[Bug target/80210] New: ICE in in extract_insn, at recog.c:2311 on ppc64 for with __builtin_pow

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80210

            Bug ID: 80210
           Summary: ICE in in extract_insn, at recog.c:2311 on ppc64 for
                    with __builtin_pow
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
  Target Milestone: ---
              Host: x86_64-linux-gnu
            Target: ppc64-linux-gnu

Following test-case ICEs:

$ cat /tmp/ice.c
double
do_pow_0_5_default (double a)
{
  return __builtin_pow (a, 0.5);        /* should generate fsqrt */
}

#pragma GCC target "no-powerpc-gpopt,no-powerpc-gfxopt"

#pragma GCC reset_options

$ ppc64-linux-gnu-gcc -Ofast /tmp/ice.c
/tmp/ice.c: In function ‘do_pow_0_5_default’:
/tmp/ice.c:5:1: error: unrecognizable insn:
 }
 ^
(insn 6 3 10 2 (set (reg:DF 155 [ <retval> ])
        (sqrt:DF (reg/v:DF 156 [ a ]))) "/tmp/ice.c":4 -1
     (nil))
/tmp/ice.c:5:1: internal compiler error: in extract_insn, at recog.c:2311
0xb0d1d8 _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
        .././../gcc/rtl-error.c:108
0xb0d209 _fatal_insn_not_found(rtx_def const*, char const*, int, char const*)
        .././../gcc/rtl-error.c:116
0xade5f1 extract_insn(rtx_insn*)
        .././../gcc/recog.c:2311
0x8a1ee3 instantiate_virtual_regs_in_insn
        .././../gcc/function.c:1589
0x8a1ee3 instantiate_virtual_regs
        .././../gcc/function.c:1957
0x8a1ee3 execute
        .././../gcc/function.c:2006