Add BlockFrequency::getEntryFrequency()

llvm-svn: 136618

2 files changed, 11 insertions, 7 deletions

diff --git a/llvm/include/llvm/Analysis/BlockFrequencyImpl.h b/llvm/include/llvm/Analysis/BlockFrequencyImpl.h
index c0bc1015999..0fb2bd7db50 100644
--- a/llvm/include/llvm/Analysis/BlockFrequencyImpl.h
+++ b/llvm/include/llvm/Analysis/BlockFrequencyImpl.h
@@ -49,7 +49,7 @@ class BlockFrequencyImpl {
 
   typedef GraphTraits< Inverse<BlockT *> > GT;
 
-  static const uint32_t START_FREQ = 1024;
+  const uint32_t EntryFreq;
 
   std::string getBlockName(BasicBlock *BB) const {
     return BB->getNameStr();
@@ -176,7 +176,7 @@ class BlockFrequencyImpl {
     setBlockFreq(BB, 0);
 
     if (BB == LoopHead) {
-      setBlockFreq(BB, START_FREQ);
+      setBlockFreq(BB, EntryFreq);
       return;
     }
 
@@ -211,10 +211,10 @@ class BlockFrequencyImpl {
     if (!isLoopHead)
       return;
 
-    assert(START_FREQ >= CycleProb[BB]);
+    assert(EntryFreq >= CycleProb[BB]);
     uint32_t CProb = CycleProb[BB];
-    uint32_t Numerator = START_FREQ - CProb ? START_FREQ - CProb : 1;
-    divBlockFreq(BB, BranchProbability(Numerator, START_FREQ));
+    uint32_t Numerator = EntryFreq - CProb ? EntryFreq - CProb : 1;
+    divBlockFreq(BB, BranchProbability(Numerator, EntryFreq));
   }
 
   /// doLoop - Propagate block frequency down throught the loop.
@@ -243,8 +243,8 @@ class BlockFrequencyImpl {
       if (isReachable(Pred) && isBackedge(Pred, Head)) {
         uint64_t N = getEdgeFreq(Pred, Head).getFrequency();
         uint64_t D = getBlockFreq(Head).getFrequency();
-        assert(N <= 1024 && "Backedge frequency must be <= 1024!");
-        uint64_t Res = (N * START_FREQ) / D;
+        assert(N <= EntryFreq && "Backedge frequency must be <= EntryFreq!");
+        uint64_t Res = (N * EntryFreq) / D;
 
         assert(Res <= UINT32_MAX);
         CycleProb[Head] += (uint32_t) Res;
@@ -257,6 +257,8 @@ class BlockFrequencyImpl {
   friend class BlockFrequencyInfo;
   friend class MachineBlockFrequencyInfo;
 
+  BlockFrequencyImpl() : EntryFreq(BlockFrequency::getEntryFrequency()) { }
+
   void doFunction(FunctionT *fn, BlockProbInfoT *bpi) {
     Fn = fn;
     BPI = bpi;
diff --git a/llvm/include/llvm/Support/BlockFrequency.h b/llvm/include/llvm/Support/BlockFrequency.h
index 36aca807f78..554b7845696 100644
--- a/llvm/include/llvm/Support/BlockFrequency.h
+++ b/llvm/include/llvm/Support/BlockFrequency.h
@@ -23,10 +23,12 @@ class BranchProbability;
 class BlockFrequency {
 
   uint64_t Frequency;
+  static const int64_t ENTRY_FREQ = 1024;
 
 public:
   BlockFrequency(uint64_t Freq = 0) : Frequency(Freq) { }
 
+  static uint64_t getEntryFrequency() { return ENTRY_FREQ; }
   uint64_t getFrequency() const { return Frequency; }
 
   BlockFrequency &operator*=(const BranchProbability &Prob);