[Bug tree-optimization/123843] New: [13/14/15/16 Regression] during GIMPLE pass: forwprop ICE: verify_gimple failed: statement marked for throw, but doesn't with -O -ftrapv -finstrument-functions -fnon-call-exceptions

[zsojka at seznam dot cz via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123843

            Bug ID: 123843
           Summary: [13/14/15/16 Regression] during GIMPLE pass: forwprop
                    ICE: verify_gimple failed: statement marked for throw,
                    but doesn't with -O -ftrapv -finstrument-functions
                    -fnon-call-exceptions
           Product: gcc
           Version: 16.0
            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
            Target: x86_64-pc-linux-gnu

Created attachment 63501
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=63501&action=edit
reduced testcase

Compiler output:
$ x86_64-pc-linux-gnu-gcc -O -ftrapv -finstrument-functions
-fnon-call-exceptions testcase.c 
testcase.c: In function 'asn1_do_lock':
testcase.c:8:1: error: statement marked for throw, but doesn't
    8 | }
      | ^
_12 = (int) _20;
during GIMPLE pass: forwprop
testcase.c:8:1: internal compiler error: verify_gimple failed
0x2c97dbd internal_error(char const*, ...)
        /repo/gcc-trunk/gcc/diagnostic-global-context.cc:787
0x1690e0d verify_gimple_in_cfg(function*, bool, bool)
        /repo/gcc-trunk/gcc/tree-cfg.cc:5599
0x14db0fa execute_function_todo
        /repo/gcc-trunk/gcc/passes.cc:2100
0x14db637 execute_todo
        /repo/gcc-trunk/gcc/passes.cc:2152
/repo/gcc-trunk/binary-trunk-20260127192034-r16-7075-gfe050fa9d1249a-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/16.0.1/cc1
-quiet -iprefix
/repo/gcc-trunk/binary-trunk-20260127192034-r16-7075-gfe050fa9d1249a-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/../lib/gcc/x86_64-pc-linux-gnu/16.0.1/
testcase.c -quiet -dumpdir a- -dumpbase testcase.c -dumpbase-ext .c
-mtune=generic -march=x86-64 -O -ftrapv -finstrument-functions
-fnon-call-exceptions -o /tmp/cczrMJ7Q.s
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-20260127192034-r16-7075-gfe050fa9d1249a-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/16.0.1/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
--disable-bootstrap --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 --enable-libsanitizer
--disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-20260127192034-r16-7075-gfe050fa9d1249a-checking-yes-rtl-df-extra-nobootstrap-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 16.0.1 20260127 (experimental) (GCC)