[Bug tree-optimization/113737] New: ICE: in lower_stmt, at gimple-lower-bitint.cc:5455 with _BitInt() used in switch at -O2

[Bug tree-optimization/113737] New: ICE: in lower_stmt, at gimple-lower-bitint.cc:5455 with _BitInt() used in switch at -O2

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113737

            Bug ID: 113737
           Summary: ICE: in lower_stmt, at gimple-lower-bitint.cc:5455
                    with _BitInt() used in switch at -O2
           Product: gcc
           Version: 14.0
            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
                CC: jakub at gcc dot gnu.org
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu

Created attachment 57304
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57304&action=edit
reduced testcase (from gcc.dg/pr80823.c)

Compiler output:
$ x86_64-pc-linux-gnu-gcc -O2 testcase.c 
during GIMPLE pass: bitintlower
testcase.c: In function 'fn2':
testcase.c:16:1: internal compiler error: in lower_stmt, at
gimple-lower-bitint.cc:5455
   16 | fn2(int i)
      | ^~~
0xd898b9 lower_stmt
        /repo/gcc-trunk/gcc/gimple-lower-bitint.cc:5455
0x274dc73 gimple_lower_bitint
        /repo/gcc-trunk/gcc/gimple-lower-bitint.cc:6575
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
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-r14-8771-20240203001826-g4b7d4d8a4af-checking-yes-rtl-df-extra-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/14.0.1/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
--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-r14-8771-20240203001826-g4b7d4d8a4af-checking-yes-rtl-df-extra-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 14.0.1 20240203 (experimental) (GCC)

[Bug tree-optimization/113737] ICE: in lower_stmt, at gimple-lower-bitint.cc:5455 with _BitInt() used in switch at -O2

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113737

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
   Last reconfirmed|                            |2024-02-03
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |ASSIGNED

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 57311
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57311&action=edit
gcc14-pr113737.patch

Untested fix.

[Bug tree-optimization/113737] ICE: in lower_stmt, at gimple-lower-bitint.cc:5455 with _BitInt() used in switch at -O2

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113737

--- Comment #2 from GCC 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:dede174fbb57bdd3e26f322b6096d53edf0089c4

commit r14-8798-gdede174fbb57bdd3e26f322b6096d53edf0089c4
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Mon Feb 5 10:57:39 2024 +0100

    lower-bitint: Remove single label _BitInt switches [PR113737]

    The following testcase ICEs, because group_case_labels_stmt optimizes
      switch (a.0_7) <default: <L6> [50.00%], case 0: <L7> [50.00%], case 2:
<L7> [50.00%]>
    where L7 block starts with __builtin_unreachable (); to
      switch (a.0_7) <default: <L6> [50.00%]>
    and single label GIMPLE_SWITCH is something the switch expansion refuses to
    lower:
      if (gimple_switch_num_labels (m_switch) == 1
          || range_check_type (index_type) == NULL_TREE)
        return false;
    (range_check_type never returns NULL for BITINT_TYPE), but the gimple
    lowering pass relies on all large/huge _BitInt switches to be lowered
    by that pass.

    The following patch just removes those after making the single successor
    edge EDGE_FALLTHRU.  I've done it even if !optimize just in case in case
    we'd end up with single case label from earlier passes.

    2024-02-05  Jakub Jelinek  <jakub@redhat.com>

            PR tree-optimization/113737
            * gimple-lower-bitint.cc (gimple_lower_bitint): If GIMPLE_SWITCH
            has just a single label, remove it and make single successor edge
            EDGE_FALLTHRU.

            * gcc.dg/bitint-84.c: New test.

[Bug tree-optimization/113737] ICE: in lower_stmt, at gimple-lower-bitint.cc:5455 with _BitInt() used in switch at -O2

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113737

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

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

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Fixed.