[Bug middle-end/56548] New: [4.8 Regression] ICE in emit_move_insn, at expr.c:3486 with -march=pentium{pro,2,3} -O3

["d.g.gorbachev at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56548

             Bug #: 56548
           Summary: [4.8 Regression] ICE in emit_move_insn, at expr.c:3486
                    with -march=pentium{pro,2,3} -O3
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: d.g.gorbachev@gmail.com


GCC 4.8.0 20130303 (experimental).

$ cat > bug.c
short foo(short x)
{
  int i;

  for (i = 0; i < 3; i++)
    if (x > 0)
      x--;

  return x;
}
^D
$ gcc -S -O3 -march=pentium3 bug.c
bug.c: In function 'foo':
bug.c:9:3: internal compiler error: in emit_move_insn, at expr.c:3486
   return x;
   ^
0x834eaa1 emit_move_insn(rtx_def*, rtx_def*)
    ../../gcc-4.8/gcc/expr.c:3485
0x8600ef9 expand_value_return
    ../../gcc-4.8/gcc/stmt.c:1461
0x86068d8 expand_return(tree_node*)
    ../../gcc-4.8/gcc/stmt.c:1547
0x825eefc expand_gimple_stmt_1
    ../../gcc-4.8/gcc/cfgexpand.c:2182
0x825f82c expand_gimple_stmt
    ../../gcc-4.8/gcc/cfgexpand.c:2304
0x8262484 expand_gimple_basic_block
    ../../gcc-4.8/gcc/cfgexpand.c:4083
0x82648c8 gimple_expand_cfg
    ../../gcc-4.8/gcc/cfgexpand.c:4602

GCC 20121118 (r193607) - fails, 20121111 (r193417) - works.