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

src/ia32/code-stubs-ia32.h

Index: src/ia32/code-stubs-ia32.h
===================================================================
--- src/ia32/code-stubs-ia32.h	(revision 5984)
+++ src/ia32/code-stubs-ia32.h	(working copy)
@@ -45,6 +45,7 @@
   void Generate(MacroAssembler* masm);
  private:
   TranscendentalCache::Type type_;
+
   Major MajorKey() { return TranscendentalCache; }
   int MinorKey() { return type_; }
   Runtime::FunctionId RuntimeFunction();
@@ -52,6 +53,24 @@
 };
 
 
+// Check the transcendental cache, or generate the result, using SSE2.
+// The argument and result will be in xmm1.
+// Only supports TranscendentalCache::LOG at this point.
+class TranscendentalCacheSSE2Stub: public CodeStub {
+ public:
+  explicit TranscendentalCacheSSE2Stub(TranscendentalCache::Type type)
+      : type_(type) {}
+  void Generate(MacroAssembler* masm);
+ private:
+  TranscendentalCache::Type type_;
+
+  Major MajorKey() { return TranscendentalCacheSSE2; }
+  int MinorKey() { return type_; }
+  Runtime::FunctionId RuntimeFunction();
+  void GenerateOperation(MacroAssembler* masm);
+};
+
+
 class ToBooleanStub: public CodeStub {
  public:
   ToBooleanStub() { }