[Bug target/54716] Select best typed instruction for bitwise operations

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54716

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-09-26 15:40:53 UTC ---
On
#define vector __attribute__ ((vector_size (16)))

__attribute__((noinline, noclone))
vector float foo(vector float f, vector float h)
{
  vector int g = { 0x80000000, 0, 0x80000000, 0 };
  vector int f_int = (vector int) f;
  return ((vector float) (f_int ^ g)) + h;
}

vector float a = { 1.0, 2.0, 3.0, 4.0 }, b = { 5.0, 6.0, 7.0, 8.0 }, c = { 9.0,
10.0, 11.0, 12.0 }, r;

int
main ()
{
  int i;
  for (i = 0; i < 1000000000; i++)
    {
      asm volatile ("" : : : "memory");
      r = foo(a + b, a + c) - a;
      asm volatile ("" : : : "memory");
    }
  return 0;
}

I haven't noticed a measurable performance difference though on Intel SNB 2600
CPU though, so perhaps the patch isn't needed.