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Re: Loop unrolling-related SPEC regressions?
- From: David Edelsohn <dje at watson dot ibm dot com>
- To: Jan Hubicka <jh at suse dot cz>
- Cc: Joe Buck <jbuck at synopsys dot com>, Paolo Carlini <pcarlini at unitus dot it>, gcc at gcc dot gnu dot org, rth at redhat dot com
- Date: Tue, 05 Feb 2002 12:48:22 -0500
- Subject: Re: Loop unrolling-related SPEC regressions?
>>>>> Jan Hubicka writes:
Jan> Anyway I would like to see the recent regressions solved. Some of them
Jan> appears to be due to patch:
Jan> 2001-11-17 Corey Minyard <firstname.lastname@example.org>
Jan> Richard Henderson <email@example.com>
Jan> * unroll.c (loop_iterations): Detect one situation in which we
Jan> overestimate the number of iterations.
Jan> 2001-11-30 Zoltan Hidvegi <firstname.lastname@example.org>
Jan> * unroll.c (unroll_loop): Correct special exit cases.
Does this regression also exist on the GCC 3.0 branch? When I
tried to integrate Zoli's patch into the GCC trunk, I ran into conflicts
with Richard's patch. Richard duplicated some of Zoli's work with a
similar patch. Richard's patch to unroll.c is a subset of Zoli's patch.
After the problem getting Zoli's original patch reviewed and
approved, I decided to wait and see if Richard's subset was enough. Given
the hostile reception to Zoli's original patches, it is unfortunate that
Richard had to duplicate the work and create nearly identical fixes.
I would suggest you investigate whether replacing Richard's
partial patch with Zoli's complete version of the patch for unroll.c fixes
Zoli's patch already was approved by Mark Mitchell. Zoli's
complete version of the patch is in GCC 3.0 branch. Unless Richard
objects, if Zoli's complete patch fixes the problem, we should be able to
substitute Zoli's patch for Richard's.