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Re: Does unrolling prevents doloop optimizations?
- From: Ayal Zaks <ZAKS at il dot ibm dot com>
- To: Zdenek Dvorak <rakdver at kam dot mff dot cuni dot cz>
- Cc: gcc at gcc dot gnu dot org, Mircea Namolaru <namolaru at il dot ibm dot com>, Vladimir Yanovsky <volodyan at gmail dot com>
- Date: Sat, 30 Jun 2007 12:56:24 +0300
- Subject: Re: Does unrolling prevents doloop optimizations?
Zdenek Dvorak <rakdver@kam.mff.cuni.cz> wrote on 30/06/2007 10:52:32:
> Hello,
>
> > It doesn't seem that the number of iterations analysis from loop-iv.c
deals
> > with EQ closing branches.
>
> loop-iv works just fine for EQ closing branches.
>
Thanks for the clarification (I didn't see EQ in iv_number_of_iterations's
switch (cond)). In that case, sms should definitely try to use it.
Ayal.
> Zdenek
>
> > One option is for sms to use
> > doloop_condition_get/loop-iv analysis in their current form, and if
failed
> > check (on our own) for reversed doloop patterns. Another is to try and
> > reverse the closing branch before calling doloop_condition_get/loop-iv
> > analysis; any suitable branch reversal facility available?
> >
> > Ayal.