optimization/8492: [3.3 regression] GCC spins forever compiling loop

[Eric Botcazou]

The following reply was made to PR optimization/8492; it has been noted by GNATS.

From: Eric Botcazou <ebotcazou@libertysurf.fr>
To: janis187@us.ibm.com
Cc: gcc-gnats@gcc.gnu.org,
 gcc-prs@gcc.gnu.org,
 gcc-bugs@gcc.gnu.org,
 nobody@gcc.gnu.org,
 thorpej@shagadelic.org,
 jh@suse.cz
Subject: Re: optimization/8492: [3.3 regression] GCC spins forever compiling loop
Date: Sat, 21 Dec 2002 11:54:46 +0100

 > The mainline regression reported in PR optimization/8492
 > (an infinite loop in the compiler) showed up starting with
 > this patch:
 >
 > Sun Jul 21 00:54:54 CEST 2002  Jan Hubicka  <jh@suse.cz>
 >
 >         * gcse.c: Include cselib.h
 >         (constptop_register): Break out from ...
 >         (cprop_insn): ... here; kill basic_block argument.
 >         (do_local_cprop, local_cprop_pass): New functions.
 >         (one_cprop_pass): Call local_cprop_pass.
 >
 
 Ha! I understand now... see the analysis:
 http://gcc.gnu.org/ml/gcc/2002-12/msg00039.html
 
 I think the CFG should be cleaned up between the local cprop pass and the=
 =20
 global cprop pass, but I guess doing so won't particularly speed up the=20
 compiler, to say the least.
 
 --=20
 Eric Botcazou