From 34414a634e0e98cc4c2e3a9c31f0e959884736b6 Mon Sep 17 00:00:00 2001 From: Bob Wilson Date: Tue, 4 May 2010 20:03:21 +0000 Subject: [PATCH] Defer adding critical edges to the "toSplit" list until after checking for indirect branches in all the predecessors. This avoids unnecessarily splitting edges in cases where load PRE is not possible anyway. Thanks to Jakub Staszak for pointing this out. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103034 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/GVN.cpp | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp index 321def7eb61..65b34b13dd4 100644 --- a/lib/Transforms/Scalar/GVN.cpp +++ b/lib/Transforms/Scalar/GVN.cpp @@ -1584,7 +1584,7 @@ bool GVN::processNonLocalLoad(LoadInst *LI, for (unsigned i = 0, e = UnavailableBlocks.size(); i != e; ++i) FullyAvailableBlocks[UnavailableBlocks[i]] = false; - bool NeedToSplitEdges = false; + SmallVector, 4> NeedToSplit; for (pred_iterator PI = pred_begin(LoadBB), E = pred_end(LoadBB); PI != E; ++PI) { BasicBlock *Pred = *PI; @@ -1600,12 +1600,13 @@ bool GVN::processNonLocalLoad(LoadInst *LI, return false; } unsigned SuccNum = GetSuccessorNumber(Pred, LoadBB); - toSplit.push_back(std::make_pair(Pred->getTerminator(), SuccNum)); - NeedToSplitEdges = true; + NeedToSplit.push_back(std::make_pair(Pred->getTerminator(), SuccNum)); } } - if (NeedToSplitEdges) + if (!NeedToSplit.empty()) { + toSplit.append(NeedToSplit.size(), NeedToSplit.front()); return false; + } // Decide whether PRE is profitable for this load. unsigned NumUnavailablePreds = PredLoads.size(); -- 2.11.0