From 80f6a507d4e11ba066ad0e53e12ad25ad8cf07ba Mon Sep 17 00:00:00 2001 From: Cameron Zwarich Date: Sat, 8 Jan 2011 17:01:52 +0000 Subject: Make more passes preserve dominators (or state that they preserve dominators if they all ready do). This removes two dominator recomputations prior to isel, which is a 1% improvement in total llc time for 403.gcc. The only potentially suspect thing is making GCStrategy recompute dominators if it used a custom lowering strategy. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123064 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Utils/Local.cpp | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'lib/Transforms/Utils/Local.cpp') diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp index 4c2bdbc226..30e88e976f 100644 --- a/lib/Transforms/Utils/Local.cpp +++ b/lib/Transforms/Utils/Local.cpp @@ -22,6 +22,7 @@ #include "llvm/IntrinsicInst.h" #include "llvm/ADT/DenseMap.h" #include "llvm/ADT/SmallPtrSet.h" +#include "llvm/Analysis/Dominators.h" #include "llvm/Analysis/ConstantFolding.h" #include "llvm/Analysis/InstructionSimplify.h" #include "llvm/Analysis/ProfileInfo.h" @@ -401,6 +402,12 @@ void llvm::MergeBasicBlockIntoOnlyPred(BasicBlock *DestBB, Pass *P) { PredBB->replaceAllUsesWith(DestBB); if (P) { + DominatorTree *DT = P->getAnalysisIfAvailable(); + if (DT) { + BasicBlock *PredBBIDom = DT->getNode(PredBB)->getIDom()->getBlock(); + DT->changeImmediateDominator(DestBB, PredBBIDom); + DT->eraseNode(PredBB); + } ProfileInfo *PI = P->getAnalysisIfAvailable(); if (PI) { PI->replaceAllUses(PredBB, DestBB); -- cgit v1.2.3-18-g5258