drm/radeon: refactor register check loop
drm/radeon: refactor register check loop

After this patch the register check loop does the same thing as before,
except that now gcc does better job optimizing it: it now sees that
end_reg was already checked against PACKET3_SET_CONTEXT_REG_END and can
optimize REG_SAFE_BM_SIZE comparison out of evergreen_is_safe_reg()
as (PACKET3_SET_CONTEXT_REG_END >> 7) < REG_SAFE_BM_SIZE.

Reviewed-by: Dave Airlie <f2295d84e358395675bc8031be58672073ae065e@redhat.com>
Signed-off-by: Grazvydas Ignotas <eac34e836c3bc120048c86fead6dd0257a872a9e@gmail.com>
Signed-off-by: Alex Deucher <08dc22c6156113f2deff178e35e3ed9b24d6af9e@amd.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs