Summary: This change enables all kind of carry out ISD opcodes to be selected according to the node divergence.
Reviewers: rampitec, arsenm, vpykhtin
Reviewed By: rampitec
Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78091
Summary:
Currently we custom select add/sub with carry out to scalar form relying on later replacing them to vector form if necessary.
This change enables custom selection code to take the divergence of adde/addc SDNodes into account and select the appropriate form in one step.
Reviewers: arsenm, vpykhtin, rampitec
Reviewed By: arsenm, vpykhtin
Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, kerbowa
Differential Revision: https://reviews.llvm.org/D76371
Summary:
pickNodeBidirectional tried to compare the best top candidate and the
best bottom candidate by examining TopCand.Reason and BotCand.Reason.
This is unsound because, after calling pickNodeFromQueue, Cand.Reason
does not reflect the most important reason why Cand was chosen. Rather
it reflects the most recent reason why it beat some other potential
candidate, which could have been for some low priority tie breaker
reason.
I have seen this cause problems where TopCand is a good candidate, but
because TopCand.Reason is ORDER (which is very low priority) it is
repeatedly ignored in favour of a mediocre BotCand. This is not how
bidirectional scheduling is supposed to work.
To fix this I changed the code to always compare TopCand and BotCand
directly, like the generic implementation of pickNodeBidirectional does.
This removes some uncommented AMDGPU-specific logic; if this logic turns
out to be important then perhaps it could be moved into an override of
tryCandidate instead.
Graphics shader benchmarking on gfx10 shows a lot more positive than
negative effects from this change.
Reviewers: arsenm, tstellar, rampitec, kzhuravl, vpykhtin, dstuttard, tpr, atrick, MatzeB
Subscribers: jvesely, wdng, nhaehnle, yaxunl, t-tye, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68338
We probably want this, and I've meant to turn this on for a long
time. SC actually emits a special case to early-out for a 1
denominator, which perhaps should also be considered.
Summary:
This fixes some tests that did not specify -mcpu. Doing that disables
all subtarget features, which gives behavior that (a) does not
necessarily correspond to any actual target, and (b) can change as we
add new subtarget features.
Also added gfx1010 to memtime test.
Differential Revision: https://reviews.llvm.org/D74594
Change-Id: I8c0fe4fa03e9a93ef8bb722cd42d22e064526309
I didn't realize we were already expanding 24/32-bit division here
already. Use the available IntegerDivision utilities. This uses loops,
so produces significantly smaller code than the inline DAG expansion.
This now requires width reductions of 64-bit divisions before
introducing the expanded loops.
This helps work around missing legalization in GlobalISel for
division, which are the only remaining core instructions that didn't
work at all.
I think this is plausibly a better implementation than exists in the
DAG, although turning it on by default misses out on the constant
value optimizations and also needs benchmarking.
alex-t