[Bug target/64821] [AArch64] Improve target folding for vsqrt_f64 intrinsic

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64821

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
One more testcase where we get folding now:
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-optimized" } */
/* { dg-final { scan-tree-dump-times ".SQRT" 0 "optimized" } } */
/* { dg-final { scan-tree-dump-times "2.0" 1 "optimized" } } */
/* { dg-final { scan-assembler-times "fsqrt" 0 } } */
/* We should produce a fmov to d0 with 2.0 but currently don't, see PR 103959.
*/
/* { dg-final { scan-assembler-times "\n\tfmov\td0, 2.0e.0" 1 { xfail *-*-* } }
} */

#include <arm_neon.h>

float64x1_t f64(void)
{
   float64x1_t a = (float64x1_t){4.0};
   return vsqrt_f64 (a);
}