Re: BUG: GCC-4.4.x changes the function frame on some functions

From: H. Peter Anvin
Date: Thu Nov 19 2009 - 10:52:35 EST


On 11/19/2009 07:37 AM, Thomas Gleixner wrote:
>
> modified function start on a handful of functions only seen with gcc
> 4.4.x on x86 32 bit:
>
> push %edi
> lea 0x8(%esp),%edi
> and $0xfffffff0,%esp
> pushl -0x4(%edi)
> push %ebp
> mov %esp,%ebp
> ...
> call mcount
>

The real questions is why we're aligning the stack in the kernel. It is
probably not what we want -- we don't use SSE for anything but a handful
of special cases in the kernel, and we don't want the overhead.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.

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