[PATCH] D33058: [LV] Sink casts to unravel first order recurrence

[Ayal Zaks via Phabricator via llvm-commits]

Ayal added inline comments.


================
Comment at: lib/Transforms/Utils/LoopUtils.cpp:564
+    auto *I = Phi->user_back();
+    if (I->isCast() && (I->getParent() == Phi->getParent()) && I->hasOneUse() &
+        DT->dominates(Previous, I->user_back())) {
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Ayal wrote:
> aemerson wrote:
> > Bug here, bitwise `&` used. Which is also telling me that there aren't sufficient tests for this, especially the case where Previous doesn't dominate the cast's user and so the cast can't be legally sunk past Previous.
> Right, thanks!
Fixed. (Missing '&' fell off column 80 I guess ;-)

Added a test as mentioned above where Previous (the load) doesn't dominate the cast's user, so the cast cannot be legally sunk past Previous w/o sinking this user along with it.


https://reviews.llvm.org/D33058