[PATCH] D158291: [PoC][WIP] Add an AArch64 specific pass for loop idiom recognition

[David Sherwood via Phabricator via llvm-commits]

david-arm marked 7 inline comments as done.
david-arm added inline comments.


================
Comment at: llvm/lib/Target/AArch64/AArch64LoopIdiomRecognize.cpp:159
+bool AArch64LoopIdiomRecognize::run(Loop *L) {
+  CurLoop = L;
+
----------------
craig.topper wrote:
> craig.topper wrote:
> > Do we need to check `skipLoop` for opt-bisect-limit?
> Maybe skipLoop is handled directly by the new pass manager? I'm too used to old pass manager.
For the legacy pass manager we do!


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Comment at: llvm/lib/Target/AArch64/AArch64LoopIdiomRecognize.cpp:206
+  auto *EntryBI = dyn_cast<BranchInst>(PH->getTerminator());
+  if (!EntryBI || EntryBI->isConditional())
+    return false;
----------------
craig.topper wrote:
> Doesn't being a "preheader" guarantee it's not conditional?
You're right. I've simplified the logic here to assume a canonical form, particularly since we rejected loops without preheaders in AArch64LoopIdiomRecognize::run


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  https://reviews.llvm.org/D158291/new/

https://reviews.llvm.org/D158291