IA32: Optimize instanceof...

src/code-stubs.h

Index: src/code-stubs.h
===================================================================
--- src/code-stubs.h	(revision 6041)
+++ src/code-stubs.h	(working copy)
@@ -326,13 +326,24 @@
 
 class InstanceofStub: public CodeStub {
  public:
-  InstanceofStub() { }
+  enum Flags {
+    kNoFlags = 0,
+    kArgsInRegisters = 1 << 0
+  };
 
+  explicit InstanceofStub(Flags flags) : flags_(flags) { }
+
   void Generate(MacroAssembler* masm);
 
  private:
   Major MajorKey() { return Instanceof; }
-  int MinorKey() { return 0; }
+  int MinorKey() { return args_in_registers() ? 1 : 0; }
+
+  bool args_in_registers() {
+    return (flags_ & kArgsInRegisters) != 0;
+  }
+
+  Flags flags_;
 };