[v8-dev] ARM: Improve Lithium register constraints.

src/arm/lithium-arm.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 648 matching lines @@
 
   LOperand* left() { return inputs_[0]; }
   LOperand* right() { return inputs_[1]; }
   LOperand* temp() { return temps_[0]; }
 
   DECLARE_CONCRETE_INSTRUCTION(MathFloorOfDiv, "math-floor-of-div")
   DECLARE_HYDROGEN_ACCESSOR(MathFloorOfDiv)
 };
 
 
-class LMulI: public LTemplateInstruction<1, 2, 1> {
+class LMulI: public LTemplateInstruction<1, 2, 0> {
  public:
-  LMulI(LOperand* left, LOperand* right, LOperand* temp) {
+  LMulI(LOperand* left, LOperand* right) {
     inputs_[0] = left;
     inputs_[1] = right;
-    temps_[0] = temp;
   }
 
   LOperand* left() { return inputs_[0]; }
   LOperand* right() { return inputs_[1]; }
-  LOperand* temp() { return temps_[0]; }
 
   DECLARE_CONCRETE_INSTRUCTION(MulI, "mul-i")
   DECLARE_HYDROGEN_ACCESSOR(Mul)
 };
 
 
 // Instruction for computing multiplier * multiplicand + addend.
 class LMultiplyAddD: public LTemplateInstruction<1, 3, 0> {
  public:
   LMultiplyAddD(LOperand* addend, LOperand* multiplier,
@@ skipping 1980 matching lines @@
   // Operand created by UseRegisterAtStart is guaranteed to be live only at
   // instruction start. Register allocator is free to assign the same register
   // to some other operand used inside instruction (i.e. temporary or
   // output).
   MUST_USE_RESULT LOperand* UseRegister(HValue* value);
   MUST_USE_RESULT LOperand* UseRegisterAtStart(HValue* value);
 
   // An input operand in a register that may be trashed.
   MUST_USE_RESULT LOperand* UseTempRegister(HValue* value);
 
-  // An input operand in a register or stack slot.
+  // An input operand in a register or stack slot. It can be
+  // a stack slot iff the value use count is 1.
   MUST_USE_RESULT LOperand* Use(HValue* value);
   MUST_USE_RESULT LOperand* UseAtStart(HValue* value);
 
   // An input operand in a register, stack slot or a constant operand.
+  // It can be a stack slot iff the value use count is 1.
   MUST_USE_RESULT LOperand* UseOrConstant(HValue* value);
   MUST_USE_RESULT LOperand* UseOrConstantAtStart(HValue* value);
 
   // An input operand in a register or a constant operand.
   MUST_USE_RESULT LOperand* UseRegisterOrConstant(HValue* value);
   MUST_USE_RESULT LOperand* UseRegisterOrConstantAtStart(HValue* value);
 
   // An input operand in a constant operand.
   MUST_USE_RESULT LOperand* UseConstant(HValue* value);
 
@@ skipping 66 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_LITHIUM_ARM_H_