[wasm] Int64Lowering of Int64Sub on ia32 and arm.

src/compiler/arm/instruction-selector-arm.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/base/bits.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
@@ skipping 766 matching lines @@
                                  g.UseUniqueRegister(node->InputAt(2)),
                                  g.UseUniqueRegister(node->InputAt(3))};
 
   InstructionOperand outputs[] = {
       g.DefineAsRegister(node),
       g.DefineAsRegister(NodeProperties::FindProjection(node, 1))};
 
   Emit(kArmAddPair, 2, outputs, 4, inputs);
 }
 
+void InstructionSelector::VisitInt32PairSub(Node* node) {
+  ArmOperandGenerator g(this);
+
+  // We use UseUniqueRegister here to avoid register sharing with the output
+  // register.
+  InstructionOperand inputs[] = {
+      g.UseRegister(node->InputAt(0)), g.UseUniqueRegister(node->InputAt(1)),
+      g.UseRegister(node->InputAt(2)), g.UseUniqueRegister(node->InputAt(3))};
+
+  InstructionOperand outputs[] = {
+      g.DefineAsRegister(node),
+      g.DefineAsRegister(NodeProperties::FindProjection(node, 1))};
+
+  Emit(kArmSubPair, 2, outputs, 4, inputs);
+}
+
 void InstructionSelector::VisitWord32PairShl(Node* node) {
   ArmOperandGenerator g(this);
   Int32Matcher m(node->InputAt(2));
   InstructionOperand shift_operand;
   if (m.HasValue()) {
     shift_operand = g.UseImmediate(m.node());
   } else {
     shift_operand = g.UseUniqueRegister(m.node());
   }
 
@@ skipping 955 matching lines @@
              MachineOperatorBuilder::kFloat64RoundTiesAway |
              MachineOperatorBuilder::kFloat32RoundTiesEven |
              MachineOperatorBuilder::kFloat64RoundTiesEven;
   }
   return flags;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8