PPC/s390: [builtins] Introduce proper Float64Exp operator.

src/crankshaft/s390/lithium-s390.cc

Index: src/crankshaft/s390/lithium-s390.cc
diff --git a/src/crankshaft/s390/lithium-s390.cc b/src/crankshaft/s390/lithium-s390.cc
index d0937e57078c356e6d6133835473114609a72b1d..cb3cd6806af74571297e984570504325d27a2209 100644
--- a/src/crankshaft/s390/lithium-s390.cc
+++ b/src/crankshaft/s390/lithium-s390.cc
@@ -1034,8 +1034,8 @@ LInstruction* LChunkBuilder::DoMathAbs(HUnaryMathOperation* instr) {
 LInstruction* LChunkBuilder::DoMathLog(HUnaryMathOperation* instr) {
   DCHECK(instr->representation().IsDouble());
   DCHECK(instr->value()->representation().IsDouble());
-  LOperand* input = UseFixedDouble(instr->value(), d1);
-  return MarkAsCall(DefineFixedDouble(new (zone()) LMathLog(input), d1), instr);
+  LOperand* input = UseFixedDouble(instr->value(), d0);
+  return MarkAsCall(DefineFixedDouble(new (zone()) LMathLog(input), d0), instr);
 }
 
 LInstruction* LChunkBuilder::DoMathClz32(HUnaryMathOperation* instr) {
@@ -1047,12 +1047,8 @@ LInstruction* LChunkBuilder::DoMathClz32(HUnaryMathOperation* instr) {
 LInstruction* LChunkBuilder::DoMathExp(HUnaryMathOperation* instr) {
   DCHECK(instr->representation().IsDouble());
   DCHECK(instr->value()->representation().IsDouble());
-  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);
+  LOperand* input = UseFixedDouble(instr->value(), d0);
+  return MarkAsCall(DefineFixedDouble(new (zone()) LMathExp(input), d0), instr);
 }
 
 LInstruction* LChunkBuilder::DoMathSqrt(HUnaryMathOperation* instr) {