[Bug tree-optimization/110671] New: ICE on valid code at -O2 and -O3 on x86_64-linux-gnu: in gimple_phi_arg_def_from_edge, at gimple.h:4699

[zhendong.su at inf dot ethz.ch via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110671

            Bug ID: 110671
           Summary: ICE on valid code at -O2 and -O3 on x86_64-linux-gnu:
                    in gimple_phi_arg_def_from_edge, at gimple.h:4699
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zhendong.su at inf dot ethz.ch
  Target Milestone: ---

It appears to be a very recent regression.

[631] % gcctk -v
Using built-in specs.
COLLECT_GCC=gcctk
COLLECT_LTO_WRAPPER=/local/home/suz/suz-local/software/local/gcc-trunk/bin/../libexec/gcc/x86_64-pc-linux-gnu/14.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-trunk/configure --disable-bootstrap
--enable-checking=yes --prefix=/local/suz-local/software/local/gcc-trunk
--enable-sanitizers --enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 14.0.0 20230714 (experimental) (GCC) 
[632] % 
[632] % gcctk -O2 -c small.c
during GIMPLE pass: sccp
small.c: In function ‘main’:
small.c:3:5: internal compiler error: in gimple_phi_arg_def_from_edge, at
gimple.h:4699
    3 | int main() {
      |     ^~~~
0x80ec9d gimple_phi_arg_def_from_edge(gphi const*, edge_def const*)
        ../../gcc-trunk/gcc/gimple.h:4699
0x8101ae gimple_phi_arg_def_from_edge(gphi const*, edge_def const*)
        ../../gcc-trunk/gcc/tree.h:3700
0x8101ae final_value_replacement_loop(loop*)
        ../../gcc-trunk/gcc/tree-scalar-evolution.cc:3732
0x118a1a5 execute
        ../../gcc-trunk/gcc/tree-ssa-loop.cc:411
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.
[633] % 
[633] % cat small.c
extern void f();
int a;
int main() {
  int *b = &a, c = 1, d;
 L:
  if (a)
    for (; d < 1; d++) {
      if (a)
        f();
      *b |= c;
    }
  c = 0;
  if (a)
    goto L;
  return 0;
}