Add HLoadRoot hydrogen instruction.

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/23601038

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16807 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/lithium-arm.cc

@@ -2169,6 +2169,11 @@ LInstruction* LChunkBuilder::DoLoadFunctionPrototype(
 }
 
 
+LInstruction* LChunkBuilder::DoLoadRoot(HLoadRoot* instr) {
+  return DefineAsRegister(new(zone()) LLoadRoot);
+}
+
+
 LInstruction* LChunkBuilder::DoLoadExternalArrayPointer(
     HLoadExternalArrayPointer* instr) {
   LOperand* input = UseRegisterAtStart(instr->value());

src/arm/lithium-arm.h

@@ -119,6 +119,7 @@ class LCodeGen;
   V(LazyBailout)                                \
   V(LoadContextSlot)                            \
   V(LoadExternalArrayPointer)                   \
+  V(LoadRoot)                                   \
   V(LoadFieldByIndex)                           \
   V(LoadFunctionPrototype)                      \
   V(LoadGlobalCell)                             \
@@ -1579,6 +1580,15 @@ class LLoadFunctionPrototype V8_FINAL : public LTemplateInstruction<1, 1, 0> {
 };
 
 
+class LLoadRoot V8_FINAL : public LTemplateInstruction<1, 0, 0> {
+ public:
+  DECLARE_CONCRETE_INSTRUCTION(LoadRoot, "load-root")
+  DECLARE_HYDROGEN_ACCESSOR(LoadRoot)
+
+  Heap::RootListIndex index() const { return hydrogen()->index(); }
+};
+
+
 class LLoadExternalArrayPointer V8_FINAL
     : public LTemplateInstruction<1, 1, 0> {
  public:

src/arm/lithium-codegen-arm.cc

@@ -3149,6 +3149,12 @@ void LCodeGen::DoLoadFunctionPrototype(LLoadFunctionPrototype* instr) {
 }
 
 
+void LCodeGen::DoLoadRoot(LLoadRoot* instr) {
+  Register result = ToRegister(instr->result());
+  __ LoadRoot(result, instr->index());
+}
+
+
 void LCodeGen::DoLoadExternalArrayPointer(
     LLoadExternalArrayPointer* instr) {
   Register to_reg = ToRegister(instr->result());

src/hydrogen-instructions.h

@@ -142,6 +142,7 @@ class LChunkBuilder;
   V(LoadKeyedGeneric)                          \
   V(LoadNamedField)                            \
   V(LoadNamedGeneric)                          \
+  V(LoadRoot)                                  \
   V(MapEnumLength)                             \
   V(MathFloorOfDiv)                            \
   V(MathMinMax)                                \
@@ -2514,6 +2515,40 @@ class HUnaryMathOperation V8_FINAL : public HTemplateInstruction<2> {
 };
 
 
+class HLoadRoot V8_FINAL : public HTemplateInstruction<0> {
+ public:
+  DECLARE_INSTRUCTION_FACTORY_P1(HLoadRoot, Heap::RootListIndex);
+  DECLARE_INSTRUCTION_FACTORY_P2(HLoadRoot, Heap::RootListIndex, HType);
+
+  virtual Representation RequiredInputRepresentation(int index) V8_OVERRIDE {
+    return Representation::None();
+  }
+
+  Heap::RootListIndex index() const { return index_; }
+
+  DECLARE_CONCRETE_INSTRUCTION(LoadRoot)
+
+ protected:
+  virtual bool DataEquals(HValue* other) V8_OVERRIDE {
+    HLoadRoot* b = HLoadRoot::cast(other);
+    return index_ == b->index_;
+  }
+
+ private:
+  HLoadRoot(Heap::RootListIndex index, HType type = HType::Tagged())
+      : HTemplateInstruction<0>(type), index_(index) {
+    SetFlag(kUseGVN);
+    // TODO(bmeurer): We'll need kDependsOnRoots once we add the
+    // corresponding HStoreRoot instruction.
+    SetGVNFlag(kDependsOnCalls);
+  }
+
+  virtual bool IsDeletable() const V8_OVERRIDE { return true; }
+
+  const Heap::RootListIndex index_;
+};
+
+
 class HLoadExternalArrayPointer V8_FINAL : public HUnaryOperation {
  public:
   DECLARE_INSTRUCTION_FACTORY_P1(HLoadExternalArrayPointer, HValue*);

src/ia32/lithium-codegen-ia32.cc

@@ -3365,6 +3365,12 @@ void LCodeGen::DoLoadFunctionPrototype(LLoadFunctionPrototype* instr) {
 }
 
 
+void LCodeGen::DoLoadRoot(LLoadRoot* instr) {
+  Register result = ToRegister(instr->result());
+  __ LoadRoot(result, instr->index());
+}
+
+
 void LCodeGen::DoLoadExternalArrayPointer(
     LLoadExternalArrayPointer* instr) {
   Register result = ToRegister(instr->result());

src/ia32/lithium-ia32.cc

@@ -2202,6 +2202,11 @@ LInstruction* LChunkBuilder::DoLoadFunctionPrototype(
 }
 
 
+LInstruction* LChunkBuilder::DoLoadRoot(HLoadRoot* instr) {
+  return DefineAsRegister(new(zone()) LLoadRoot);
+}
+
+
 LInstruction* LChunkBuilder::DoLoadExternalArrayPointer(
     HLoadExternalArrayPointer* instr) {
   LOperand* input = UseRegisterAtStart(instr->value());

src/ia32/lithium-ia32.h

@@ -129,6 +129,7 @@ class LCodeGen;
   V(LoadKeyedGeneric)                           \
   V(LoadNamedField)                             \
   V(LoadNamedGeneric)                           \
+  V(LoadRoot)                                   \
   V(MapEnumLength)                              \
   V(MathAbs)                                    \
   V(MathCos)                                    \
@@ -1591,6 +1592,15 @@ class LLoadFunctionPrototype V8_FINAL : public LTemplateInstruction<1, 1, 1> {
 };
 
 
+class LLoadRoot V8_FINAL : public LTemplateInstruction<1, 0, 0> {
+ public:
+  DECLARE_CONCRETE_INSTRUCTION(LoadRoot, "load-root")
+  DECLARE_HYDROGEN_ACCESSOR(LoadRoot)
+
+  Heap::RootListIndex index() const { return hydrogen()->index(); }
+};
+
+
 class LLoadExternalArrayPointer V8_FINAL
     : public LTemplateInstruction<1, 1, 0> {
  public:

src/x64/lithium-codegen-x64.cc

@@ -2869,6 +2869,12 @@ void LCodeGen::DoLoadFunctionPrototype(LLoadFunctionPrototype* instr) {
 }
 
 
+void LCodeGen::DoLoadRoot(LLoadRoot* instr) {
+  Register result = ToRegister(instr->result());
+  __ LoadRoot(result, instr->index());
+}
+
+
 void LCodeGen::DoLoadExternalArrayPointer(
     LLoadExternalArrayPointer* instr) {
   Register result = ToRegister(instr->result());

src/x64/lithium-x64.cc

@@ -2069,6 +2069,11 @@ LInstruction* LChunkBuilder::DoLoadFunctionPrototype(
 }
 
 
+LInstruction* LChunkBuilder::DoLoadRoot(HLoadRoot* instr) {
+  return DefineAsRegister(new(zone()) LLoadRoot);
+}
+
+
 LInstruction* LChunkBuilder::DoLoadExternalArrayPointer(
     HLoadExternalArrayPointer* instr) {
   LOperand* input = UseRegisterAtStart(instr->value());

src/x64/lithium-x64.h

@@ -119,6 +119,7 @@ class LCodeGen;
   V(LazyBailout)                                \
   V(LoadContextSlot)                            \
   V(LoadExternalArrayPointer)                   \
+  V(LoadRoot)                                   \
   V(LoadFieldByIndex)                           \
   V(LoadFunctionPrototype)                      \
   V(LoadGlobalCell)                             \
@@ -1521,6 +1522,15 @@ class LLoadFunctionPrototype V8_FINAL : public LTemplateInstruction<1, 1, 0> {
 };
 
 
+class LLoadRoot V8_FINAL : public LTemplateInstruction<1, 0, 0> {
+ public:
+  DECLARE_CONCRETE_INSTRUCTION(LoadRoot, "load-root")
+  DECLARE_HYDROGEN_ACCESSOR(LoadRoot)
+
+  Heap::RootListIndex index() const { return hydrogen()->index(); }
+};
+
+
 class LLoadExternalArrayPointer V8_FINAL
     : public LTemplateInstruction<1, 1, 0> {
  public: