[PATCH] D23214: [MDA] Treat invariant.start as non-dependence

[Daniel Berlin via llvm-commits]

dberlin accepted this revision.
dberlin added a comment.
This revision is now accepted and ready to land.

Fix the comments, then LGTM


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Comment at: lib/Analysis/BasicAliasAnalysis.cpp:785
@@ +784,3 @@
+  // Like assumes, invariant.start intrinsics are also marked as arbitrarily
+  // writing so that proper control dependencies are maintained but they never
+  // mod any particular memory location visible to the IR.
----------------
Errr, this is now wrong?

Maybe you mean "were both also marked"?

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Comment at: lib/Analysis/BasicAliasAnalysis.cpp:787
@@ +786,3 @@
+  // mod any particular memory location visible to the IR.
+  // *Unlike* assumes, invariant intrinsic is modeled as reading memory, since
+  // DSE should not assume that stores to same location can be DSE'd. Consider:
----------------
invariant.start is modeled (invariant.end is still modeled as writing)


https://reviews.llvm.org/D23214