Compare IC: add SYMBOLS state.

Review URL: http://codereview.chromium.org/6960011

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7824 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/code-stubs-arm.cc

@@ -5961,6 +5961,44 @@ void ICCompareStub::GenerateHeapNumbers(MacroAssembler* masm) {
 }
 
 
+void ICCompareStub::GenerateSymbols(MacroAssembler* masm) {
+  ASSERT(state_ == CompareIC::SYMBOLS);
+  Label miss;
+
+  // Registers containing left and right operands respectively.
+  Register left = r1;
+  Register right = r0;
+  Register tmp1 = r2;
+  Register tmp2 = r3;
+
+  // Check that both operands are heap objects.
+  __ JumpIfEitherSmi(left, right, &miss);
+
+  // Check that both operands are symbols.
+  __ ldr(tmp1, FieldMemOperand(left, HeapObject::kMapOffset));
+  __ ldr(tmp2, FieldMemOperand(right, HeapObject::kMapOffset));
+  __ ldrb(tmp1, FieldMemOperand(tmp1, Map::kInstanceTypeOffset));
+  __ ldrb(tmp2, FieldMemOperand(tmp2, Map::kInstanceTypeOffset));
+  STATIC_ASSERT(kSymbolTag != 0);
+  __ and_(tmp1, tmp1, Operand(tmp2));
+  __ tst(tmp1, Operand(kIsSymbolMask));
+  __ b(eq, &miss);
+
+  // Symbols are compared by identity.
+  __ cmp(left, right);
+  // Make sure r0 is non-zero. At this point input operands are
+  // guaranteed to be non-zero.
+  ASSERT(right.is(r0));
+  STATIC_ASSERT(EQUAL == 0);
+  STATIC_ASSERT(kSmiTag == 0);
+  __ mov(r0, Operand(Smi::FromInt(EQUAL)), LeaveCC, eq);
+  __ Ret();
+
+  __ bind(&miss);
+  GenerateMiss(masm);
+}
+
+
 void ICCompareStub::GenerateStrings(MacroAssembler* masm) {
   ASSERT(state_ == CompareIC::STRINGS);
   Label miss;

src/code-stubs.cc

@@ -200,6 +200,9 @@ void ICCompareStub::Generate(MacroAssembler* masm) {
     case CompareIC::STRINGS:
       GenerateStrings(masm);
       break;
+    case CompareIC::SYMBOLS:
+      GenerateSymbols(masm);
+      break;
     case CompareIC::OBJECTS:
       GenerateObjects(masm);
       break;

src/code-stubs.h

@@ -426,6 +426,7 @@ class ICCompareStub: public CodeStub {
 
   void GenerateSmis(MacroAssembler* masm);
   void GenerateHeapNumbers(MacroAssembler* masm);
+  void GenerateSymbols(MacroAssembler* masm);
   void GenerateStrings(MacroAssembler* masm);
   void GenerateObjects(MacroAssembler* masm);
   void GenerateMiss(MacroAssembler* masm);

src/ia32/code-stubs-ia32.cc

@@ -5854,6 +5854,52 @@ void ICCompareStub::GenerateHeapNumbers(MacroAssembler* masm) {
 }
 
 
+void ICCompareStub::GenerateSymbols(MacroAssembler* masm) {
+  ASSERT(state_ == CompareIC::SYMBOLS);
+  ASSERT(GetCondition() == equal);
+
+  // Registers containing left and right operands respectively.
+  Register left = edx;
+  Register right = eax;
+  Register tmp1 = ecx;
+  Register tmp2 = ebx;
+
+  // Check that both operands are heap objects.
+  NearLabel miss;
+  __ mov(tmp1, Operand(left));
+  STATIC_ASSERT(kSmiTag == 0);
+  __ and_(tmp1, Operand(right));
+  __ test(tmp1, Immediate(kSmiTagMask));
+  __ j(zero, &miss);
+
+  // Check that both operands are symbols.
+  __ mov(tmp1, FieldOperand(left, HeapObject::kMapOffset));
+  __ mov(tmp2, FieldOperand(right, HeapObject::kMapOffset));
+  __ movzx_b(tmp1, FieldOperand(tmp1, Map::kInstanceTypeOffset));
+  __ movzx_b(tmp2, FieldOperand(tmp2, Map::kInstanceTypeOffset));
+  STATIC_ASSERT(kSymbolTag != 0);
+  __ and_(tmp1, Operand(tmp2));
+  __ test(tmp1, Immediate(kIsSymbolMask));
+  __ j(zero, &miss);
+
+  // Symbols are compared by identity.
+  NearLabel done;
+  __ cmp(left, Operand(right));
+  // Make sure eax is non-zero. At this point input operands are
+  // guaranteed to be non-zero.
+  ASSERT(right.is(eax));
+  __ j(not_equal, &done);
+  STATIC_ASSERT(EQUAL == 0);
+  STATIC_ASSERT(kSmiTag == 0);
+  __ Set(eax, Immediate(Smi::FromInt(EQUAL)));
+  __ bind(&done);
+  __ ret(0);
+
+  __ bind(&miss);
+  GenerateMiss(masm);
+}
+
+
 void ICCompareStub::GenerateStrings(MacroAssembler* masm) {
   ASSERT(state_ == CompareIC::STRINGS);
   ASSERT(GetCondition() == equal);

src/ic.cc

@@ -2141,6 +2141,7 @@ const char* CompareIC::GetStateName(State state) {
     case SMIS: return "SMIS";
     case HEAP_NUMBERS: return "HEAP_NUMBERS";
     case OBJECTS: return "OBJECTS";
+    case SYMBOLS: return "SYMBOLS";
     case STRINGS: return "STRINGS";
     case GENERIC: return "GENERIC";
     default:
@@ -2154,12 +2155,16 @@ CompareIC::State CompareIC::TargetState(State state,
                                         bool has_inlined_smi_code,
                                         Handle<Object> x,
                                         Handle<Object> y) {
-  if (!has_inlined_smi_code && state != UNINITIALIZED) return GENERIC;
+  if (!has_inlined_smi_code && state != UNINITIALIZED && state != SYMBOLS) {
+    return GENERIC;
+  }
   if (state == UNINITIALIZED && x->IsSmi() && y->IsSmi()) return SMIS;
   if ((state == UNINITIALIZED || (state == SMIS && has_inlined_smi_code)) &&
       x->IsNumber() && y->IsNumber()) return HEAP_NUMBERS;
   if (op_ != Token::EQ && op_ != Token::EQ_STRICT) return GENERIC;
   if (state == UNINITIALIZED &&
+      x->IsSymbol() && y->IsSymbol()) return SYMBOLS;
+  if ((state == UNINITIALIZED || state == SYMBOLS) &&
       x->IsString() && y->IsString()) return STRINGS;
   if (state == UNINITIALIZED &&
       x->IsJSObject() && y->IsJSObject()) return OBJECTS;

src/ic.h

@@ -592,6 +592,7 @@ class CompareIC: public IC {
     UNINITIALIZED,
     SMIS,
     HEAP_NUMBERS,
+    SYMBOLS,
     STRINGS,
     OBJECTS,
     GENERIC

src/x64/code-stubs-x64.cc

@@ -4739,6 +4739,49 @@ void ICCompareStub::GenerateHeapNumbers(MacroAssembler* masm) {
 }
 
 
+void ICCompareStub::GenerateSymbols(MacroAssembler* masm) {
+  ASSERT(state_ == CompareIC::SYMBOLS);
+  ASSERT(GetCondition() == equal);
+
+  // Registers containing left and right operands respectively.
+  Register left = rdx;
+  Register right = rax;
+  Register tmp1 = rcx;
+  Register tmp2 = rbx;
+
+  // Check that both operands are heap objects.
+  NearLabel miss;
+  Condition cond = masm->CheckEitherSmi(left, right, tmp1);
+  __ j(cond, &miss);
+
+  // Check that both operands are symbols.
+  __ movq(tmp1, FieldOperand(left, HeapObject::kMapOffset));
+  __ movq(tmp2, FieldOperand(right, HeapObject::kMapOffset));
+  __ movzxbq(tmp1, FieldOperand(tmp1, Map::kInstanceTypeOffset));
+  __ movzxbq(tmp2, FieldOperand(tmp2, Map::kInstanceTypeOffset));
+  STATIC_ASSERT(kSymbolTag != 0);
+  __ and_(tmp1, tmp2);
+  __ testb(tmp1, Immediate(kIsSymbolMask));
+  __ j(zero, &miss);
+
+  // Symbols are compared by identity.
+  NearLabel done;
+  __ cmpq(left, right);
+  // Make sure rax is non-zero. At this point input operands are
+  // guaranteed to be non-zero.
+  ASSERT(right.is(rax));
+  __ j(not_equal, &done);
+  STATIC_ASSERT(EQUAL == 0);
+  STATIC_ASSERT(kSmiTag == 0);
+  __ Move(rax, Smi::FromInt(EQUAL));
+  __ bind(&done);
+  __ ret(0);
+
+  __ bind(&miss);
+  GenerateMiss(masm);
+}
+
+
 void ICCompareStub::GenerateStrings(MacroAssembler* masm) {
   ASSERT(state_ == CompareIC::STRINGS);
   ASSERT(GetCondition() == equal);
@@ -4764,7 +4807,7 @@ void ICCompareStub::GenerateStrings(MacroAssembler* masm) {
   __ movq(tmp3, tmp1);
   STATIC_ASSERT(kNotStringTag != 0);
   __ or_(tmp3, tmp2);
-  __ testl(tmp3, Immediate(kIsNotStringMask));
+  __ testb(tmp3, Immediate(kIsNotStringMask));
   __ j(not_zero, &miss);
 
   // Fast check for identical strings.
@@ -4784,7 +4827,7 @@ void ICCompareStub::GenerateStrings(MacroAssembler* masm) {
   NearLabel do_compare;
   STATIC_ASSERT(kSymbolTag != 0);
   __ and_(tmp1, tmp2);
-  __ testl(tmp1, Immediate(kIsSymbolMask));
+  __ testb(tmp1, Immediate(kIsSymbolMask));
   __ j(zero, &do_compare);
   // Make sure rax is non-zero. At this point input operands are
   // guaranteed to be non-zero.