From c951003faf4d475d221f5e839971673d2350b983 Mon Sep 17 00:00:00 2001 From: Hal Finkel Date: Mon, 11 Feb 2013 23:02:17 +0000 Subject: [PATCH] BBVectorize: Don't over-search when building the dependency map When building the pairable-instruction dependency map, don't search past the last pairable instruction. For large blocks that have been divided into multiple instruction groups, searching past the last instruction in each group is very wasteful. This gives a 32% speedup on the csa.ll test case from PR15222 (when using 50 instructions in each group). No functionality change intended. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174915 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Vectorize/BBVectorize.cpp | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/lib/Transforms/Vectorize/BBVectorize.cpp b/lib/Transforms/Vectorize/BBVectorize.cpp index b14d91dd8e6..c11d9f679d4 100644 --- a/lib/Transforms/Vectorize/BBVectorize.cpp +++ b/lib/Transforms/Vectorize/BBVectorize.cpp @@ -1380,20 +1380,28 @@ namespace { // Iterate through the basic block, recording all users of each // pairable instruction. - BasicBlock::iterator E = BB.end(); + BasicBlock::iterator E = BB.end(), EL = + BasicBlock::iterator(cast(PairableInsts.back())); for (BasicBlock::iterator I = BB.getFirstInsertionPt(); I != E; ++I) { if (IsInPair.find(I) == IsInPair.end()) continue; DenseSet Users; AliasSetTracker WriteSet(*AA); - for (BasicBlock::iterator J = llvm::next(I); J != E; ++J) + for (BasicBlock::iterator J = llvm::next(I); J != E; ++J) { (void) trackUsesOfI(Users, WriteSet, I, J); + if (J == EL) + break; + } + for (DenseSet::iterator U = Users.begin(), E = Users.end(); U != E; ++U) { if (IsInPair.find(*U) == IsInPair.end()) continue; PairableInstUsers.insert(ValuePair(I, *U)); } + + if (I == EL) + break; } }