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Re: [PATCH] PR 16373: -fomit-frame-pointer when optimizing on x86


On Monday 12 July 2004 04:53, Andi Kleen wrote:
> Roger Sayle <roger@eyesopen.com> writes:
> > On Sun, 11 Jul 2004, Joseph S. Myers wrote:
> >> Performance statistics (compile time, run time and code size)?  After
> >> all, the point of this change is presumably that it improves
> >> performance.
> >
> > Do you have any doubt at all that this patch won't improve run-time,
> > reduce code size and speed up a bootstrapped compiler?  :>
>
> It won't reduce code size - ebp references are smaller than esp
> references.  This means if the function does more than four or five
> local variable references it will be bigger.
>
> But it will be likely faster.

However you also have ebp available as a general purpose register, which will 
tend to mean less spills, reducing both code size and stack usage.

Paul


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