[Bug c/21761] New: mainline gcc causing internal compiler error.

["uttamp at us dot ibm dot com" <gcc-bugzilla at gcc dot gnu dot org>]

test case:
$ cat bug1.c
void f1()
{
  long bit=0, exponent;
  exponent = -exponent;
  for (bit = 1; exponent; bit <<= 1)
      if (exponent & bit)
              exponent ^= bit;
}

# Compilation parameters
$ gcc -c -O3 -m64 bug1,c

gcc gives internal compiler error on Powerpc platform.

bug1.c: In function &#8216;f1&#8217;:
bug1.c:8: error: could not split insn
(insn:TI 13 11 14 (parallel [
            (set (reg:CC 75 7 [125])
                (compare:CC (neg:DI (reg/v:DI 0 0 [orig:119 exponent ] [119]))
                    (const_int 0 [0x0])))
            (set (reg/v:DI 0 0 [orig:118 exponent.1 ] [118])
                (neg:DI (reg/v:DI 0 0 [orig:119 exponent ] [119])))
        ]) 76 {*rs6000.md:1653} (nil)
    (nil))
bug1.c:8: internal compiler error: in final_scan_insn, at final.c:2419
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

Compiler works with all other optimization flags.

After doing reghunt I found a patch, which may not necessarily have caused the
above failure but compiler started failing after application of this patch, 

http://gcc.gnu.org/ml/gcc-cvs/2005-05/msg00232.html

-- 
           Summary: mainline gcc causing internal compiler error.
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: uttamp at us dot ibm dot com
                CC: gcc-bugs at gcc dot gnu dot org,geoffk at gcc dot gnu
                    dot org,uttamp at us dot ibm dot com
 GCC build triplet: powerpc64-linux
  GCC host triplet: powerpc64-linux
GCC target triplet: powerpc64-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21761