[C++11] Add range based accessors for the Use-Def chain of a Value.

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

diff --git a/lib/Analysis/BranchProbabilityInfo.cpp b/lib/Analysis/BranchProbabilityInfo.cpp
index a6481cf359bfbab8d28037a28e0e55c0a6c71af0..b901c546270a8e161c7cf8033cd345e2d6c39dab 100644 (file)
--- a/lib/Analysis/BranchProbabilityInfo.cpp
+++ b/lib/Analysis/BranchProbabilityInfo.cpp
@@ -11,15 +11,16 @@
 //
 //===----------------------------------------------------------------------===//
 
+#define DEBUG_TYPE "branch-prob"
 #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;
@@ -151,8 +152,8 @@ bool BranchProbabilityInfo::calcUnreachableHeuristics(BasicBlock *BB) {
 
   uint32_t UnreachableWeight =
     std::max(UR_TAKEN_WEIGHT / (unsigned)UnreachableEdges.size(), MIN_WEIGHT);
-  for (SmallVector<unsigned, 4>::iterator I = UnreachableEdges.begin(),
-                                          E = UnreachableEdges.end();
+  for (SmallVectorImpl<unsigned>::iterator I = UnreachableEdges.begin(),
+                                           E = UnreachableEdges.end();
        I != E; ++I)
     setEdgeWeight(BB, *I, UnreachableWeight);
 
@@ -161,8 +162,8 @@ bool BranchProbabilityInfo::calcUnreachableHeuristics(BasicBlock *BB) {
   uint32_t ReachableWeight =
     std::max(UR_NONTAKEN_WEIGHT / (unsigned)ReachableEdges.size(),
              NORMAL_WEIGHT);
-  for (SmallVector<unsigned, 4>::iterator I = ReachableEdges.begin(),
-                                          E = ReachableEdges.end();
+  for (SmallVectorImpl<unsigned>::iterator I = ReachableEdges.begin(),
+                                           E = ReachableEdges.end();
        I != E; ++I)
     setEdgeWeight(BB, *I, ReachableWeight);
 
@@ -251,8 +252,8 @@ bool BranchProbabilityInfo::calcColdCallHeuristics(BasicBlock *BB) {
 
   uint32_t ColdWeight =
       std::max(CC_TAKEN_WEIGHT / (unsigned) ColdEdges.size(), MIN_WEIGHT);
-  for (SmallVector<unsigned, 4>::iterator I = ColdEdges.begin(),
-                                          E = ColdEdges.end();
+  for (SmallVectorImpl<unsigned>::iterator I = ColdEdges.begin(),
+                                           E = ColdEdges.end();
        I != E; ++I)
     setEdgeWeight(BB, *I, ColdWeight);
 
@@ -260,8 +261,8 @@ bool BranchProbabilityInfo::calcColdCallHeuristics(BasicBlock *BB) {
     return true;
   uint32_t NormalWeight = std::max(
       CC_NONTAKEN_WEIGHT / (unsigned) NormalEdges.size(), NORMAL_WEIGHT);
-  for (SmallVector<unsigned, 4>::iterator I = NormalEdges.begin(),
-                                          E = NormalEdges.end();
+  for (SmallVectorImpl<unsigned>::iterator I = NormalEdges.begin(),
+                                           E = NormalEdges.end();
        I != E; ++I)
     setEdgeWeight(BB, *I, NormalWeight);
 
@@ -326,7 +327,7 @@ bool BranchProbabilityInfo::calcLoopBranchHeuristics(BasicBlock *BB) {
     if (backWeight < NORMAL_WEIGHT)
       backWeight = NORMAL_WEIGHT;
 
-    for (SmallVector<unsigned, 8>::iterator EI = BackEdges.begin(),
+    for (SmallVectorImpl<unsigned>::iterator EI = BackEdges.begin(),
          EE = BackEdges.end(); EI != EE; ++EI) {
       setEdgeWeight(BB, *EI, backWeight);
     }
@@ -337,7 +338,7 @@ bool BranchProbabilityInfo::calcLoopBranchHeuristics(BasicBlock *BB) {
     if (inWeight < NORMAL_WEIGHT)
       inWeight = NORMAL_WEIGHT;
 
-    for (SmallVector<unsigned, 8>::iterator EI = InEdges.begin(),
+    for (SmallVectorImpl<unsigned>::iterator EI = InEdges.begin(),
          EE = InEdges.end(); EI != EE; ++EI) {
       setEdgeWeight(BB, *EI, inWeight);
     }
@@ -348,7 +349,7 @@ bool BranchProbabilityInfo::calcLoopBranchHeuristics(BasicBlock *BB) {
     if (exitWeight < MIN_WEIGHT)
       exitWeight = MIN_WEIGHT;
 
-    for (SmallVector<unsigned, 8>::iterator EI = ExitingEdges.begin(),
+    for (SmallVectorImpl<unsigned>::iterator EI = ExitingEdges.begin(),
          EE = ExitingEdges.end(); EI != EE; ++EI) {
       setEdgeWeight(BB, *EI, exitWeight);
     }
@@ -398,10 +399,24 @@ 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;
   }
@@ -469,6 +484,8 @@ 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());
@@ -577,6 +594,13 @@ getEdgeWeight(const BasicBlock *Src, unsigned IndexInSuccessors) const {
   return DEFAULT_WEIGHT;
 }
 
+uint32_t
+BranchProbabilityInfo::
+getEdgeWeight(const BasicBlock *Src, succ_const_iterator Dst) const {
+  size_t index = std::distance(succ_begin(Src), Dst);
+  return getEdgeWeight(Src, index);
+}
+
 /// 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::