From a26a08cb52d4dd7fe69312930da01e1c55b91036 Mon Sep 17 00:00:00 2001 From: Piotr Padlewski Date: Fri, 18 May 2018 23:52:57 +0000 Subject: Constant fold launder of null and undef Summary: This might be useful because clang will add some barriers for pointer comparisons. Reviewers: majnemer, dberlin, hfinkel, nlewycky, davide, rsmith, amharc, kuhar Subscribers: davide, amharc, llvm-commits Differential Revision: https://reviews.llvm.org/D32423 llvm-svn: 332786 --- llvm/lib/Transforms/Utils/Local.cpp | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'llvm/lib/Transforms/Utils') diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp index 5eaeccb5a29..0be05d81fbd 100644 --- a/llvm/lib/Transforms/Utils/Local.cpp +++ b/llvm/lib/Transforms/Utils/Local.cpp @@ -384,8 +384,9 @@ bool llvm::wouldInstructionBeTriviallyDead(Instruction *I, // Special case intrinsics that "may have side effects" but can be deleted // when dead. if (IntrinsicInst *II = dyn_cast(I)) { - // Safe to delete llvm.stacksave if dead. - if (II->getIntrinsicID() == Intrinsic::stacksave) + // Safe to delete llvm.stacksave and launder.invariant.group if dead. + if (II->getIntrinsicID() == Intrinsic::stacksave || + II->getIntrinsicID() == Intrinsic::launder_invariant_group) return true; // Lifetime intrinsics are dead when their right-hand is undef. -- cgit v1.2.3