[Bug tree-optimization/100292] New: [12 Regression] ICE: verify_gimple failed: invalid operands in ternary operation (during GIMPLE pass: veclower) with vectors

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100292

            Bug ID: 100292
           Summary: [12 Regression] ICE: verify_gimple failed: invalid
                    operands in ternary operation (during GIMPLE pass:
                    veclower) with vectors
           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 50690
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50690&action=edit
reduced testcase

This seems to be a recent regression; r12-100 is OK, r12-159 is BAD.
I searched the bug database, and even though I am triggering this often on
various targets, I didn't find any duplicate.

Compiler output:
$ x86_64-pc-linux-gnu-gcc testcase.c
testcase.c: In function 'foo':
testcase.c:6:1: error: invalid operands in ternary operation
    6 | foo (char c)
      | ^~~
_13 = (signed char) c.1_2 >= 0 ? -1 : 0;
during GIMPLE pass: veclower
testcase.c:6:1: internal compiler error: verify_gimple failed
0x10b888a verify_gimple_in_cfg(function*, bool)
        /repo/gcc-trunk/gcc/tree-cfg.c:5507
0xf6f67f execute_function_todo
        /repo/gcc-trunk/gcc/passes.c:2042
0xf704f3 do_per_function
        /repo/gcc-trunk/gcc/passes.c:1687
0xf704f3 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-trunk-r12-159-20210427154247-g83d26d0e1b3-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r12-159-20210427154247-g83d26d0e1b3-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-r12-159-20210427154247-g83d26d0e1b3-checking-yes-rtl-df-extra-nobootstrap-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.0.0 20210427 (experimental) (GCC)