[Bug other/79437] Redundant move instruction when getting sign bit of double on 32-bit architecture

[mizvekov at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79437

--- Comment #1 from Matheus Izvekov <mizvekov at gmail dot com> ---
Forgot to mention above, all gcc versions including the unreleased 7.0 and
below as far as I could test (4.6) are affected by this.

For comparison, clang generates optimal code for all cases.