[Bug tree-optimization/102141] New: [12 Regression] ICE: verify_ssa failed during GIMPLE pass: bswap at -O2

[Bug tree-optimization/102141] New: [12 Regression] ICE: verify_ssa failed during GIMPLE pass: bswap at -O2

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102141

            Bug ID: 102141
           Summary: [12 Regression] ICE: verify_ssa failed during GIMPLE
                    pass: bswap at -O2
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu

Created attachment 51386
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51386&action=edit
reduced testcase

Compiler output:
$ x86_64-pc-linux-gnu-gcc -O2 testcase.c
testcase.c: In function 'foo':
testcase.c:4:1: error: definition in block 2 follows the use
    4 | foo (unsigned long x)
      | ^~~
for SSA_NAME: bswapdst_14 in statement:
_15 = (unsigned int) bswapdst_14;
during GIMPLE pass: bswap
testcase.c:4:1: internal compiler error: verify_ssa failed
0x14f5bb1 verify_ssa(bool, bool)
        /repo/gcc-trunk/gcc/tree-ssa.c:1214
0x11b7d85 execute_function_todo
        /repo/gcc-trunk/gcc/passes.c:2049
0x11b8af3 do_per_function
        /repo/gcc-trunk/gcc/passes.c:1687
0x11b8af3 execute_todo
        /repo/gcc-trunk/gcc/passes.c:2096
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r12-3244-20210831062827-gaba800615e1-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/12.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--disable-bootstrap --with-cloog --with-ppl --with-isl
--build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu
--target=x86_64-pc-linux-gnu --with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r12-3244-20210831062827-gaba800615e1-checking-yes-rtl-df-extra-nobootstrap-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.0.0 20210831 (experimental) (GCC)

[Bug tree-optimization/102141] [12 Regression] ICE: verify_ssa failed during GIMPLE pass: bswap at -O2

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102141

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-08-31
   Target Milestone|---                         |12.0

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed, most likely caused by r12-3072.

[Bug tree-optimization/102141] [12 Regression] ICE: verify_ssa failed during GIMPLE pass: bswap at -O2 since r12-3072-gb320edc0c29c838b

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102141

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|11.2.0                      |
            Summary|[12 Regression] ICE:        |[12 Regression] ICE:
                   |verify_ssa failed during    |verify_ssa failed during
                   |GIMPLE pass: bswap at -O2   |GIMPLE pass: bswap at -O2
                   |                            |since
                   |                            |r12-3072-gb320edc0c29c838b
           Priority|P3                          |P1
                 CC|                            |jakub at gcc dot gnu.org,
                   |                            |marxin at gcc dot gnu.org
   Last reconfirmed|2021-08-31 00:00:00         |

--- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> ---
Thanks for the report, started with r12-3072-gb320edc0c29c838b.

[Bug tree-optimization/102141] [12 Regression] ICE: with single element vector and the bswap pass at -O2 since r12-3072-gb320edc0c29c838b

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102141

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=101540

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I cannot get this to reproduce any other way than with a constructor of a
single element vector.

[Bug tree-optimization/102141] [12 Regression] ICE: with single element vector and the bswap pass at -O2 since r12-3072-gb320edc0c29c838b

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102141

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |jakub at gcc dot gnu.org
             Status|NEW                         |ASSIGNED

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 51387
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51387&action=edit
gcc12-pr102141.patch

Untested fix.

[Bug tree-optimization/102141] [12 Regression] ICE: with single element vector and the bswap pass at -O2 since r12-3072-gb320edc0c29c838b

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102141

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:45ff12512e568089a4c7b85b5322ab8019723cd9

commit r12-3280-g45ff12512e568089a4c7b85b5322ab8019723cd9
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Wed Sep 1 12:06:25 2021 +0200

    bswap: Fix up bswap_view_convert handling [PR102141]

    bswap_view_convert is used twice in spots where gsi_insert_before is the
    right thing, but in the last one it wants to insert preparation stmts
    for the VIEW_CONVERT_EXPR emitted with gsi_insert_after, where at the
    gsi we still need to insert bswap_stmt and maybe mask_stmt whose lhs
    the preparation stmts will use.
    So, this patch adds a BEFORE argument to the function and emits the
    preparation statements before or after depending on that.

    2021-09-01  Jakub Jelinek  <jakub@redhat.com>

            PR tree-optimization/102141
            * gimple-ssa-store-merging.c (bswap_view_convert): Add BEFORE
            argument.  If false, emit stmts after gsi instead of before, and
            with GSI_NEW_STMT.
            (bswap_replace): Adjust callers.  When converting output of bswap,
            emit VIEW_CONVERT prepratation stmts after a copy of gsi instead
            of before it.

            * gcc.dg/pr102141.c: New test.

[Bug tree-optimization/102141] [12 Regression] ICE: with single element vector and the bswap pass at -O2 since r12-3072-gb320edc0c29c838b

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102141

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

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

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Fixed.