[objc-arc] Introduce the concept of RCIdentity and rename all relevant functions...

[oota-llvm.git] / lib / Analysis / BranchProbabilityInfo.cpp

diff --git a/lib/Analysis/BranchProbabilityInfo.cpp b/lib/Analysis/BranchProbabilityInfo.cpp
index 7cdf828c2f4b42694c839b069493867da2f0b7dd..8cd6ea46d3c57e6ae7142995b6001bd3565a334e 100644 (file)
--- a/lib/Analysis/BranchProbabilityInfo.cpp
+++ b/lib/Analysis/BranchProbabilityInfo.cpp
@@ -14,19 +14,21 @@
 #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)
+INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
 INITIALIZE_PASS_END(BranchProbabilityInfo, "branch-prob",
                     "Branch Probability Analysis", false, true)
 
@@ -194,7 +196,8 @@ bool BranchProbabilityInfo::calcMetadataWeights(BasicBlock *BB) {
   SmallVector<uint32_t, 2> Weights;
   Weights.reserve(TI->getNumSuccessors());
   for (unsigned i = 1, e = WeightsNode->getNumOperands(); i != e; ++i) {
-    ConstantInt *Weight = dyn_cast<ConstantInt>(WeightsNode->getOperand(i));
+    ConstantInt *Weight =
+        mdconst::dyn_extract<ConstantInt>(WeightsNode->getOperand(i));
     if (!Weight)
       return false;
     Weights.push_back(
@@ -321,6 +324,9 @@ 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)
@@ -398,10 +404,24 @@ bool BranchProbabilityInfo::calcZeroHeuristics(BasicBlock *BB) {
     // InstCombine canonicalizes X <= 0 into X < 1.
     // X <= 0   ->  Unlikely
     isProb = false;
-  } else if (CV->isAllOnesValue() && CI->getPredicate() == CmpInst::ICMP_SGT) {
-    // InstCombine canonicalizes X >= 0 into X > -1.
-    // X >= 0   ->  Likely
-    isProb = true;
+  } else if (CV->isAllOnesValue()) {
+    switch (CI->getPredicate()) {
+    case CmpInst::ICMP_EQ:
+      // X == -1  ->  Unlikely
+      isProb = false;
+      break;
+    case CmpInst::ICMP_NE:
+      // X != -1  ->  Likely
+      isProb = true;
+      break;
+    case CmpInst::ICMP_SGT:
+      // InstCombine canonicalizes X >= 0 into X > -1.
+      // X >= 0   ->  Likely
+      isProb = true;
+      break;
+    default:
+      return false;
+    }
   } else {
     return false;
   }
@@ -464,13 +484,15 @@ bool BranchProbabilityInfo::calcInvokeHeuristics(BasicBlock *BB) {
 }
 
 void BranchProbabilityInfo::getAnalysisUsage(AnalysisUsage &AU) const {
-  AU.addRequired<LoopInfo>();
+  AU.addRequired<LoopInfoWrapperPass>();
   AU.setPreservesAll();
 }
 
 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>();
+  LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
   assert(PostDominatedByUnreachable.empty());
   assert(PostDominatedByColdCall.empty());
 
@@ -540,7 +562,7 @@ 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;
@@ -560,7 +582,7 @@ 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
@@ -577,6 +599,11 @@ 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::