We also add a DCE pass to cleanup the result of this pass, which turns
out to also be necessary to cleanup the result of nir->gpir in some
cases that we didn't hit until the next commit.
Reviewed-by: Vasily Khoruzhick <anarsoul@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4125>
Optimize the result of a conditional break/continue. In NIR something
like:
loop {
...
if (cond)
continue;
would get lowered to:
block_0:
...
block_1:
branch_cond !cond block_3
block_2:
branch_uncond block_0
block_3:
...
We recognize the conditional branch skipping over the unconditional
branch, and turn it into:
block_0:
...
block_1:
branch_cond cond block_0
block_2:
block_3:
Reviewed-by: Vasily Khoruzhick <anarsoul@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4125>
Eric Engestrom
Vasily Khoruzhick
Connor Abbott