MIPS: [turbofan] Make Int32Div and Uint32Div safe.

src/compiler/mips64/instruction-selector-mips64.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 653 matching lines @@
       Int64BinopMatcher rightInput(right), leftInput(left);
       if (rightInput.right().Is(32) && leftInput.right().Is(32)) {
         // Combine both shifted operands with Ddiv.
         Emit(kMips64Ddiv, g.DefineSameAsFirst(node),
              g.UseRegister(leftInput.left().node()),
              g.UseRegister(rightInput.left().node()));
         return;
       }
     }
   }
-  Emit(kMips64Div, g.DefineAsRegister(node), g.UseRegister(m.left().node()),
+  Emit(kMips64Div, g.DefineSameAsFirst(node), g.UseRegister(m.left().node()),
        g.UseRegister(m.right().node()));
 }
 
 
 void InstructionSelector::VisitUint32Div(Node* node) {
   Mips64OperandGenerator g(this);
   Int32BinopMatcher m(node);
-  Emit(kMips64DivU, g.DefineAsRegister(node), g.UseRegister(m.left().node()),
+  Emit(kMips64DivU, g.DefineSameAsFirst(node), g.UseRegister(m.left().node()),
        g.UseRegister(m.right().node()));
 }
 
 
 void InstructionSelector::VisitInt32Mod(Node* node) {
   Mips64OperandGenerator g(this);
   Int32BinopMatcher m(node);
   Node* left = node->InputAt(0);
   Node* right = node->InputAt(1);
   if (CanCover(node, left) && CanCover(node, right)) {
@@ skipping 18 matching lines @@
   Mips64OperandGenerator g(this);
   Int32BinopMatcher m(node);
   Emit(kMips64ModU, g.DefineAsRegister(node), g.UseRegister(m.left().node()),
        g.UseRegister(m.right().node()));
 }
 
 
 void InstructionSelector::VisitInt64Div(Node* node) {
   Mips64OperandGenerator g(this);
   Int64BinopMatcher m(node);
-  Emit(kMips64Ddiv, g.DefineAsRegister(node), g.UseRegister(m.left().node()),
+  Emit(kMips64Ddiv, g.DefineSameAsFirst(node), g.UseRegister(m.left().node()),
        g.UseRegister(m.right().node()));
 }
 
 
 void InstructionSelector::VisitUint64Div(Node* node) {
   Mips64OperandGenerator g(this);
   Int64BinopMatcher m(node);
-  Emit(kMips64DdivU, g.DefineAsRegister(node), g.UseRegister(m.left().node()),
+  Emit(kMips64DdivU, g.DefineSameAsFirst(node), g.UseRegister(m.left().node()),
        g.UseRegister(m.right().node()));
 }
 
 
 void InstructionSelector::VisitInt64Mod(Node* node) {
   Mips64OperandGenerator g(this);
   Int64BinopMatcher m(node);
   Emit(kMips64Dmod, g.DefineAsRegister(node), g.UseRegister(m.left().node()),
        g.UseRegister(m.right().node()));
 }
@@ skipping 906 matching lines @@
   Node* right = node->InputAt(1);
   Emit(kMips64Float64InsertHighWord32, g.DefineSameAsFirst(node),
        g.UseRegister(left), g.UseRegister(right));
 }
 
 
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
   return MachineOperatorBuilder::kWord32ShiftIsSafe |
+         MachineOperatorBuilder::kInt32DivIsSafe |
+         MachineOperatorBuilder::kUint32DivIsSafe |
          MachineOperatorBuilder::kFloat64Min |
          MachineOperatorBuilder::kFloat64Max |
          MachineOperatorBuilder::kFloat32Min |
          MachineOperatorBuilder::kFloat32Max |
          MachineOperatorBuilder::kFloat64RoundDown |
          MachineOperatorBuilder::kFloat32RoundDown |
          MachineOperatorBuilder::kFloat64RoundUp |
          MachineOperatorBuilder::kFloat32RoundUp |
          MachineOperatorBuilder::kFloat64RoundTruncate |
          MachineOperatorBuilder::kFloat32RoundTruncate |
          MachineOperatorBuilder::kFloat64RoundTiesEven |
          MachineOperatorBuilder::kFloat32RoundTiesEven;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8