From 69b28c878234ed98456c7f6f4d386c3b4826ae0c Mon Sep 17 00:00:00 2001 From: Sanjoy Das Date: Wed, 26 Jul 2017 01:32:19 +0000 Subject: [PATCH] [SCEV] Remove unnecessary call to forgetMemoizedResults `SCEVUnknown::allUsesReplacedWith` does not need to call `forgetMemoizedResults` since RAUW does a value-equivalent replacement by assumption. If this assumption was false then the later setValPtr(New) call would be incorrect too. This is a non-trivial performance optimization for functions with a large number of loops since `forgetMemoizedResults` walks all loop backedge taken counts to see if any of them use the SCEVUnknown being RAUWed. However, this improvement is difficult to demonstrate without checking in an excessively large IR file. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309072 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/ScalarEvolution.cpp | 3 --- 1 file changed, 3 deletions(-) diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp index b726fd97b70..4d7b59c4763 100644 --- a/lib/Analysis/ScalarEvolution.cpp +++ b/lib/Analysis/ScalarEvolution.cpp @@ -415,9 +415,6 @@ void SCEVUnknown::deleted() { } void SCEVUnknown::allUsesReplacedWith(Value *New) { - // Clear this SCEVUnknown from various maps. - SE->forgetMemoizedResults(this); - // Remove this SCEVUnknown from the uniquing map. SE->UniqueSCEVs.RemoveNode(this); -- 2.50.1