From: palfia@homejinni.com <palfia@homejinni.com@ce2b1a6d-e550-0410-aec6-3dcde31c8c00>
Date: Thu, 20 Jun 2013 20:18:58 +0000 (+0000)
Subject: MIPS: Lithium codegen should not pass around block_ids.
X-Git-Tag: upstream/4.7.83~13740
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b58d0d2af70dd678e6c4ae6bbb4dc8761c12a9bf;p=platform%2Fupstream%2Fv8.git

MIPS: Lithium codegen should not pass around block_ids.

Port r15235 (95a844b)

Original commit message:
Rather encapsulate the basic block to assembly label mapping in the LInstruction.

BUG=

Review URL: https://codereview.chromium.org/17504002
Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15257 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
---

diff --git a/src/mips/lithium-codegen-mips.cc b/src/mips/lithium-codegen-mips.cc
index b255ed7..c50e066 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -1970,12 +1970,13 @@ int LCodeGen::GetNextEmittedBlock() const {
   return -1;
 }
 
-
-void LCodeGen::EmitBranch(int left_block, int right_block,
+template<class InstrType>
+void LCodeGen::EmitBranch(InstrType instr,
                           Condition cc, Register src1, const Operand& src2) {
+  int right_block = instr->FalseDestination(chunk_);
+  int left_block = instr->TrueDestination(chunk_);
+
   int next_block = GetNextEmittedBlock();
-  right_block = chunk_->LookupDestination(right_block);
-  left_block = chunk_->LookupDestination(left_block);
   if (right_block == left_block) {
     EmitGoto(left_block);
   } else if (left_block == next_block) {
@@ -1990,11 +1991,13 @@ void LCodeGen::EmitBranch(int left_block, int right_block,
 }
 
 
-void LCodeGen::EmitBranchF(int left_block, int right_block,
+template<class InstrType>
+void LCodeGen::EmitBranchF(InstrType instr,
                            Condition cc, FPURegister src1, FPURegister src2) {
+  int right_block = instr->FalseDestination(chunk_);
+  int left_block = instr->TrueDestination(chunk_);
+
   int next_block = GetNextEmittedBlock();
-  right_block = chunk_->LookupDestination(right_block);
-  left_block = chunk_->LookupDestination(left_block);
   if (right_block == left_block) {
     EmitGoto(left_block);
   } else if (left_block == next_block) {
@@ -2015,19 +2018,16 @@ void LCodeGen::DoDebugBreak(LDebugBreak* instr) {
 
 
 void LCodeGen::DoBranch(LBranch* instr) {
-  int true_block = chunk_->LookupDestination(instr->true_block_id());
-  int false_block = chunk_->LookupDestination(instr->false_block_id());
-
   Representation r = instr->hydrogen()->value()->representation();
   if (r.IsInteger32() || r.IsSmi()) {
     ASSERT(!info()->IsStub());
     Register reg = ToRegister(instr->value());
-    EmitBranch(true_block, false_block, ne, reg, Operand(zero_reg));
+    EmitBranch(instr, ne, reg, Operand(zero_reg));
   } else if (r.IsDouble()) {
     ASSERT(!info()->IsStub());
     DoubleRegister reg = ToDoubleRegister(instr->value());
     // Test the double value. Zero and NaN are false.
-    EmitBranchF(true_block, false_block, nue, reg, kDoubleRegZero);
+    EmitBranchF(instr, nue, reg, kDoubleRegZero);
   } else {
     ASSERT(r.IsTagged());
     Register reg = ToRegister(instr->value());
@@ -2035,14 +2035,11 @@ void LCodeGen::DoBranch(LBranch* instr) {
     if (type.IsBoolean()) {
       ASSERT(!info()->IsStub());
       __ LoadRoot(at, Heap::kTrueValueRootIndex);
-      EmitBranch(true_block, false_block, eq, reg, Operand(at));
+      EmitBranch(instr, eq, reg, Operand(at));
     } else if (type.IsSmi()) {
       ASSERT(!info()->IsStub());
-      EmitBranch(true_block, false_block, ne, reg, Operand(zero_reg));
+      EmitBranch(instr, ne, reg, Operand(zero_reg));
     } else {
-      Label* true_label = chunk_->GetAssemblyLabel(true_block);
-      Label* false_label = chunk_->GetAssemblyLabel(false_block);
-
       ToBooleanStub::Types expected = instr->hydrogen()->expected_input_types();
       // Avoid deopts in the case where we've never executed this path before.
       if (expected.IsEmpty()) expected = ToBooleanStub::all_types();
@@ -2050,25 +2047,25 @@ void LCodeGen::DoBranch(LBranch* instr) {
       if (expected.Contains(ToBooleanStub::UNDEFINED)) {
         // undefined -> false.
         __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
-        __ Branch(false_label, eq, reg, Operand(at));
+        __ Branch(instr->FalseLabel(chunk_), eq, reg, Operand(at));
       }
       if (expected.Contains(ToBooleanStub::BOOLEAN)) {
         // Boolean -> its value.
         __ LoadRoot(at, Heap::kTrueValueRootIndex);
-        __ Branch(true_label, eq, reg, Operand(at));
+        __ Branch(instr->TrueLabel(chunk_), eq, reg, Operand(at));
         __ LoadRoot(at, Heap::kFalseValueRootIndex);
-        __ Branch(false_label, eq, reg, Operand(at));
+        __ Branch(instr->FalseLabel(chunk_), eq, reg, Operand(at));
       }
       if (expected.Contains(ToBooleanStub::NULL_TYPE)) {
         // 'null' -> false.
         __ LoadRoot(at, Heap::kNullValueRootIndex);
-        __ Branch(false_label, eq, reg, Operand(at));
+        __ Branch(instr->FalseLabel(chunk_), eq, reg, Operand(at));
       }
 
       if (expected.Contains(ToBooleanStub::SMI)) {
         // Smis: 0 -> false, all other -> true.
-        __ Branch(false_label, eq, reg, Operand(zero_reg));
-        __ JumpIfSmi(reg, true_label);
+        __ Branch(instr->FalseLabel(chunk_), eq, reg, Operand(zero_reg));
+        __ JumpIfSmi(reg, instr->TrueLabel(chunk_));
       } else if (expected.NeedsMap()) {
         // If we need a map later and have a Smi -> deopt.
         __ And(at, reg, Operand(kSmiTagMask));
@@ -2082,14 +2079,15 @@ void LCodeGen::DoBranch(LBranch* instr) {
           // Undetectable -> false.
           __ lbu(at, FieldMemOperand(map, Map::kBitFieldOffset));
           __ And(at, at, Operand(1 << Map::kIsUndetectable));
-          __ Branch(false_label, ne, at, Operand(zero_reg));
+          __ Branch(instr->FalseLabel(chunk_), ne, at, Operand(zero_reg));
         }
       }
 
       if (expected.Contains(ToBooleanStub::SPEC_OBJECT)) {
         // spec object -> true.
         __ lbu(at, FieldMemOperand(map, Map::kInstanceTypeOffset));
-        __ Branch(true_label, ge, at, Operand(FIRST_SPEC_OBJECT_TYPE));
+        __ Branch(instr->TrueLabel(chunk_),
+                  ge, at, Operand(FIRST_SPEC_OBJECT_TYPE));
       }
 
       if (expected.Contains(ToBooleanStub::STRING)) {
@@ -2098,8 +2096,8 @@ void LCodeGen::DoBranch(LBranch* instr) {
         __ lbu(at, FieldMemOperand(map, Map::kInstanceTypeOffset));
         __ Branch(&not_string, ge , at, Operand(FIRST_NONSTRING_TYPE));
         __ lw(at, FieldMemOperand(reg, String::kLengthOffset));
-        __ Branch(true_label, ne, at, Operand(zero_reg));
-        __ Branch(false_label);
+        __ Branch(instr->TrueLabel(chunk_), ne, at, Operand(zero_reg));
+        __ Branch(instr->FalseLabel(chunk_));
         __ bind(&not_string);
       }
 
@@ -2107,7 +2105,7 @@ void LCodeGen::DoBranch(LBranch* instr) {
         // Symbol value -> true.
         const Register scratch = scratch1();
         __ lbu(scratch, FieldMemOperand(map, Map::kInstanceTypeOffset));
-        __ Branch(true_label, eq, scratch, Operand(SYMBOL_TYPE));
+        __ Branch(instr->TrueLabel(chunk_), eq, scratch, Operand(SYMBOL_TYPE));
       }
 
       if (expected.Contains(ToBooleanStub::HEAP_NUMBER)) {
@@ -2117,9 +2115,10 @@ void LCodeGen::DoBranch(LBranch* instr) {
         __ LoadRoot(at, Heap::kHeapNumberMapRootIndex);
         __ Branch(&not_heap_number, ne, map, Operand(at));
         __ ldc1(dbl_scratch, FieldMemOperand(reg, HeapNumber::kValueOffset));
-        __ BranchF(true_label, false_label, ne, dbl_scratch, kDoubleRegZero);
+        __ BranchF(instr->TrueLabel(chunk_), instr->FalseLabel(chunk_),
+                   ne, dbl_scratch, kDoubleRegZero);
         // Falls through if dbl_scratch == 0.
-        __ Branch(false_label);
+        __ Branch(instr->FalseLabel(chunk_));
         __ bind(&not_heap_number);
       }
 
@@ -2132,7 +2131,7 @@ void LCodeGen::DoBranch(LBranch* instr) {
 
 void LCodeGen::EmitGoto(int block) {
   if (!IsNextEmittedBlock(block)) {
-    __ jmp(chunk_->GetAssemblyLabel(chunk_->LookupDestination(block)));
+    __ jmp(chunk_->GetAssemblyLabel(LookupDestination(block)));
   }
 }
 
@@ -2173,18 +2172,14 @@ Condition LCodeGen::TokenToCondition(Token::Value op, bool is_unsigned) {
 void LCodeGen::DoCmpIDAndBranch(LCmpIDAndBranch* instr) {
   LOperand* left = instr->left();
   LOperand* right = instr->right();
-  int false_block = chunk_->LookupDestination(instr->false_block_id());
-  int true_block = chunk_->LookupDestination(instr->true_block_id());
-
   Condition cond = TokenToCondition(instr->op(), false);
 
   if (left->IsConstantOperand() && right->IsConstantOperand()) {
     // We can statically evaluate the comparison.
     double left_val = ToDouble(LConstantOperand::cast(left));
     double right_val = ToDouble(LConstantOperand::cast(right));
-    int next_block =
-      EvalComparison(instr->op(), left_val, right_val) ? true_block
-                                                       : false_block;
+    int next_block = EvalComparison(instr->op(), left_val, right_val) ?
+        instr->TrueDestination(chunk_) : instr->FalseDestination(chunk_);
     EmitGoto(next_block);
   } else {
     if (instr->is_double()) {
@@ -2195,10 +2190,10 @@ void LCodeGen::DoCmpIDAndBranch(LCmpIDAndBranch* instr) {
 
       // If a NaN is involved, i.e. the result is unordered,
       // jump to false block label.
-      __ BranchF(NULL, chunk_->GetAssemblyLabel(false_block), eq,
+      __ BranchF(NULL, instr->FalseLabel(chunk_), eq,
                  left_reg, right_reg);
 
-      EmitBranchF(true_block, false_block, cond, left_reg, right_reg);
+      EmitBranchF(instr, cond, left_reg, right_reg);
     } else {
       Register cmp_left;
       Operand cmp_right = Operand(0);
@@ -2228,7 +2223,7 @@ void LCodeGen::DoCmpIDAndBranch(LCmpIDAndBranch* instr) {
         cmp_right = Operand(ToRegister(right));
       }
 
-      EmitBranch(true_block, false_block, cond, cmp_left, cmp_right);
+      EmitBranch(instr, cond, cmp_left, cmp_right);
     }
   }
 }
@@ -2237,20 +2232,15 @@ void LCodeGen::DoCmpIDAndBranch(LCmpIDAndBranch* instr) {
 void LCodeGen::DoCmpObjectEqAndBranch(LCmpObjectEqAndBranch* instr) {
   Register left = ToRegister(instr->left());
   Register right = ToRegister(instr->right());
-  int false_block = chunk_->LookupDestination(instr->false_block_id());
-  int true_block = chunk_->LookupDestination(instr->true_block_id());
 
-  EmitBranch(true_block, false_block, eq, left, Operand(right));
+  EmitBranch(instr, eq, left, Operand(right));
 }
 
 
 void LCodeGen::DoCmpConstantEqAndBranch(LCmpConstantEqAndBranch* instr) {
   Register left = ToRegister(instr->left());
-  int true_block = chunk_->LookupDestination(instr->true_block_id());
-  int false_block = chunk_->LookupDestination(instr->false_block_id());
 
-  EmitBranch(true_block, false_block, eq, left,
-             Operand(instr->hydrogen()->right()));
+  EmitBranch(instr, eq, left, Operand(instr->hydrogen()->right()));
 }
 
 
@@ -2285,15 +2275,11 @@ void LCodeGen::DoIsObjectAndBranch(LIsObjectAndBranch* instr) {
   Register temp1 = ToRegister(instr->temp());
   Register temp2 = scratch0();
 
-  int true_block = chunk_->LookupDestination(instr->true_block_id());
-  int false_block = chunk_->LookupDestination(instr->false_block_id());
-  Label* true_label = chunk_->GetAssemblyLabel(true_block);
-  Label* false_label = chunk_->GetAssemblyLabel(false_block);
-
   Condition true_cond =
-      EmitIsObject(reg, temp1, temp2, false_label, true_label);
+      EmitIsObject(reg, temp1, temp2,
+          instr->FalseLabel(chunk_), instr->TrueLabel(chunk_));
 
-  EmitBranch(true_block, false_block, true_cond, temp2,
+  EmitBranch(instr, true_cond, temp2,
              Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE));
 }
 
@@ -2312,25 +2298,18 @@ void LCodeGen::DoIsStringAndBranch(LIsStringAndBranch* instr) {
   Register reg = ToRegister(instr->value());
   Register temp1 = ToRegister(instr->temp());
 
-  int true_block = chunk_->LookupDestination(instr->true_block_id());
-  int false_block = chunk_->LookupDestination(instr->false_block_id());
-  Label* false_label = chunk_->GetAssemblyLabel(false_block);
-
   Condition true_cond =
-      EmitIsString(reg, temp1, false_label);
+      EmitIsString(reg, temp1, instr->FalseLabel(chunk_));
 
-  EmitBranch(true_block, false_block, true_cond, temp1,
+  EmitBranch(instr, true_cond, temp1,
              Operand(FIRST_NONSTRING_TYPE));
 }
 
 
 void LCodeGen::DoIsSmiAndBranch(LIsSmiAndBranch* instr) {
-  int true_block = chunk_->LookupDestination(instr->true_block_id());
-  int false_block = chunk_->LookupDestination(instr->false_block_id());
-
   Register input_reg = EmitLoadRegister(instr->value(), at);
   __ And(at, input_reg, kSmiTagMask);
-  EmitBranch(true_block, false_block, eq, at, Operand(zero_reg));
+  EmitBranch(instr, eq, at, Operand(zero_reg));
 }
 
 
@@ -2338,14 +2317,11 @@ void LCodeGen::DoIsUndetectableAndBranch(LIsUndetectableAndBranch* instr) {
   Register input = ToRegister(instr->value());
   Register temp = ToRegister(instr->temp());
 
-  int true_block = chunk_->LookupDestination(instr->true_block_id());
-  int false_block = chunk_->LookupDestination(instr->false_block_id());
-
-  __ JumpIfSmi(input, chunk_->GetAssemblyLabel(false_block));
+  __ JumpIfSmi(input, instr->FalseLabel(chunk_));
   __ lw(temp, FieldMemOperand(input, HeapObject::kMapOffset));
   __ lbu(temp, FieldMemOperand(temp, Map::kBitFieldOffset));
   __ And(at, temp, Operand(1 << Map::kIsUndetectable));
-  EmitBranch(true_block, false_block, ne, at, Operand(zero_reg));
+  EmitBranch(instr, ne, at, Operand(zero_reg));
 }
 
 
@@ -2371,15 +2347,13 @@ static Condition ComputeCompareCondition(Token::Value op) {
 
 void LCodeGen::DoStringCompareAndBranch(LStringCompareAndBranch* instr) {
   Token::Value op = instr->op();
-  int true_block = chunk_->LookupDestination(instr->true_block_id());
-  int false_block = chunk_->LookupDestination(instr->false_block_id());
 
   Handle<Code> ic = CompareIC::GetUninitialized(isolate(), op);
   CallCode(ic, RelocInfo::CODE_TARGET, instr);
 
   Condition condition = ComputeCompareCondition(op);
 
-  EmitBranch(true_block, false_block, condition, v0, Operand(zero_reg));
+  EmitBranch(instr, condition, v0, Operand(zero_reg));
 }
 
 
@@ -2407,16 +2381,10 @@ void LCodeGen::DoHasInstanceTypeAndBranch(LHasInstanceTypeAndBranch* instr) {
   Register scratch = scratch0();
   Register input = ToRegister(instr->value());
 
-  int true_block = chunk_->LookupDestination(instr->true_block_id());
-  int false_block = chunk_->LookupDestination(instr->false_block_id());
-
-  Label* false_label = chunk_->GetAssemblyLabel(false_block);
-
-  __ JumpIfSmi(input, false_label);
+  __ JumpIfSmi(input, instr->FalseLabel(chunk_));
 
   __ GetObjectType(input, scratch, scratch);
-  EmitBranch(true_block,
-             false_block,
+  EmitBranch(instr,
              BranchCondition(instr->hydrogen()),
              scratch,
              Operand(TestType(instr->hydrogen())));
@@ -2439,13 +2407,10 @@ void LCodeGen::DoHasCachedArrayIndexAndBranch(
   Register input = ToRegister(instr->value());
   Register scratch = scratch0();
 
-  int true_block = chunk_->LookupDestination(instr->true_block_id());
-  int false_block = chunk_->LookupDestination(instr->false_block_id());
-
   __ lw(scratch,
          FieldMemOperand(input, String::kHashFieldOffset));
   __ And(at, scratch, Operand(String::kContainsCachedArrayIndexMask));
-  EmitBranch(true_block, false_block, eq, at, Operand(zero_reg));
+  EmitBranch(instr, eq, at, Operand(zero_reg));
 }
 
 
@@ -2521,26 +2486,19 @@ void LCodeGen::DoClassOfTestAndBranch(LClassOfTestAndBranch* instr) {
   Register temp2 = ToRegister(instr->temp());
   Handle<String> class_name = instr->hydrogen()->class_name();
 
-  int true_block = chunk_->LookupDestination(instr->true_block_id());
-  int false_block = chunk_->LookupDestination(instr->false_block_id());
-
-  Label* true_label = chunk_->GetAssemblyLabel(true_block);
-  Label* false_label = chunk_->GetAssemblyLabel(false_block);
-
-  EmitClassOfTest(true_label, false_label, class_name, input, temp, temp2);
+  EmitClassOfTest(instr->TrueLabel(chunk_), instr->FalseLabel(chunk_),
+                  class_name, input, temp, temp2);
 
-  EmitBranch(true_block, false_block, eq, temp, Operand(class_name));
+  EmitBranch(instr, eq, temp, Operand(class_name));
 }
 
 
 void LCodeGen::DoCmpMapAndBranch(LCmpMapAndBranch* instr) {
   Register reg = ToRegister(instr->value());
   Register temp = ToRegister(instr->temp());
-  int true_block = instr->true_block_id();
-  int false_block = instr->false_block_id();
 
   __ lw(temp, FieldMemOperand(reg, HeapObject::kMapOffset));
-  EmitBranch(true_block, false_block, eq, temp, Operand(instr->map()));
+  EmitBranch(instr, eq, temp, Operand(instr->map()));
 }
 
 
@@ -5534,16 +5492,12 @@ void LCodeGen::DoTypeof(LTypeof* instr) {
 
 void LCodeGen::DoTypeofIsAndBranch(LTypeofIsAndBranch* instr) {
   Register input = ToRegister(instr->value());
-  int true_block = chunk_->LookupDestination(instr->true_block_id());
-  int false_block = chunk_->LookupDestination(instr->false_block_id());
-  Label* true_label = chunk_->GetAssemblyLabel(true_block);
-  Label* false_label = chunk_->GetAssemblyLabel(false_block);
 
   Register cmp1 = no_reg;
   Operand cmp2 = Operand(no_reg);
 
-  Condition final_branch_condition = EmitTypeofIs(true_label,
-                                                  false_label,
+  Condition final_branch_condition = EmitTypeofIs(instr->TrueLabel(chunk_),
+                                                  instr->FalseLabel(chunk_),
                                                   input,
                                                   instr->type_literal(),
                                                   cmp1,
@@ -5553,7 +5507,7 @@ void LCodeGen::DoTypeofIsAndBranch(LTypeofIsAndBranch* instr) {
   ASSERT(!cmp2.is_reg() || cmp2.rm().is_valid());
 
   if (final_branch_condition != kNoCondition) {
-    EmitBranch(true_block, false_block, final_branch_condition, cmp1, cmp2);
+    EmitBranch(instr, final_branch_condition, cmp1, cmp2);
   }
 }
 
@@ -5666,12 +5620,10 @@ Condition LCodeGen::EmitTypeofIs(Label* true_label,
 
 void LCodeGen::DoIsConstructCallAndBranch(LIsConstructCallAndBranch* instr) {
   Register temp1 = ToRegister(instr->temp());
-  int true_block = chunk_->LookupDestination(instr->true_block_id());
-  int false_block = chunk_->LookupDestination(instr->false_block_id());
 
   EmitIsConstructCall(temp1, scratch0());
 
-  EmitBranch(true_block, false_block, eq, temp1,
+  EmitBranch(instr, eq, temp1,
              Operand(Smi::FromInt(StackFrame::CONSTRUCT)));
 }
 
diff --git a/src/mips/lithium-codegen-mips.h b/src/mips/lithium-codegen-mips.h
index 9a8f7e3..75a03be 100644
--- a/src/mips/lithium-codegen-mips.h
+++ b/src/mips/lithium-codegen-mips.h
@@ -78,7 +78,6 @@ class LCodeGen BASE_EMBEDDED {
   Heap* heap() const { return isolate()->heap(); }
   Zone* zone() const { return zone_; }
 
-  // TODO(svenpanne) Use this consistently.
   int LookupDestination(int block_id) const {
     return chunk()->LookupDestination(block_id);
   }
@@ -322,13 +321,13 @@ class LCodeGen BASE_EMBEDDED {
 
   static Condition TokenToCondition(Token::Value op, bool is_unsigned);
   void EmitGoto(int block);
-  void EmitBranch(int left_block,
-                  int right_block,
+  template<class InstrType>
+  void EmitBranch(InstrType instr,
                   Condition cc,
                   Register src1,
                   const Operand& src2);
-  void EmitBranchF(int left_block,
-                   int right_block,
+  template<class InstrType>
+  void EmitBranchF(InstrType instr,
                    Condition cc,
                    FPURegister src1,
                    FPURegister src2);
diff --git a/src/mips/lithium-mips.h b/src/mips/lithium-mips.h
index f4b6294..358eca9 100644
--- a/src/mips/lithium-mips.h
+++ b/src/mips/lithium-mips.h
@@ -488,17 +488,44 @@ class LUnknownOSRValue: public LTemplateInstruction<1, 0, 0> {
 template<int I, int T>
 class LControlInstruction: public LTemplateInstruction<0, I, T> {
  public:
+  LControlInstruction() : false_label_(NULL), true_label_(NULL) { }
+
   virtual bool IsControl() const { return true; }
 
   int SuccessorCount() { return hydrogen()->SuccessorCount(); }
   HBasicBlock* SuccessorAt(int i) { return hydrogen()->SuccessorAt(i); }
-  int true_block_id() { return hydrogen()->SuccessorAt(0)->block_id(); }
-  int false_block_id() { return hydrogen()->SuccessorAt(1)->block_id(); }
+
+  int TrueDestination(LChunk* chunk) {
+    return chunk->LookupDestination(true_block_id());
+  }
+  int FalseDestination(LChunk* chunk) {
+    return chunk->LookupDestination(false_block_id());
+  }
+
+  Label* TrueLabel(LChunk* chunk) {
+    if (true_label_ == NULL) {
+      true_label_ = chunk->GetAssemblyLabel(TrueDestination(chunk));
+    }
+    return true_label_;
+  }
+  Label* FalseLabel(LChunk* chunk) {
+    if (false_label_ == NULL) {
+      false_label_ = chunk->GetAssemblyLabel(FalseDestination(chunk));
+    }
+    return false_label_;
+  }
+
+ protected:
+  int true_block_id() { return SuccessorAt(0)->block_id(); }
+  int false_block_id() { return SuccessorAt(1)->block_id(); }
 
  private:
   HControlInstruction* hydrogen() {
     return HControlInstruction::cast(this->hydrogen_value());
   }
+
+  Label* false_label_;
+  Label* true_label_;
 };
 
 
@@ -1216,7 +1243,7 @@ class LBranch: public LControlInstruction<1, 0> {
 };
 
 
-class LCmpMapAndBranch: public LTemplateInstruction<0, 1, 1> {
+class LCmpMapAndBranch: public LControlInstruction<1, 1> {
  public:
   LCmpMapAndBranch(LOperand* value, LOperand* temp) {
     inputs_[0] = value;
@@ -1229,15 +1256,7 @@ class LCmpMapAndBranch: public LTemplateInstruction<0, 1, 1> {
   DECLARE_CONCRETE_INSTRUCTION(CmpMapAndBranch, "cmp-map-and-branch")
   DECLARE_HYDROGEN_ACCESSOR(CompareMap)
 
-  virtual bool IsControl() const { return true; }
-
   Handle<Map> map() const { return hydrogen()->map(); }
-  int true_block_id() const {
-    return hydrogen()->FirstSuccessor()->block_id();
-  }
-  int false_block_id() const {
-    return hydrogen()->SecondSuccessor()->block_id();
-  }
 };