[Bug target/47800] New: [4.6 Regression] i?86 peephole related ICE

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47800

           Summary: [4.6 Regression] i?86 peephole related ICE
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: jakub@gcc.gnu.org
        ReportedBy: jakub@gcc.gnu.org
            Target: x86_64-linux


int
foo (unsigned char *x, unsigned char *y)
{
  unsigned char a;
  for (a = 0; x < y; x++)
    if (a & 0x80)
      a = (unsigned char) (a << 1) + 1 + *x;
    else
      a = (unsigned char) (a << 1) + *x;
  return a;
}

ICEs at -O2 -march=nocona:
rh678530.i: In function 'foo':
rh678530.i:11:1: error: unrecognizable insn:
(insn 79 29 80 5 (set (subreg:SI (reg:DI 2 cx) 0)
        (mem:QI (reg/v/f:DI 5 di [orig:85 x ] [85]) [0 *x_21+0 S1 A8]))
rh678530.i:7 -1
     (nil))
rh678530.i:11:1: internal compiler error: in extract_insn, at recog.c:2109
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

starting with
http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=161570