aco: disable omod if the sign of zeros should be preserved

The RDNA ISA doc says that omod doesn't preserve -0.0 in 6.2.2. LLVM
appears to always disable omod in this situation, but clamp is unaffected.

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Fixes: df645fa369d ("aco: implement VK_KHR_shader_float_controls")
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7605>
(cherry picked from commit 558daa73f9adb1275ddcf00515c7f79f726b7ae1)
2 files changed