MIPS: Replace LoadNamedFieldPolymorphic with explicit branches.

Port r16133 (dce32514)

BUG=

Review URL: https://codereview.chromium.org/22255005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16151 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/lithium-codegen-mips.cc

@@ -2921,90 +2921,6 @@ void LCodeGen::DoLoadNamedField(LLoadNamedField* instr) {
 }
 
 
-void LCodeGen::EmitLoadFieldOrConstantFunction(Register result,
-                                               Register object,
-                                               Handle<Map> type,
-                                               Handle<String> name,
-                                               LEnvironment* env) {
-  LookupResult lookup(isolate());
-  type->LookupDescriptor(NULL, *name, &lookup);
-  ASSERT(lookup.IsFound() || lookup.IsCacheable());
-  if (lookup.IsField()) {
-    int index = lookup.GetLocalFieldIndexFromMap(*type);
-    int offset = index * kPointerSize;
-    if (index < 0) {
-      // Negative property indices are in-object properties, indexed
-      // from the end of the fixed part of the object.
-      __ lw(result, FieldMemOperand(object, offset + type->instance_size()));
-    } else {
-      // Non-negative property indices are in the properties array.
-      __ lw(result, FieldMemOperand(object, JSObject::kPropertiesOffset));
-      __ lw(result, FieldMemOperand(result, offset + FixedArray::kHeaderSize));
-    }
-  } else if (lookup.IsConstant()) {
-    Handle<Object> constant(lookup.GetConstantFromMap(*type), isolate());
-    __ LoadObject(result, constant);
-  } else {
-    // Negative lookup.
-    // Check prototypes.
-    Handle<HeapObject> current(HeapObject::cast((*type)->prototype()));
-    Heap* heap = type->GetHeap();
-    while (*current != heap->null_value()) {
-      __ LoadHeapObject(result, current);
-      __ lw(result, FieldMemOperand(result, HeapObject::kMapOffset));
-      DeoptimizeIf(ne, env, result, Operand(Handle<Map>(current->map())));
-      current =
-          Handle<HeapObject>(HeapObject::cast(current->map()->prototype()));
-    }
-    __ LoadRoot(result, Heap::kUndefinedValueRootIndex);
-  }
-}
-
-
-void LCodeGen::DoLoadNamedFieldPolymorphic(LLoadNamedFieldPolymorphic* instr) {
-  Register object = ToRegister(instr->object());
-  Register result = ToRegister(instr->result());
-  Register object_map = scratch0();
-
-  int map_count = instr->hydrogen()->types()->length();
-  bool need_generic = instr->hydrogen()->need_generic();
-
-  if (map_count == 0 && !need_generic) {
-    DeoptimizeIf(al, instr->environment());
-    return;
-  }
-  Handle<String> name = instr->hydrogen()->name();
-  Label done;
-  __ lw(object_map, FieldMemOperand(object, HeapObject::kMapOffset));
-  for (int i = 0; i < map_count; ++i) {
-    bool last = (i == map_count - 1);
-    Handle<Map> map = instr->hydrogen()->types()->at(i);
-    Label check_passed;
-    __ CompareMapAndBranch(object_map, map, &check_passed, eq, &check_passed);
-    if (last && !need_generic) {
-      DeoptimizeIf(al, instr->environment());
-      __ bind(&check_passed);
-      EmitLoadFieldOrConstantFunction(
-          result, object, map, name, instr->environment());
-    } else {
-      Label next;
-      __ Branch(&next);
-      __ bind(&check_passed);
-      EmitLoadFieldOrConstantFunction(
-          result, object, map, name, instr->environment());
-      __ Branch(&done);
-      __ bind(&next);
-    }
-  }
-  if (need_generic) {
-    __ li(a2, Operand(name));
-    Handle<Code> ic = isolate()->builtins()->LoadIC_Initialize();
-    CallCode(ic, RelocInfo::CODE_TARGET, instr);
-  }
-  __ bind(&done);
-}
-
-
 void LCodeGen::DoLoadNamedGeneric(LLoadNamedGeneric* instr) {
   ASSERT(ToRegister(instr->object()).is(a0));
   ASSERT(ToRegister(instr->result()).is(v0));

src/mips/lithium-codegen-mips.h

@@ -378,12 +378,6 @@ class LCodeGen BASE_EMBEDDED {
   // Caller should branch on equal condition.
   void EmitIsConstructCall(Register temp1, Register temp2);
 
-  void EmitLoadFieldOrConstantFunction(Register result,
-                                       Register object,
-                                       Handle<Map> type,
-                                       Handle<String> name,
-                                       LEnvironment* env);
-
   // Emits optimized code to deep-copy the contents of statically known
   // object graphs (e.g. object literal boilerplate).
   void EmitDeepCopy(Handle<JSObject> object,

src/mips/lithium-mips.cc

@@ -2067,23 +2067,6 @@ LInstruction* LChunkBuilder::DoLoadNamedField(HLoadNamedField* instr) {
 }
 
 
-LInstruction* LChunkBuilder::DoLoadNamedFieldPolymorphic(
-    HLoadNamedFieldPolymorphic* instr) {
-  ASSERT(instr->representation().IsTagged());
-  if (instr->need_generic()) {
-    LOperand* obj = UseFixed(instr->object(), a0);
-    LLoadNamedFieldPolymorphic* result =
-        new(zone()) LLoadNamedFieldPolymorphic(obj);
-    return MarkAsCall(DefineFixed(result, v0), instr);
-  } else {
-    LOperand* obj = UseRegisterAtStart(instr->object());
-    LLoadNamedFieldPolymorphic* result =
-        new(zone()) LLoadNamedFieldPolymorphic(obj);
-    return AssignEnvironment(DefineAsRegister(result));
-  }
-}
-
-
 LInstruction* LChunkBuilder::DoLoadNamedGeneric(HLoadNamedGeneric* instr) {
   LOperand* object = UseFixed(instr->object(), a0);
   LInstruction* result = DefineFixed(new(zone()) LLoadNamedGeneric(object), v0);

src/mips/lithium-mips.h

@@ -126,7 +126,6 @@ class LCodeGen;
   V(LoadKeyed)                                  \
   V(LoadKeyedGeneric)                           \
   V(LoadNamedField)                             \
-  V(LoadNamedFieldPolymorphic)                  \
   V(LoadNamedGeneric)                           \
   V(MapEnumLength)                              \
   V(MathAbs)                                    \
@@ -1505,19 +1504,6 @@ class LLoadNamedField: public LTemplateInstruction<1, 1, 0> {
 };
 
 
-class LLoadNamedFieldPolymorphic: public LTemplateInstruction<1, 1, 0> {
- public:
-  explicit LLoadNamedFieldPolymorphic(LOperand* object) {
-    inputs_[0] = object;
-  }
-
-  LOperand* object() { return inputs_[0]; }
-
-  DECLARE_CONCRETE_INSTRUCTION(LoadNamedField, "load-named-field-polymorphic")
-  DECLARE_HYDROGEN_ACCESSOR(LoadNamedFieldPolymorphic)
-};
-
-
 class LLoadNamedGeneric: public LTemplateInstruction<1, 1, 0> {
  public:
   explicit LLoadNamedGeneric(LOperand* object) {