Use reserve() to avoid vector reallocation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167991 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/RegisterCoalescer.cpp b/lib/CodeGen/RegisterCoalescer.cpp
index 7e662e5385b40d4b8265b9d9b1eafe209c18a764..df67975286055501f7c514e7b1a24c03ca49e174 100644 (file)
--- a/lib/CodeGen/RegisterCoalescer.cpp
+++ b/lib/CodeGen/RegisterCoalescer.cpp
@@ -2068,6 +2068,7 @@ void RegisterCoalescer::joinAllIntervals() {
   assert(WorkList.empty() && LocalWorkList.empty() && "Old data still around.");
 
   std::vector<MBBPriorityInfo> MBBs;
+  MBBs.reserve(MF->size());
   for (MachineFunction::iterator I = MF->begin(), E = MF->end();I != E;++I){
     MachineBasicBlock *MBB = I;
     MBBs.push_back(MBBPriorityInfo(MBB, Loops->getLoopDepth(MBB),