[Bug target/96177] New: ICE: in extract_insn, at recog.c:2294 (error: unrecognizable insn)

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96177

            Bug ID: 96177
           Summary: ICE: in extract_insn, at recog.c:2294 (error:
                    unrecognizable insn)
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---
            Target: powerpc-*-linux-gnu

gcc-11.0.0-alpha20200705 snapshot (g:cc9a9229285a26ac12bc8de53237ce9c4d42f867)
ICEs when compiling the following testcase, extracted from
gcc/testsuite/gcc.target/powerpc/xxgenpc-runnable.c, w/ -mcpu=power10:

__attribute__ ((altivec (vector__))) char
ew (__attribute__ ((altivec (vector__))) char uk)
{
  return __builtin_vec_xxgenpcvm (uk, 1);
}

% powerpc-e300c3-linux-gnu-gcc-11.0.0 -mcpu=power10 -c rwmfukd0.c
rwmfukd0.c: In function 'ew':
rwmfukd0.c:5:1: error: unrecognizable insn:
    5 | }
      | ^
(insn 7 6 10 2 (set (reg:V16QI 117 [ _2 ])
        (unspec:V16QI [
                (reg:V16QI 119)
                (const_int 1 [0x1])
            ] UNSPEC_XXGENPCV)) "rwmfukd0.c":4:10 -1
     (nil))
during RTL pass: vregs
rwmfukd0.c:5:1: internal compiler error: in extract_insn, at recog.c:2294
0x696456 _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-11.0.0_alpha20200705/work/gcc-11-20200705/gcc/rtl-error.c:108
0x696476 _fatal_insn_not_found(rtx_def const*, char const*, int, char const*)
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-11.0.0_alpha20200705/work/gcc-11-20200705/gcc/rtl-error.c:116
0x694697 extract_insn(rtx_insn*)
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-11.0.0_alpha20200705/work/gcc-11-20200705/gcc/recog.c:2294
0xb23a93 instantiate_virtual_regs_in_insn
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-11.0.0_alpha20200705/work/gcc-11-20200705/gcc/function.c:1607
0xb23a93 instantiate_virtual_regs
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-11.0.0_alpha20200705/work/gcc-11-20200705/gcc/function.c:1977
0xb23a93 execute
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-11.0.0_alpha20200705/work/gcc-11-20200705/gcc/function.c:2026