[Bug rtl-optimization/62041] vector fneg codegen uses a subtract instead of an xor (x86-64)

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62041

--- Comment #2 from Marc Glisse <glisse at gcc dot gnu.org> ---
https://gcc.gnu.org/ml/gcc-patches/2014-07/msg01812.html would most likely fix
it...