[llvm-commits] [llvm-gcc-4.2] r103976 - /llvm-gcc-4.2/trunk/gcc/config/i386/i386.h

[Bill Wendling]

On May 17, 2010, at 11:38 PM, Duncan Sands wrote:

> Hi Bill,
> 
>> Turn on "--disable-non-leaf-fp-elim" if -momit-leaf-frame-pointer is specified.
> 
> if -fomit-frame-pointer and -momit-leaf-frame-pointer are both specified,
> then the frame pointer should be omitted for all functions.  Will your
> patch do this?

Of course.

> Also, if -fomit-frame-pointer is not specified, but
> -momit-leaf-frame-pointer is, I hope -disable-fp-elim is not passed to
> llc.  How does that work?

The "flag_frame_pointer" is set to 3 in this case. So --disable-fp-elim isn't passed to llc.

> Presumably due to how gcc is setting up the
> various flags.  Can you please add some comments.
> 

That would involve documenting all of the effects that the "flag_frame_pointer" variable has. That's beyond the scope of this patch. And I think that the code is clear enough (certainly enough for GCC-derived code).

-bw