.first != name_linkname.second) {
+ possibleBlockLinks[name_linkname.first].push_back(block);
+ }
+ }
+ }
+ // Find the live variables in this block, mark them as unnecessary to
+ // check for conflicts (we mark all live vars as conflicting later)
+ std::vector<size_t> liveJVarNums;
+ liveJVarNums.reserve(junc.live.size());
+ for (auto name : junc.live) {
+ size_t jVarNum = nameToNum[name];
+ liveJVarNums.push_back(jVarNum);
+ possibleBlockConflictsMap.erase(name);
+ }
+ // Extract just the variables we might want to check for conflicts
+ for (auto kv : possibleBlockConflictsMap) {
+ possibleBlockConflicts.push_back(std::make_pair(nameToNum[kv.first], kv.second));
+ }
+
+ for (size_t jVarNum : liveJVarNums) {
+ JuncVar& jvar = juncVars[jVarNum];
+ IString name = numToName[jVarNum];
+ // It conflicts with all other names live at this junction.
+ for (size_t liveJVarNum : liveJVarNums) {
+ jvar.conf[liveJVarNum] = true;
+ }
+ jvar.conf[jVarNum] = false; // except for itself, of course
+
+ // It conflicts with any output vars of successor blocks,
+ // if they're assigned before it goes dead in that block.
+ for (auto jvarnum_blocks : possibleBlockConflicts) {
+ size_t otherJVarNum = jvarnum_blocks.first;
+ IString otherName = numToName[otherJVarNum];
+ for (auto block : jvarnum_blocks.second) {
+ if (block->lastKillLoc[otherName] < block->firstDeadLoc[name]) {
+ jvar.conf[otherJVarNum] = true;
+ juncVars[otherJVarNum].conf[jVarNum] = true;
+ break;
+ }
+ }
+ }
+
+ // It links with any linkages in the outgoing blocks.
+ for (auto block: possibleBlockLinks[name]) {
+ IString linkName = block->link[name];
+ jvar.link.insert(linkName);
+ juncVars[nameToNum[linkName]].link.insert(name);
+ }
+ }
+ }
+
+#ifdef PROFILING
+ tjuncvaruniqassign += clock() - start;
+ start = clock();
+#endif
+
+ // Attempt to sort the junction variables to heuristically reduce conflicts.
+ // Simple starting point: handle the most-conflicted variables first.
+ // This seems to work pretty well.
+
+ std::vector<size_t> sortedJVarNums;
+ sortedJVarNums.reserve(juncVars.size());
+ std::vector<size_t> jVarConfCounts(numLocals);
+ for (size_t jVarNum = 0; jVarNum < juncVars.size(); jVarNum++) {
+ JuncVar& jVar = juncVars[jVarNum];
+ if (!jVar.used) continue;
+ jVarConfCounts[jVarNum] = std::count(jVar.conf.begin(), jVar.conf.end(), true);
+ sortedJVarNums.push_back(jVarNum);
+ }
+ std::sort(sortedJVarNums.begin(), sortedJVarNums.end(), [&](const size_t vi1, const size_t vi2) {
+ // sort by # of conflicts
+ if (jVarConfCounts[vi1] < jVarConfCounts[vi2]) return true;
+ if (jVarConfCounts[vi1] == jVarConfCounts[vi2]) return numToName[vi1] < numToName[vi2];
+ return false;
+ });
+
+#ifdef PROFILING
+ tjuncvarsort += clock() - start;
+ start = clock();
+#endif
+
+ // We can now assign a register to each junction variable.
+ // Process them in order, trying available registers until we find
+ // one that works, and propagating the choice to linked/conflicted
+ // variables as we go.
+
+ std::function<bool (IString, int)> tryAssignRegister = [&](IString name, int reg) {
+ // Try to assign the given register to the given variable,
+ // and propagate that choice throughout the graph.
+ // Returns true if successful, false if there was a conflict.
+ JuncVar& jv = juncVars[nameToNum[name]];
+ if (jv.reg > 0) {
+ return jv.reg == reg;
+ }
+ if (jv.excl.count(reg) > 0) {
+ return false;
+ }
+ jv.reg = reg;
+ // Exclude use of this register at all conflicting variables.
+ for (size_t confNameNum = 0; confNameNum < jv.conf.size(); confNameNum++) {
+ if (jv.conf[confNameNum]) {
+ juncVars[confNameNum].excl.insert(reg);
+ }
+ }
+ // Try to propagate it into linked variables.
+ // It's not an error if we can't.
+ for (auto linkName : jv.link) {
+ tryAssignRegister(linkName, reg);
+ }
+ return true;
+ };
+ for (size_t jVarNum : sortedJVarNums) {
+ // It may already be assigned due to linked-variable propagation.
+ if (juncVars[jVarNum].reg > 0) {
+ continue;
+ }
+ IString name = numToName[jVarNum];
+ // Try to use existing registers first.
+ auto& allRegs = allRegsByType[asmData.getType(name)];
+ bool moar = false;
+ for (auto reg : allRegs) {
+ if (tryAssignRegister(name, reg.first)) {
+ moar = true;
+ break;
+ }
+ }
+ if (moar) continue;
+ // They're all taken, create a new one.
+ tryAssignRegister(name, createReg(name));
+ }
+
+#ifdef PROFILING
+ tregassign += clock() - start;
+ start = clock();
+#endif
+
+ // Each basic block can now be processed in turn.
+ // There may be internal-use-only variables that still need a register
+ // assigned, but they can be treated just for this block. We know
+ // that all inter-block variables are in a good state thanks to
+ // junction variable consistency.
+
+ for (size_t i = 0; i < blocks.size(); i++) {
+ Block* block = blocks[i];
+ if (block->nodes.size() == 0) continue;
+ Junction& jEnter = junctions[block->entry];
+ Junction& jExit = junctions[block->exit];
+ // Mark the point at which each input reg becomes dead.
+ // Variables alive before this point must not be assigned
+ // to that register.
+ StringSet inputVars;
+ std::unordered_map<int, int> inputDeadLoc;
+ std::unordered_map<int, IString> inputVarsByReg;
+ for (auto name : jExit.live) {
+ if (!block->kill.has(name)) {
+ inputVars.insert(name);
+ int reg = juncVars[nameToNum[name]].reg;
+ assert(reg > 0); // 'input variable doesnt have a register');
+ inputDeadLoc[reg] = block->firstDeadLoc[name];
+ inputVarsByReg[reg] = name;
+ }
+ }
+ for (auto pair : block->use) {
+ IString name = pair.first;
+ if (!inputVars.has(name)) {
+ inputVars.insert(name);
+ int reg = juncVars[nameToNum[name]].reg;
+ assert(reg > 0); // 'input variable doesnt have a register');
+ inputDeadLoc[reg] = block->firstDeadLoc[name];
+ inputVarsByReg[reg] = name;
+ }
+ }
+ // TODO assert(setSize(setSub(inputVars, jEnter.live)) == 0);
+ // Scan through backwards, allocating registers on demand.
+ // Be careful to avoid conflicts with the input registers.
+ // We consume free registers in last-used order, which helps to
+ // eliminate "x=y" assignments that are the last use of "y".
+ StringIntMap assignedRegs;
+ auto freeRegsByTypePre = allRegsByType; // XXX copy
+ // Begin with all live vars assigned per the exit junction.
+ for (auto name : jExit.live) {
+ int reg = juncVars[nameToNum[name]].reg;
+ assert(reg > 0); // 'output variable doesnt have a register');
+ assignedRegs[name] = reg;
+ freeRegsByTypePre[asmData.getType(name)].erase(reg); // XXX assert?
+ }
+ std::vector<std::vector<int>> freeRegsByType;
+ freeRegsByType.resize(freeRegsByTypePre.size());
+ for (size_t j = 0; j < freeRegsByTypePre.size(); j++) {
+ for (auto pair : freeRegsByTypePre[j]) {
+ freeRegsByType[j].push_back(pair.first);
+ }
+ }
+ // Scan through the nodes in sequence, modifying each node in-place
+ // and grabbing/freeing registers as needed.
+ std::vector<std::pair<int, Ref>> maybeRemoveNodes;
+ for (int j = block->nodes.size() - 1; j >= 0; j--) {
+ Ref node = block->nodes[j];
+ IString name = (node[0] == ASSIGN ? node[2][1] : node[1])->getIString();
+ IntStringMap& allRegs = allRegsByType[asmData.getType(name)];
+ std::vector<int>& freeRegs = freeRegsByType[asmData.getType(name)];
+ int reg = assignedRegs[name]; // XXX may insert a zero
+ if (node[0] == NAME) {
+ // A use. Grab a register if it doesn't have one.
+ if (reg <= 0) {
+ if (inputVars.has(name) && j <= block->firstDeadLoc[name]) {
+ // Assignment to an input variable, must use pre-assigned reg.
+ reg = juncVars[nameToNum[name]].reg;
+ assignedRegs[name] = reg;
+ for (int k = freeRegs.size() - 1; k >= 0; k--) {
+ if (freeRegs[k] == reg) {
+ freeRegs.erase(freeRegs.begin() + k);
+ break;
+ }
+ }
+ } else {
+ // Try to use one of the existing free registers.
+ // It must not conflict with an input register.
+ for (int k = freeRegs.size() - 1; k >= 0; k--) {
+ reg = freeRegs[k];
+ // Check for conflict with input registers.
+ if (inputDeadLoc.count(reg) > 0) {
+ if (block->firstKillLoc[name] <= inputDeadLoc[reg]) {
+ if (name != inputVarsByReg[reg]) {
+ continue;
+ }
+ }
+ }
+ // Found one!
+ assignedRegs[name] = reg;
+ assert(reg > 0);
+ freeRegs.erase(freeRegs.begin() + k);
+ break;
+ }
+ // If we didn't find a suitable register, create a new one.
+ if (assignedRegs[name] <= 0) {
+ reg = createReg(name);
+ assignedRegs[name] = reg;
+ }
+ }
+ }
+ node[1]->setString(allRegs[reg]);
+ } else {
+ // A kill. This frees the assigned register.
+ assert(reg > 0); //, 'live variable doesnt have a reg?')
+ node[2][1]->setString(allRegs[reg]);
+ freeRegs.push_back(reg);
+ assignedRegs.erase(name);
+ if (node[3][0] == NAME && asmData.isLocal(node[3][1]->getIString())) {
+ maybeRemoveNodes.push_back(std::pair<int, Ref>(j, node));
+ }
+ }
+ }
+ // If we managed to create any "x=x" assignments, remove them.
+ for (size_t j = 0; j < maybeRemoveNodes.size(); j++) {
+ Ref node = maybeRemoveNodes[j].second;
+ if (node[2][1] == node[3][1]) {
+ if (block->isexpr[maybeRemoveNodes[j].first]) {
+ safeCopy(node, node[2]);
+ } else {
+ safeCopy(node, makeEmpty());
+ }
+ }
+ }
+ }
+
+#ifdef PROFILING
+ tblockproc += clock() - start;
+ start = clock();
+#endif
+
+ // Assign registers to function params based on entry junction
+
+ StringSet paramRegs;
+ if (!!fun[2]) {
+ for (size_t i = 0; i < fun[2]->size(); i++) {
+ auto& allRegs = allRegsByType[asmData.getType(fun[2][i]->getIString())];
+ fun[2][i]->setString(allRegs[juncVars[nameToNum[fun[2][i]->getIString()]].reg]);
+ paramRegs.insert(fun[2][i]->getIString());
+ }
+ }
+
+ // That's it!
+ // Re-construct the function with appropriate variable definitions.
+
+ asmData.locals.clear();
+ asmData.params.clear();
+ asmData.vars.clear();
+ for (int i = 1; i < nextReg; i++) {
+ for (size_t type = 0; type < allRegsByType.size(); type++) {
+ if (allRegsByType[type].count(i) > 0) {
+ IString reg = allRegsByType[type][i];
+ if (!paramRegs.has(reg)) {
+ asmData.addVar(reg, intToAsmType(type));
+ } else {
+ asmData.addParam(reg, intToAsmType(type));
+ }
+ break;
+ }
+ }
+ }
+ asmData.denormalize();
+
+ removeAllUselessSubNodes(fun); // XXX vacuum? vacuum(fun);
+
+#ifdef PROFILING
+ treconstruct += clock() - start;
+ start = clock();
+#endif
+
+ });
+#ifdef PROFILING
+ errv(" RH stages: a:%li fl:%li lf:%li bf:%li jvua:%li jvs:%li jra:%li bp:%li r:%li",
+ tasmdata, tflowgraph, tlabelfix, tbackflow, tjuncvaruniqassign, tjuncvarsort, tregassign, tblockproc, treconstruct);
+#endif
+}
+// end registerizeHarder
+
+// minified names generation
+StringSet RESERVED("do if in for new try var env let");
+const char *VALID_MIN_INITS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_$";
+const char *VALID_MIN_LATERS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_$0123456789";
+
+StringVec minifiedNames;
+std::vector<int> minifiedState;
+
+void ensureMinifiedNames(int n) { // make sure the nth index in minifiedNames exists. done 100% deterministically
+ static int VALID_MIN_INITS_LEN = strlen(VALID_MIN_INITS);
+ static int VALID_MIN_LATERS_LEN = strlen(VALID_MIN_LATERS);
+
+ while ((int)minifiedNames.size() < n+1) {
+ // generate the current name
+ std::string name;
+ name += VALID_MIN_INITS[minifiedState[0]];
+ for (size_t i = 1; i < minifiedState.size(); i++) {
+ name += VALID_MIN_LATERS[minifiedState[i]];
+ }
+ IString str(strdupe(name.c_str())); // leaked!
+ if (!RESERVED.has(str)) minifiedNames.push_back(str);
+ // increment the state
+ size_t i = 0;
+ while (1) {
+ minifiedState[i]++;
+ if (minifiedState[i] < (i == 0 ? VALID_MIN_INITS_LEN : VALID_MIN_LATERS_LEN)) break;
+ // overflow
+ minifiedState[i] = 0;
+ i++;
+ if (i == minifiedState.size()) minifiedState.push_back(-1); // will become 0 after increment in next loop head
+ }
+ }
+}
+
+void minifyLocals(Ref ast) {
+ assert(!!extraInfo);
+ IString GLOBALS("globals");
+ assert(extraInfo->has(GLOBALS));
+ Ref globals = extraInfo[GLOBALS];
+
+ if (minifiedState.size() == 0) minifiedState.push_back(0);
+
+ traverseFunctions(ast, [&globals](Ref fun) {
+ // Analyse the asmjs to figure out local variable names,
+ // but operate on the original source tree so that we don't
+ // miss any global names in e.g. variable initializers.
+ AsmData asmData(fun);
+ asmData.denormalize(); // TODO: we can avoid modifying at all here - we just need a list of local vars+params
+
+ StringStringMap newNames;
+ StringSet usedNames;
+
+ // Find all the globals that we need to minify using
+ // pre-assigned names. Don't actually minify them yet
+ // as that might interfere with local variable names.
+ traversePre(fun, [&](Ref node) {
+ if (node[0] == NAME) {
+ IString name = node[1]->getIString();
+ if (!asmData.isLocal(name)) {
+ if (globals->has(name)) {
+ IString minified = globals[name]->getIString();
+ assert(!!minified);
+ newNames[name] = minified;
+ usedNames.insert(minified);
+ }
+ }
+ }
+ });
+
+ // The first time we encounter a local name, we assign it a
+ // minified name that's not currently in use. Allocating on
+ // demand means they're processed in a predictable order,
+ // which is very handy for testing/debugging purposes.
+ int nextMinifiedName = 0;
+ auto getNextMinifiedName = [&]() {
+ IString minified;
+ while (1) {
+ ensureMinifiedNames(nextMinifiedName);
+ minified = minifiedNames[nextMinifiedName++];
+ // TODO: we can probably remove !isLocalName here
+ if (!usedNames.has(minified) && !asmData.isLocal(minified)) {
+ return minified;
+ }
+ }
+ };
+
+ // We can also minify loop labels, using a separate namespace
+ // to the variable declarations.
+ StringStringMap newLabels;
+ int nextMinifiedLabel = 0;
+ auto getNextMinifiedLabel = [&]() {
+ ensureMinifiedNames(nextMinifiedLabel);
+ return minifiedNames[nextMinifiedLabel++];
+ };
+
+ // Traverse and minify all names.
+ if (globals->has(fun[1]->getIString())) {
+ fun[1]->setString(globals[fun[1]->getIString()]->getIString());
+ assert(!!fun[1]);
+ }
+ if (!!fun[2]) {
+ for (size_t i = 0; i < fun[2]->size(); i++) {
+ IString minified = getNextMinifiedName();
+ newNames[fun[2][i]->getIString()] = minified;
+ fun[2][i]->setString(minified);
+ }
+ }
+ traversePre(fun[3], [&](Ref node) {
+ Ref type = node[0];
+ if (type == NAME) {
+ IString name = node[1]->getIString();
+ IString minified = newNames[name];
+ if (!!minified) {
+ node[1]->setString(minified);
+ } else if (asmData.isLocal(name)) {
+ minified = getNextMinifiedName();
+ newNames[name] = minified;
+ node[1]->setString(minified);
+ }
+ } else if (type == VAR) {
+ for (size_t i = 0; i < node[1]->size(); i++) {
+ Ref defn = node[1][i];
+ IString name = defn[0]->getIString();
+ if (!(newNames.has(name))) {
+ newNames[name] = getNextMinifiedName();
+ }
+ defn[0]->setString(newNames[name]);
+ }
+ } else if (type == LABEL) {
+ IString name = node[1]->getIString();
+ if (!newLabels.has(name)) {
+ newLabels[name] = getNextMinifiedLabel();
+ }
+ node[1]->setString(newLabels[name]);
+ } else if (type == BREAK || type == CONTINUE) {
+ if (node->size() > 1 && !!node[1]) {
+ node[1]->setString(newLabels[node[1]->getIString()]);
+ }
+ }
+ });
+ });
+}
+
+void asmLastOpts(Ref ast) {
+ std::vector<Ref> statsStack;
+ traverseFunctions(ast, [&](Ref fun) {
+ traversePrePost(fun, [&](Ref node) {
+ Ref type = node[0];
+ Ref stats = getStatements(node);
+ if (!!stats) statsStack.push_back(stats);
+ if (CONDITION_CHECKERS.has(type)) {
+ node[1] = simplifyCondition(node[1]);
+ }
+ if (type == WHILE && node[1][0] == NUM && node[1][1]->getNumber() == 1 && node[2][0] == BLOCK && node[2]->size() == 2) {
+ // This is at the end of the pipeline, we can assume all other optimizations are done, and we modify loops
+ // into shapes that might confuse other passes
+
+ // while (1) { .. if (..) { break } } ==> do { .. } while(..)
+ Ref stats = node[2][1];
+ Ref last = stats->back();
+ if (!!last && last[0] == IF && (last->size() < 4 || !last[3]) && last[2][0] == BLOCK && !!last[2][1][0]) {
+ Ref lastStats = last[2][1];
+ int lastNum = lastStats->size();
+ Ref lastLast = lastStats[lastNum-1];
+ if (!(lastLast[0] == BREAK && !lastLast[1])) return;// if not a simple break, dangerous
+ for (int i = 0; i < lastNum; i++) {
+ if (lastStats[i][0] != STAT && lastStats[i][0] != BREAK) return; // something dangerous
+ }
+ // ok, a bunch of statements ending in a break
+ bool abort = false;
+ int stack = 0;
+ int breaks = 0;
+ traversePrePost(stats, [&](Ref node) {
+ Ref type = node[0];
+ if (type == CONTINUE) {
+ if (stack == 0 || !!node[1]) { // abort if labeled (we do not analyze labels here yet), or a continue directly on us
+ abort = true;
+ }
+ } else if (type == BREAK) {
+ if (stack == 0 || !!node[1]) { // relevant if labeled (we do not analyze labels here yet), or a break directly on us
+ breaks++;
+ }
+ } else if (LOOP.has(type)) {
+ stack++;
+ }
+ }, [&](Ref node) {
+ if (LOOP.has(node[0])) {
+ stack--;
+ }
+ });
+ if (abort) return;
+ assert(breaks > 0);
+ if (lastStats->size() > 1 && breaks != 1) return; // if we have code aside from the break, we can only move it out if there is just one break
+ if (statsStack.size() < 1) return; // no chance we have this stats on hand
+ // start to optimize
+ if (lastStats->size() > 1) {
+ Ref parent = statsStack.back();
+ int me = parent->indexOf(node);
+ if (me < 0) return; // not always directly on a stats, could be in a label for example
+ parent->insert(me+1, lastStats->size()-1);
+ for (size_t i = 0; i+1 < lastStats->size(); i++) {
+ parent[me+1+i] = lastStats[i];
+ }
+ }
+ Ref conditionToBreak = last[1];
+ stats->pop_back();
+ node[0]->setString(DO);
+ node[1] = simplifyNotCompsDirect(make2(UNARY_PREFIX, L_NOT, conditionToBreak));
+ }
+ } else if (type == BINARY) {
+ if (node[1] == AND) {
+ if (node[3][0] == UNARY_PREFIX && node[3][1] == MINUS && node[3][2][0] == NUM && node[3][2][1]->getNumber() == 1) {
+ // Change &-1 into |0, at this point the hint is no longer needed
+ node[1]->setString(OR);
+ node[3] = node[3][2];
+ node[3][1]->setNumber(0);
+ }
+ } else if (node[1] == MINUS && node[3][0] == UNARY_PREFIX) {
+ // avoid X - (-Y) because some minifiers buggily emit X--Y which is invalid as -- can be a unary. Transform to
+ // X + Y
+ if (node[3][1] == MINUS) { // integer
+ node[1]->setString(PLUS);
+ node[3] = node[3][2];
+ } else if (node[3][1] == PLUS) { // float
+ if (node[3][2][0] == UNARY_PREFIX && node[3][2][1] == MINUS) {
+ node[1]->setString(PLUS);
+ node[3][2] = node[3][2][2];
+ }
+ }
+ }
+ }
+ }, [&](Ref node) {
+ if (statsStack.size() > 0) {
+ Ref stats = getStatements(node);
+ if (!!stats) statsStack.pop_back();
+ }
+ });
+ // convert { singleton } into singleton
+ traversePre(fun, [](Ref node) {
+ if (node[0] == BLOCK && !!getStatements(node) && node[1]->size() == 1) {
+ safeCopy(node, node[1][0]);
+ }
+ });
+ // convert L: do { .. } while(0) into L: { .. }
+ traversePre(fun, [](Ref node) {
+ if (node[0] == LABEL && node[1]->isString() /* careful of var label = 5 */ &&
+ node[2][0] == DO && node[2][1][0] == NUM && node[2][1][1]->getNumber() == 0 && node[2][2][0] == BLOCK) {
+ // there shouldn't be any continues on this, not direct break or continue
+ IString label = node[1]->getIString();
+ bool abort = false;
+ int breakCaptured = 0, continueCaptured = 0;
+ traversePrePost(node[2][2], [&](Ref node) {
+ if (node[0] == CONTINUE) {
+ if (!node[1] && !continueCaptured) {
+ abort = true;
+ } else if (node[1]->isString() && node[1]->getIString() == label) {
+ abort = true;
+ }
+ }
+ if (node[0] == BREAK && !node[1] && !breakCaptured) {
+ abort = true;
+ }
+ if (BREAK_CAPTURERS.has(node[0])) {
+ breakCaptured++;
+ }
+ if (CONTINUE_CAPTURERS.has(node[0])) {
+ continueCaptured++;
+ }
+ }, [&](Ref node) {
+ if (BREAK_CAPTURERS.has(node[0])) {
+ breakCaptured--;
+ }
+ if (CONTINUE_CAPTURERS.has(node[0])) {
+ continueCaptured--;
+ }
+ });
+ if (abort) return;
+ safeCopy(node[2], node[2][2]);
+ }
+ });
+ });
+}
+
+// Contrary to the name this does not eliminate actual dead functions, only
+// those marked as such with DEAD_FUNCTIONS
+void eliminateDeadFuncs(Ref ast) {
+ assert(!!extraInfo);
+ IString DEAD_FUNCTIONS("dead_functions");
+ IString ABORT("abort");
+ assert(extraInfo->has(DEAD_FUNCTIONS));
+ StringSet deadFunctions;
+ for (size_t i = 0; i < extraInfo[DEAD_FUNCTIONS]->size(); i++) {
+ deadFunctions.insert(extraInfo[DEAD_FUNCTIONS][i]->getIString());
+ }
+ traverseFunctions(ast, [&](Ref fun) {
+ if (!deadFunctions.has(fun[1].get()->getIString())) {
+ return;
+ }
+ AsmData asmData(fun);
+ fun[3]->setSize(1);
+ fun[3][0] = make1(STAT, make2(CALL, makeName(ABORT), &(makeArray(1))->push_back(makeNum(-1))));
+ asmData.vars.clear();
+ asmData.denormalize();
+ });
+}
+
diff --git a/src/optimizer.h b/src/optimizer.h
new file mode 100644
index 000000000..04ee7dddf
--- /dev/null
+++ b/src/optimizer.h
@@ -0,0 +1,119 @@
+extern bool preciseF32,
+ receiveJSON,
+ emitJSON,
+ minifyWhitespace,
+ last;
+
+extern Ref extraInfo;
+
+void eliminateDeadFuncs(Ref ast);
+void eliminate(Ref ast, bool memSafe=false);
+void eliminateMemSafe(Ref ast);
+void simplifyExpressions(Ref ast);
+void optimizeFrounds(Ref ast);
+void simplifyIfs(Ref ast);
+void registerize(Ref ast);
+void registerizeHarder(Ref ast);
+void minifyLocals(Ref ast);
+void asmLastOpts(Ref ast);
+
+//
+
+enum AsmType {
+ ASM_INT = 0,
+ ASM_DOUBLE,
+ ASM_FLOAT,
+ ASM_FLOAT32X4,
+ ASM_FLOAT64X2,
+ ASM_INT8X16,
+ ASM_INT16X8,
+ ASM_INT32X4,
+ ASM_NONE // number of types
+};
+
+struct AsmData;
+
+AsmType detectType(Ref node, AsmData *asmData=nullptr, bool inVarDef=false);
+
+struct AsmData {
+ struct Local {
+ Local() {}
+ Local(AsmType type, bool param) : type(type), param(param) {}
+ AsmType type;
+ bool param; // false if a var
+ };
+ typedef std::unordered_map<IString, Local> Locals;
+
+ Locals locals;
+ std::vector<IString> params; // in order
+ std::vector<IString> vars; // in order
+ AsmType ret;
+
+ Ref func;
+
+ AsmType getType(const IString& name) {
+ auto ret = locals.find(name);
+ if (ret != locals.end()) return ret->second.type;
+ return ASM_NONE;
+ }
+ void setType(const IString& name, AsmType type) {
+ locals[name].type = type;
+ }
+
+ bool isLocal(const IString& name) {
+ return locals.count(name) > 0;
+ }
+ bool isParam(const IString& name) {
+ return isLocal(name) && locals[name].param;
+ }
+ bool isVar(const IString& name) {
+ return isLocal(name) && !locals[name].param;
+ }
+
+ AsmData() {} // if you want to fill in the data yourself
+ AsmData(Ref f); // if you want to read data from f, and modify it as you go (parallel to denormalize)
+
+ void denormalize();
+
+ void addParam(IString name, AsmType type) {
+ locals[name] = Local(type, true);
+ params.push_back(name);
+ }
+ void addVar(IString name, AsmType type) {
+ locals[name] = Local(type, false);
+ vars.push_back(name);
+ }
+
+ void deleteVar(IString name) {
+ locals.erase(name);
+ for (size_t i = 0; i < vars.size(); i++) {
+ if (vars[i] == name) {
+ vars.erase(vars.begin() + i);
+ break;
+ }
+ }
+ }
+};
+
+bool isInteger(double x);
+
+bool isInteger32(double x);
+
+extern IString ASM_FLOAT_ZERO;
+
+extern IString SIMD_INT8X16_CHECK,
+ SIMD_INT16X8_CHECK,
+ SIMD_INT32X4_CHECK,
+ SIMD_FLOAT32X4_CHECK,
+ SIMD_FLOAT64X2_CHECK;
+
+int parseInt(const char *str);
+
+struct HeapInfo {
+ bool valid, unsign, floaty;
+ int bits;
+ AsmType type;
+};
+
+HeapInfo parseHeap(const char *name);
+
diff --git a/src/parser.cpp b/src/parser.cpp
new file mode 100644
index 000000000..06e455b0b
--- /dev/null
+++ b/src/parser.cpp
@@ -0,0 +1,144 @@
+
+#include "parser.h"
+
+namespace cashew {
+
+// common strings
+
+IString TOPLEVEL("toplevel"),
+ DEFUN("defun"),
+ BLOCK("block"),
+ STAT("stat"),
+ ASSIGN("assign"),
+ NAME("name"),
+ VAR("var"),
+ CONST("const"),
+ CONDITIONAL("conditional"),
+ BINARY("binary"),
+ RETURN("return"),
+ IF("if"),
+ ELSE("else"),
+ WHILE("while"),
+ DO("do"),
+ FOR("for"),
+ SEQ("seq"),
+ SUB("sub"),
+ CALL("call"),
+ NUM("num"),
+ LABEL("label"),
+ BREAK("break"),
+ CONTINUE("continue"),
+ SWITCH("switch"),
+ STRING("string"),
+ INF("inf"),
+ NaN("nan"),
+ TEMP_RET0("tempRet0"),
+ UNARY_PREFIX("unary-prefix"),
+ UNARY_POSTFIX("unary-postfix"),
+ MATH_FROUND("Math_fround"),
+ SIMD_FLOAT32X4("SIMD_Float32x4"),
+ SIMD_FLOAT64X2("SIMD_Float64x2"),
+ SIMD_INT8X16("SIMD_Int8x16"),
+ SIMD_INT16X8("SIMD_Int16x8"),
+ SIMD_INT32X4("SIMD_Int32x4"),
+ PLUS("+"),
+ MINUS("-"),
+ OR("|"),
+ AND("&"),
+ XOR("^"),
+ L_NOT("!"),
+ B_NOT("~"),
+ LT("<"),
+ GE(">="),
+ LE("<="),
+ GT(">"),
+ EQ("=="),
+ NE("!="),
+ DIV("/"),
+ MOD("%"),
+ MUL("*"),
+ RSHIFT(">>"),
+ LSHIFT("<<"),
+ TRSHIFT(">>>"),
+ TEMP_DOUBLE_PTR("tempDoublePtr"),
+ HEAP8("HEAP8"),
+ HEAP16("HEAP16"),
+ HEAP32("HEAP32"),
+ HEAPF32("HEAPF32"),
+ HEAPU8("HEAPU8"),
+ HEAPU16("HEAPU16"),
+ HEAPU32("HEAPU32"),
+ HEAPF64("HEAPF64"),
+ F0("f0"),
+ EMPTY(""),
+ FUNCTION("function"),
+ OPEN_PAREN("("),
+ OPEN_BRACE("["),
+ OPEN_CURLY("{"),
+ CLOSE_CURLY("}"),
+ COMMA(","),
+ QUESTION("?"),
+ COLON(":"),
+ CASE("case"),
+ DEFAULT("default"),
+ DOT("dot"),
+ PERIOD("."),
+ NEW("new"),
+ ARRAY("array"),
+ OBJECT("object"),
+ THROW("throw"),
+ SET("=");
+
+IStringSet keywords("var const function if else do while for break continue return switch case default throw try catch finally true false null new");
+
+const char *OPERATOR_INITS = "+-*/%<>&^|~=!,?:.",
+ *SEPARATORS = "([;{}";
+
+int MAX_OPERATOR_SIZE = 3;
+
+std::vector<OperatorClass> operatorClasses;
+
+static std::vector<std::unordered_map<IString, int>> precedences; // op, type => prec
+
+struct Init {
+ Init() {
+ // operators, rtl, type
+ operatorClasses.push_back(OperatorClass(".", false, OperatorClass::Binary));
+ operatorClasses.push_back(OperatorClass("! ~ + -", true, OperatorClass::Prefix));
+ operatorClasses.push_back(OperatorClass("* / %", false, OperatorClass::Binary));
+ operatorClasses.push_back(OperatorClass("+ -", false, OperatorClass::Binary));
+ operatorClasses.push_back(OperatorClass("<< >> >>>", false, OperatorClass::Binary));
+ operatorClasses.push_back(OperatorClass("< <= > >=", false, OperatorClass::Binary));
+ operatorClasses.push_back(OperatorClass("== !=", false, OperatorClass::Binary));
+ operatorClasses.push_back(OperatorClass("&", false, OperatorClass::Binary));
+ operatorClasses.push_back(OperatorClass("^", false, OperatorClass::Binary));
+ operatorClasses.push_back(OperatorClass("|", false, OperatorClass::Binary));
+ operatorClasses.push_back(OperatorClass("? :", true, OperatorClass::Tertiary));
+ operatorClasses.push_back(OperatorClass("=", true, OperatorClass::Binary));
+ operatorClasses.push_back(OperatorClass(",", true, OperatorClass::Binary));
+
+ precedences.resize(OperatorClass::Tertiary + 1);
+
+ for (size_t prec = 0; prec < operatorClasses.size(); prec++) {
+ for (auto curr : operatorClasses[prec].ops) {
+ precedences[operatorClasses[prec].type][curr] = prec;
+ }
+ }
+ }
+};
+
+Init init;
+
+int OperatorClass::getPrecedence(Type type, IString op) {
+ return precedences[type][op];
+}
+
+bool OperatorClass::getRtl(int prec) {
+ return operatorClasses[prec].rtl;
+}
+
+bool isIdentInit(char x) { return (x >= 'a' && x <= 'z') || (x >= 'A' && x <= 'Z') || x == '_' || x == '$'; }
+bool isIdentPart(char x) { return isIdentInit(x) || (x >= '0' && x <= '9'); }
+
+} // namespace cashew
+
diff --git a/src/parser.h b/src/parser.h
new file mode 100644
index 000000000..9f5b6c3a7
--- /dev/null
+++ b/src/parser.h
@@ -0,0 +1,900 @@
+// Pure parsing. Calls methods on a Builder (template argument) to actually construct the AST
+//
+// XXX All parsing methods assume they take ownership of the input string. This lets them reuse
+// parts of it. You will segfault if the input string cannot be reused and written to.
+
+#include <vector>
+#include <iostream>
+#include <algorithm>
+
+#include <stdio.h>
+
+#include "istring.h"
+
+namespace cashew {
+
+// common strings
+
+extern IString TOPLEVEL,
+ DEFUN,
+ BLOCK,
+ STAT,
+ ASSIGN,
+ NAME,
+ VAR,
+ CONST,
+ CONDITIONAL,
+ BINARY,
+ RETURN,
+ IF,
+ ELSE,
+ WHILE,
+ DO,
+ FOR,
+ SEQ,
+ SUB,
+ CALL,
+ NUM,
+ LABEL,
+ BREAK,
+ CONTINUE,
+ SWITCH,
+ STRING,
+ INF,
+ NaN,
+ TEMP_RET0,
+ UNARY_PREFIX,
+ UNARY_POSTFIX,
+ MATH_FROUND,
+ SIMD_FLOAT32X4,
+ SIMD_FLOAT64X2,
+ SIMD_INT8X16,
+ SIMD_INT16X8,
+ SIMD_INT32X4,
+ PLUS,
+ MINUS,
+ OR,
+ AND,
+ XOR,
+ L_NOT,
+ B_NOT,
+ LT,
+ GE,
+ LE,
+ GT,
+ EQ,
+ NE,
+ DIV,
+ MOD,
+ MUL,
+ RSHIFT,
+ LSHIFT,
+ TRSHIFT,
+ TEMP_DOUBLE_PTR,
+ HEAP8,
+ HEAP16,
+ HEAP32,
+ HEAPF32,
+ HEAPU8,
+ HEAPU16,
+ HEAPU32,
+ HEAPF64,
+ F0,
+ EMPTY,
+ FUNCTION,
+ OPEN_PAREN,
+ OPEN_BRACE,
+ OPEN_CURLY,
+ CLOSE_CURLY,
+ COMMA,
+ QUESTION,
+ COLON,
+ CASE,
+ DEFAULT,
+ DOT,
+ PERIOD,
+ NEW,
+ ARRAY,
+ OBJECT,
+ THROW,
+ SET;
+
+extern IStringSet keywords;
+
+extern const char *OPERATOR_INITS, *SEPARATORS;
+
+extern int MAX_OPERATOR_SIZE, LOWEST_PREC;
+
+struct OperatorClass {
+ enum Type {
+ Binary = 0,
+ Prefix = 1,
+ Postfix = 2,
+ Tertiary = 3
+ };
+
+ IStringSet ops;
+ bool rtl;
+ Type type;
+
+ OperatorClass(const char* o, bool r, Type t) : ops(o), rtl(r), type(t) {}
+
+ static int getPrecedence(Type type, IString op);
+ static bool getRtl(int prec);
+};
+
+extern std::vector<OperatorClass> operatorClasses;
+
+extern bool isIdentInit(char x);
+extern bool isIdentPart(char x);
+
+// parser
+
+template<class NodeRef, class Builder>
+class Parser {
+
+ static bool isSpace(char x) { return x == 32 || x == 9 || x == 10 || x == 13; } /* space, tab, linefeed/newline, or return */
+ static void skipSpace(char*& curr) {
+ while (*curr) {
+ if (isSpace(*curr)) {
+ curr++;
+ continue;
+ }
+ if (curr[0] == '/' && curr[1] == '/') {
+ curr += 2;
+ while (*curr && *curr != '\n') curr++;
+ if (*curr) curr++;
+ continue;
+ }
+ if (curr[0] == '/' && curr[1] == '*') {
+ curr += 2;
+ while (*curr && (curr[0] != '*' || curr[1] != '/')) curr++;
+ curr += 2;
+ continue;
+ }
+ return;
+ }
+ }
+
+ static bool isDigit(char x) { return x >= '0' && x <= '9'; }
+
+ static bool hasChar(const char* list, char x) { while (*list) if (*list++ == x) return true; return false; }
+
+ static bool is32Bit(double x) {
+ return x == (int)x || x == (unsigned int)x;
+ }
+
+ // An atomic fragment of something. Stops at a natural boundary.
+ enum FragType {
+ KEYWORD = 0,
+ OPERATOR = 1,
+ IDENT = 2,
+ STRING = 3, // without quotes
+ INT = 4,
+ DOUBLE = 5,
+ SEPARATOR = 6
+ };
+
+ struct Frag {
+#ifndef _MSC_VER // MSVC does not allow unrestricted unions: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2544.pdf
+ union {
+#endif
+ IString str;
+ double num;
+#ifndef _MSC_VER
+ };
+#endif
+ int size;
+ FragType type;
+
+ bool isNumber() const {
+ return type == INT || type == DOUBLE;
+ }
+
+ explicit Frag(char* src) {
+ char *start = src;
+ if (isIdentInit(*src)) {
+ // read an identifier or a keyword
+ src++;
+ while (isIdentPart(*src)) {
+ src++;
+ }
+ if (*src == 0) {
+ str.set(start);
+ } else {
+ char temp = *src;
+ *src = 0;
+ str.set(start, false);
+ *src = temp;
+ }
+ type = keywords.has(str) ? KEYWORD : IDENT;
+ } else if (isDigit(*src) || (src[0] == '.' && isDigit(src[1]))) {
+ if (src[0] == '0' && (src[1] == 'x' || src[1] == 'X')) {
+ // Explicitly parse hex numbers of form "0x...", because strtod
+ // supports hex number strings only in C++11, and Visual Studio 2013 does
+ // not yet support that functionality.
+ src += 2;
+ num = 0;
+ while (1) {
+ if (*src >= '0' && *src <= '9') { num *= 16; num += *src - '0'; }
+ else if (*src >= 'a' && *src <= 'f') { num *= 16; num += *src - 'a' + 10; }
+ else if (*src >= 'A' && *src <= 'F') { num *= 16; num += *src - 'F' + 10; }
+ else break;
+ src++;
+ }
+ } else {
+ num = strtod(start, &src);
+ }
+ // asm.js must have a '.' for double values. however, we also tolerate
+ // uglify's tendency to emit without a '.' (and fix it later with a +).
+ // for valid asm.js input, the '.' should be enough, and for uglify
+ // in the emscripten optimizer pipeline, we use simple_ast where INT/DOUBLE
+ // is quite the same at this point anyhow
+ type = (std::find(start, src, '.') == src && is32Bit(num)) ? INT : DOUBLE;
+ assert(src > start);
+ } else if (hasChar(OPERATOR_INITS, *src)) {
+ switch (*src) {
+ case '!': str = src[1] == '=' ? NE : L_NOT; break;
+ case '%': str = MOD; break;
+ case '&': str = AND; break;
+ case '*': str = MUL; break;
+ case '+': str = PLUS; break;
+ case ',': str = COMMA; break;
+ case '-': str = MINUS; break;
+ case '.': str = PERIOD; break;
+ case '/': str = DIV; break;
+ case ':': str = COLON; break;
+ case '<': str = src[1] == '<' ? LSHIFT : (src[1] == '=' ? LE : LT); break;
+ case '=': str = src[1] == '=' ? EQ : SET; break;
+ case '>': str = src[1] == '>' ? (src[2] == '>' ? TRSHIFT : RSHIFT) : (src[1] == '=' ? GE : GT); break;
+ case '?': str = QUESTION; break;
+ case '^': str = XOR; break;
+ case '|': str = OR; break;
+ case '~': str = B_NOT; break;
+ default: abort();
+ }
+ size = strlen(str.str);
+#ifndef NDEBUG
+ char temp = start[size];
+ start[size] = 0;
+ assert(strcmp(str.str, start) == 0);
+ start[size] = temp;
+#endif
+ type = OPERATOR;
+ return;
+ } else if (hasChar(SEPARATORS, *src)) {
+ type = SEPARATOR;
+ char temp = src[1];
+ src[1] = 0;
+ str.set(src, false);
+ src[1] = temp;
+ src++;
+ } else if (*src == '"' || *src == '\'') {
+ char *end = strchr(src+1, *src);
+ *end = 0;
+ str.set(src+1);
+ src = end+1;
+ type = STRING;
+ } else {
+ dump("frag parsing", src);
+ abort();
+ }
+ size = src - start;
+ }
+ };
+
+ struct ExpressionElement {
+ bool isNode;
+#ifndef _MSC_VER // MSVC does not allow unrestricted unions: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2544.pdf
+ union {
+#endif
+ NodeRef node;
+ IString op;
+#ifndef _MSC_VER
+ };
+#endif
+ ExpressionElement(NodeRef n) : isNode(true), node(n) {}
+ ExpressionElement(IString o) : isNode(false), op(o) {}
+
+ NodeRef getNode() {
+ assert(isNode);
+ return node;
+ }
+ IString getOp() {
+ assert(!isNode);
+ return op;
+ }
+ };
+
+ // This is a list of the current stack of node-operator-node-operator-etc.
+ // this works by each parseExpression call appending to the vector; then recursing out, and the toplevel sorts it all
+ typedef std::vector<ExpressionElement> ExpressionParts;
+ std::vector<ExpressionParts> expressionPartsStack;
+
+ // Parses an element in a list of such elements, e.g. list of statements in a block, or list of parameters in a call
+ NodeRef parseElement(char*& src, const char* seps=";") {
+ //dump("parseElement", src);
+ skipSpace(src);
+ Frag frag(src);
+ src += frag.size;
+ switch (frag.type) {
+ case KEYWORD: {
+ return parseAfterKeyword(frag, src, seps);
+ }
+ case IDENT: {
+ return parseAfterIdent(frag, src, seps);
+ }
+ case STRING:
+ case INT:
+ case DOUBLE: {
+ return parseExpression(parseFrag(frag), src, seps);
+ }
+ case SEPARATOR: {
+ if (frag.str == OPEN_PAREN) return parseExpression(parseAfterParen(src), src, seps);
+ if (frag.str == OPEN_BRACE) return parseExpression(parseAfterBrace(src), src, seps);
+ if (frag.str == OPEN_CURLY) return parseExpression(parseAfterCurly(src), src, seps);
+ abort();
+ }
+ case OPERATOR: {
+ return parseExpression(frag.str, src, seps);
+ }
+ default: /* dump("parseElement", src); printf("bad frag type: %d\n", frag.type); */ abort();
+ }
+ return nullptr;
+ }
+
+ NodeRef parseFrag(Frag& frag) {
+ switch (frag.type) {
+ case IDENT: return Builder::makeName(frag.str);
+ case STRING: return Builder::makeString(frag.str);
+ case INT: return Builder::makeInt(uint32_t(frag.num));
+ case DOUBLE: return Builder::makeDouble(frag.num);
+ default: abort();
+ }
+ return nullptr;
+ }
+
+ NodeRef parseAfterKeyword(Frag& frag, char*& src, const char* seps) {
+ skipSpace(src);
+ if (frag.str == FUNCTION) return parseFunction(src, seps);
+ else if (frag.str == VAR) return parseVar(src, seps, false);
+ else if (frag.str == CONST) return parseVar(src, seps, true);
+ else if (frag.str == RETURN) return parseReturn(src, seps);
+ else if (frag.str == IF) return parseIf(src, seps);
+ else if (frag.str == DO) return parseDo(src, seps);
+ else if (frag.str == WHILE) return parseWhile(src, seps);
+ else if (frag.str == BREAK) return parseBreak(src, seps);
+ else if (frag.str == CONTINUE) return parseContinue(src, seps);
+ else if (frag.str == SWITCH) return parseSwitch(src, seps);
+ else if (frag.str == NEW) return parseNew(src, seps);
+ dump(frag.str.str, src);
+ abort();
+ return nullptr;
+ }
+
+ NodeRef parseFunction(char*& src, const char* seps) {
+ Frag name(src);
+ if (name.type == IDENT) {
+ src += name.size;
+ } else {
+ assert(name.type == SEPARATOR && name.str[0] == '(');
+ name.str = IString();
+ }
+ NodeRef ret = Builder::makeFunction(name.str);
+ skipSpace(src);
+ assert(*src == '(');
+ src++;
+ while (1) {
+ skipSpace(src);
+ if (*src == ')') break;
+ Frag arg(src);
+ assert(arg.type == IDENT);
+ src += arg.size;
+ Builder::appendArgumentToFunction(ret, arg.str);
+ skipSpace(src);
+ if (*src == ')') break;
+ if (*src == ',') {
+ src++;
+ continue;
+ }
+ abort();
+ }
+ src++;
+ Builder::setBlockContent(ret, parseBracketedBlock(src));
+ // TODO: parse expression?
+ return ret;
+ }
+
+ NodeRef parseVar(char*& src, const char* seps, bool is_const) {
+ NodeRef ret = Builder::makeVar(is_const);
+ while (1) {
+ skipSpace(src);
+ if (*src == ';') break;
+ Frag name(src);
+ assert(name.type == IDENT);
+ NodeRef value;
+ src += name.size;
+ skipSpace(src);
+ if (*src == '=') {
+ src++;
+ skipSpace(src);
+ value = parseElement(src, ";,");
+ }
+ Builder::appendToVar(ret, name.str, value);
+ skipSpace(src);
+ if (*src == ';') break;
+ if (*src == ',') {
+ src++;
+ continue;
+ }
+ abort();
+ }
+ src++;
+ return ret;
+ }
+
+ NodeRef parseReturn(char*& src, const char* seps) {
+ skipSpace(src);
+ NodeRef value = !hasChar(seps, *src) ? parseElement(src, seps) : nullptr;
+ skipSpace(src);
+ assert(hasChar(seps, *src));
+ if (*src == ';') src++;
+ return Builder::makeReturn(value);
+ }
+
+ NodeRef parseIf(char*& src, const char* seps) {
+ NodeRef condition = parseParenned(src);
+ NodeRef ifTrue = parseMaybeBracketed(src, seps);
+ skipSpace(src);
+ NodeRef ifFalse;
+ if (!hasChar(seps, *src)) {
+ Frag next(src);
+ if (next.type == KEYWORD && next.str == ELSE) {
+ src += next.size;
+ ifFalse = parseMaybeBracketed(src, seps);
+ }
+ }
+ return Builder::makeIf(condition, ifTrue, ifFalse);
+ }
+
+ NodeRef parseDo(char*& src, const char* seps) {
+ NodeRef body = parseMaybeBracketed(src, seps);
+ skipSpace(src);
+ Frag next(src);
+ assert(next.type == KEYWORD && next.str == WHILE);
+ src += next.size;
+ NodeRef condition = parseParenned(src);
+ return Builder::makeDo(body, condition);
+ }
+
+ NodeRef parseWhile(char*& src, const char* seps) {
+ NodeRef condition = parseParenned(src);
+ NodeRef body = parseMaybeBracketed(src, seps);
+ return Builder::makeWhile(condition, body);
+ }
+
+ NodeRef parseBreak(char*& src, const char* seps) {
+ skipSpace(src);
+ Frag next(src);
+ if (next.type == IDENT) src += next.size;
+ return Builder::makeBreak(next.type == IDENT ? next.str : IString());
+ }
+
+ NodeRef parseContinue(char*& src, const char* seps) {
+ skipSpace(src);
+ Frag next(src);
+ if (next.type == IDENT) src += next.size;
+ return Builder::makeContinue(next.type == IDENT ? next.str : IString());
+ }
+
+ NodeRef parseSwitch(char*& src, const char* seps) {
+ NodeRef ret = Builder::makeSwitch(parseParenned(src));
+ skipSpace(src);
+ assert(*src == '{');
+ src++;
+ while (1) {
+ // find all cases and possibly a default
+ skipSpace(src);
+ if (*src == '}') break;
+ Frag next(src);
+ if (next.type == KEYWORD) {
+ if (next.str == CASE) {
+ src += next.size;
+ skipSpace(src);
+ NodeRef arg;
+ Frag value(src);
+ if (value.isNumber()) {
+ arg = parseFrag(value);
+ src += value.size;
+ } else {
+ assert(value.type == OPERATOR);
+ assert(value.str == MINUS);
+ src += value.size;
+ skipSpace(src);
+ Frag value2(src);
+ assert(value2.isNumber());
+ arg = Builder::makePrefix(MINUS, parseFrag(value2));
+ src += value2.size;
+ }
+ Builder::appendCaseToSwitch(ret, arg);
+ skipSpace(src);
+ assert(*src == ':');
+ src++;
+ continue;
+ } else if (next.str == DEFAULT) {
+ src += next.size;
+ Builder::appendDefaultToSwitch(ret);
+ skipSpace(src);
+ assert(*src == ':');
+ src++;
+ continue;
+ }
+ // otherwise, may be some keyword that happens to start a block (e.g. case 1: _return_ 5)
+ }
+ // not case X: or default: or }, so must be some code
+ skipSpace(src);
+ bool explicitBlock = *src == '{';
+ NodeRef subBlock = explicitBlock ? parseBracketedBlock(src) : parseBlock(src, ";}", CASE, DEFAULT);
+ Builder::appendCodeToSwitch(ret, subBlock, explicitBlock);
+ }
+ skipSpace(src);
+ assert(*src == '}');
+ src++;
+ return ret;
+ }
+
+ NodeRef parseNew(char*& src, const char* seps) {
+ return Builder::makeNew(parseElement(src, seps));
+ }
+
+ NodeRef parseAfterIdent(Frag& frag, char*& src, const char* seps) {
+ skipSpace(src);
+ if (*src == '(') return parseExpression(parseCall(parseFrag(frag), src), src, seps);
+ if (*src == '[') return parseExpression(parseIndexing(parseFrag(frag), src), src, seps);
+ if (*src == ':' && expressionPartsStack.back().size() == 0) {
+ src++;
+ skipSpace(src);
+ NodeRef inner;
+ if (*src == '{') { // context lets us know this is not an object, but a block
+ inner = parseBracketedBlock(src);
+ } else {
+ inner = parseElement(src, seps);
+ }
+ return Builder::makeLabel(frag.str, inner);
+ }
+ if (*src == '.') return parseExpression(parseDotting(parseFrag(frag), src), src, seps);
+ return parseExpression(parseFrag(frag), src, seps);
+ }
+
+ NodeRef parseCall(NodeRef target, char*& src) {
+ expressionPartsStack.resize(expressionPartsStack.size()+1);
+ assert(*src == '(');
+ src++;
+ NodeRef ret = Builder::makeCall(target);
+ while (1) {
+ skipSpace(src);
+ if (*src == ')') break;
+ Builder::appendToCall(ret, parseElement(src, ",)"));
+ skipSpace(src);
+ if (*src == ')') break;
+ if (*src == ',') {
+ src++;
+ continue;
+ }
+ abort();
+ }
+ src++;
+ assert(expressionPartsStack.back().size() == 0);
+ expressionPartsStack.pop_back();
+ return ret;
+ }
+
+ NodeRef parseIndexing(NodeRef target, char*& src) {
+ expressionPartsStack.resize(expressionPartsStack.size()+1);
+ assert(*src == '[');
+ src++;
+ NodeRef ret = Builder::makeIndexing(target, parseElement(src, "]"));
+ skipSpace(src);
+ assert(*src == ']');
+ src++;
+ assert(expressionPartsStack.back().size() == 0);
+ expressionPartsStack.pop_back();
+ return ret;
+ }
+
+ NodeRef parseDotting(NodeRef target, char*& src) {
+ assert(*src == '.');
+ src++;
+ Frag key(src);
+ assert(key.type == IDENT);
+ src += key.size;
+ return Builder::makeDot(target, key.str);
+ }
+
+ NodeRef parseAfterParen(char*& src) {
+ expressionPartsStack.resize(expressionPartsStack.size()+1);
+ skipSpace(src);
+ NodeRef ret = parseElement(src, ")");
+ skipSpace(src);
+ assert(*src == ')');
+ src++;
+ assert(expressionPartsStack.back().size() == 0);
+ expressionPartsStack.pop_back();
+ return ret;
+ }
+
+ NodeRef parseAfterBrace(char*& src) {
+ expressionPartsStack.resize(expressionPartsStack.size()+1);
+ NodeRef ret = Builder::makeArray();
+ while (1) {
+ skipSpace(src);
+ assert(*src);
+ if (*src == ']') break;
+ NodeRef element = parseElement(src, ",]");
+ Builder::appendToArray(ret, element);
+ skipSpace(src);
+ if (*src == ']') break;
+ if (*src == ',') {
+ src++;
+ continue;
+ }
+ abort();
+ }
+ src++;
+ return ret;
+ }
+
+ NodeRef parseAfterCurly(char*& src) {
+ expressionPartsStack.resize(expressionPartsStack.size()+1);
+ NodeRef ret = Builder::makeObject();
+ while (1) {
+ skipSpace(src);
+ assert(*src);
+ if (*src == '}') break;
+ Frag key(src);
+ assert(key.type == IDENT || key.type == STRING);
+ src += key.size;
+ skipSpace(src);
+ assert(*src == ':');
+ src++;
+ NodeRef value = parseElement(src, ",}");
+ Builder::appendToObject(ret, key.str, value);
+ skipSpace(src);
+ if (*src == '}') break;
+ if (*src == ',') {
+ src++;
+ continue;
+ }
+ abort();
+ }
+ src++;
+ return ret;
+ }
+
+ void dumpParts(ExpressionParts& parts, int i) {
+ printf("expressionparts: %d (at %d)\n", parts.size(), i);
+ printf("| ");
+ for (int i = 0; i < parts.size(); i++) {
+ if (parts[i].isNode) {
+ parts[i].getNode()->stringify(std::cout);
+ printf(" ");
+ } else {
+ printf(" _%s_ ", parts[i].getOp().str);
+ }
+ }
+ printf("|\n");
+ }
+
+ NodeRef makeBinary(NodeRef left, IString op, NodeRef right) {
+ if (op == PERIOD) {
+ return Builder::makeDot(left, right);
+ } else {
+ return Builder::makeBinary(left, op ,right);
+ }
+ }
+
+ NodeRef parseExpression(ExpressionElement initial, char*&src, const char* seps) {
+ //dump("parseExpression", src);
+ ExpressionParts& parts = expressionPartsStack.back();
+ skipSpace(src);
+ if (*src == 0 || hasChar(seps, *src)) {
+ if (parts.size() > 0) {
+ parts.push_back(initial); // cherry on top of the cake
+ }
+ return initial.getNode();
+ }
+ bool top = parts.size() == 0;
+ if (initial.isNode) {
+ Frag next(src);
+ if (next.type == OPERATOR) {
+ parts.push_back(initial);
+ src += next.size;
+ parts.push_back(next.str);
+ } else {
+ if (*src == '(') {
+ initial = parseCall(initial.getNode(), src);
+ } else if (*src == '[') {
+ initial = parseIndexing(initial.getNode(), src);
+ } else {
+ dump("bad parseExpression state", src);
+ abort();
+ }
+ return parseExpression(initial, src, seps);
+ }
+ } else {
+ parts.push_back(initial);
+ }
+ NodeRef last = parseElement(src, seps);
+ if (!top) return last;
+ {
+ ExpressionParts& parts = expressionPartsStack.back(); // |parts| may have been invalidated by that call
+ // we are the toplevel. sort it all out
+ // collapse right to left, highest priority first
+ //dumpParts(parts, 0);
+ for (auto& ops : operatorClasses) {
+ if (ops.rtl) {
+ // right to left
+ for (int i = parts.size()-1; i >= 0; i--) {
+ if (parts[i].isNode) continue;
+ IString op = parts[i].getOp();
+ if (!ops.ops.has(op)) continue;
+ if (ops.type == OperatorClass::Binary && i > 0 && i < (int)parts.size()-1) {
+ parts[i] = makeBinary(parts[i-1].getNode(), op, parts[i+1].getNode());
+ parts.erase(parts.begin() + i + 1);
+ parts.erase(parts.begin() + i - 1);
+ } else if (ops.type == OperatorClass::Prefix && i < (int)parts.size()-1) {
+ if (i > 0 && parts[i-1].isNode) continue; // cannot apply prefix operator if it would join two nodes
+ parts[i] = Builder::makePrefix(op, parts[i+1].getNode());
+ parts.erase(parts.begin() + i + 1);
+ } else if (ops.type == OperatorClass::Tertiary) {
+ // we must be at X ? Y : Z
+ // ^
+ //dumpParts(parts, i);
+ if (op != COLON) continue;
+ assert(i < (int)parts.size()-1 && i >= 3);
+ if (parts[i-2].getOp() != QUESTION) continue; // e.g. x ? y ? 1 : 0 : 2
+ parts[i-3] = Builder::makeConditional(parts[i-3].getNode(), parts[i-1].getNode(), parts[i+1].getNode());
+ parts.erase(parts.begin() + i - 2, parts.begin() + i + 2);
+ i = parts.size(); // basically a reset, due to things like x ? y ? 1 : 0 : 2
+ } // TODO: postfix
+ }
+ } else {
+ // left to right
+ for (int i = 0; i < (int)parts.size(); i++) {
+ if (parts[i].isNode) continue;
+ IString op = parts[i].getOp();
+ if (!ops.ops.has(op)) continue;
+ if (ops.type == OperatorClass::Binary && i > 0 && i < (int)parts.size()-1) {
+ parts[i] = makeBinary(parts[i-1].getNode(), op, parts[i+1].getNode());
+ parts.erase(parts.begin() + i + 1);
+ parts.erase(parts.begin() + i - 1);
+ i--;
+ } else if (ops.type == OperatorClass::Prefix && i < (int)parts.size()-1) {
+ if (i > 0 && parts[i-1].isNode) continue; // cannot apply prefix operator if it would join two nodes
+ parts[i] = Builder::makePrefix(op, parts[i+1].getNode());
+ parts.erase(parts.begin() + i + 1);
+ i = std::max(i-2, 0); // allow a previous prefix operator to cascade
+ } // TODO: tertiary, postfix
+ }
+ }
+ }
+ assert(parts.size() == 1);
+ NodeRef ret = parts[0].getNode();
+ parts.clear();
+ return ret;
+ }
+ }
+
+ // Parses a block of code (e.g. a bunch of statements inside {,}, or the top level of o file)
+ NodeRef parseBlock(char*& src, const char* seps=";", IString keywordSep1=IString(), IString keywordSep2=IString()) {
+ NodeRef block = Builder::makeBlock();
+ //dump("parseBlock", src);
+ while (1) {
+ skipSpace(src);
+ if (*src == 0) break;
+ if (*src == ';') {
+ src++; // skip a statement in this block
+ continue;
+ }
+ if (hasChar(seps, *src)) break;
+ if (!!keywordSep1) {
+ Frag next(src);
+ if (next.type == KEYWORD && next.str == keywordSep1) break;
+ }
+ if (!!keywordSep2) {
+ Frag next(src);
+ if (next.type == KEYWORD && next.str == keywordSep2) break;
+ }
+ NodeRef element = parseElementOrStatement(src, seps);
+ Builder::appendToBlock(block, element);
+ }
+ return block;
+ }
+
+ NodeRef parseBracketedBlock(char*& src) {
+ skipSpace(src);
+ assert(*src == '{');
+ src++;
+ NodeRef block = parseBlock(src, ";}"); // the two are not symmetrical, ; is just internally separating, } is the final one - parseBlock knows all this
+ assert(*src == '}');
+ src++;
+ return block;
+ }
+
+ NodeRef parseElementOrStatement(char*& src, const char *seps) {
+ skipSpace(src);
+ if (*src == ';') {
+ src++;
+ return Builder::makeBlock(); // we don't need the brackets here, but oh well
+ }
+ NodeRef ret = parseElement(src, seps);
+ skipSpace(src);
+ if (*src == ';') {
+ ret = Builder::makeStatement(ret);
+ src++;
+ }
+ return ret;
+ }
+
+ NodeRef parseMaybeBracketed(char*& src, const char *seps) {
+ skipSpace(src);
+ return *src == '{' ? parseBracketedBlock(src) : parseElementOrStatement(src, seps);
+ }
+
+ NodeRef parseParenned(char*& src) {
+ skipSpace(src);
+ assert(*src == '(');
+ src++;
+ NodeRef ret = parseElement(src, ")");
+ skipSpace(src);
+ assert(*src == ')');
+ src++;
+ return ret;
+ }
+
+ // Debugging
+
+ char *allSource;
+ int allSize;
+
+ static void dump(const char *where, char* curr) {
+ /*
+ printf("%s:\n=============\n", where);
+ for (int i = 0; i < allSize; i++) printf("%c", allSource[i] ? allSource[i] : '?');
+ printf("\n");
+ for (int i = 0; i < (curr - allSource); i++) printf(" ");
+ printf("^\n=============\n");
+ */
+ fprintf(stderr, "%s:\n==========\n", where);
+ int newlinesLeft = 2;
+ int charsLeft = 200;
+ while (*curr) {
+ if (*curr == '\n') {
+ newlinesLeft--;
+ if (newlinesLeft == 0) break;
+ }
+ charsLeft--;
+ if (charsLeft == 0) break;
+ fprintf(stderr, "%c", *curr++);
+ }
+ fprintf(stderr, "\n\n");
+ }
+
+public:
+
+ Parser() : allSource(nullptr), allSize(0) {
+ expressionPartsStack.resize(1);
+ }
+
+ // Highest-level parsing, as of a JavaScript script file.
+ NodeRef parseToplevel(char* src) {
+ allSource = src;
+ allSize = strlen(src);
+ NodeRef toplevel = Builder::makeToplevel();
+ Builder::setBlockContent(toplevel, parseBlock(src));
+ return toplevel;
+ }
+};
+
+} // namespace cashew
+
diff --git a/src/simple_ast.cpp b/src/simple_ast.cpp
new file mode 100644
index 000000000..3027010d1
--- /dev/null
+++ b/src/simple_ast.cpp
@@ -0,0 +1,255 @@
+
+#include "simple_ast.h"
+
+// Ref methods
+
+Ref& Ref::operator[](unsigned x) {
+ return (*get())[x];
+}
+
+Ref& Ref::operator[](IString x) {
+ return (*get())[x];
+}
+
+bool Ref::operator==(const char *str) {
+ return get()->isString() && !strcmp(get()->str.str, str);
+}
+
+bool Ref::operator!=(const char *str) {
+ return get()->isString() ? !!strcmp(get()->str.str, str) : true;
+}
+
+bool Ref::operator==(const IString &str) {
+ return get()->isString() && get()->str == str;
+}
+
+bool Ref::operator!=(const IString &str) {
+ return get()->isString() && get()->str != str;
+}
+
+bool Ref::operator==(Ref other) {
+ return **this == *other;
+}
+
+bool Ref::operator!() {
+ return !get() || get()->isNull();
+}
+
+// Arena
+
+Arena arena;
+
+Ref Arena::alloc() {
+ if (chunks.size() == 0 || index == CHUNK_SIZE) {
+ chunks.push_back(new Value[CHUNK_SIZE]);
+ index = 0;
+ }
+ return &chunks.back()[index++];
+}
+
+ArrayStorage* Arena::allocArray() {
+ if (arr_chunks.size() == 0 || arr_index == CHUNK_SIZE) {
+ arr_chunks.push_back(new ArrayStorage[CHUNK_SIZE]);
+ arr_index = 0;
+ }
+ return &arr_chunks.back()[arr_index++];
+}
+
+// dump
+
+void dump(const char *str, Ref node, bool pretty) {
+ std::cerr << str << ": ";
+ if (!!node) node->stringify(std::cerr, pretty);
+ else std::cerr << "(nullptr)";
+ std::cerr << std::endl;
+}
+
+// AST traversals
+
+// Traversals
+
+struct TraverseInfo {
+ TraverseInfo() {}
+ TraverseInfo(Ref node, ArrayStorage* arr) : node(node), arr(arr), index(0) {}
+ Ref node;
+ ArrayStorage* arr;
+ int index;
+};
+
+template <class T, int init>
+struct StackedStack { // a stack, on the stack
+ T stackStorage[init];
+ T* storage;
+ int used, available; // used amount, available amount
+ bool alloced;
+
+ StackedStack() : used(0), available(init), alloced(false) {
+ storage = stackStorage;
+ }
+ ~StackedStack() {
+ if (alloced) free(storage);
+ }
+
+ int size() { return used; }
+
+ void push_back(const T& t) {
+ assert(used <= available);
+ if (used == available) {
+ available *= 2;
+ if (!alloced) {
+ T* old = storage;
+ storage = (T*)malloc(sizeof(T)*available);
+ memcpy(storage, old, sizeof(T)*used);
+ alloced = true;
+ } else {
+ T *newStorage = (T*)realloc(storage, sizeof(T)*available);
+ assert(newStorage);
+ storage = newStorage;
+ }
+ }
+ assert(used < available);
+ assert(storage);
+ storage[used++] = t;
+ }
+
+ T& back() {
+ assert(used > 0);
+ return storage[used-1];
+ }
+
+ void pop_back() {
+ assert(used > 0);
+ used--;
+ }
+};
+
+#define visitable(node) (node->isArray() && node->size() > 0)
+
+#define TRAV_STACK 40
+
+// Traverse, calling visit before the children
+void traversePre(Ref node, std::function<void (Ref)> visit) {
+ if (!visitable(node)) return;
+ visit(node);
+ StackedStack<TraverseInfo, TRAV_STACK> stack;
+ int index = 0;
+ ArrayStorage* arr = &node->getArray();
+ int arrsize = (int)arr->size();
+ Ref* arrdata = arr->data();
+ stack.push_back(TraverseInfo(node, arr));
+ while (1) {
+ if (index < arrsize) {
+ Ref sub = *(arrdata+index);
+ index++;
+ if (visitable(sub)) {
+ stack.back().index = index;
+ index = 0;
+ visit(sub);
+ arr = &sub->getArray();
+ arrsize = (int)arr->size();
+ arrdata = arr->data();
+ stack.push_back(TraverseInfo(sub, arr));
+ }
+ } else {
+ stack.pop_back();
+ if (stack.size() == 0) break;
+ TraverseInfo& back = stack.back();
+ index = back.index;
+ arr = back.arr;
+ arrsize = (int)arr->size();
+ arrdata = arr->data();
+ }
+ }
+}
+
+// Traverse, calling visitPre before the children and visitPost after
+void traversePrePost(Ref node, std::function<void (Ref)> visitPre, std::function<void (Ref)> visitPost) {
+ if (!visitable(node)) return;
+ visitPre(node);
+ StackedStack<TraverseInfo, TRAV_STACK> stack;
+ int index = 0;
+ ArrayStorage* arr = &node->getArray();
+ int arrsize = (int)arr->size();
+ Ref* arrdata = arr->data();
+ stack.push_back(TraverseInfo(node, arr));
+ while (1) {
+ if (index < arrsize) {
+ Ref sub = *(arrdata+index);
+ index++;
+ if (visitable(sub)) {
+ stack.back().index = index;
+ index = 0;
+ visitPre(sub);
+ arr = &sub->getArray();
+ arrsize = (int)arr->size();
+ arrdata = arr->data();
+ stack.push_back(TraverseInfo(sub, arr));
+ }
+ } else {
+ visitPost(stack.back().node);
+ stack.pop_back();
+ if (stack.size() == 0) break;
+ TraverseInfo& back = stack.back();
+ index = back.index;
+ arr = back.arr;
+ arrsize = (int)arr->size();
+ arrdata = arr->data();
+ }
+ }
+}
+
+// Traverse, calling visitPre before the children and visitPost after. If pre returns false, do not traverse children
+void traversePrePostConditional(Ref node, std::function<bool (Ref)> visitPre, std::function<void (Ref)> visitPost) {
+ if (!visitable(node)) return;
+ if (!visitPre(node)) return;
+ StackedStack<TraverseInfo, TRAV_STACK> stack;
+ int index = 0;
+ ArrayStorage* arr = &node->getArray();
+ int arrsize = (int)arr->size();
+ Ref* arrdata = arr->data();
+ stack.push_back(TraverseInfo(node, arr));
+ while (1) {
+ if (index < arrsize) {
+ Ref sub = *(arrdata+index);
+ index++;
+ if (visitable(sub)) {
+ if (visitPre(sub)) {
+ stack.back().index = index;
+ index = 0;
+ arr = &sub->getArray();
+ arrsize = (int)arr->size();
+ arrdata = arr->data();
+ stack.push_back(TraverseInfo(sub, arr));
+ }
+ }
+ } else {
+ visitPost(stack.back().node);
+ stack.pop_back();
+ if (stack.size() == 0) break;
+ TraverseInfo& back = stack.back();
+ index = back.index;
+ arr = back.arr;
+ arrsize = (int)arr->size();
+ arrdata = arr->data();
+ }
+ }
+}
+
+// Traverses all the top-level functions in the document
+void traverseFunctions(Ref ast, std::function<void (Ref)> visit) {
+ if (!ast || ast->size() == 0) return;
+ if (ast[0] == TOPLEVEL) {
+ Ref stats = ast[1];
+ for (size_t i = 0; i < stats->size(); i++) {
+ Ref curr = stats[i];
+ if (curr[0] == DEFUN) visit(curr);
+ }
+ } else if (ast[0] == DEFUN) {
+ visit(ast);
+ }
+}
+
+// ValueBuilder
+
+IStringSet ValueBuilder::statable("assign call binary unary-prefix if name num conditional dot new sub seq string object array");
+
diff --git a/src/simple_ast.h b/src/simple_ast.h
new file mode 100644
index 000000000..5d5e3f201
--- /dev/null
+++ b/src/simple_ast.h
@@ -0,0 +1,1518 @@
+
+#include <assert.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+
+#include <vector>
+#include <ostream>
+#include <iostream>
+#include <iomanip>
+#include <functional>
+#include <algorithm>
+#include <set>
+#include <unordered_set>
+#include <unordered_map>
+
+#include "parser.h"
+
+#include "snprintf.h"
+
+#define err(str) fprintf(stderr, str "\n");
+#define errv(str, ...) fprintf(stderr, str "\n", __VA_ARGS__);
+#define printErr err
+
+using namespace cashew;
+
+struct Ref;
+struct Value;
+
+void dump(const char *str, Ref node, bool pretty=false);
+
+// Reference to a value, plus some operators for convenience
+struct Ref {
+ Value* inst;
+
+ Ref(Value *v=nullptr) : inst(v) {}
+
+ Value* get() { return inst; }
+
+ Value& operator*() { return *inst; }
+ Value* operator->() { return inst; }
+ Ref& operator[](unsigned x);
+ Ref& operator[](IString x);
+
+ // special conveniences
+ bool operator==(const char *str); // comparison to string, which is by value
+ bool operator!=(const char *str);
+ bool operator==(const IString &str);
+ bool operator!=(const IString &str);
+ bool operator==(double d) { abort(); return false; } // prevent Ref == number, which is potentially ambiguous; use ->getNumber() == number
+ bool operator==(Ref other);
+ bool operator!(); // check if null, in effect
+};
+
+// Arena allocation, free it all on process exit
+
+typedef std::vector<Ref> ArrayStorage;
+
+struct Arena {
+ #define CHUNK_SIZE 1000
+ std::vector<Value*> chunks;
+ int index; // in last chunk
+
+ std::vector<ArrayStorage*> arr_chunks;
+ int arr_index;
+
+ Arena() : index(0), arr_index(0) {}
+
+ Ref alloc();
+ ArrayStorage* allocArray();
+};
+
+extern Arena arena;
+
+// Main value type
+struct Value {
+ enum Type {
+ String = 0,
+ Number = 1,
+ Array = 2,
+ Null = 3,
+ Bool = 4,
+ Object = 5
+ };
+
+ Type type;
+
+ typedef std::unordered_map<IString, Ref> ObjectStorage;
+
+#ifdef _MSC_VER // MSVC does not allow unrestricted unions: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2544.pdf
+ IString str;
+#endif
+ union { // TODO: optimize
+#ifndef _MSC_VER
+ IString str;
+#endif
+ double num;
+ ArrayStorage *arr;
+ bool boo;
+ ObjectStorage *obj;
+ };
+
+ // constructors all copy their input
+ Value() : type(Null), num(0) {}
+ explicit Value(const char *s) : type(Null) {
+ setString(s);
+ }
+ explicit Value(double n) : type(Null) {
+ setNumber(n);
+ }
+ explicit Value(ArrayStorage &a) : type(Null) {
+ setArray();
+ *arr = a;
+ }
+ // no bool constructor - would endanger the double one (int might convert the wrong way)
+
+ ~Value() {
+ free();
+ }
+
+ void free() {
+ if (type == Array) { arr->clear(); arr->shrink_to_fit(); }
+ else if (type == Object) delete obj;
+ type = Null;
+ num = 0;
+ }
+
+ Value& setString(const char *s) {
+ free();
+ type = String;
+ str.set(s);
+ return *this;
+ }
+ Value& setString(const IString &s) {
+ free();
+ type = String;
+ str.set(s);
+ return *this;
+ }
+ Value& setNumber(double n) {
+ free();
+ type = Number;
+ num = n;
+ return *this;
+ }
+ Value& setArray(ArrayStorage &a) {
+ free();
+ type = Array;
+ arr = arena.allocArray();
+ *arr = a;
+ return *this;
+ }
+ Value& setArray(int size_hint=0) {
+ free();
+ type = Array;
+ arr = arena.allocArray();
+ arr->reserve(size_hint);
+ return *this;
+ }
+ Value& setNull() {
+ free();
+ type = Null;
+ return *this;
+ }
+ Value& setBool(bool b) { // Bool in the name, as otherwise might overload over int
+ free();
+ type = Bool;
+ boo = b;
+ return *this;
+ }
+ Value& setObject() {
+ free();
+ type = Object;
+ obj = new ObjectStorage();
+ return *this;
+ }
+
+ bool isString() { return type == String; }
+ bool isNumber() { return type == Number; }
+ bool isArray() { return type == Array; }
+ bool isNull() { return type == Null; }
+ bool isBool() { return type == Bool; }
+ bool isObject() { return type == Object; }
+
+ bool isBool(bool b) { return type == Bool && b == boo; } // avoid overloading == as it might overload over int
+
+ const char* getCString() {
+ assert(isString());
+ return str.str;
+ }
+ IString& getIString() {
+ assert(isString());
+ return str;
+ }
+ double& getNumber() {
+ assert(isNumber());
+ return num;
+ }
+ ArrayStorage& getArray() {
+ assert(isArray());
+ return *arr;
+ }
+ bool& getBool() {
+ assert(isBool());
+ return boo;
+ }
+
+ int getInteger() { // convenience function to get a known integer
+ assert(fmod(getNumber(), 1) == 0);
+ int ret = int(getNumber());
+ assert(double(ret) == getNumber()); // no loss in conversion
+ return ret;
+ }
+
+ Value& operator=(const Value& other) {
+ free();
+ switch (other.type) {
+ case String:
+ setString(other.str);
+ break;
+ case Number:
+ setNumber(other.num);
+ break;
+ case Array:
+ setArray(*other.arr);
+ break;
+ case Null:
+ setNull();
+ break;
+ case Bool:
+ setBool(other.boo);
+ break;
+ case Object:
+ abort(); // TODO
+ }
+ return *this;
+ }
+
+ bool operator==(const Value& other) {
+ if (type != other.type) return false;
+ switch (other.type) {
+ case String:
+ return str == other.str;
+ case Number:
+ return num == other.num;
+ case Array:
+ return this == &other; // if you want a deep compare, use deepCompare
+ case Null:
+ break;
+ case Bool:
+ return boo == other.boo;
+ case Object:
+ return this == &other; // if you want a deep compare, use deepCompare
+ }
+ return true;
+ }
+
+ bool deepCompare(Ref ref) {
+ Value& other = *ref;
+ if (*this == other) return true; // either same pointer, or identical value type (string, number, null or bool)
+ if (type != other.type) return false;
+ if (type == Array) {
+ if (arr->size() != other.arr->size()) return false;
+ for (unsigned i = 0; i < arr->size(); i++) {
+ if (!(*arr)[i]->deepCompare((*other.arr)[i])) return false;
+ }
+ return true;
+ } else if (type == Object) {
+ if (obj->size() != other.obj->size()) return false;
+ for (auto i : *obj) {
+ if (other.obj->count(i.first) == 0) return false;
+ if (i.second->deepCompare((*other.obj)[i.first])) return false;
+ }
+ return true;
+ }
+ return false;
+ }
+
+ char* parse(char* curr) {
+ #define is_json_space(x) (x == 32 || x == 9 || x == 10 || x == 13) /* space, tab, linefeed/newline, or return */
+ #define skip() { while (*curr && is_json_space(*curr)) curr++; }
+ skip();
+ if (*curr == '"') {
+ // String
+ curr++;
+ char *close = strchr(curr, '"');
+ assert(close);
+ *close = 0; // end this string, and reuse it straight from the input
+ setString(curr);
+ curr = close+1;
+ } else if (*curr == '[') {
+ // Array
+ curr++;
+ skip();
+ setArray();
+ while (*curr != ']') {
+ Ref temp = arena.alloc();
+ arr->push_back(temp);
+ curr = temp->parse(curr);
+ skip();
+ if (*curr == ']') break;
+ assert(*curr == ',');
+ curr++;
+ skip();
+ }
+ curr++;
+ } else if (*curr == 'n') {
+ // Null
+ assert(strncmp(curr, "null", 4) == 0);
+ setNull();
+ curr += 4;
+ } else if (*curr == 't') {
+ // Bool true
+ assert(strncmp(curr, "true", 4) == 0);
+ setBool(true);
+ curr += 4;
+ } else if (*curr == 'f') {
+ // Bool false
+ assert(strncmp(curr, "false", 5) == 0);
+ setBool(false);
+ curr += 5;
+ } else if (*curr == '{') {
+ // Object
+ curr++;
+ skip();
+ setObject();
+ while (*curr != '}') {
+ assert(*curr == '"');
+ curr++;
+ char *close = strchr(curr, '"');
+ assert(close);
+ *close = 0; // end this string, and reuse it straight from the input
+ IString key(curr);
+ curr = close+1;
+ skip();
+ assert(*curr == ':');
+ curr++;
+ skip();
+ Ref value = arena.alloc();
+ curr = value->parse(curr);
+ (*obj)[key] = value;
+ skip();
+ if (*curr == '}') break;
+ assert(*curr == ',');
+ curr++;
+ skip();
+ }
+ curr++;
+ } else {
+ // Number
+ char *after;
+ setNumber(strtod(curr, &after));
+ curr = after;
+ }
+ return curr;
+ }
+
+ void stringify(std::ostream &os, bool pretty=false) {
+ static int indent = 0;
+ #define indentify() { for (int i = 0; i < indent; i++) os << " "; }
+ switch (type) {
+ case String:
+ os << '"' << str.str << '"';
+ break;
+ case Number:
+ os << std::setprecision(17) << num; // doubles can have 17 digits of precision
+ break;
+ case Array:
+ if (arr->size() == 0) {
+ os << "[]";
+ break;
+ }
+ os << '[';
+ if (pretty) {
+ os << std::endl;
+ indent++;
+ }
+ for (unsigned i = 0; i < arr->size(); i++) {
+ if (i > 0) {
+ if (pretty) os << "," << std::endl;
+ else os << ", ";
+ }
+ indentify();
+ (*arr)[i]->stringify(os, pretty);
+ }
+ if (pretty) {
+ os << std::endl;
+ indent--;
+ }
+ indentify();
+ os << ']';
+ break;
+ case Null:
+ os << "null";
+ break;
+ case Bool:
+ os << (boo ? "true" : "false");
+ break;
+ case Object:
+ os << '{';
+ if (pretty) {
+ os << std::endl;
+ indent++;
+ }
+ bool first = true;
+ for (auto i : *obj) {
+ if (first) {
+ first = false;
+ } else {
+ os << ", ";
+ if (pretty) os << std::endl;
+ }
+ indentify();
+ os << '"' << i.first.c_str() << "\": ";
+ i.second->stringify(os, pretty);
+ }
+ if (pretty) {
+ os << std::endl;
+ indent--;
+ }
+ indentify();
+ os << '}';
+ break;
+ }
+ }
+
+ // String operations
+
+ // Number operations
+
+ // Array operations
+
+ unsigned size() {
+ assert(isArray());
+ return arr->size();
+ }
+
+ void setSize(unsigned size) {
+ assert(isArray());
+ unsigned old = arr->size();
+ if (old != size) arr->resize(size);
+ if (old < size) {
+ for (unsigned i = old; i < size; i++) {
+ (*arr)[i] = arena.alloc();
+ }
+ }
+ }
+
+ Ref& operator[](unsigned x) {
+ assert(isArray());
+ return arr->at(x);
+ }
+
+ Value& push_back(Ref r) {
+ assert(isArray());
+ arr->push_back(r);
+ return *this;
+ }
+ Ref pop_back() {
+ assert(isArray());
+ Ref ret = arr->back();
+ arr->pop_back();
+ return ret;
+ }
+
+ Ref back() {
+ assert(isArray());
+ if (arr->size() == 0) return nullptr;
+ return arr->back();
+ }
+
+ void splice(int x, int num) {
+ assert(isArray());
+ arr->erase(arr->begin() + x, arr->begin() + x + num);
+ }
+
+ void insert(int x, int num) {
+ arr->insert(arr->begin() + x, num, Ref());
+ }
+ void insert(int x, Ref node) {
+ arr->insert(arr->begin() + x, 1, node);
+ }
+
+ int indexOf(Ref other) {
+ assert(isArray());
+ for (unsigned i = 0; i < arr->size(); i++) {
+ if (other == (*arr)[i]) return i;
+ }
+ return -1;
+ }
+
+ Ref map(std::function<Ref (Ref node)> func) {
+ assert(isArray());
+ Ref ret = arena.alloc();
+ ret->setArray();
+ for (unsigned i = 0; i < arr->size(); i++) {
+ ret->push_back(func((*arr)[i]));
+ }
+ return ret;
+ }
+
+ Ref filter(std::function<bool (Ref node)> func) {
+ assert(isArray());
+ Ref ret = arena.alloc();
+ ret->setArray();
+ for (unsigned i = 0; i < arr->size(); i++) {
+ Ref curr = (*arr)[i];
+ if (func(curr)) ret->push_back(curr);
+ }
+ return ret;
+ }
+
+ /*
+ void forEach(std::function<void (Ref)> func) {
+ for (unsigned i = 0; i < arr->size(); i++) {
+ func((*arr)[i]);
+ }
+ }
+ */
+
+ // Null operations
+
+ // Bool operations
+
+ // Object operations
+
+ Ref& operator[](IString x) {
+ assert(isObject());
+ return (*obj)[x];
+ }
+
+ bool has(IString x) {
+ assert(isObject());
+ return obj->count(x) > 0;
+ }
+};
+
+// AST traversals
+
+// Traverse, calling visit before the children
+void traversePre(Ref node, std::function<void (Ref)> visit);
+
+// Traverse, calling visitPre before the children and visitPost after
+void traversePrePost(Ref node, std::function<void (Ref)> visitPre, std::function<void (Ref)> visitPost);
+
+// Traverse, calling visitPre before the children and visitPost after. If pre returns false, do not traverse children
+void traversePrePostConditional(Ref node, std::function<bool (Ref)> visitPre, std::function<void (Ref)> visitPost);
+
+// Traverses all the top-level functions in the document
+void traverseFunctions(Ref ast, std::function<void (Ref)> visit);
+
+// JS printer
+
+struct JSPrinter {
+ bool pretty, finalize;
+
+ char *buffer;
+ int size, used;
+
+ int indent;
+ bool possibleSpace; // add a space to separate identifiers
+
+ Ref ast;
+
+ JSPrinter(bool pretty_, bool finalize_, Ref ast_) : pretty(pretty_), finalize(finalize_), buffer(0), size(0), used(0), indent(0), possibleSpace(false), ast(ast_) {}
+
+ void printAst() {
+ print(ast);
+ buffer[used] = 0;
+ }
+
+ // Utils
+
+ void ensure(int safety=100) {
+ if (size < used + safety) {
+ size = std::max(1024, size*2) + safety;
+ if (!buffer) {
+ buffer = (char*)malloc(size);
+ if (!buffer) {
+ printf("Out of memory allocating %d bytes for output buffer!", size);
+ abort();
+ }
+ } else {
+ char *buf = (char*)realloc(buffer, size);
+ if (!buf) {
+ free(buffer);
+ printf("Out of memory allocating %d bytes for output buffer!", size);
+ abort();
+ }
+ buffer = buf;
+ }
+ }
+ }
+
+ void emit(char c) {
+ maybeSpace(c);
+ if (!pretty && c == '}' && buffer[used-1] == ';') used--; // optimize ;} into }, the ; is not separating anything
+ ensure(1);
+ buffer[used++] = c;
+ }
+
+ void emit(const char *s) {
+ maybeSpace(*s);
+ int len = strlen(s);
+ ensure(len+1);
+ strcpy(buffer + used, s);
+ used += len;
+ }
+
+ void newline() {
+ if (!pretty) return;
+ emit('\n');
+ for (int i = 0; i < indent; i++) emit(' ');
+ }
+
+ void space() {
+ if (pretty) emit(' ');
+ }
+
+ void safeSpace() {
+ if (pretty) emit(' ');
+ else possibleSpace = true;
+ }
+
+ void maybeSpace(char s) {
+ if (possibleSpace) {
+ possibleSpace = false;
+ if (isIdentPart(s)) emit(' ');
+ }
+ }
+
+ void print(Ref node) {
+ ensure();
+ IString type = node[0]->getIString();
+ //fprintf(stderr, "printing %s\n", type.str);
+ switch (type.str[0]) {
+ case 'a': {
+ if (type == ASSIGN) printAssign(node);
+ else if (type == ARRAY) printArray(node);
+ else abort();
+ break;
+ }
+ case 'b': {
+ if (type == BINARY) printBinary(node);
+ else if (type == BLOCK) printBlock(node);
+ else if (type == BREAK) printBreak(node);
+ else abort();
+ break;
+ }
+ case 'c': {
+ if (type == CALL) printCall(node);
+ else if (type == CONDITIONAL) printConditional(node);
+ else if (type == CONTINUE) printContinue(node);
+ else abort();
+ break;
+ }
+ case 'd': {
+ if (type == DEFUN) printDefun(node);
+ else if (type == DO) printDo(node);
+ else if (type == DOT) printDot(node);
+ else abort();
+ break;
+ }
+ case 'i': {
+ if (type == IF) printIf(node);
+ else abort();
+ break;
+ }
+ case 'l': {
+ if (type == LABEL) printLabel(node);
+ else abort();
+ break;
+ }
+ case 'n': {
+ if (type == NAME) printName(node);
+ else if (type == NUM) printNum(node);
+ else if (type == NEW) printNew(node);
+ else abort();
+ break;
+ }
+ case 'o': {
+ if (type == OBJECT) printObject(node);
+ break;
+ }
+ case 'r': {
+ if (type == RETURN) printReturn(node);
+ else abort();
+ break;
+ }
+ case 's': {
+ if (type == STAT) printStat(node);
+ else if (type == SUB) printSub(node);
+ else if (type == SEQ) printSeq(node);
+ else if (type == SWITCH) printSwitch(node);
+ else if (type == STRING) printString(node);
+ else abort();
+ break;
+ }
+ case 't': {
+ if (type == TOPLEVEL) printToplevel(node);
+ else abort();
+ break;
+ }
+ case 'u': {
+ if (type == UNARY_PREFIX) printUnaryPrefix(node);
+ else abort();
+ break;
+ }
+ case 'v': {
+ if (type == VAR) printVar(node);
+ else abort();
+ break;
+ }
+ case 'w': {
+ if (type == WHILE) printWhile(node);
+ else abort();
+ break;
+ }
+ default: {
+ printf("cannot yet print %s\n", type.str);
+ abort();
+ }
+ }
+ }
+
+ // print a node, and if nothing is emitted, emit something instead
+ void print(Ref node, const char *otherwise) {
+ int last = used;
+ print(node);
+ if (used == last) emit(otherwise);
+ }
+
+ void printStats(Ref stats) {
+ bool first = true;
+ for (size_t i = 0; i < stats->size(); i++) {
+ Ref curr = stats[i];
+ if (!isNothing(curr)) {
+ if (first) first = false;
+ else newline();
+ print(stats[i]);
+ }
+ }
+ }
+
+ void printToplevel(Ref node) {
+ if (node[1]->size() > 0) {
+ printStats(node[1]);
+ }
+ }
+
+ void printBlock(Ref node) {
+ if (node->size() == 1 || node[1]->size() == 0) {
+ emit("{}");
+ return;
+ }
+ emit('{');
+ indent++;
+ newline();
+ printStats(node[1]);
+ indent--;
+ newline();
+ emit('}');
+ }
+
+ void printDefun(Ref node) {
+ emit("function ");
+ emit(node[1]->getCString());
+ emit('(');
+ Ref args = node[2];
+ for (size_t i = 0; i < args->size(); i++) {
+ if (i > 0) (pretty ? emit(", ") : emit(','));
+ emit(args[i]->getCString());
+ }
+ emit(')');
+ space();
+ if (node->size() == 3 || node[3]->size() == 0) {
+ emit("{}");
+ return;
+ }
+ emit('{');
+ indent++;
+ newline();
+ printStats(node[3]);
+ indent--;
+ newline();
+ emit('}');
+ newline();
+ }
+
+ bool isNothing(Ref node) {
+ return (node[0] == TOPLEVEL && node[1]->size() == 0) || (node[0] == STAT && isNothing(node[1]));
+ }
+
+ void printStat(Ref node) {
+ if (!isNothing(node[1])) {
+ print(node[1]);
+ if (buffer[used-1] != ';') emit(';');
+ }
+ }
+
+ void printAssign(Ref node) {
+ printChild(node[2], node, -1);
+ space();
+ emit('=');
+ space();
+ printChild(node[3], node, 1);
+ }
+
+ void printName(Ref node) {
+ emit(node[1]->getCString());
+ }
+
+ void printNum(Ref node) {
+ double d = node[1]->getNumber();
+ bool neg = d < 0;
+ if (neg) d = -d;
+ // try to emit the fewest necessary characters
+ bool integer = fmod(d, 1) == 0;
+ #define BUFFERSIZE 1000
+ static char storage_f[BUFFERSIZE], storage_e[BUFFERSIZE]; // f is normal, e is scientific for float, x for integer
+ double err_f, err_e;
+ for (int e = 0; e <= 1; e++) {
+ char *buffer = e ? storage_e : storage_f;
+ double temp;
+ if (!integer) {
+ static char format[6];
+ for (int i = 0; i <= 18; i++) {
+ format[0] = '%';
+ format[1] = '.';
+ if (i < 10) {
+ format[2] = '0' + i;
+ format[3] = e ? 'e' : 'f';
+ format[4] = 0;
+ } else {
+ format[2] = '1';
+ format[3] = '0' + (i - 10);
+ format[4] = e ? 'e' : 'f';
+ format[5] = 0;
+ }
+ snprintf(buffer, BUFFERSIZE-1, format, d);
+ sscanf(buffer, "%lf", &temp);
+ //errv("%.18f, %.18e => %s => %.18f, %.18e (%d), ", d, d, buffer, temp, temp, temp == d);
+ if (temp == d) break;
+ }
+ } else {
+ // integer
+ assert(d >= 0);
+ unsigned long long uu = (unsigned long long)d;
+ if (uu == d) {
+ bool asHex = e && !finalize;
+ snprintf(buffer, BUFFERSIZE-1, asHex ? "0x%llx" : "%llu", uu);
+ if (asHex) {
+ unsigned long long tempULL;
+ sscanf(buffer, "%llx", &tempULL);
+ temp = (double)tempULL;
+ } else {
+ sscanf(buffer, "%lf", &temp);
+ }
+ } else {
+ // too large for a machine integer, just use floats
+ snprintf(buffer, BUFFERSIZE-1, e ? "%e" : "%.0f", d); // even on integers, e with a dot is useful, e.g. 1.2e+200
+ sscanf(buffer, "%lf", &temp);
+ }
+ //errv("%.18f, %.18e => %s => %.18f, %.18e, %llu (%d)\n", d, d, buffer, temp, temp, uu, temp == d);
+ }
+ (e ? err_e : err_f) = fabs(temp - d);
+ //errv("current attempt: %.18f => %s", d, buffer);
+ //assert(temp == d);
+ char *dot = strchr(buffer, '.');
+ if (dot) {
+ // remove trailing zeros
+ char *end = dot+1;
+ while (*end >= '0' && *end <= '9') end++;
+ end--;
+ while (*end == '0') {
+ char *copy = end;
+ do {
+ copy[0] = copy[1];
+ } while (*copy++ != 0);
+ end--;
+ }
+ //errv("%.18f => %s", d, buffer);
+ // remove preceding zeros
+ while (*buffer == '0') {
+ char *copy = buffer;
+ do {
+ copy[0] = copy[1];
+ } while (*copy++ != 0);
+ }
+ //errv("%.18f ===> %s", d, buffer);
+ } else if (!integer || !e) {
+ // no dot. try to change 12345000 => 12345e3
+ char *end = strchr(buffer, 0);
+ end--;
+ char *test = end;
+ // remove zeros, and also doubles can use at most 24 digits, we can truncate any extras even if not zero
+ while ((*test == '0' || test - buffer > 24) && test > buffer) test--;
+ int num = end - test;
+ if (num >= 3) {
+ test++;
+ test[0] = 'e';
+ if (num < 10) {
+ test[1] = '0' + num;
+ test[2] = 0;
+ } else if (num < 100) {
+ test[1] = '0' + (num / 10);
+ test[2] = '0' + (num % 10);
+ test[3] = 0;
+ } else {
+ assert(num < 1000);
+ test[1] = '0' + (num / 100);
+ test[2] = '0' + (num % 100) / 10;
+ test[3] = '0' + (num % 10);
+ test[4] = 0;
+ }
+ }
+ }
+ //errv("..current attempt: %.18f => %s", d, buffer);
+ }
+ //fprintf(stderr, "options:\n%s\n%s\n (first? %d)\n", storage_e, storage_f, strlen(storage_e) < strlen(storage_f));
+ if (neg) emit('-');
+ if (err_e == err_f) {
+ emit(strlen(storage_e) < strlen(storage_f) ? storage_e : storage_f);
+ } else {
+ emit(err_e < err_f ? storage_e : storage_f);
+ }
+ }
+
+ void printString(Ref node) {
+ emit('"');
+ emit(node[1]->getCString());
+ emit('"');
+ }
+
+ // Parens optimizing
+
+ bool capturesOperators(Ref node) {
+ Ref type = node[0];
+ return type == CALL || type == ARRAY || type == OBJECT || type == SEQ;
+ }
+
+ int getPrecedence(Ref node, bool parent) {
+ Ref type = node[0];
+ if (type == BINARY || type == UNARY_PREFIX) {
+ return OperatorClass::getPrecedence(type == BINARY ? OperatorClass::Binary : OperatorClass::Prefix, node[1]->getIString());
+ } else if (type == SEQ) {
+ return OperatorClass::getPrecedence(OperatorClass::Binary, COMMA);
+ } else if (type == CALL) {
+ return parent ? OperatorClass::getPrecedence(OperatorClass::Binary, COMMA) : -1; // call arguments are split by commas, but call itself is safe
+ } else if (type == ASSIGN) {
+ return OperatorClass::getPrecedence(OperatorClass::Binary, SET);
+ } else if (type == CONDITIONAL) {
+ return OperatorClass::getPrecedence(OperatorClass::Tertiary, QUESTION);
+ }
+ // otherwise, this is something that fixes precedence explicitly, and we can ignore
+ return -1; // XXX
+ }
+
+ // check whether we need parens for the child, when rendered in the parent
+ // @param childPosition -1 means it is printed to the left of parent, 0 means "anywhere", 1 means right
+ bool needParens(Ref parent, Ref child, int childPosition) {
+ int parentPrecedence = getPrecedence(parent, true);
+ int childPrecedence = getPrecedence(child, false);
+
+ if (childPrecedence > parentPrecedence) return true; // child is definitely a danger
+ if (childPrecedence < parentPrecedence) return false; // definitely cool
+ // equal precedence, so associativity (rtl/ltr) is what matters
+ // (except for some exceptions, where multiple operators can combine into confusion)
+ if (parent[0] == UNARY_PREFIX) {
+ assert(child[0] == UNARY_PREFIX);
+ if ((parent[1] == PLUS || parent[1] == MINUS) && child[1] == parent[1]) {
+ // cannot emit ++x when we mean +(+x)
+ return true;
+ }
+ }
+ if (childPosition == 0) return true; // child could be anywhere, so always paren
+ if (childPrecedence < 0) return false; // both precedences are safe
+ // check if child is on the dangerous side
+ if (OperatorClass::getRtl(parentPrecedence)) return childPosition < 0;
+ else return childPosition > 0;
+ }
+
+ void printChild(Ref child, Ref parent, int childPosition=0) {
+ bool parens = needParens(parent, child, childPosition);
+ if (parens) emit('(');
+ print(child);
+ if (parens) emit(')');
+ }
+
+ void printBinary(Ref node) {
+ printChild(node[2], node, -1);
+ space();
+ emit(node[1]->getCString());
+ space();
+ printChild(node[3], node, 1);
+ }
+
+ void printUnaryPrefix(Ref node) {
+ if (finalize && node[1] == PLUS && (node[2][0] == NUM ||
+ (node[2][0] == UNARY_PREFIX && node[2][1] == MINUS && node[2][2][0] == NUM))) {
+ // emit a finalized number
+ int last = used;
+ print(node[2]);
+ ensure(1); // we temporarily append a 0
+ char *curr = buffer + last; // ensure might invalidate
+ buffer[used] = 0;
+ if (strchr(curr, '.')) return; // already a decimal point, all good
+ char *e = strchr(curr, 'e');
+ if (!e) {
+ emit(".0");
+ return;
+ }
+ ensure(3);
+ curr = buffer + last; // ensure might invalidate
+ char *end = strchr(curr, 0);
+ while (end >= e) {
+ end[2] = end[0];
+ end--;
+ }
+ e[0] = '.';
+ e[1] = '0';
+ used += 2;
+ return;
+ }
+ if ((buffer[used-1] == '-' && node[1] == MINUS) ||
+ (buffer[used-1] == '+' && node[1] == PLUS)) {
+ emit(' '); // cannot join - and - to --, looks like the -- operator
+ }
+ emit(node[1]->getCString());
+ printChild(node[2], node, 1);
+ }
+
+ void printConditional(Ref node) {
+ printChild(node[1], node, -1);
+ space();
+ emit('?');
+ space();
+ printChild(node[2], node, 0);
+ space();
+ emit(':');
+ space();
+ printChild(node[3], node, 1);
+ }
+
+ void printCall(Ref node) {
+ printChild(node[1], node, 0);
+ emit('(');
+ Ref args = node[2];
+ for (size_t i = 0; i < args->size(); i++) {
+ if (i > 0) (pretty ? emit(", ") : emit(','));
+ printChild(args[i], node, 0);
+ }
+ emit(')');
+ }
+
+ void printSeq(Ref node) {
+ printChild(node[1], node, -1);
+ emit(',');
+ space();
+ printChild(node[2], node, 1);
+ }
+
+ void printDot(Ref node) {
+ print(node[1]);
+ emit('.');
+ emit(node[2]->getCString());
+ }
+
+ void printSwitch(Ref node) {
+ emit("switch");
+ space();
+ emit('(');
+ print(node[1]);
+ emit(')');
+ space();
+ emit('{');
+ newline();
+ Ref cases = node[2];
+ for (size_t i = 0; i < cases->size(); i++) {
+ Ref c = cases[i];
+ if (!c[0]) {
+ emit("default:");
+ } else {
+ emit("case ");
+ print(c[0]);
+ emit(':');
+ }
+ if (c[1]->size() > 0) {
+ indent++;
+ newline();
+ int curr = used;
+ printStats(c[1]);
+ indent--;
+ if (curr != used) newline();
+ else used--; // avoid the extra indentation we added tentatively
+ } else {
+ newline();
+ }
+ }
+ emit('}');
+ }
+
+ void printSub(Ref node) {
+ printChild(node[1], node, -1);
+ emit('[');
+ print(node[2]);
+ emit(']');
+ }
+
+ void printVar(Ref node) {
+ emit("var ");
+ Ref args = node[1];
+ for (size_t i = 0; i < args->size(); i++) {
+ if (i > 0) (pretty ? emit(", ") : emit(','));
+ emit(args[i][0]->getCString());
+ if (args[i]->size() > 1) {
+ space();
+ emit('=');
+ space();
+ print(args[i][1]);
+ }
+ }
+ emit(';');
+ }
+
+ static bool ifHasElse(Ref node) {
+ assert(node[0] == IF);
+ return node->size() >= 4 && !!node[3];
+ }
+
+ void printIf(Ref node) {
+ emit("if");
+ safeSpace();
+ emit('(');
+ print(node[1]);
+ emit(')');
+ space();
+ // special case: we need braces to save us from ambiguity, if () { if () } else. otherwise else binds to inner if
+ // also need to recurse for if () { if () { } else { if () } else
+ // (note that this is only a problem if the if body has a single element in it, not a block or such, as then
+ // the block would be braced)
+ // this analysis is a little conservative - it assumes any child if could be confused with us, which implies
+ // all other braces vanished (the worst case for us, we are not saved by other braces).
+ bool needBraces = false;
+ bool hasElse = ifHasElse(node);
+ if (hasElse) {
+ Ref child = node[2];
+ while (child[0] == IF) {
+ if (!ifHasElse(child)) {
+ needBraces = true;
+ break;
+ }
+ child = child[3]; // continue into the else
+ }
+ }
+ if (needBraces) {
+ emit('{');
+ indent++;
+ newline();
+ print(node[2]);
+ indent--;
+ newline();
+ emit('}');
+ } else {
+ print(node[2], "{}");
+ }
+ if (hasElse) {
+ space();
+ emit("else");
+ safeSpace();
+ print(node[3], "{}");
+ }
+ }
+
+ void printDo(Ref node) {
+ emit("do");
+ safeSpace();
+ print(node[2], "{}");
+ space();
+ emit("while");
+ space();
+ emit('(');
+ print(node[1]);
+ emit(')');
+ emit(';');
+ }
+
+ void printWhile(Ref node) {
+ emit("while");
+ space();
+ emit('(');
+ print(node[1]);
+ emit(')');
+ space();
+ print(node[2], "{}");
+ }
+
+ void printLabel(Ref node) {
+ emit(node[1]->getCString());
+ space();
+ emit(':');
+ space();
+ print(node[2]);
+ }
+
+ void printReturn(Ref node) {
+ emit("return");
+ if (!!node[1]) {
+ emit(' ');
+ print(node[1]);
+ }
+ emit(';');
+ }
+
+ void printBreak(Ref node) {
+ emit("break");
+ if (!!node[1]) {
+ emit(' ');
+ emit(node[1]->getCString());
+ }
+ emit(';');
+ }
+
+ void printContinue(Ref node) {
+ emit("continue");
+ if (!!node[1]) {
+ emit(' ');
+ emit(node[1]->getCString());
+ }
+ emit(';');
+ }
+
+ void printNew(Ref node) {
+ emit("new ");
+ print(node[1]);
+ }
+
+ void printArray(Ref node) {
+ emit('[');
+ Ref args = node[1];
+ for (size_t i = 0; i < args->size(); i++) {
+ if (i > 0) (pretty ? emit(", ") : emit(','));
+ print(args[i]);
+ }
+ emit(']');
+ }
+
+ void printObject(Ref node) {
+ emit('{');
+ indent++;
+ newline();
+ Ref args = node[1];
+ for (size_t i = 0; i < args->size(); i++) {
+ if (i > 0) {
+ pretty ? emit(", ") : emit(',');
+ newline();
+ }
+ emit('"');
+ emit(args[i][0]->getCString());
+ emit("\":");
+ space();
+ print(args[i][1]);
+ }
+ indent--;
+ newline();
+ emit('}');
+ }
+};
+
+// cashew builder
+
+class ValueBuilder {
+ static IStringSet statable;
+
+ static Ref makeRawString(const IString& s) {
+ return &arena.alloc()->setString(s);
+ }
+
+ static Ref makeRawArray(int size_hint=0) {
+ return &arena.alloc()->setArray(size_hint);
+ }
+
+ static Ref makeNull() {
+ return &arena.alloc()->setNull();
+ }
+
+public:
+ static Ref makeToplevel() {
+ return &makeRawArray(2)->push_back(makeRawString(TOPLEVEL))
+ .push_back(makeRawArray());
+ }
+
+ static Ref makeString(IString str) {
+ return &makeRawArray(2)->push_back(makeRawString(STRING))
+ .push_back(makeRawString(str));
+ }
+
+ static Ref makeBlock() {
+ return &makeRawArray(2)->push_back(makeRawString(BLOCK))
+ .push_back(makeRawArray());
+ }
+
+ static Ref makeName(IString name) {
+ return &makeRawArray(2)->push_back(makeRawString(NAME))
+ .push_back(makeRawString(name));
+ }
+
+ static void setBlockContent(Ref target, Ref block) {
+ if (target[0] == TOPLEVEL) {
+ target[1]->setArray(block[1]->getArray());
+ } else if (target[0] == DEFUN) {
+ target[3]->setArray(block[1]->getArray());
+ } else abort();
+ }
+
+ static void appendToBlock(Ref block, Ref element) {
+ assert(block[0] == BLOCK);
+ block[1]->push_back(element);
+ }
+
+ static Ref makeCall(Ref target) {
+ return &makeRawArray(3)->push_back(makeRawString(CALL))
+ .push_back(target)
+ .push_back(makeRawArray());
+ }
+
+ static void appendToCall(Ref call, Ref element) {
+ assert(call[0] == CALL);
+ call[2]->push_back(element);
+ }
+
+ static Ref makeStatement(Ref contents) {
+ if (statable.has(contents[0]->getIString())) {
+ return &makeRawArray(2)->push_back(makeRawString(STAT))
+ .push_back(contents);
+ } else {
+ return contents; // only very specific things actually need to be stat'ed
+ }
+ }
+
+ static Ref makeDouble(double num) {
+ return &makeRawArray(2)->push_back(makeRawString(NUM))
+ .push_back(&arena.alloc()->setNumber(num));
+ }
+ static Ref makeInt(uint32_t num) {
+ return makeDouble(double(num));
+ }
+
+ static Ref makeBinary(Ref left, IString op, Ref right) {
+ if (op == SET) {
+ return &makeRawArray(4)->push_back(makeRawString(ASSIGN))
+ .push_back(&arena.alloc()->setBool(true))
+ .push_back(left)
+ .push_back(right);
+ } else if (op == COMMA) {
+ return &makeRawArray(3)->push_back(makeRawString(SEQ))
+ .push_back(left)
+ .push_back(right);
+ } else {
+ return &makeRawArray(4)->push_back(makeRawString(BINARY))
+ .push_back(makeRawString(op))
+ .push_back(left)
+ .push_back(right);
+ }
+ }
+
+ static Ref makePrefix(IString op, Ref right) {
+ return &makeRawArray(3)->push_back(makeRawString(UNARY_PREFIX))
+ .push_back(makeRawString(op))
+ .push_back(right);
+ }
+
+ static Ref makeFunction(IString name) {
+ return &makeRawArray(4)->push_back(makeRawString(DEFUN))
+ .push_back(makeRawString(name))
+ .push_back(makeRawArray())
+ .push_back(makeRawArray());
+ }
+
+ static void appendArgumentToFunction(Ref func, IString arg) {
+ assert(func[0] == DEFUN);
+ func[2]->push_back(makeRawString(arg));
+ }
+
+ static Ref makeVar(bool is_const) {
+ return &makeRawArray(2)->push_back(makeRawString(VAR))
+ .push_back(makeRawArray());
+ }
+
+ static void appendToVar(Ref var, IString name, Ref value) {
+ assert(var[0] == VAR);
+ Ref array = &makeRawArray(1)->push_back(makeRawString(name));
+ if (!!value) array->push_back(value);
+ var[1]->push_back(array);
+ }
+
+ static Ref makeReturn(Ref value) {
+ return &makeRawArray(2)->push_back(makeRawString(RETURN))
+ .push_back(!!value ? value : makeNull());
+ }
+
+ static Ref makeIndexing(Ref target, Ref index) {
+ return &makeRawArray(3)->push_back(makeRawString(SUB))
+ .push_back(target)
+ .push_back(index);
+ }
+
+ static Ref makeIf(Ref condition, Ref ifTrue, Ref ifFalse) {
+ return &makeRawArray(4)->push_back(makeRawString(IF))
+ .push_back(condition)
+ .push_back(ifTrue)
+ .push_back(!!ifFalse ? ifFalse : makeNull());
+ }
+
+ static Ref makeConditional(Ref condition, Ref ifTrue, Ref ifFalse) {
+ return &makeRawArray(4)->push_back(makeRawString(CONDITIONAL))
+ .push_back(condition)
+ .push_back(ifTrue)
+ .push_back(ifFalse);
+ }
+
+ static Ref makeDo(Ref body, Ref condition) {
+ return &makeRawArray(3)->push_back(makeRawString(DO))
+ .push_back(condition)
+ .push_back(body);
+ }
+
+ static Ref makeWhile(Ref condition, Ref body) {
+ return &makeRawArray(3)->push_back(makeRawString(WHILE))
+ .push_back(condition)
+ .push_back(body);
+ }
+
+ static Ref makeBreak(IString label) {
+ return &makeRawArray(2)->push_back(makeRawString(BREAK))
+ .push_back(!!label ? makeRawString(label) : makeNull());
+ }
+
+ static Ref makeContinue(IString label) {
+ return &makeRawArray(2)->push_back(makeRawString(CONTINUE))
+ .push_back(!!label ? makeRawString(label) : makeNull());
+ }
+
+ static Ref makeLabel(IString name, Ref body) {
+ return &makeRawArray(3)->push_back(makeRawString(LABEL))
+ .push_back(makeRawString(name))
+ .push_back(body);
+ }
+
+ static Ref makeSwitch(Ref input) {
+ return &makeRawArray(3)->push_back(makeRawString(SWITCH))
+ .push_back(input)
+ .push_back(makeRawArray());
+ }
+
+ static void appendCaseToSwitch(Ref switch_, Ref arg) {
+ assert(switch_[0] == SWITCH);
+ switch_[2]->push_back(&makeRawArray(2)->push_back(arg)
+ .push_back(makeRawArray()));
+ }
+
+ static void appendDefaultToSwitch(Ref switch_) {
+ assert(switch_[0] == SWITCH);
+ switch_[2]->push_back(&makeRawArray(2)->push_back(makeNull())
+ .push_back(makeRawArray()));
+ }
+
+ static void appendCodeToSwitch(Ref switch_, Ref code, bool explicitBlock) {
+ assert(switch_[0] == SWITCH);
+ assert(code[0] == BLOCK);
+ if (!explicitBlock) {
+ for (size_t i = 0; i < code[1]->size(); i++) {
+ switch_[2]->back()->back()->push_back(code[1][i]);
+ }
+ } else {
+ switch_[2]->back()->back()->push_back(code);
+ }
+ }
+
+ static Ref makeDot(Ref obj, IString key) {
+ return &makeRawArray(3)->push_back(makeRawString(DOT))
+ .push_back(obj)
+ .push_back(makeRawString(key));
+ }
+
+ static Ref makeDot(Ref obj, Ref key) {
+ assert(key[0] == NAME);
+ return makeDot(obj, key[1]->getIString());
+ }
+
+ static Ref makeNew(Ref call) {
+ return &makeRawArray(2)->push_back(makeRawString(NEW))
+ .push_back(call);
+ }
+
+ static Ref makeArray() {
+ return &makeRawArray(2)->push_back(makeRawString(ARRAY))
+ .push_back(makeRawArray());
+ }
+
+ static void appendToArray(Ref array, Ref element) {
+ assert(array[0] == ARRAY);
+ array[1]->push_back(element);
+ }
+
+ static Ref makeObject() {
+ return &makeRawArray(2)->push_back(makeRawString(OBJECT))
+ .push_back(makeRawArray());
+ }
+
+ static void appendToObject(Ref array, IString key, Ref value) {
+ assert(array[0] == OBJECT);
+ array[1]->push_back(&makeRawArray(2)->push_back(makeRawString(key))
+ .push_back(value));
+ }
+};
+
diff --git a/src/wasm.h b/src/wasm.h
new file mode 100644
index 000000000..d313c6e4b
--- /dev/null
+++ b/src/wasm.h
@@ -0,0 +1,818 @@
+//
+// WebAssembly representation and processing library
+//
+
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
+#include <map>
+#include <vector>
+
+#include "colors.h"
+
+namespace wasm {
+
+// Utilities
+
+// Arena allocation for mixed-type data.
+struct Arena {
+ std::vector<char*> chunks;
+ int index; // in last chunk
+
+ template<class T>
+ T* alloc() {
+ const size_t CHUNK = 10000;
+ size_t currSize = (sizeof(T) + 7) & (-8); // same alignment as malloc TODO optimize?
+ assert(currSize < CHUNK);
+ if (chunks.size() == 0 || index + currSize >= CHUNK) {
+ chunks.push_back(new char[CHUNK]);
+ index = 0;
+ }
+ T* ret = (T*)(chunks.back() + index);
+ index += currSize;
+ new (ret) T();
+ return ret;
+ }
+
+ void clear() {
+ for (char* chunk : chunks) {
+ delete[] chunk;
+ }
+ chunks.clear();
+ }
+
+ ~Arena() {
+ clear();
+ }
+};
+
+std::ostream &doIndent(std::ostream &o, unsigned indent) {
+ for (unsigned i = 0; i < indent; i++) {
+ o << " ";
+ }
+ return o;
+}
+void incIndent(std::ostream &o, unsigned& indent) {
+ o << '\n';
+ indent++;
+}
+void decIndent(std::ostream &o, unsigned& indent) {
+ indent--;
+ doIndent(o, indent);
+ o << ')';
+}
+
+// Basics
+
+struct Name : public cashew::IString {
+ Name() : cashew::IString() {}
+ Name(const char *str) : cashew::IString(str) {}
+ Name(cashew::IString str) : cashew::IString(str) {}
+
+ std::ostream& print(std::ostream &o) {
+ assert(str);
+ o << '$' << str; // reference interpreter requires we prefix all names
+ return o;
+ }
+};
+
+// Types
+
+enum BasicType {
+ none,
+ i32,
+ i64,
+ f32,
+ f64
+};
+
+std::ostream& printBasicType(std::ostream &o, BasicType type) {
+ switch (type) {
+ case BasicType::none: o << "none"; break;
+ case BasicType::i32: o << "i32"; break;
+ case BasicType::i64: o << "i64"; break;
+ case BasicType::f32: o << "f32"; break;
+ case BasicType::f64: o << "f64"; break;
+ }
+ return o;
+}
+
+unsigned getBasicTypeSize(BasicType type) {
+ switch (type) {
+ case BasicType::none: abort();
+ case BasicType::i32: return 4;
+ case BasicType::i64: return 8;
+ case BasicType::f32: return 4;
+ case BasicType::f64: return 8;
+ }
+}
+
+bool isFloat(BasicType type) {
+ switch (type) {
+ case f32:
+ case f64: return true;
+ }
+ return false;
+}
+
+BasicType getBasicType(unsigned size, bool float_) {
+ if (size < 4) return BasicType::i32;
+ if (size == 4) return float_ ? BasicType::f32 : BasicType::i32;
+ if (size == 8) return float_ ? BasicType::f64 : BasicType::i64;
+ abort();
+}
+
+void prepareMajorColor(std::ostream &o) {
+ Colors::red(o);
+ Colors::bold(o);
+}
+
+void prepareColor(std::ostream &o) {
+ Colors::magenta(o);
+ Colors::bold(o);
+}
+
+void prepareMinorColor(std::ostream &o) {
+ Colors::orange(o);
+}
+
+void restoreNormalColor(std::ostream &o) {
+ Colors::normal(o);
+}
+
+std::ostream& printText(std::ostream &o, const char *str) {
+ o << '"';
+ Colors::green(o);
+ o << str;
+ Colors::normal(o);
+ o << '"';
+ return o;
+}
+
+struct Literal {
+ BasicType type;
+ union {
+ int32_t i32;
+ int64_t i64;
+ float f32;
+ double f64;
+ };
+
+ Literal() : type(BasicType::none) {}
+ Literal(int32_t init) : type(BasicType::i32), i32(init) {}
+ Literal(int64_t init) : type(BasicType::i64), i64(init) {}
+ Literal(float init) : type(BasicType::f32), f32(init) {}
+ Literal(double init) : type(BasicType::f64), f64(init) {}
+
+ std::ostream& print(std::ostream &o) {
+ o << '(';
+ prepareMinorColor(o);
+ printBasicType(o, type) << ".const ";
+ switch (type) {
+ case none: abort();
+ case BasicType::i32: o << i32; break;
+ case BasicType::i64: o << i64; break;
+ case BasicType::f32: o << f32; break;
+ case BasicType::f64: o << f64; break;
+ }
+ restoreNormalColor(o);
+ o << ')';
+ return o;
+ }
+};
+
+// Operators
+
+enum UnaryOp {
+ Clz, Ctz, Popcnt, // int
+ Neg, Abs, Ceil, Floor, Trunc, Nearest, Sqrt // float
+};
+
+enum BinaryOp {
+ Add, Sub, Mul, // int or float
+ DivS, DivU, RemS, RemU, And, Or, Xor, Shl, ShrU, ShrS, // int
+ Div, CopySign, Min, Max // float
+};
+
+enum RelationalOp {
+ Eq, Ne, // int or float
+ LtS, LtU, LeS, LeU, GtS, GtU, GeS, GeU, // int
+ Lt, Le, Gt, Ge // float
+};
+
+enum ConvertOp {
+ ExtendSInt32, ExtendUInt32, WrapInt64, TruncSFloat32, TruncUFloat32, TruncSFloat64, TruncUFloat64, ReinterpretFloat, // int
+ ConvertSInt32, ConvertUInt32, ConvertSInt64, ConvertUInt64, PromoteFloat32, DemoteFloat64, ReinterpretInt // float
+};
+
+enum HostOp {
+ PageSize, MemorySize, GrowMemory, HasFeature
+};
+
+// Expressions
+
+class Expression {
+public:
+ BasicType type;
+
+ Expression() : type(type) {}
+
+ virtual std::ostream& print(std::ostream &o, unsigned indent) = 0;
+
+ template<class T>
+ bool is() {
+ return !!dynamic_cast<T*>(this);
+ }
+};
+
+std::ostream& printFullLine(std::ostream &o, unsigned indent, Expression *expression) {
+ doIndent(o, indent);
+ expression->print(o, indent);
+ o << '\n';
+}
+
+std::ostream& printOpening(std::ostream &o, const char *str, bool major=false) {
+ o << '(';
+ major ? prepareMajorColor(o) : prepareColor(o);
+ o << str;
+ restoreNormalColor(o);
+ return o;
+}
+
+std::ostream& printMinorOpening(std::ostream &o, const char *str) {
+ o << '(';
+ prepareMinorColor(o);
+ o << str;
+ restoreNormalColor(o);
+ return o;
+}
+
+typedef std::vector<Expression*> ExpressionList; // TODO: optimize
+
+class Nop : public Expression {
+ std::ostream& print(std::ostream &o, unsigned indent) override {
+ o << "nop";
+ return o;
+ }
+};
+
+class Block : public Expression {
+public:
+ Name var;
+ ExpressionList list;
+
+ std::ostream& print(std::ostream &o, unsigned indent) override {
+ printOpening(o, "block");
+ if (var.is()) {
+ o << " ";
+ var.print(o);
+ }
+ incIndent(o, indent);
+ for (auto expression : list) {
+ printFullLine(o, indent, expression);
+ }
+ decIndent(o, indent);
+ return o;
+ }
+};
+
+class If : public Expression {
+public:
+ Expression *condition, *ifTrue, *ifFalse;
+
+ std::ostream& print(std::ostream &o, unsigned indent) override {
+ printOpening(o, "if");
+ incIndent(o, indent);
+ printFullLine(o, indent, condition);
+ printFullLine(o, indent, ifTrue);
+ if (ifFalse) printFullLine(o, indent, ifFalse);
+ decIndent(o, indent);
+ return o;
+ }
+};
+
+class Loop : public Expression {
+public:
+ Name out, in;
+ Expression *body;
+
+ std::ostream& print(std::ostream &o, unsigned indent) override {
+ printOpening(o, "loop");
+ if (out.is()) {
+ o << " ";
+ out.print(o);
+ if (in.is()) {
+ o << " ";
+ in.print(o);
+ }
+ }
+ incIndent(o, indent);
+ printFullLine(o, indent, body);
+ decIndent(o, indent);
+ return o;
+ }
+};
+
+class Label : public Expression {
+public:
+ Name var;
+};
+
+class Break : public Expression {
+public:
+ Name var;
+ Expression *condition, *value;
+
+ std::ostream& print(std::ostream &o, unsigned indent) override {
+ printOpening(o, "break ");
+ var.print(o);
+ incIndent(o, indent);
+ if (condition) printFullLine(o, indent, condition);
+ if (value) printFullLine(o, indent, value);
+ decIndent(o, indent);
+ return o;
+ }
+};
+
+class Switch : public Expression {
+public:
+ struct Case {
+ Literal value;
+ Expression *body;
+ bool fallthru;
+ };
+
+ Name var;
+ Expression *value;
+ std::vector<Case> cases;
+ Expression *default_;
+
+ std::ostream& print(std::ostream &o, unsigned indent) override {
+ printOpening(o, "switch ");
+ var.print(o);
+ incIndent(o, indent);
+ printFullLine(o, indent, value);
+ o << "TODO: cases/default\n";
+ decIndent(o, indent);
+ return o;
+ }
+
+};
+
+class Call : public Expression {
+public:
+ Name target;
+ ExpressionList operands;
+
+ std::ostream& print(std::ostream &o, unsigned indent) override {
+ printOpening(o, "call ");
+ target.print(o);
+ if (operands.size() > 0) {
+ incIndent(o, indent);
+ for (auto operand : operands) {
+ printFullLine(o, indent, operand);
+ }
+ decIndent(o, indent);
+ } else {
+ o << ')';
+ }
+ return o;
+ }
+};
+
+class CallImport : public Call {
+};
+
+class FunctionType {
+public:
+ Name name;
+ BasicType result;
+ std::vector<BasicType> params;
+
+ std::ostream& print(std::ostream &o, unsigned indent, bool full=false) {
+ if (full) {
+ printOpening(o, "type") << ' ';
+ name.print(o);
+ }
+ if (params.size() > 0) {
+ o << ' ';
+ printMinorOpening(o, "param");
+ for (auto& param : params) {
+ o << ' ';
+ printBasicType(o, param);
+ }
+ o << ')';
+ }
+ if (result != none) {
+ o << ' ';
+ printMinorOpening(o, "result ");
+ printBasicType(o, result) << ')';
+ }
+ if (full) {
+ o << ')';
+ }
+ return o;
+ }
+
+ bool operator==(FunctionType& b) {
+ if (name != b.name) return false; // XXX
+ if (result != b.result) return false;
+ if (params.size() != b.params.size()) return false;
+ for (size_t i = 0; i < params.size(); i++) {
+ if (params[i] != b.params[i]) return false;
+ }
+ return true;
+ }
+ bool operator!=(FunctionType& b) {
+ return !(*this == b);
+ }
+};
+
+class CallIndirect : public Expression {
+public:
+ FunctionType *type;
+ Expression *target;
+ ExpressionList operands;
+
+ std::ostream& print(std::ostream &o, unsigned indent) override {
+ printOpening(o, "call_indirect ");
+ type->name.print(o);
+ incIndent(o, indent);
+ printFullLine(o, indent, target);
+ for (auto operand : operands) {
+ printFullLine(o, indent, operand);
+ }
+ decIndent(o, indent);
+ return o;
+ }
+};
+
+class GetLocal : public Expression {
+public:
+ Name id;
+
+ std::ostream& print(std::ostream &o, unsigned indent) override {
+ printOpening(o, "get_local ");
+ id.print(o) << ')';
+ return o;
+ }
+};
+
+class SetLocal : public Expression {
+public:
+ Name id;
+ Expression *value;
+
+ std::ostream& print(std::ostream &o, unsigned indent) override {
+ printOpening(o, "set_local ");
+ id.print(o);
+ incIndent(o, indent);
+ printFullLine(o, indent, value);
+ decIndent(o, indent);
+ return o;
+ }
+};
+
+class Load : public Expression {
+public:
+ unsigned bytes;
+ bool signed_;
+ bool float_;
+ int offset;
+ unsigned align;
+ Expression *ptr;
+
+ std::ostream& print(std::ostream &o, unsigned indent) override {
+ o << '(';
+ prepareColor(o);
+ printBasicType(o, getBasicType(bytes, float_)) << ".load";
+ if (bytes < 4) {
+ if (bytes == 1) {
+ o << '8';
+ } else if (bytes == 2) {
+ o << "16";
+ } else {
+ abort();
+ }
+ if (!signed_) o << "_u";
+ }
+ restoreNormalColor(o);
+ o << " align=" << align;
+ assert(!offset);
+ incIndent(o, indent);
+ printFullLine(o, indent, ptr);
+ decIndent(o, indent);
+ return o;
+ }
+};
+
+class Store : public Expression {
+public:
+ unsigned bytes;
+ bool float_;
+ int offset;
+ unsigned align;
+ Expression *ptr, *value;
+
+ std::ostream& print(std::ostream &o, unsigned indent) override {
+ o << '(';
+ prepareColor(o);
+ printBasicType(o, getBasicType(bytes, float_)) << ".store";
+ if (bytes < 4) {
+ if (bytes == 1) {
+ o << '8';
+ } else if (bytes == 2) {
+ o << "16";
+ } else {
+ abort();
+ }
+ }
+ restoreNormalColor(o);
+ o << " align=" << align;
+ assert(!offset);
+ incIndent(o, indent);
+ printFullLine(o, indent, ptr);
+ printFullLine(o, indent, value);
+ decIndent(o, indent);
+ return o;
+ }
+};
+
+class Const : public Expression {
+public:
+ Literal value;
+
+ Const* set(Literal value_) {
+ value = value_;
+ return this;
+ }
+
+ std::ostream& print(std::ostream &o, unsigned indent) override {
+ value.print(o);
+ return o;
+ }
+};
+
+class Unary : public Expression {
+public:
+ UnaryOp op;
+ Expression *value;
+
+ std::ostream& print(std::ostream &o, unsigned indent) override {
+ printOpening(o, "unary ");
+ switch (op) {
+ case Neg: o << "neg"; break;
+ default: abort();
+ }
+ incIndent(o, indent);
+ printFullLine(o, indent, value);
+ decIndent(o, indent);
+ return o;
+ }
+};
+
+class Binary : public Expression {
+public:
+ BinaryOp op;
+ Expression *left, *right;
+
+ std::ostream& print(std::ostream &o, unsigned indent) override {
+ o << '(';
+ prepareColor(o);
+ printBasicType(o, type) << '.';
+ switch (op) {
+ case Add: o << "add"; break;
+ case Sub: o << "sub"; break;
+ case Mul: o << "mul"; break;
+ case DivS: o << "div_s"; break;
+ case DivU: o << "div_u"; break;
+ case RemS: o << "rem_s"; break;
+ case RemU: o << "rem_u"; break;
+ case And: o << "and"; break;
+ case Or: o << "or"; break;
+ case Xor: o << "xor"; break;
+ case Shl: o << "shl"; break;
+ case ShrU: o << "shr_u"; break;
+ case ShrS: o << "shr_s"; break;
+ case Div: o << "div"; break;
+ case CopySign: o << "copysign"; break;
+ case Min: o << "min"; break;
+ case Max: o << "max"; break;
+ default: abort();
+ }
+ restoreNormalColor(o);
+ incIndent(o, indent);
+ printFullLine(o, indent, left);
+ printFullLine(o, indent, right);
+ decIndent(o, indent);
+ return o;
+ }
+};
+
+class Compare : public Expression {
+public:
+ RelationalOp op;
+ Expression *left, *right;
+
+ Compare() {
+ type = BasicType::i32;
+ }
+
+ std::ostream& print(std::ostream &o, unsigned indent) override {
+ o << '(';
+ prepareColor(o);
+ printBasicType(o, type) << '.';
+ switch (op) {
+ case Eq: o << "eq"; break;
+ case Ne: o << "ne"; break;
+ case LtS: o << "lt_s"; break;
+ case LtU: o << "lt_u"; break;
+ case LeS: o << "le_s"; break;
+ case LeU: o << "le_u"; break;
+ case GtS: o << "gt_s"; break;
+ case GtU: o << "gt_u"; break;
+ case GeS: o << "ge_s"; break;
+ case GeU: o << "ge_u"; break;
+ case Lt: o << "lt"; break;
+ case Le: o << "le"; break;
+ case Gt: o << "gt"; break;
+ case Ge: o << "ge"; break;
+ default: abort();
+ }
+ restoreNormalColor(o);
+ incIndent(o, indent);
+ printFullLine(o, indent, left);
+ printFullLine(o, indent, right);
+ decIndent(o, indent);
+ return o;
+ }
+};
+
+class Convert : public Expression {
+public:
+ ConvertOp op;
+ Expression *value;
+
+ std::ostream& print(std::ostream &o, unsigned indent) override {
+ printOpening(o, "convert ");
+ switch (op) {
+ case ConvertUInt32: o << "uint32toDouble"; break;
+ case ConvertSInt32: o << "sint32toDouble"; break;
+ case TruncSFloat64: o << "float64tosint32"; break;
+ default: abort();
+ }
+ incIndent(o, indent);
+ printFullLine(o, indent, value);
+ decIndent(o, indent);
+ return o;
+ }
+};
+
+class Host : public Expression {
+public:
+ HostOp op;
+ ExpressionList operands;
+};
+
+// Globals
+
+struct NameType {
+ Name name;
+ BasicType type;
+ NameType() : name(nullptr), type(none) {}
+ NameType(Name name, BasicType type) : name(name), type(type) {}
+};
+
+class Function {
+public:
+ Name name;
+ BasicType result;
+ std::vector<NameType> params;
+ std::vector<NameType> locals;
+ Expression *body;
+
+ std::ostream& print(std::ostream &o, unsigned indent) {
+ printOpening(o, "func ", true);
+ name.print(o);
+ if (params.size() > 0) {
+ for (auto& param : params) {
+ o << ' ';
+ printMinorOpening(o, "param ");
+ param.name.print(o) << " ";
+ printBasicType(o, param.type) << ")";
+ }
+ }
+ if (result != none) {
+ o << ' ';
+ printMinorOpening(o, "result ");
+ printBasicType(o, result) << ")";
+ }
+ incIndent(o, indent);
+ for (auto& local : locals) {
+ doIndent(o, indent);
+ printMinorOpening(o, "local ");
+ local.name.print(o) << " ";
+ printBasicType(o, local.type) << ")\n";
+ }
+ printFullLine(o, indent, body);
+ decIndent(o, indent);
+ return o;
+ }
+};
+
+class Import {
+public:
+ Name name, module, base; // name = module.base
+ FunctionType type;
+
+ std::ostream& print(std::ostream &o, unsigned indent) {
+ printOpening(o, "import ");
+ name.print(o) << ' ';
+ printText(o, module.str) << ' ';
+ printText(o, base.str) << ' ';
+ type.print(o, indent);
+ o << ')';
+ return o;
+ }
+};
+
+class Export {
+public:
+ Name name;
+ Name value;
+
+ std::ostream& print(std::ostream &o, unsigned indent) {
+ printOpening(o, "export") << ' ';
+ name.print(o) << ' ';
+ printText(o, name.str) << ' ';
+ value.print(o);
+ o << ')';
+ return o;
+ }
+};
+
+class Table {
+public:
+ std::vector<Name> vars;
+
+ std::ostream& print(std::ostream &o, unsigned indent) {
+ printOpening(o, "table");
+ for (auto var : vars) {
+ o << ' ';
+ var.print(o);
+ }
+ o << ')';
+ return o;
+ }
+};
+
+class Module {
+protected:
+ // wasm contents
+ std::map<Name, FunctionType*> functionTypes;
+ std::map<Name, Import> imports;
+ std::vector<Export> exports;
+ Table table;
+ std::vector<Function*> functions;
+
+ // internals
+ std::map<Name, void*> map; // maps var ids/names to things
+ unsigned nextVar;
+
+public:
+ Module() : nextVar(1) {}
+
+ std::ostream& print(std::ostream &o) {
+ unsigned indent = 0;
+ printOpening(o, "module", true);
+ incIndent(o, indent);
+ for (auto& curr : functionTypes) {
+ doIndent(o, indent);
+ curr.second->print(o, indent, true);
+ o << '\n';
+ }
+ for (auto& curr : imports) {
+ doIndent(o, indent);
+ curr.second.print(o, indent);
+ o << '\n';
+ }
+ for (auto& curr : exports) {
+ doIndent(o, indent);
+ curr.print(o, indent);
+ o << '\n';
+ }
+ doIndent(o, indent);
+ table.print(o, indent);
+ o << '\n';
+ for (auto& curr : functions) {
+ doIndent(o, indent);
+ curr->print(o, indent);
+ o << '\n';
+ }
+ decIndent(o, indent);
+ o << '\n';
+ }
+};
+
+} // namespace wasm
+
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