[Bug tree-optimization/104497] New: SEGV during GIMPLE pass: pre

[jbeulich at suse dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104497

            Bug ID: 104497
           Summary: SEGV during GIMPLE pass: pre
           Product: gcc
           Version: 11.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jbeulich at suse dot com
  Target Milestone: ---

Compiling this

// -msse2 (on ix86) or -msse4 or -mavx
// -O0 and -O1 are okay; -Os and -O2 are not

typedef float __attribute__((mode(SF), vector_size(16))) vec_t;

extern vec_t src, inv;

void aux(vec_t);

void test(void)
{
    unsigned int i;
    vec_t y;

    for (i = 0; i < (16 / 4); ++i)
        y[i] = (i & 1 ? inv : src)[i];

    aux(y);
}

yields

$ gccver=11.2.0-base gccx -Wall -W -Os -msse2 -c simd-test2.c
during GIMPLE pass: pre
simd-test2.c: In function ‘test’:
simd-test2.c:10:6: internal compiler error: Segmentation fault
   10 | void test(void)
      |      ^~~~
0x877d21a crash_signal
        /usr/local/src/gcc-11.2.0/gcc/toplev.c:327
0x88d5bdd phi_translate_1
        /usr/local/src/gcc-11.2.0/gcc/tree-ssa-pre.c:1717
0x88d67f9 phi_translate
        /usr/local/src/gcc-11.2.0/gcc/tree-ssa-pre.c:1770
0x88d8d4b phi_translate_set
        /usr/local/src/gcc-11.2.0/gcc/tree-ssa-pre.c:1815
0x88d9067 compute_antic_aux
        /usr/local/src/gcc-11.2.0/gcc/tree-ssa-pre.c:2155
0x88da2c5 compute_antic
        /usr/local/src/gcc-11.2.0/gcc/tree-ssa-pre.c:2501
0x88da2c5 execute
        /usr/local/src/gcc-11.2.0/gcc/tree-ssa-pre.c:4386

This same code compiles fine with gcc 10.