Relax register constraints for LMathSqrt.

src/x64/lithium-x64.cc

 // Copyright 2012 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.
 
 #include "v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "lithium-allocator-inl.h"
 #include "x64/lithium-x64.h"
@@ skipping 1164 matching lines @@
   ASSERT(instr->value()->representation().IsDouble());
   LOperand* value = UseTempRegister(instr->value());
   LOperand* temp1 = TempRegister();
   LOperand* temp2 = TempRegister();
   LMathExp* result = new(zone()) LMathExp(value, temp1, temp2);
   return DefineAsRegister(result);
 }
 
 
 LInstruction* LChunkBuilder::DoMathSqrt(HUnaryMathOperation* instr) {
-  LOperand* input = UseRegisterAtStart(instr->value());
-  LMathSqrt* result = new(zone()) LMathSqrt(input);
-  return DefineSameAsFirst(result);
+  LOperand* input = UseAtStart(instr->value());
+  return DefineAsRegister(new(zone()) LMathSqrt(input));
 }
 
 
 LInstruction* LChunkBuilder::DoMathPowHalf(HUnaryMathOperation* instr) {
   LOperand* input = UseRegisterAtStart(instr->value());
   LMathPowHalf* result = new(zone()) LMathPowHalf(input);
   return DefineSameAsFirst(result);
 }
 
 
@@ skipping 1404 matching lines @@
   LOperand* index = UseTempRegister(instr->index());
   LLoadFieldByIndex* load = new(zone()) LLoadFieldByIndex(object, index);
   LInstruction* result = DefineSameAsFirst(load);
   return AssignPointerMap(result);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64