Use registers to pass arguments to GenericBinaryOpStub....

src/ia32/codegen-ia32.h

 // Copyright 2006-2008 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 680 matching lines @@
            | FlagBits::encode(flags_)
            | SSE3Bits::encode(use_sse3_)
            | ArgsInRegistersBits::encode(args_in_registers_)
            | ArgsReversedBits::encode(args_reversed_);
   }
 
   void Generate(MacroAssembler* masm);
   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);
   }
 
   void SetArgsInRegisters() { args_in_registers_ = true; }
   void SetArgsReversed() { args_reversed_ = true; }
   bool HasSmiCodeInStub() { return (flags_ & NO_SMI_CODE_IN_STUB) == 0; }
   bool HasArgumentsInRegisters() { return args_in_registers_; }

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

I'm not sure why HasArguments is spelled out but SetArgs is not.  It should be
consistent and I don't mind abbreviating Args.  You could change it since you're
already modifying this code.

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

Done.

   bool HasArgumentsReversed() { return args_reversed_; }
 };
 
 
 // Flag that indicates how to generate code for the stub StringAddStub.
 enum StringAddFlags {
   NO_STRING_ADD_FLAGS = 0,
   NO_STRING_CHECK_IN_STUB = 1 << 0  // Omit string check in stub.
 };
 
@@ skipping 70 matching lines @@
   Major MajorKey() { return StringCompare; }
   int MinorKey() { return 0; }
 
   void Generate(MacroAssembler* masm);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_CODEGEN_IA32_H_