[PATCH] D75808: [ValueTracking] isKnownNonZero, computeKnownBits for freeze

[Nikita Popov via Phabricator via llvm-commits]

nikic accepted this revision.
nikic added a comment.

LGTM. This does seem useful as at least assumes and dominating conditions always imply non-poison.



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Comment at: llvm/lib/Analysis/ValueTracking.cpp:1876
+  case Instruction::Freeze:
+    if (isGuaranteedNotToBePoison(I->getOperand(0), Q.CxtI, Q.DT, Depth))
+      computeKnownBits(I->getOperand(0), Known, Depth + 1, Q);
----------------
Should be `Depth + 1` here?


================
Comment at: llvm/lib/Analysis/ValueTracking.cpp:2586
+  else if (const FreezeInst *FI = dyn_cast<FreezeInst>(V)) {
+    auto Op = FI->getOperand(0);
+    if (isKnownNonZero(Op, Depth, Q) &&
----------------
Please fix this tidy warning.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D75808/new/

https://reviews.llvm.org/D75808