Re: middle-end/10336: [3.4 regression] ICE with -Wunreachable-code

[Steven Bosscher <s.bosscher@student.tudelft.nl>]

The following reply was made to PR middle-end/10336; it has been noted by GNATS.

From: Steven Bosscher <s.bosscher@student.tudelft.nl>
To: gcc-gnats@gcc.gnu.org, reichelt@igpm.rwth-aachen.de,
	gcc-bugs@gcc.gnu.org, gcc-prs@gcc.gnu.org, jason@gcc.gnu.org,
	bangerth@gcc.gnu.org
Cc:  
Subject: Re: middle-end/10336: [3.4 regression] ICE with -Wunreachable-code
Date: Tue, 29 Apr 2003 00:29:12 +0200

 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10336
 
 Jason,
 
 Your patch added this line:
 
 + for (insn = PREV_INSN (avoided_insn); ; insn = PREV_INSN (insn))
 
 I fixed a bug some time ago where such a loop ignored
 BARRIER insns, walked the whole list of INSNs until insn
 was NULL, which caused a segfault.  It seems that for
 this test case, the same thing happens in your new loop.
 
 You can see in gdb that the C front end is ignoring
 "(barrier 14 13 15)".  Two insns later you have a the
 segfault...
 
 So maybe something like this would fix it??
 
 + for (insn = PREV_INSN (avoided_insn);
 +      GET_CODE (insn) != BARRIER;
 +      insn = PREV_INSN (insn))
 
 Assuming PREV_INSN (avoided_insn) is never NULL, but of
 course we make that assumption now, too.
 
 Can't test it this week.  Wolfgang, maybe you can, and if
 it works, submit a patch and use your new privileges? :-)
 
 Greetz
 Steven