X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FAnalysis%2FBranchProbabilityInfo.cpp;h=bbd87505952216d88b8cad5f042b36e03ecf7288;hb=66b380b6b60f96816346fa50f049b5463512387f;hp=86560ca33d0c8d4c86316670aaec8db2ab71aa88;hpb=e14fb073574dcb74de05bdeedbfb3fcffbfa1bf6;p=oota-llvm.git

diff --git a/lib/Analysis/BranchProbabilityInfo.cpp b/lib/Analysis/BranchProbabilityInfo.cpp
index 86560ca33d0..bbd87505952 100644
--- a/lib/Analysis/BranchProbabilityInfo.cpp
+++ b/lib/Analysis/BranchProbabilityInfo.cpp
@@ -14,16 +14,18 @@
 #include "llvm/Analysis/BranchProbabilityInfo.h"
 #include "llvm/ADT/PostOrderIterator.h"
 #include "llvm/Analysis/LoopInfo.h"
+#include "llvm/IR/CFG.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Metadata.h"
-#include "llvm/Support/CFG.h"
 #include "llvm/Support/Debug.h"
 
 using namespace llvm;
 
+#define DEBUG_TYPE "branch-prob"
+
 INITIALIZE_PASS_BEGIN(BranchProbabilityInfo, "branch-prob",
                       "Branch Probability Analysis", false, true)
 INITIALIZE_PASS_DEPENDENCY(LoopInfo)
@@ -321,6 +323,9 @@ bool BranchProbabilityInfo::calcLoopBranchHeuristics(BasicBlock *BB) {
       InEdges.push_back(I.getSuccessorIndex());
   }
 
+  if (BackEdges.empty() && ExitingEdges.empty())
+    return false;
+
   if (uint32_t numBackEdges = BackEdges.size()) {
     uint32_t backWeight = LBH_TAKEN_WEIGHT / numBackEdges;
     if (backWeight < NORMAL_WEIGHT)
@@ -483,6 +488,8 @@ void BranchProbabilityInfo::getAnalysisUsage(AnalysisUsage &AU) const {
 }
 
 bool BranchProbabilityInfo::runOnFunction(Function &F) {
+  DEBUG(dbgs() << "---- Branch Probability Info : " << F.getName()
+               << " ----\n\n");
   LastF = &F; // Store the last function we ran on for printing.
   LI = &getAnalysis<LoopInfo>();
   assert(PostDominatedByUnreachable.empty());
@@ -554,7 +561,7 @@ isEdgeHot(const BasicBlock *Src, const BasicBlock *Dst) const {
 BasicBlock *BranchProbabilityInfo::getHotSucc(BasicBlock *BB) const {
   uint32_t Sum = 0;
   uint32_t MaxWeight = 0;
-  BasicBlock *MaxSucc = 0;
+  BasicBlock *MaxSucc = nullptr;
 
   for (succ_iterator I = succ_begin(BB), E = succ_end(BB); I != E; ++I) {
     BasicBlock *Succ = *I;
@@ -574,7 +581,7 @@ BasicBlock *BranchProbabilityInfo::getHotSucc(BasicBlock *BB) const {
   if (BranchProbability(MaxWeight, Sum) > BranchProbability(4, 5))
     return MaxSucc;
 
-  return 0;
+  return nullptr;
 }
 
 /// Get the raw edge weight for the edge. If can't find it, return
@@ -591,6 +598,11 @@ getEdgeWeight(const BasicBlock *Src, unsigned IndexInSuccessors) const {
   return DEFAULT_WEIGHT;
 }
 
+uint32_t BranchProbabilityInfo::getEdgeWeight(const BasicBlock *Src,
+                                              succ_const_iterator Dst) const {
+  return getEdgeWeight(Src, Dst.getSuccessorIndex());
+}
+
 /// Get the raw edge weight calculated for the block pair. This returns the sum
 /// of all raw edge weights from Src to Dst.
 uint32_t BranchProbabilityInfo::