[Bug target/94680] New: Missed optimization with __builtin_shuffle and zero vector

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94680

            Bug ID: 94680
           Summary: Missed optimization with __builtin_shuffle and zero
                    vector
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jakub at gcc dot gnu.org
  Target Milestone: ---

typedef float V __attribute__((vector_size(16)));
typedef int VI __attribute__((vector_size(16)));

V
foo (V x)
{
  return __builtin_shuffle (x, (V) { 0, 0, 0, 0 }, (VI) {0, 1, 4, 5});
}

can be done using movq or vmovq in a single insn, rather than zeroing a
register and doing movlhps.