optimization/8110: GCC 3.2: wrong code optimization with -O2

optimization/8110: GCC 3.2: wrong code optimization with -O2

[dyatchkov]

>Number:         8110
>Category:       optimization
>Synopsis:       GCC 3.2: wrong code optimization with -O2
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          wrong-code
>Submitter-Id:   net
>Arrival-Date:   Tue Oct 01 09:26:00 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     Ilia Dyatchkov
>Release:        3.2
>Organization:
>Environment:
System: SunOS 5.8 (Solaris 8)
Architecture: sparc
host: sparc-sun-solaris2.8
build: sparc-sun-solaris2.8
target: sparc-sun-solaris2.8
configured with: /home/username/src/gcc-3.2/configure --prefix=/home/username/usr --disable-multilib --enable-languages=c,c++,f77 --norecursion
>Description:
cc1 in spec's CINT2000 176.gcc aborts when it made by gcc 3.2 with -O2 (or higher) option. The test works correctly when we use gcc with lower optimization. The test also works after compiling by gcc 2.95.2  with -Os.
It aborts at the end of expand_expr function (in expr.c) because temp=0 (in what way?).
>How-To-Repeat:
Configure SPEC CPU2000 with following settings

ext		= compsys
tune		= base
iterations	= 1
size		= test
OPTIMIZE	= -O2 // or higher

and run runspec.

Or you can make $(SPEC)/benchspec/CINT2000/176.gcc/src/ and then run (spec)cc1 for compiling $(SPEC)/benchspec/CINT2000/176.gcc/data/train/input/cp-decl.i.
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted:

Re: optimization/8110: GCC 3.2: wrong code optimization with -O2

[rth]

Synopsis: GCC 3.2: wrong code optimization with -O2

State-Changed-From-To: open->closed
State-Changed-By: rth
State-Changed-When: Tue Oct  1 14:19:00 2002
State-Changed-Why:
    The code in rtx_alloc is broken in spec2k.  Use the following.
    
    --- rtl.c.orig  Tue Oct  1 14:16:34 2002
    +++ rtl.c       Tue Oct  1 14:17:35 2002
    @@ -234,9 +234,7 @@
          one int, but we don't want to assume that and it isn't very portable
          anyway; this is.  */
     
    -  length = (sizeof (struct rtx_def) - sizeof (rtunion) - 1) / sizeof (int);
    -  for (; length >= 0; length--)
    -    ((int *) rt)[length] = 0;
    +  memset (rt, 0, sizeof (struct rtx_def) - sizeof (rtunion));
     
       PUT_CODE (rt, code);
     

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8110