NFC: Use range-based for loops and more consistent naming.

No functional changes intended.

(I plan on doing some modifications to this function and would like to
have as few unrelated changes as possible in the patch)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229649 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/MachineBlockPlacement.cpp

@@ -347,29 +347,27 @@ MachineBasicBlock *MachineBlockPlacement::selectBestSuccessor(
   uint32_t WeightScale = 0;
   uint32_t SumWeight = MBPI->getSumForBlock(BB, WeightScale);
   DEBUG(dbgs() << "Attempting merge from: " << getBlockName(BB) << "\n");
-  for (MachineBasicBlock::succ_iterator SI = BB->succ_begin(),
-                                        SE = BB->succ_end();
-       SI != SE; ++SI) {
-    if (BlockFilter && !BlockFilter->count(*SI))
+  for (MachineBasicBlock *Succ : BB->successors()) {
+    if (BlockFilter && !BlockFilter->count(Succ))
       continue;
-    BlockChain &SuccChain = *BlockToChain[*SI];
+    BlockChain &SuccChain = *BlockToChain[Succ];
     if (&SuccChain == &Chain) {
-      DEBUG(dbgs() << "    " << getBlockName(*SI) << " -> Already merged!\n");
+      DEBUG(dbgs() << "    " << getBlockName(Succ) << " -> Already merged!\n");
       continue;
     }
-    if (*SI != *SuccChain.begin()) {
-      DEBUG(dbgs() << "    " << getBlockName(*SI) << " -> Mid chain!\n");
+    if (Succ != *SuccChain.begin()) {
+      DEBUG(dbgs() << "    " << getBlockName(Succ) << " -> Mid chain!\n");
       continue;
     }
 
-    uint32_t SuccWeight = MBPI->getEdgeWeight(BB, *SI);
+    uint32_t SuccWeight = MBPI->getEdgeWeight(BB, Succ);
     BranchProbability SuccProb(SuccWeight / WeightScale, SumWeight);
 
     // Only consider successors which are either "hot", or wouldn't violate
     // any CFG constraints.
     if (SuccChain.LoopPredecessors != 0) {
       if (SuccProb < HotProb) {
-        DEBUG(dbgs() << "    " << getBlockName(*SI) << " -> " << SuccProb
+        DEBUG(dbgs() << "    " << getBlockName(Succ) << " -> " << SuccProb
                      << " (prob) (CFG conflict)\n");
         continue;
       }
@@ -379,33 +377,31 @@ MachineBasicBlock *MachineBlockPlacement::selectBestSuccessor(
       BlockFrequency CandidateEdgeFreq =
           MBFI->getBlockFreq(BB) * SuccProb * HotProb.getCompl();
       bool BadCFGConflict = false;
-      for (MachineBasicBlock::pred_iterator PI = (*SI)->pred_begin(),
-                                            PE = (*SI)->pred_end();
-           PI != PE; ++PI) {
-        if (*PI == *SI || (BlockFilter && !BlockFilter->count(*PI)) ||
-            BlockToChain[*PI] == &Chain)
+      for (MachineBasicBlock *Pred : Succ->predecessors()) {
+        if (Pred == Succ || (BlockFilter && !BlockFilter->count(Pred)) ||
+            BlockToChain[Pred] == &Chain)
           continue;
         BlockFrequency PredEdgeFreq =
-            MBFI->getBlockFreq(*PI) * MBPI->getEdgeProbability(*PI, *SI);
+            MBFI->getBlockFreq(Pred) * MBPI->getEdgeProbability(Pred, Succ);
         if (PredEdgeFreq >= CandidateEdgeFreq) {
           BadCFGConflict = true;
           break;
         }
       }
       if (BadCFGConflict) {
-        DEBUG(dbgs() << "    " << getBlockName(*SI) << " -> " << SuccProb
+        DEBUG(dbgs() << "    " << getBlockName(Succ) << " -> " << SuccProb
                      << " (prob) (non-cold CFG conflict)\n");
         continue;
       }
     }
 
-    DEBUG(dbgs() << "    " << getBlockName(*SI) << " -> " << SuccProb
+    DEBUG(dbgs() << "    " << getBlockName(Succ) << " -> " << SuccProb
                  << " (prob)"
                  << (SuccChain.LoopPredecessors != 0 ? " (CFG break)" : "")
                  << "\n");
     if (BestSucc && BestWeight >= SuccWeight)
       continue;
-    BestSucc = *SI;
+    BestSucc = Succ;
     BestWeight = SuccWeight;
   }
   return BestSucc;