[Bug middle-end/68393] New: internal compiler error: in convert_move, at expr.c:286

["anton at samba dot org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68393

            Bug ID: 68393
           Summary: internal compiler error: in convert_move, at
                    expr.c:286
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: anton at samba dot org
  Target Milestone: ---

I'm seeing an ICE on powerpc64le when building trunk:

x.c:3:9: internal compiler error: in convert_move, at expr.c:286
  return __builtin_clzll(x);
         ^~~~~~~~~~~~~~~~~~

0x104a8907 convert_move(rtx_def*, rtx_def*, int)
        ../../gcc/gcc/expr.c:286
0x105c12ab expand_direct_optab_fn
        ../../gcc/gcc/internal-fn.c:2114
0x105c1f17 expand_internal_call(internal_fn, gcall*)
        ../../gcc/gcc/internal-fn.c:2245
0x10348443 expand_call_stmt
        ../../gcc/gcc/cfgexpand.c:2565
0x10348443 expand_gimple_stmt_1
        ../../gcc/gcc/cfgexpand.c:3525
0x10348443 expand_gimple_stmt
        ../../gcc/gcc/cfgexpand.c:3688
0x1034a5df expand_gimple_basic_block
        ../../gcc/gcc/cfgexpand.c:5694
0x10351c87 execute
        ../../gcc/gcc/cfgexpand.c:6309

A testcase:

unsigned long foo(x)
{
        return __builtin_clzll(x);
}