Use registers to pass arguments to GenericBinaryOpStub....

src/ia32/codegen-ia32.h

Index: src/ia32/codegen-ia32.h
===================================================================
--- src/ia32/codegen-ia32.h	(revision 3685)
+++ src/ia32/codegen-ia32.h	(working copy)
@@ -698,11 +698,15 @@
   void GenerateSmiCode(MacroAssembler* masm, Label* slow);
   void GenerateLoadArguments(MacroAssembler* masm);
   void GenerateReturn(MacroAssembler* masm);
+  void GenerateHeapResultAllocation(MacroAssembler* masm, Label* alloc_failure);
 
+  // Args in registers are always OK for ADD and SUB. Floating-point MUL and DIV
+  // are also OK. Though MUL and DIV on SMIs modify the original registers so
+  // we need to push args on stack anyway. 
   bool ArgsInRegistersSupported() {
-    return ((op_ == Token::ADD) || (op_ == Token::SUB)
-            || (op_ == Token::MUL) || (op_ == Token::DIV))
-        && flags_ != NO_SMI_CODE_IN_STUB;
+  return ((op_ == Token::ADD) || (op_ == Token::SUB)) ||

[Kevin Millikin (Chromium), 2010/01/25 16:27:44]

You lost a two-space indent here.

This is a complicated comparison, I like the following better:

bool ArgsInRegistersSupported() {
  if (op_ == Token::ADD || op_ == Token::SUB) return true;
  if (op_ == Token::MUL || op_ == Token::DIV) {
    return NO_SMI_CODE_IN_STUB;
  }
  return false;
}

You might also rename this to SupportsArgsInRegisters, to parallel
HasArgsInRegisters.

[Vladislav Kaznacheev, 2010/01/25 17:44:53]

Done.

+         (((op_ == Token::MUL) || (op_ == Token::DIV))
+          && (flags_ == NO_SMI_CODE_IN_STUB));
   }
   bool IsOperationCommutative() {
     return (op_ == Token::ADD) || (op_ == Token::MUL);