[Bug c/11319] New: [3.3 regression] loop miscompiled on ppc32

[marcus at jet dot franken dot de]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11319

           Summary: [3.3 regression] loop miscompiled on ppc32
           Product: gcc
           Version: 3.3
            Status: UNCONFIRMED
          Severity: critical
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: marcus at jet dot franken dot de
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: powerpc-unknown-linux-gnu
  GCC host triplet: powerpc-unknown-linux-gnu
GCC target triplet: powerpc-unknown-linux-gnu

Hi,  
  
attached testcase, extracted from the cast-256.c crypto module in libmcrypt,   
miscompiles on ppc32 with 3.2, 3.3 branch (gcc version 3.3.1 20030625 
(prerelease)) and HEAD (gcc version 3.4 20030625 (experimental)) with -O2:  
 
$ gcc -o xx ~meissner/cast-256.c  -O2  
$ ./xx  
xx: xx.c:27: main: Assertion `a == 0x13' failed.  
$  
  
With -fno-strength-reduce it starts to work:  
$ gcc -o xx ~meissner/cast-256.c  -O2 -fno-strength-reduce  
$ ./xx