[Bug tree-optimization/103517] New: ICE in as_a, at is-a.h:242 with -O2 -march=skylake-avx512

[vsevolod.livinskij at frtk dot ru]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103517

            Bug ID: 103517
           Summary: ICE in as_a, at is-a.h:242 with -O2
                    -march=skylake-avx512
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vsevolod.livinskij at frtk dot ru
  Target Milestone: ---

The same error exists for Sapphire Rapids

Reproducer:
int a;
short b, c;
extern short d[];
void e() {
  for (short f = 1; f < (short)a; f += 2)
    if (d[f + 1]) {
      b = d[f];
      c = d[f + 1];
    }
}

Error:
>$ g++ -O2 -march=skylake-avx512 -c func.cpp
during GIMPLE pass: vect
func.cpp: In function 'void e()':
func.cpp:4:6: internal compiler error: in as_a, at is-a.h:242
    4 | void e() {
      |      ^
0x8bc06a gphi const* as_a<gphi const*, gimple const>(gimple const*)
        /testing/gcc/gcc_src_master/gcc/is-a.h:242
0x8bc684 gcall* as_a<gcall*, gimple>(gimple*)
        /testing/gcc/gcc_src_master/gcc/tree-vect-slp.c:991
0x8bc684 vect_build_slp_tree_1
        /testing/gcc/gcc_src_master/gcc/tree-vect-slp.c:1155
0x14880cc vect_build_slp_tree_2
        /testing/gcc/gcc_src_master/gcc/tree-vect-slp.c:1711
0x1487a0c vect_build_slp_tree
        /testing/gcc/gcc_src_master/gcc/tree-vect-slp.c:1544
0x1488884 vect_build_slp_tree_2
        /testing/gcc/gcc_src_master/gcc/tree-vect-slp.c:2206
0x1487a0c vect_build_slp_tree
        /testing/gcc/gcc_src_master/gcc/tree-vect-slp.c:1544
0x148c230 vect_build_slp_instance
        /testing/gcc/gcc_src_master/gcc/tree-vect-slp.c:3019
0x148d6b5 vect_analyze_slp_instance
        /testing/gcc/gcc_src_master/gcc/tree-vect-slp.c:3339
0x14920d4 vect_analyze_slp(vec_info*, unsigned int)
        /testing/gcc/gcc_src_master/gcc/tree-vect-slp.c:3422
0x146d24a vect_analyze_loop_2
        /testing/gcc/gcc_src_master/gcc/tree-vect-loop.c:2331
0x146eef9 vect_analyze_loop_1
        /testing/gcc/gcc_src_master/gcc/tree-vect-loop.c:2830
0x146f40a vect_analyze_loop(loop*, vec_info_shared*)
        /testing/gcc/gcc_src_master/gcc/tree-vect-loop.c:2952
0x14a3359 try_vectorize_loop_1
        /testing/gcc/gcc_src_master/gcc/tree-vectorizer.c:1047
0x14a3359 try_vectorize_loop
        /testing/gcc/gcc_src_master/gcc/tree-vectorizer.c:1162
0x14a3fb4 execute
        /testing/gcc/gcc_src_master/gcc/tree-vectorizer.c:1278

gcc version 12.0.0 20211130 (6b8ecbc6d6652d061d7c72c64352d51eca2df6ca) (GCC)