From: Chris Lattner <sabre@nondot.org>
Date: Wed, 1 Nov 2006 00:38:31 +0000 (+0000)
Subject: enable branch folding with an option
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=d8ccff0c3e5028019a02dd44bf7d906efc9effd8;p=oota-llvm.git

enable branch folding with an option


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31335 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp
index 9ca0091d203..11381466548 100644
--- a/lib/CodeGen/BranchFolding.cpp
+++ b/lib/CodeGen/BranchFolding.cpp
@@ -30,6 +30,7 @@ using namespace llvm;
 static Statistic<> NumDeadBlocks("branchfold", "Number of dead blocks removed");
 static Statistic<> NumBranchOpts("branchfold", "Number of branches optimized");
 static Statistic<> NumTailMerge ("branchfold", "Number of block tails merged");
+static cl::opt<bool> EnableTailMerge("enable-tail-merge", cl::Hidden);
 
 namespace {
   struct BranchFolder : public MachineFunctionPass {
@@ -258,7 +259,7 @@ void BranchFolder::ReplaceTailWithBranchTo(MachineBasicBlock::iterator OldInst,
 bool BranchFolder::TailMergeBlocks(MachineFunction &MF) {
   MadeChange = false;
   
-  return false;
+  if (!EnableTailMerge) return false;
   
   // Find blocks with no successors.
   std::vector<std::pair<unsigned,MachineBasicBlock*> > MergePotentials;