ARM: Emit RSB (reverse-subtract) for subtraction with constant lhs

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 148 matching lines @@
   V(StoreKeyed)                                 \
   V(StoreKeyedGeneric)                          \
   V(StoreNamedField)                            \
   V(StoreNamedGeneric)                          \
   V(StringAdd)                                  \
   V(StringCharCodeAt)                           \
   V(StringCharFromCode)                         \
   V(StringCompareAndBranch)                     \
   V(StringLength)                               \
   V(SubI)                                       \
+  V(RSubI)                                      \
   V(TaggedToI)                                  \
   V(ThisFunction)                               \
   V(Throw)                                      \
   V(ToFastProperties)                           \
   V(TransitionElementsKind)                     \
   V(Typeof)                                     \
   V(TypeofIsAndBranch)                          \
   V(UnaryMathOperation)                         \
   V(UnknownOSRValue)                            \
   V(ValueOf)                                    \
@@ skipping 818 matching lines @@
   }
 
   LOperand* left() { return inputs_[0]; }
   LOperand* right() { return inputs_[1]; }
 
   DECLARE_CONCRETE_INSTRUCTION(SubI, "sub-i")
   DECLARE_HYDROGEN_ACCESSOR(Sub)
 };
 
 
+class LRSubI: public LTemplateInstruction<1, 2, 0> {
+ public:
+  LRSubI(LOperand* left, LOperand* right) {
+    inputs_[0] = left;
+    inputs_[1] = right;
+  }
+
+  LOperand* left() { return inputs_[0]; }
+  LOperand* right() { return inputs_[1]; }
+
+  DECLARE_CONCRETE_INSTRUCTION(RSubI, "rsub-i")
+  DECLARE_HYDROGEN_ACCESSOR(Sub)
+};
+
+
 class LConstantI: public LTemplateInstruction<1, 0, 0> {
  public:
   DECLARE_CONCRETE_INSTRUCTION(ConstantI, "constant-i")
   DECLARE_HYDROGEN_ACCESSOR(Constant)
 
   int32_t value() const { return hydrogen()->Integer32Value(); }
 };
 
 
 class LConstantD: public LTemplateInstruction<1, 0, 0> {
@@ skipping 1392 matching lines @@
 
   // Build the sequence for the graph.
   LPlatformChunk* Build();
 
   // Declare methods that deal with the individual node types.
 #define DECLARE_DO(type) LInstruction* Do##type(H##type* node);
   HYDROGEN_CONCRETE_INSTRUCTION_LIST(DECLARE_DO)
 #undef DECLARE_DO
 
   LInstruction* DoMultiplyAdd(HMul* mul, HValue* addend);
+  LInstruction* DoRSub(HSub* instr);
 
   static bool HasMagicNumberForDivisor(int32_t divisor);
   static HValue* SimplifiedDividendForMathFloorOfDiv(HValue* val);
   static HValue* SimplifiedDivisorForMathFloorOfDiv(HValue* val);
 
  private:
   enum Status {
     UNUSED,
     BUILDING,
     DONE,
@@ skipping 116 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_LITHIUM_ARM_H_