[PATCH] D113105: [InstCombine] Extend stacksave/restore elimination

[Itay Bookstein via Phabricator via llvm-commits]

nextsilicon-itay-bookstein added inline comments.


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp:1813-1814
+        for (++BI; &*BI != II; ++BI) {
+          if (Classify(&*BI) == ClassifyResult::None)
+            continue;
+
----------------
lebedev.ri wrote:
> nextsilicon-itay-bookstein wrote:
> > lebedev.ri wrote:
> > > What about stackrestore from the same stacksave?
> > Then it will have been eliminated when it was the subject of the enclosing switch statement, before this one was. I will add an appropriate comment.
> I'm mainly highlighting that it might not have already happened because of the processing order.
> It would be really hard to come up with an appropriate test manually,
> but i suspect it is possible.
I see. So it's a matter of not not deferring the work to the next InstCombine iteration (or missing the opportunity if it's we're at the iteration cap). Would you prefer that I replace the comment with the check?


Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D113105/new/

https://reviews.llvm.org/D113105