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

[ktkachov at gcc dot gnu.org]

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

            Bug ID: 64821
           Summary: [AArch64] Improve target folding for vsqrt_f64
                    intrinsic
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: minor
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ktkachov at gcc dot gnu.org

Following the implementation of vsqrt_f64 with a target builtin:
https://gcc.gnu.org/ml/gcc-patches/2015-01/msg00699.html

it was suggested to add some target folding code into a sqrt when
-fno-math-errno is given:
https://gcc.gnu.org/ml/gcc-patches/2015-01/msg00710.html

This issue tracks that work that should be done for GCC 6