This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: Fix regression on PR46590 (slow compile with -O0)

From: Michael Matz <matz at suse dot de>
To: Eric Botcazou <ebotcazou at adacore dot com>
Cc: gcc-patches at gcc dot gnu dot org, Richard Guenther <richard dot guenther at gmail dot com>
Date: Sat, 21 Jan 2012 01:10:37 +0100 (CET)
Subject: Re: Fix regression on PR46590 (slow compile with -O0)
References: <Pine.LNX.4.64.1201131807540.16449@wotan.suse.de> <CAFiYyc1fXq+WN2T=LLZikhjKHATXiE32D2F7Er+84fpGEHHfwA@mail.gmail.com> <Pine.LNX.4.64.1201191611170.16449@wotan.suse.de> <201201202153.37433.ebotcazou@adacore.com>

Hi,

On Fri, 20 Jan 2012, Eric Botcazou wrote:

> Is it supposed to change the generated code or...?

It was supposed to not change the set of conflicts, no.  But I made a 
thinko, and sometimes too many conflicts are generated.  On the testcases 
I tried that wasn't the case, so thanks for finding one :) Trivially 
fixing the thinko (iterating over (work bit-and old_conflict) in the first 
inner loop) would fix the testcase but in general create too few 
conflicts, i.e. generate wrong code.  I need some time to think about this 
again.


Ciao,
Michael.

Follow-Ups:
- Re: Fix regression on PR46590 (slow compile with -O0)
  - From: Eric Botcazou

References:
- Fix regression on PR46590 (slow compile with -O0)
  - From: Michael Matz
- Re: Fix regression on PR46590 (slow compile with -O0)
  - From: Richard Guenther
- Re: Fix regression on PR46590 (slow compile with -O0)
  - From: Michael Matz
- Re: Fix regression on PR46590 (slow compile with -O0)
  - From: Eric Botcazou

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]