GLBenchmark 2.7's shaders contain conditional blocks like:
if (x) {
if (y) {
...
}
}
where the outer conditional's then clause contains exactly one statement
(the nested if) and there are no else clauses. This can easily be
optimized into:
if (x && y) {
...
}
This saves a few instructions in GLBenchmark 2.7:
total instructions in shared programs: 11833 -> 11649 (-1.55%)
instructions in affected programs: 8234 -> 8050 (-2.23%)
It also helps CS:GO slightly (-0.05%/-0.22%). More importantly,
however, it simplifies the control flow graph, which could enable other
optimizations.
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
