Allow optimizing compiler to compute Math.log using untagged doubles.

src/ia32/lithium-codegen-ia32.cc

 // Copyright 2010 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 2217 matching lines @@
 
   // Return value is in st(0) on ia32.
   // Store it into the (fixed) result register.
   __ sub(Operand(esp), Immediate(kDoubleSize));
   __ fstp_d(Operand(esp, 0));
   __ movdbl(ToDoubleRegister(instr->result()), Operand(esp, 0));
   __ add(Operand(esp), Immediate(kDoubleSize));
 }
 
 
+void LCodeGen::DoMathLog(LUnaryMathOperation* instr) {
+  ASSERT(ToDoubleRegister(instr->result()).is(xmm1));
+  TranscendentalCacheSSE2Stub stub(TranscendentalCache::LOG);
+  CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
+}
+
+
 void LCodeGen::DoUnaryMathOperation(LUnaryMathOperation* instr) {
   switch (instr->op()) {
     case kMathAbs:
       DoMathAbs(instr);
       break;
     case kMathFloor:
       DoMathFloor(instr);
       break;
     case kMathRound:
       DoMathRound(instr);
       break;
     case kMathSqrt:
       DoMathSqrt(instr);
       break;
     case kMathPowHalf:
       DoMathPowHalf(instr);
       break;
+    case kMathLog:
+      DoMathLog(instr);
+      break;
+
     default:
       UNREACHABLE();
   }
 }
 
 
 void LCodeGen::DoCallKeyed(LCallKeyed* instr) {
   ASSERT(ToRegister(instr->result()).is(eax));
 
   int arity = instr->arity();
@@ skipping 890 matching lines @@
   ASSERT(!environment->HasBeenRegistered());
   RegisterEnvironmentForDeoptimization(environment);
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal