Re: c/5250: ICE in print_rtl_and_abort, at flow.c:6458 with -O3

[Gwenole Beauchesne <gbeauchesne@mandrakesoft.com>]

The following reply was made to PR c/5250; it has been noted by GNATS.

From: Gwenole Beauchesne <gbeauchesne@mandrakesoft.com>
To: dmuell@gmx.net, gerold.jury@utanet.at, joel@gcc.gnu.org, maciej@imsa.edu,
        utx@penguin.cz, relf@os2.ru, snowwolf@one2one-networks.com,
        gcc-gnats@gcc.gnu.org, gcc-prs@gcc.gnu.org, gcc-bugs@gcc.gnu.org,
        nobody@gcc.gnu.org, nottelm@uni-muenster.de
Cc:  
Subject: Re: c/5250: ICE in print_rtl_and_abort, at flow.c:6458 with -O3
Date: Fri, 08 Feb 2002 23:09:39 +0100

 Hi,
 
 PR c/4257, PR c/5409, PR c/5250 appear to have been fixed in gcc-3.1 
 when Jan Hubicka killed jump_optimize: 
 <http://gcc.gnu.org/ml/gcc-patches/2001-07/msg01430.html> .
 
 I don't know if I get it right but the following patch attempts to 
 disable the NOOP_MOVES jump_optimization prior to register renaming.
 
 2002-02-08  Gwenole Beauchesne  <gbeauchesne@mandrakesoft.com>
 
     PR c/4257, PR c/5049, PR c/5250
     * toplev.c (rest_of_compilation): Don't perform NOOP_MOVES
     jump_optimization prior to register renaming. However, tidy the
     CFG by deleting unreachable code.
     * gcc.c-torture/compile/20020208-1.c: New test.
 
 --- 
 gcc-3.0.4/gcc/testsuite/gcc.c-torture/compile/20020208-1.c.no-noop_moves    
 Fri Feb  8 20:28:37 2002
 +++ gcc-3.0.4/gcc/testsuite/gcc.c-torture/compile/20020208-1.c    Fri 
 Feb  8 20:28:37 2002
 @@ -0,0 +1,11 @@
 +/* Origin: PR c/4257 from Volker Reichelt <reichelt@igpm.rwth-aachen.de>. 
 */
 +/* This testcase caused gcc-3.0.1 to ICE if compiled with -O1
 +   -frename-registers.  */
 +
 +void f ()
 +{
 +  unsigned int *p;
 +  p++;
 +  *p += *p / (*p < 2);
 +}
 +
 --- gcc-3.0.4/gcc/toplev.c.no-noop_moves    Fri Feb  8 20:01:51 2002
 +++ gcc-3.0.4/gcc/toplev.c    Fri Feb  8 20:01:51 2002
 @@ -3546,9 +3546,8 @@
    timevar_push (TV_FLOW2);
    open_dump_file (DFI_flow2, decl);
  
 -  jump_optimize (insns, !JUMP_CROSS_JUMP,
 -         JUMP_NOOP_MOVES, !JUMP_AFTER_REGSCAN);
    find_basic_blocks (insns, max_reg_num (), rtl_dump_file);
 +  cleanup_cfg ();
  
    /* On some machines, the prologue and epilogue code, or parts thereof,
       can be represented as RTL.  Doing so lets us schedule insns between
 
 
 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=5250