Revert of [builtins] Introduce proper Float64Exp operator.

src/crankshaft/mips64/lithium-mips64.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 "src/crankshaft/mips64/lithium-mips64.h"
 
 #include <sstream>
 
 #if V8_TARGET_ARCH_MIPS64
 
@@ skipping 1089 matching lines @@
 LInstruction* LChunkBuilder::DoMathClz32(HUnaryMathOperation* instr) {
   LOperand* input = UseRegisterAtStart(instr->value());
   LMathClz32* result = new(zone()) LMathClz32(input);
   return DefineAsRegister(result);
 }
 
 
 LInstruction* LChunkBuilder::DoMathExp(HUnaryMathOperation* instr) {
   DCHECK(instr->representation().IsDouble());
   DCHECK(instr->value()->representation().IsDouble());
-  LOperand* input = UseFixedDouble(instr->value(), f4);
-  return MarkAsCall(DefineFixedDouble(new (zone()) LMathExp(input), f4), instr);
+  LOperand* input = UseRegister(instr->value());
+  LOperand* temp1 = TempRegister();
+  LOperand* temp2 = TempRegister();
+  LOperand* double_temp = TempDoubleRegister();
+  LMathExp* result = new(zone()) LMathExp(input, double_temp, temp1, temp2);
+  return DefineAsRegister(result);
 }
 
 
 LInstruction* LChunkBuilder::DoMathPowHalf(HUnaryMathOperation* instr) {
   // Input cannot be the same as the result, see LCodeGen::DoMathPowHalf.
   LOperand* input = UseFixedDouble(instr->value(), f8);
   LOperand* temp = TempDoubleRegister();
   LMathPowHalf* result = new(zone()) LMathPowHalf(input, temp);
   return DefineFixedDouble(result, f4);
 }
@@ skipping 1328 matching lines @@
   LOperand* index = UseTempRegister(instr->index());
   LLoadFieldByIndex* load = new(zone()) LLoadFieldByIndex(object, index);
   LInstruction* result = DefineSameAsFirst(load);
   return AssignPointerMap(result);
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS64