[PATCH] D40613: [LoopIdiom] Recognize unordered atomic memset

[Daniel Neilson via Phabricator via llvm-commits]

dneilson added inline comments.


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Comment at: lib/Transforms/Scalar/LoopIdiomRecognize.cpp:923
+    const auto *SI = dyn_cast<StoreInst>(TheStore);
+    if (!(SI && SI->isAtomic()))
+      NewCall =
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anna wrote:
> Why do we not check that the "ordinary memset" was substituting a store?
> In other words, shouldn't there be a check for `SI`
> 
> This is the behaviour before your change as well (we dont check for store), but somehow it struck me as weird. 
processLoopStridedStore() kind of has two modes of operation.
1) A loop of stores being converted into a single memset call 
2) A loop of memset calls being merged into a single memset call

I made the atomic case explicitly check for a store instruction here because the "loop of atomic memsets" hasn't been implemented yet.


https://reviews.llvm.org/D40613