[Bug tree-optimization/126475] New: [13/14/15/16/17 Regression] x * { 0.0f, 1.0f, ... } must not become x & mask when NaNs/Infs are honoured

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126475

            Bug ID: 126475
           Summary: [13/14/15/16/17 Regression] x * { 0.0f, 1.0f, ... }
                    must not become x & mask when NaNs/Infs are honoured
           Product: gcc
           Version: 17.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ktkachov at gcc dot gnu.org
  Target Milestone: ---

typedef float v4sf __attribute__((vector_size (16)));

__attribute__((noipa))
static v4sf f (v4sf x)
{
  return x * (v4sf) { 0.0f, 1.0f, 0.0f, 1.0f };
}

__attribute__((noipa))
static v4sf mk (float a, float b, float c, float d)
{
  v4sf r = { a, b, c, d };
  return r;
}

int main (void)
{
  v4sf x = mk (__builtin_inff (), 1.0f, __builtin_nanf (""), 3.0f);
  v4sf r = f (x);

  __builtin_printf ("r = %f %f %f %f\n", (double) r[0], (double) r[1],
                    (double) r[2], (double) r[3]);
  __builtin_printf ("isnan(r[0]) = %d  isnan(r[2]) = %d\n",
                    __builtin_isnan (r[0]), __builtin_isnan (r[2]));

  if (r[1] != 1.0f || r[3] != 3.0f)
    __builtin_abort ();
  /* +Inf * 0.0f and NaN * 0.0f are both NaN in IEEE-754.  */
  if (!__builtin_isnan (r[0]) || !__builtin_isnan (r[2]))
    __builtin_abort ();
  return 0;
}

aborts at -O2 -fno-signed-zeros on aarch64. GCC 8 seems to work fine, so
marking as regression.