aco: don't do divergent break+discard
If the shader does:
loop {
if (divergent)
discard
else
a()
b()
}
then a()'s block will dominate b()'s block in the logical CFG, but not the
linear CFG. This will cause value numbering to try to combine SLAU from
a() and b().
This didn't happen with break/continue because sanitize_if() would move
a() out of the branch. Using sanitize_if() to fix this doesn't look easy,
because discards are not control flow instructions in NIR.
No fossil-db changes.
Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7216>
1 file changed
