[wasm] Int64Lowering of Int64Mul on ia32 and arm.

src/compiler/ia32/instruction-selector-ia32.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/base/adapters.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
 namespace v8 {
@@ skipping 601 matching lines @@
 
   InstructionOperand outputs[] = {
       g.DefineSameAsFirst(node),
       g.DefineAsRegister(NodeProperties::FindProjection(node, 1))};
 
   InstructionOperand temps[] = {g.TempRegister()};
 
   Emit(kIA32SubPair, 2, outputs, 4, inputs, 1, temps);
 }
 
+void InstructionSelector::VisitInt32PairMul(Node* node) {
+  IA32OperandGenerator g(this);
+
+  // InputAt(3) explicitly shares ecx with OutputRegister(1) to save one
+  // register and one mov instruction.
+  InstructionOperand inputs[] = {
+      g.UseUnique(node->InputAt(0)), g.UseUnique(node->InputAt(1)),
+      g.UseUniqueRegister(node->InputAt(2)), g.UseFixed(node->InputAt(3), ecx)};
+
+  InstructionOperand outputs[] = {
+      g.DefineAsFixed(node, eax),
+      g.DefineAsFixed(NodeProperties::FindProjection(node, 1), ecx)};
+
+  InstructionOperand temps[] = {g.TempRegister(edx)};
+
+  Emit(kIA32MulPair, 2, outputs, 4, inputs, 1, temps);
+}
+
 void InstructionSelector::VisitWord32PairShl(Node* node) {
   IA32OperandGenerator g(this);
 
   Node* shift = node->InputAt(2);
   InstructionOperand shift_operand;
   if (g.CanBeImmediate(shift)) {
     shift_operand = g.UseImmediate(shift);
   } else {
     shift_operand = g.UseFixed(shift, ecx);
   }
@@ skipping 909 matching lines @@
              MachineOperatorBuilder::kFloat64RoundTruncate |
              MachineOperatorBuilder::kFloat32RoundTiesEven |
              MachineOperatorBuilder::kFloat64RoundTiesEven;
   }
   return flags;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8