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-rw-r--r--src/asm2wasm.h164
-rw-r--r--test/wasm-only.asm.js36
-rw-r--r--test/wasm-only.fromasm.imprecise.no-opts132
-rw-r--r--test/wasm-only.fromasm.no-opts132
4 files changed, 412 insertions, 52 deletions
diff --git a/src/asm2wasm.h b/src/asm2wasm.h
index 34825eb61..f7f084376 100644
--- a/src/asm2wasm.h
+++ b/src/asm2wasm.h
@@ -2089,6 +2089,7 @@ Function* Asm2WasmBuilder::processFunction(Ref ast) {
Ref cases = ast[2];
bool seen = false;
int64_t min = 0; // the lowest index we see; we will offset to it
+ int64_t max = 0; // the highest, to check if the range is too big
for (unsigned i = 0; i < cases->size(); i++) {
Ref curr = cases[i];
Ref condition = curr[0];
@@ -2097,71 +2098,130 @@ Function* Asm2WasmBuilder::processFunction(Ref ast) {
if (!seen) {
seen = true;
min = index;
+ max = index;
} else {
if (index < min) min = index;
+ if (index > max) max = index;
}
}
}
- if (br->condition->type == i32) {
- Binary* offsetor = allocator.alloc<Binary>();
- offsetor->op = BinaryOp::SubInt32;
- offsetor->left = br->condition;
- offsetor->right = builder.makeConst(Literal(int32_t(min)));
- offsetor->type = i32;
- br->condition = offsetor;
- } else {
- assert(br->condition->type == i64);
- // 64-bit condition. after offsetting it must be in a reasonable range, but the offsetting itself must be 64-bit
- Binary* offsetor = allocator.alloc<Binary>();
- offsetor->op = BinaryOp::SubInt64;
- offsetor->left = br->condition;
- offsetor->right = builder.makeConst(Literal(int64_t(min)));
- offsetor->type = i64;
- br->condition = builder.makeUnary(UnaryOp::WrapInt64, offsetor); // TODO: check this fits in 32 bits
- }
+ // we can use a switch if it's not too big
+ auto range = double(max) - double(min); // test using doubles to avoid UB
+ bool canSwitch = 0 <= range && range < 10240;
auto top = allocator.alloc<Block>();
- top->list.push_back(br);
- top->finalize();
-
- for (unsigned i = 0; i < cases->size(); i++) {
- Ref curr = cases[i];
- Ref condition = curr[0];
- Ref body = curr[1];
- auto case_ = processStatements(body, 0);
- Name name;
- if (condition->isNull()) {
- name = br->default_ = nameMapper.pushLabelName("switch-default");
+ if (canSwitch) {
+ if (br->condition->type == i32) {
+ Binary* offsetor = allocator.alloc<Binary>();
+ offsetor->op = BinaryOp::SubInt32;
+ offsetor->left = br->condition;
+ offsetor->right = builder.makeConst(Literal(int32_t(min)));
+ offsetor->type = i32;
+ br->condition = offsetor;
} else {
- auto index = getLiteral(condition).getInteger();
- assert(index >= min);
- index -= min;
- assert(index >= 0);
- uint64_t index_s = index;
- name = nameMapper.pushLabelName("switch-case");
- if (br->targets.size() <= index_s) {
- br->targets.resize(index_s + 1);
+ assert(br->condition->type == i64);
+ // 64-bit condition. after offsetting it must be in a reasonable range, but the offsetting itself must be 64-bit
+ Binary* offsetor = allocator.alloc<Binary>();
+ offsetor->op = BinaryOp::SubInt64;
+ offsetor->left = br->condition;
+ offsetor->right = builder.makeConst(Literal(int64_t(min)));
+ offsetor->type = i64;
+ br->condition = builder.makeUnary(UnaryOp::WrapInt64, offsetor); // TODO: check this fits in 32 bits
+ }
+
+ top->list.push_back(br);
+ top->finalize();
+
+ for (unsigned i = 0; i < cases->size(); i++) {
+ Ref curr = cases[i];
+ Ref condition = curr[0];
+ Ref body = curr[1];
+ auto case_ = processStatements(body, 0);
+ Name name;
+ if (condition->isNull()) {
+ name = br->default_ = nameMapper.pushLabelName("switch-default");
+ } else {
+ auto index = getLiteral(condition).getInteger();
+ assert(index >= min);
+ index -= min;
+ assert(index >= 0);
+ uint64_t index_s = index;
+ name = nameMapper.pushLabelName("switch-case");
+ if (br->targets.size() <= index_s) {
+ br->targets.resize(index_s + 1);
+ }
+ br->targets[index_s] = name;
}
- br->targets[index_s] = name;
+ auto next = allocator.alloc<Block>();
+ top->name = name;
+ next->list.push_back(top);
+ next->list.push_back(case_);
+ next->finalize();
+ top = next;
+ nameMapper.popLabelName(name);
}
- auto next = allocator.alloc<Block>();
+
+ // the outermost block can be branched to to exit the whole switch
top->name = name;
- next->list.push_back(top);
- next->list.push_back(case_);
- next->finalize();
- top = next;
- nameMapper.popLabelName(name);
- }
- // the outermost block can be branched to to exit the whole switch
- top->name = name;
+ // ensure a default
+ if (br->default_.isNull()) {
+ br->default_ = top->name;
+ }
+ for (size_t i = 0; i < br->targets.size(); i++) {
+ if (br->targets[i].isNull()) br->targets[i] = br->default_;
+ }
+ } else {
+ // we can't switch, make an if-chain instead of br_table
+ auto var = Builder::addVar(function, br->condition->type);
+ top->list.push_back(builder.makeSetLocal(var, br->condition));
+ auto* brHolder = top;
+ If* chain = nullptr;
+ If* first = nullptr;
+
+ for (unsigned i = 0; i < cases->size(); i++) {
+ Ref curr = cases[i];
+ Ref condition = curr[0];
+ Ref body = curr[1];
+ auto case_ = processStatements(body, 0);
+ Name name;
+ if (condition->isNull()) {
+ name = br->default_ = nameMapper.pushLabelName("switch-default");
+ } else {
+ name = nameMapper.pushLabelName("switch-case");
+ auto* iff = builder.makeIf(
+ builder.makeBinary(
+ br->condition->type == i32 ? EqInt32 : EqInt64,
+ builder.makeGetLocal(var, br->condition->type),
+ builder.makeConst(getLiteral(condition))
+ ),
+ builder.makeBreak(name),
+ chain
+ );
+ chain = iff;
+ if (!first) first = iff;
+ }
+ auto next = allocator.alloc<Block>();
+ top->name = name;
+ next->list.push_back(top);
+ next->list.push_back(case_);
+ next->finalize();
+ top = next;
+ nameMapper.popLabelName(name);
+ }
- // ensure a default
- if (br->default_.isNull()) {
- br->default_ = top->name;
- }
- for (size_t i = 0; i < br->targets.size(); i++) {
- if (br->targets[i].isNull()) br->targets[i] = br->default_;
+ // the outermost block can be branched to to exit the whole switch
+ top->name = name;
+
+ // ensure a default
+ if (br->default_.isNull()) {
+ br->default_ = top->name;
+ }
+
+ first->ifFalse = builder.makeBreak(br->default_);
+
+ brHolder->list.push_back(chain);
+ brHolder->finalize();
}
breakStack.pop_back();
diff --git a/test/wasm-only.asm.js b/test/wasm-only.asm.js
index 3adacf5be..371197173 100644
--- a/test/wasm-only.asm.js
+++ b/test/wasm-only.asm.js
@@ -248,6 +248,42 @@ function asm(global, env, buffer) {
}
return;
}
+ function switch64TOOMUCH($a444) {
+ $a444 = i64($a444);
+ var $waka = 0;
+ switch (i64($a444)) {
+ case i64_const(0,1073741824): // spread is huge here, we should not make a jump table!
+ case i64_const(0,2147483648): {
+ return 40;
+ }
+ default: {
+ $waka = 1;
+ }
+ }
+ switch (100) {
+ case 107374182: // similar, but 32-bit
+ case 214748364: {
+ return 41;
+ }
+ default: {
+ $waka = 1001;
+ }
+ }
+ // no defaults
+ switch (i64($a444)) {
+ case i64_const(0,1073741824): // spread is huge here, we should not make a jump table!
+ case i64_const(0,2147483648): {
+ return 42;
+ }
+ }
+ switch (100) {
+ case 107374182: // similar, but 32-bit
+ case 214748364: {
+ return 43;
+ }
+ }
+ return 44;
+ }
function keepAlive() {
loads();
stores();
diff --git a/test/wasm-only.fromasm.imprecise.no-opts b/test/wasm-only.fromasm.imprecise.no-opts
index 4b079e33e..4db467f47 100644
--- a/test/wasm-only.fromasm.imprecise.no-opts
+++ b/test/wasm-only.fromasm.imprecise.no-opts
@@ -757,6 +757,138 @@
)
(return)
)
+ (func $switch64TOOMUCH (param $$a444 i64) (result i32)
+ (local $$waka i32)
+ (local $2 i64)
+ (local $3 i32)
+ (local $4 i64)
+ (local $5 i32)
+ (block $switch
+ (block $switch-default
+ (block $switch-case0
+ (block $switch-case
+ (set_local $2
+ (get_local $$a444)
+ )
+ (if
+ (i64.eq
+ (get_local $2)
+ (i64.const -9223372036854775808)
+ )
+ (br $switch-case0)
+ (if
+ (i64.eq
+ (get_local $2)
+ (i64.const 4611686018427387904)
+ )
+ (br $switch-case)
+ (br $switch-default)
+ )
+ )
+ )
+ (nop)
+ )
+ (return
+ (i32.const 40)
+ )
+ )
+ (set_local $$waka
+ (i32.const 1)
+ )
+ )
+ (block $switch1
+ (block $switch-default4
+ (block $switch-case3
+ (block $switch-case2
+ (set_local $3
+ (i32.const 100)
+ )
+ (if
+ (i32.eq
+ (get_local $3)
+ (i32.const 214748364)
+ )
+ (br $switch-case3)
+ (if
+ (i32.eq
+ (get_local $3)
+ (i32.const 107374182)
+ )
+ (br $switch-case2)
+ (br $switch-default4)
+ )
+ )
+ )
+ (nop)
+ )
+ (return
+ (i32.const 41)
+ )
+ )
+ (set_local $$waka
+ (i32.const 1001)
+ )
+ )
+ (block $switch5
+ (block $switch-case7
+ (block $switch-case6
+ (set_local $4
+ (get_local $$a444)
+ )
+ (if
+ (i64.eq
+ (get_local $4)
+ (i64.const -9223372036854775808)
+ )
+ (br $switch-case7)
+ (if
+ (i64.eq
+ (get_local $4)
+ (i64.const 4611686018427387904)
+ )
+ (br $switch-case6)
+ (br $switch5)
+ )
+ )
+ )
+ (nop)
+ )
+ (return
+ (i32.const 42)
+ )
+ )
+ (block $switch8
+ (block $switch-case10
+ (block $switch-case9
+ (set_local $5
+ (i32.const 100)
+ )
+ (if
+ (i32.eq
+ (get_local $5)
+ (i32.const 214748364)
+ )
+ (br $switch-case10)
+ (if
+ (i32.eq
+ (get_local $5)
+ (i32.const 107374182)
+ )
+ (br $switch-case9)
+ (br $switch8)
+ )
+ )
+ )
+ (nop)
+ )
+ (return
+ (i32.const 43)
+ )
+ )
+ (return
+ (i32.const 44)
+ )
+ )
(func $keepAlive
(call $loads)
(call $stores)
diff --git a/test/wasm-only.fromasm.no-opts b/test/wasm-only.fromasm.no-opts
index b1f72e6dc..e71e6b2b2 100644
--- a/test/wasm-only.fromasm.no-opts
+++ b/test/wasm-only.fromasm.no-opts
@@ -805,6 +805,138 @@
)
(return)
)
+ (func $switch64TOOMUCH (param $$a444 i64) (result i32)
+ (local $$waka i32)
+ (local $2 i64)
+ (local $3 i32)
+ (local $4 i64)
+ (local $5 i32)
+ (block $switch
+ (block $switch-default
+ (block $switch-case0
+ (block $switch-case
+ (set_local $2
+ (get_local $$a444)
+ )
+ (if
+ (i64.eq
+ (get_local $2)
+ (i64.const -9223372036854775808)
+ )
+ (br $switch-case0)
+ (if
+ (i64.eq
+ (get_local $2)
+ (i64.const 4611686018427387904)
+ )
+ (br $switch-case)
+ (br $switch-default)
+ )
+ )
+ )
+ (nop)
+ )
+ (return
+ (i32.const 40)
+ )
+ )
+ (set_local $$waka
+ (i32.const 1)
+ )
+ )
+ (block $switch1
+ (block $switch-default4
+ (block $switch-case3
+ (block $switch-case2
+ (set_local $3
+ (i32.const 100)
+ )
+ (if
+ (i32.eq
+ (get_local $3)
+ (i32.const 214748364)
+ )
+ (br $switch-case3)
+ (if
+ (i32.eq
+ (get_local $3)
+ (i32.const 107374182)
+ )
+ (br $switch-case2)
+ (br $switch-default4)
+ )
+ )
+ )
+ (nop)
+ )
+ (return
+ (i32.const 41)
+ )
+ )
+ (set_local $$waka
+ (i32.const 1001)
+ )
+ )
+ (block $switch5
+ (block $switch-case7
+ (block $switch-case6
+ (set_local $4
+ (get_local $$a444)
+ )
+ (if
+ (i64.eq
+ (get_local $4)
+ (i64.const -9223372036854775808)
+ )
+ (br $switch-case7)
+ (if
+ (i64.eq
+ (get_local $4)
+ (i64.const 4611686018427387904)
+ )
+ (br $switch-case6)
+ (br $switch5)
+ )
+ )
+ )
+ (nop)
+ )
+ (return
+ (i32.const 42)
+ )
+ )
+ (block $switch8
+ (block $switch-case10
+ (block $switch-case9
+ (set_local $5
+ (i32.const 100)
+ )
+ (if
+ (i32.eq
+ (get_local $5)
+ (i32.const 214748364)
+ )
+ (br $switch-case10)
+ (if
+ (i32.eq
+ (get_local $5)
+ (i32.const 107374182)
+ )
+ (br $switch-case9)
+ (br $switch8)
+ )
+ )
+ )
+ (nop)
+ )
+ (return
+ (i32.const 43)
+ )
+ )
+ (return
+ (i32.const 44)
+ )
+ )
(func $keepAlive
(call $loads)
(call $stores)
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