Re: c/9835: ICE - segfault using -msoft-float with latest mips-elf toolchain

[<fnf at intrinsity dot com>]

The following reply was made to PR c/9835; it has been noted by GNATS.

From: <fnf at intrinsity dot com>
To: gcc-gnats at gcc dot gnu dot org
Cc:  
Subject: Re: c/9835: ICE - segfault using -msoft-float with latest mips-elf toolchain
Date: Tue, 25 Feb 2003 16:21:43 -0600 (CST)

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 From: Fred Fish <fnf at public dot ninemoons dot com>
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 Subject: Re: c/9835: ICE - segfault using -msoft-float with latest mips-elf toolchain
 To: gcc-bugs at gcc dot gnu dot org
 Date: Tue, 25 Feb 2003 10:35:19 -0700 (MST)
 Cc: kazu at cs dot umass dot edu, fnf at intrinsity dot com
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 The following code (simplified from my original reported testcase)
 triggers an internal compiler error when compiled with -O2 and
 -msoft-float by the latest mips-elf toolchain:
 
   void
   foo ()
   {
     double dval;
     unsigned int ival;
   
     if (dval == 0)
       return;
     if (dval != dval)
       {
         bar (ival);
       }
     if (dval < 0)
       {
         bar (ival);
       }
   }
 
 For example:
 
   $ ./cc1 -O2 -msoft-float segfault.i
    foo
   segfault.i: In function `foo':
   segfault.i:17: internal compiler error: Segmentation fault  
 
 Comparing with a previously working compiler, I have backtracked the
 problem to a recent change made to cprop_jump().  The following patch
 that reverts one line of that change will sidestep the problem, but is
 probably NOT the right fix.  Unfortunately my knowledge of gcc
 internals is not sufficient for me to provide a better patch at this
 time.
 
   Index: gcse.c
   ===================================================================
   RCS file: /mips/newtools/fsf/gcc/gcc/gcse.c,v
   retrieving revision 1.3
   diff -u -p -r1.3 gcse.c
   --- gcse.c    2003/02/24 15:40:41     1.3
   +++ gcse.c    2003/02/25 17:29:28
   @@ -4064,7 +4064,7 @@ cprop_jump (bb, setcc, jump, from, src)
    
          new_set = simplify_replace_rtx (SET_SRC (set),
                                       SET_DEST (setcc_set),
   -                                   setcc_set_src);
   +                                   SET_SRC (setcc_set));
        }
      else
        new_set = set;
 
 -Fred