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

["zsojka at seznam dot cz" <gcc-bugzilla@gcc.gnu.org>]

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)