[PATCH] D78852: [AArch64][GlobalISel] Add a post-legalizer combiner + remove undef stores

[Daniel Sanders via Phabricator via llvm-commits]

dsanders added inline comments.


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Comment at: llvm/lib/Target/AArch64/AArch64PostLegalizerCombiner.cpp:93
+  AU.setPreservesCFG();
+  getSelectionDAGFallbackAnalysisUsage(AU);
+  AU.addRequired<GISelKnownBitsAnalysis>();
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aemerson wrote:
> @dsanders is this SelectionDAGFallbackAnalysis necessary for a combiner?
Unfortunately yes but it should be removable when fallbacks are disabled. The only thing it's doing is marking StackProtector as preserved.

When I was adding -debugify-and-strip-all I found that it's not safe to let some analysis passes run more than once and IIRC StackProtector was one of them.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D78852/new/

https://reviews.llvm.org/D78852