[Bug tree-optimization/103253] New: [12 Regression] ICE: Segmentation fault (in convert_mult_to_fma)

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103253

            Bug ID: 103253
           Summary: [12 Regression] ICE: Segmentation fault (in
                    convert_mult_to_fma)
           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: asolokha at gmx dot com
  Target Milestone: ---
            Target: x86_64-unknown-linux-gnu

gcc-12.0.0-alpha20111114 snapshot (g:3057f1ab737582a9fb37a3fb967ed8bf3659f2f4)
ICEs when compiling the following testcase, reduced from
libgomp/testsuite/libgomp.c/examples-4/simd-8.c, w/ -march=knl -O2 -fexceptions
-fopenmp -fno-delete-dead-exceptions -fno-trapping-math:

double
do_work (double do_work_pri)
{
  int i;

#pragma omp simd
  for (i = 0; i < 17; ++i)
    do_work_pri = (!i ? 0.5 : i) * 2.0;

  return do_work_pri;
}

% x86_64-unknown-linux-gnu-gcc-12.0.0 -march=knl -O2 -fexceptions -fopenmp
-fno-delete-dead-exceptions -fno-trapping-math -c gdl8z9xi.c
during GIMPLE pass: widening_mul
gdl8z9xi.c: In function 'do_work':
gdl8z9xi.c:2:1: internal compiler error: Segmentation fault
    2 | do_work (double do_work_pri)
      | ^~~~~~~
0xeac96f crash_signal
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211114/work/gcc-12-20211114/gcc/toplev.c:322
0x104eecf contains_struct_check(tree_node*, tree_node_structure_enum, char
const*, int, char const*)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211114/work/gcc-12-20211114/gcc/tree.h:3554
0x104eecf convert_mult_to_fma
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211114/work/gcc-12-20211114/gcc/tree-ssa-math-opts.c:3227
0x105056c after_dom_children
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211114/work/gcc-12-20211114/gcc/tree-ssa-math-opts.c:4673
0x1b9ed62 dom_walker::walk(basic_block_def*)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211114/work/gcc-12-20211114/gcc/domwalk.c:352
0x10436e2 execute
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211114/work/gcc-12-20211114/gcc/tree-ssa-math-opts.c:4718