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Re: little epilogue optimization
- To: drepper at cygnus dot com (Ulrich Drepper)
- Subject: Re: little epilogue optimization
- From: Jeffrey A Law <law at cygnus dot com>
- Date: Thu, 02 Jul 1998 01:59:26 -0600
- cc: egcs-patches at cygnus dot com
- Reply-To: law at cygnus dot com
In message <r2sokqrp5s.fsf@happy.cygnus.com>you write:
> The little patch appended adds an optimization suggested in Intel's
> docs. Frames of size 4 or 8 should be removed using pop and not add.
Why? Does it schedule better or something like that? Just curious.
Is this transformation going to pessimize other x86 processors? If so
we'll need to conditionalize it.
If someone can answer that question I'll tweak the patch if appropriate
and install it.
> If somebody can suggest a way that the two generated pops get not
> separated it would be perfect.
Not easily done without hampering scheduling.
jeff