Re: [PATCH] x86: Use -m-omit-leaf-frame-pointer to shrink text size

[H. Peter Anvin]

On 12/16/2011 04:00 AM, Ingo Molnar wrote:
>>
>> Are you sure about that even if the leaf function uses rBP for 
>> a different purpose?
> 
> Well, i assumed that GCC does not mess with %bp in leaf 
> functions - a frame pointer is barely useful if it's destroyed 
> spuriously in leaf functions.
> 

We should verify that explicitly.  gcc has every "right" to treat it as
a normal callee-saved register, but I think it is a very low priority
register in gcc's register allocation scheme.

	-hpa

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

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