Use do+while instead of while for loops which obviously have a
non-zero trip count. Use SmallVector's pop_back_val().


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92734 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopIndexSplit.cpp b/lib/Transforms/Scalar/LoopIndexSplit.cpp
index 1d9dd68..16d3f2f 100644
--- a/lib/Transforms/Scalar/LoopIndexSplit.cpp
+++ b/lib/Transforms/Scalar/LoopIndexSplit.cpp
@@ -708,7 +708,7 @@
   }
 
   while (!WorkList.empty()) {
-    BasicBlock *BB = WorkList.back(); WorkList.pop_back();
+    BasicBlock *BB = WorkList.pop_back_val();
     LPM->deleteSimpleAnalysisValue(BB, LP);
     for(BasicBlock::iterator BBI = BB->begin(), BBE = BB->end(); 
         BBI != BBE; ) {
@@ -726,7 +726,7 @@
 
   // Update Frontier BBs' dominator info.
   while (!FrontierBBs.empty()) {
-    BasicBlock *FBB = FrontierBBs.back(); FrontierBBs.pop_back();
+    BasicBlock *FBB = FrontierBBs.pop_back_val();
     BasicBlock *NewDominator = FBB->getSinglePredecessor();
     if (!NewDominator) {
       pred_iterator PI = pred_begin(FBB), PE = pred_end(FBB);