[Bug c++/96273] New: ice in extract_insn, at recog.c:2294, unrecognizable insn:

[Bug c++/96273] New: ice in extract_insn, at recog.c:2294, unrecognizable insn:

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96273

            Bug ID: 96273
           Summary: ice in extract_insn, at recog.c:2294, unrecognizable
                    insn:
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

Created attachment 48911
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48911&action=edit
gzipped C++ source code

The attached C++ code does this with today's gcc trunk:

splat.cpp:1637:1: error: unrecognizable insn:
(insn 1137 1136 1138 163 (set (mem/v:BLK (scratch:DI) [0  A8])
        (unspec:BLK [
                (mem/v:BLK (scratch:DI) [0  A8])
            ] UNSPEC_MFENCE)) -1
     (nil))
during RTL pass: vregs
splat.cpp:1637:1: internal compiler error: in extract_insn, at recog.c:2294
0xef8b46 _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
        ../../trunk.git/gcc/rtl-error.c:108
0xef8b6b _fatal_insn_not_found(rtx_def const*, char const*, int, char const*)
        ../../trunk.git/gcc/rtl-error.c:116
0xebf423 extract_insn(rtx_insn*)
        ../../trunk.git/gcc/recog.c:2294

Flags -O3 -march=native required. native is Piledriver. I'll
have a go at reducing the code.

This code used to work at date 20200719, so someone has broken
something in the last day or two.

[Bug target/96273] ice in extract_insn, at recog.c:2294, unrecognizable insn:

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96273

--- Comment #1 from David Binderman <dcb314 at hotmail dot com> ---
Reduced C++ code:

int b, c, e;
int d[1];
void f() {
  int a;
  for (;;) {
    c = 0;
    for (; c <= 1000; b += 10, c++) {
      a = 0;
      for (; a < 10; a++)
        if (b)
          e += d[b] = e;
    }
  }
}

[Bug target/96273] ice in extract_insn, at recog.c:2294, unrecognizable insn:

[crazylht at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96273

Hongtao.liu <crazylht at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ubizjak at gmail dot com

--- Comment #2 from Hongtao.liu <crazylht at gmail dot com> ---
Caused by patch in PR95750?

[Bug target/96273] ice in extract_insn, at recog.c:2294, unrecognizable insn:

[ubizjak at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96273

Uroš Bizjak <ubizjak at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #3 from Uroš Bizjak <ubizjak at gmail dot com> ---
Already fixed.