Wasm2js: support i64 globals (#2021)

Split them into two i32 globals.

7 files changed, 180 insertions, 13 deletions

diff --git a/src/passes/I64ToI32Lowering.cpp b/src/passes/I64ToI32Lowering.cpp
index 42566c0e2..a1686d27d 100644
--- a/src/passes/I64ToI32Lowering.cpp
+++ b/src/passes/I64ToI32Lowering.cpp
@@ -36,9 +36,7 @@
 namespace wasm {
 
 static Name makeHighName(Name n) {
-  return Name(
-    cashew::IString((std::string(n.c_str()) + "$hi").c_str(), false)
-  );
+  return std::string(n.c_str()) + "$hi";
 }
 
 struct I64ToI32Lowering : public WalkerPass<PostWalker<I64ToI32Lowering>> {
@@ -104,12 +102,27 @@ struct I64ToI32Lowering : public WalkerPass<PostWalker<I64ToI32Lowering>> {
     if (!builder) builder = make_unique<Builder>(*module);
     // add new globals for high bits
     for (size_t i = 0, globals = module->globals.size(); i < globals; ++i) {
-      auto& curr = module->globals[i];
+      auto* curr = module->globals[i].get();
       if (curr->type != i64) continue;
+      originallyI64Globals.insert(curr->name);
       curr->type = i32;
-      auto* high = ModuleUtils::copyGlobal(curr.get(), *module);
-      high->name = makeHighName(curr->name);
+      auto* high = builder->makeGlobal(makeHighName(curr->name), i32, builder->makeConst(Literal(int32_t(0))), Builder::Mutable);
       module->addGlobal(high);
+      if (curr->imported()) {
+        Fatal() << "TODO: imported i64 globals";
+      } else {
+        if (auto* c = curr->init->dynCast<Const>()) {
+          uint64_t value = c->value.geti64();
+          c->value = Literal(uint32_t(value));
+          c->type = i32;
+          high->init = builder->makeConst(Literal(uint32_t(value >> 32)));
+        } else if (auto* get = curr->init->dynCast<GetGlobal>()) {
+          high->init = builder->makeGetGlobal(makeHighName(get->name), i32);
+        } else {
+          WASM_UNREACHABLE();
+        }
+        curr->init->type = i32;
+      }
     }
 
     // For functions that return 64-bit values, we use this global variable
@@ -425,7 +438,7 @@ struct I64ToI32Lowering : public WalkerPass<PostWalker<I64ToI32Lowering>> {
       return;
     }
     TempVar highBits = fetchOutParam(curr->value);
-    SetLocal* setHigh = builder->makeSetLocal(
+    auto* setHigh = builder->makeSetLocal(
       mappedIndex + 1,
       builder->makeGetLocal(highBits, i32)
     );
@@ -434,13 +447,30 @@ struct I64ToI32Lowering : public WalkerPass<PostWalker<I64ToI32Lowering>> {
   }
 
   void visitGetGlobal(GetGlobal* curr) {
-    if (curr->type != i64) return;
-    assert(false && "GetGlobal not implemented");
+    if (!getFunction()) return; // if in a global init, skip - we already handled that.
+    if (!originallyI64Globals.count(curr->name)) return;
+    curr->type = i32;
+    TempVar highBits = getTemp();
+    SetLocal *setHighBits = builder->makeSetLocal(
+      highBits,
+      builder->makeGetGlobal(
+        makeHighName(curr->name),
+        i32
+      )
+    );
+    Block* result = builder->blockify(setHighBits, curr);
+    replaceCurrent(result);
+    setOutParam(result, std::move(highBits));
   }
 
   void visitSetGlobal(SetGlobal* curr) {
-    if (curr->type != i64) return;
-    assert(false && "SetGlobal not implemented");
+    if (!originallyI64Globals.count(curr->name)) return;
+    TempVar highBits = fetchOutParam(curr->value);
+    auto* setHigh = builder->makeSetGlobal(
+      makeHighName(curr->name),
+      builder->makeGetLocal(highBits, i32)
+    );
+    replaceCurrent(builder->makeSequence(curr, setHigh));
   }
 
   void visitLoad(Load* curr) {
@@ -526,6 +556,7 @@ struct I64ToI32Lowering : public WalkerPass<PostWalker<I64ToI32Lowering>> {
   }
 
   void visitConst(Const* curr) {
+    if (!getFunction()) return; // if in a global init, skip - we already handled that.
     if (curr->type != i64) return;
     TempVar highBits = getTemp();
     Const* lowVal = builder->makeConst(
@@ -1606,6 +1637,7 @@ private:
   std::unordered_map<Expression*, TempVar> highBitVars;
   std::unordered_map<Name, TempVar> labelHighBitVars;
   std::unordered_map<Index, Type> tempTypes;
+  std::unordered_set<Name> originallyI64Globals;
   Index nextTemp;
 
   TempVar getTemp(Type ty = i32) {
diff --git a/src/wasm/wasm.cpp b/src/wasm/wasm.cpp
index 8b8285e35..519814cb7 100644
--- a/src/wasm/wasm.cpp
+++ b/src/wasm/wasm.cpp
@@ -907,7 +907,9 @@ Global* Module::addGlobal(Global* curr) {
   if (getGlobalOrNull(curr->name)) {
     Fatal() << "Module::addGlobal: " << curr->name << " already exists";
   }
-  globals.push_back(std::unique_ptr<Global>(curr));
+
+  globals.emplace_back(curr);
+
   globalsMap[curr->name] = curr;
   return curr;
 }
diff --git a/src/wasm2js.h b/src/wasm2js.h
index 927dbac24..ee682f58d 100644
--- a/src/wasm2js.h
+++ b/src/wasm2js.h
@@ -638,6 +638,13 @@ void Wasm2JSBuilder::addGlobal(Ref ast, Global* global) {
       fromName(global->name, NameScope::Top),
       theValue
     );
+  } else if (auto* get = global->init->dynCast<GetGlobal>()) {
+    Ref theVar = ValueBuilder::makeVar();
+    ast->push_back(theVar);
+    ValueBuilder::appendToVar(theVar,
+      fromName(global->name, NameScope::Top),
+      ValueBuilder::makeName(fromName(get->name, NameScope::Top))
+    );
   } else {
     assert(false && "Top init type not supported");
   }
diff --git a/test/passes/flatten_i64-to-i32-lowering.txt b/test/passes/flatten_i64-to-i32-lowering.txt
index 3c3535e53..6863be7e8 100644
--- a/test/passes/flatten_i64-to-i32-lowering.txt
+++ b/test/passes/flatten_i64-to-i32-lowering.txt
@@ -79,3 +79,61 @@
   )
  )
 )
+(module
+ (type $0 (func (param i32 i32)))
+ (type $1 (func))
+ (global $f (mut i32) (i32.const -1412567121))
+ (global $g (mut i32) (global.get $f))
+ (global $f$hi (mut i32) (i32.const 305419896))
+ (global $g$hi (mut i32) (global.get $f$hi))
+ (global $i64toi32_i32$HIGH_BITS (mut i32) (i32.const 0))
+ (export "exp" (func $1))
+ (func $call (; 0 ;) (type $0) (param $0 i32) (param $0$hi i32)
+  (nop)
+ )
+ (func $1 (; 1 ;) (type $1)
+  (local $0 i32)
+  (local $0$hi i32)
+  (local $i64toi32_i32$0 i32)
+  (block
+   (block
+    (local.set $0
+     (block (result i32)
+      (local.set $i64toi32_i32$0
+       (global.get $f$hi)
+      )
+      (global.get $f)
+     )
+    )
+    (local.set $0$hi
+     (local.get $i64toi32_i32$0)
+    )
+   )
+   (call $call
+    (block (result i32)
+     (local.set $i64toi32_i32$0
+      (local.get $0$hi)
+     )
+     (local.get $0)
+    )
+    (local.get $i64toi32_i32$0)
+   )
+   (nop)
+   (block
+    (global.set $f
+     (block (result i32)
+      (local.set $i64toi32_i32$0
+       (i32.const 287454020)
+      )
+      (i32.const 1432778632)
+     )
+    )
+    (global.set $f$hi
+     (local.get $i64toi32_i32$0)
+    )
+   )
+   (nop)
+  )
+  (nop)
+ )
+)
diff --git a/test/passes/flatten_i64-to-i32-lowering.wast b/test/passes/flatten_i64-to-i32-lowering.wast
index 179cac467..def4f3a34 100644
--- a/test/passes/flatten_i64-to-i32-lowering.wast
+++ b/test/passes/flatten_i64-to-i32-lowering.wast
@@ -4,4 +4,12 @@
     (i64.add (i64.const 1) (i64.const 2))
   )
 )
-
+(module
+ (global $f (mut i64) (i64.const 0x12345678ABCDEFAF))
+ (global $g (mut i64) (global.get $f))
+ (func $call (param i64))
+ (func "exp"
+  (call $call (global.get $f))
+  (global.set $f (i64.const 0x1122334455667788))
+ )
+)
diff --git a/test/wasm2js/global_i64.2asm.js b/test/wasm2js/global_i64.2asm.js
new file mode 100644
index 000000000..8b279f956
--- /dev/null
+++ b/test/wasm2js/global_i64.2asm.js
@@ -0,0 +1,51 @@
+
+function asmFunc(global, env, buffer) {
+ "use asm";
+ var HEAP8 = new global.Int8Array(buffer);
+ var HEAP16 = new global.Int16Array(buffer);
+ var HEAP32 = new global.Int32Array(buffer);
+ var HEAPU8 = new global.Uint8Array(buffer);
+ var HEAPU16 = new global.Uint16Array(buffer);
+ var HEAPU32 = new global.Uint32Array(buffer);
+ var HEAPF32 = new global.Float32Array(buffer);
+ var HEAPF64 = new global.Float64Array(buffer);
+ var Math_imul = global.Math.imul;
+ var Math_fround = global.Math.fround;
+ var Math_abs = global.Math.abs;
+ var Math_clz32 = global.Math.clz32;
+ var Math_min = global.Math.min;
+ var Math_max = global.Math.max;
+ var Math_floor = global.Math.floor;
+ var Math_ceil = global.Math.ceil;
+ var Math_sqrt = global.Math.sqrt;
+ var abort = env.abort;
+ var nan = global.NaN;
+ var infinity = global.Infinity;
+ var f = 2882400175;
+ var g = f;
+ var f$hi = 305419896;
+ var g$hi = f$hi;
+ var i64toi32_i32$HIGH_BITS = 0;
+ function call($0, $0$hi) {
+  $0 = $0 | 0;
+  $0$hi = $0$hi | 0;
+ }
+ 
+ function $1() {
+  var i64toi32_i32$0 = 0;
+  i64toi32_i32$0 = f$hi;
+  call(f | 0, i64toi32_i32$0 | 0);
+  i64toi32_i32$0 = 287454020;
+  f = 1432778632;
+  f$hi = i64toi32_i32$0;
+ }
+ 
+ var FUNCTION_TABLE = [];
+ return {
+  exp: $1
+ };
+}
+
+const memasmFunc = new ArrayBuffer(65536);
+const retasmFunc = asmFunc({Math,Int8Array,Uint8Array,Int16Array,Uint16Array,Int32Array,Uint32Array,Float32Array,Float64Array,NaN,Infinity}, {abort:function() { throw new Error('abort'); }},memasmFunc);
+export const exp = retasmFunc.exp;
diff --git a/test/wasm2js/global_i64.wast b/test/wasm2js/global_i64.wast
new file mode 100644
index 000000000..99fa419c1
--- /dev/null
+++ b/test/wasm2js/global_i64.wast
@@ -0,0 +1,9 @@
+(module
+ (global $f (mut i64) (i64.const 0x12345678ABCDEFAF))
+ (global $g (mut i64) (global.get $f))
+ (func $call (param i64))
+ (func "exp"
+  (call $call (global.get $f))
+  (global.set $f (i64.const 0x1122334455667788))
+ )
+)