[Bug tree-optimization/118273] New: [15 Regression] ICE when vectorizing uniform vector function

[tnfchris at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118273

            Bug ID: 118273
           Summary: [15 Regression] ICE when vectorizing uniform vector
                    function
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: tnfchris at gcc dot gnu.org
          Reporter: tnfchris at gcc dot gnu.org
  Target Milestone: ---

#pragma GCC target ("+sve")
extern char __attribute__ ((simd, const)) fn3 (short);
void test_fn3 (float *a, float *b, double *c, int n)
{
  for (int i = 0; i < n; ++i)
    a[i] = fn3 (c[i]);
}

segfaults when compiling with -Ofast -march=armv9-a with:

during GIMPLE pass: vect
dump file: /app/output.c.182t.vect
<source>: In function 'test_fn3':
<source>:21:6: internal compiler error: Segmentation fault
   21 | void test_fn3 (float *a, float *b, double *c, int n)
      |      ^~~~~~~~

Which happens in vect_get_loop_mask, the vectorizer registers a VNx16QI mode
mask and asks for 2 VNx8BI mode ones, which should be ok.

The rgroup is correctly created for two masks but the second entry's type is
NULL.

Mine.