[turbofan] Use special constant type for RPO block number operands.

src/compiler/code-generator-impl.h

 // Copyright 2013 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.
 
 #ifndef V8_COMPILER_CODE_GENERATOR_IMPL_H_
 #define V8_COMPILER_CODE_GENERATOR_IMPL_H_
 
 #include "src/code-stubs.h"
 #include "src/compiler/code-generator.h"
 #include "src/compiler/instruction.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/opcodes.h"
 #include "src/macro-assembler.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 // Converts InstructionOperands from a given instruction to
 // architecture-specific
 // registers and operands after they have been assigned by the register
 // allocator.
 class InstructionOperandConverter {
  public:
   InstructionOperandConverter(CodeGenerator* gen, Instruction* instr)
       : gen_(gen), instr_(instr) {}
 
+  // -- Instruction operand accesses with conversions --------------------------
+
   Register InputRegister(int index) {
     return ToRegister(instr_->InputAt(index));
   }
 
   DoubleRegister InputDoubleRegister(int index) {
     return ToDoubleRegister(instr_->InputAt(index));
   }
 
   double InputDouble(int index) { return ToDouble(instr_->InputAt(index)); }
 
@@ skipping 12 matching lines @@
   }
 
   uint8_t InputInt6(int index) {
     return static_cast<uint8_t>(InputInt32(index) & 0x3F);
   }
 
   Handle<HeapObject> InputHeapObject(int index) {
     return ToHeapObject(instr_->InputAt(index));
   }
 
-  Label* InputLabel(int index) { return gen_->GetLabel(InputRpo(index)); }
+  Label* InputLabel(int index) { return ToLabel(instr_->InputAt(index)); }
 
   BasicBlock::RpoNumber InputRpo(int index) {
-    int rpo_number = InputInt32(index);
-    return BasicBlock::RpoNumber::FromInt(rpo_number);
+    return ToRpoNumber(instr_->InputAt(index));
   }
 
   Register OutputRegister(int index = 0) {
     return ToRegister(instr_->OutputAt(index));
   }
 
+  Register TempRegister(int index) { return ToRegister(instr_->TempAt(index)); }
+
   DoubleRegister OutputDoubleRegister() {
     return ToDoubleRegister(instr_->Output());
   }
 
-  Register TempRegister(int index) { return ToRegister(instr_->TempAt(index)); }
+  // -- Conversions for operands -----------------------------------------------
+
+  Label* ToLabel(InstructionOperand* op) {
+    return gen_->GetLabel(ToRpoNumber(op));
+  }
+
+  BasicBlock::RpoNumber ToRpoNumber(InstructionOperand* op) {
+    return ToConstant(op).ToRpoNumber();
+  }
 
   Register ToRegister(InstructionOperand* op) {
     DCHECK(op->IsRegister());
     return Register::FromAllocationIndex(op->index());
   }
 
   DoubleRegister ToDoubleRegister(InstructionOperand* op) {
     DCHECK(op->IsDoubleRegister());
     return DoubleRegister::FromAllocationIndex(op->index());
   }
 
-  Constant ToConstant(InstructionOperand* operand) {
-    if (operand->IsImmediate()) {
-      return gen_->code()->GetImmediate(operand->index());
+  Constant ToConstant(InstructionOperand* op) {
+    if (op->IsImmediate()) {
+      return gen_->code()->GetImmediate(op->index());
     }
-    return gen_->code()->GetConstant(operand->index());
+    return gen_->code()->GetConstant(op->index());
   }
 
-  double ToDouble(InstructionOperand* operand) {
-    return ToConstant(operand).ToFloat64();
-  }
+  double ToDouble(InstructionOperand* op) { return ToConstant(op).ToFloat64(); }
 
-  Handle<HeapObject> ToHeapObject(InstructionOperand* operand) {
-    return ToConstant(operand).ToHeapObject();
+  Handle<HeapObject> ToHeapObject(InstructionOperand* op) {
+    return ToConstant(op).ToHeapObject();
   }
 
   Frame* frame() const { return gen_->frame(); }
   Isolate* isolate() const { return gen_->isolate(); }
   Linkage* linkage() const { return gen_->linkage(); }
 
  protected:
   CodeGenerator* gen_;
   Instruction* instr_;
 };
 
 
 // TODO(dcarney): generify this on bleeding_edge and replace this call
 // when merged.
 static inline void FinishCode(MacroAssembler* masm) {
 #if V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_ARM
   masm->CheckConstPool(true, false);
 #endif
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_CODE_GENERATOR_IMPL_H