[BPI] Replace weights by probabilities in BPI.

[oota-llvm.git] / include / llvm / Support / BranchProbability.h

diff --git a/include/llvm/Support/BranchProbability.h b/include/llvm/Support/BranchProbability.h
index 1d6a7d84fbf47131edc20a558ed700e2531d31c9..26bc888d1cabfb29c7a2b62cec086397925bd3ad 100644 (file)
--- a/include/llvm/Support/BranchProbability.h
+++ b/include/llvm/Support/BranchProbability.h
@@ -63,11 +63,6 @@ public:
   static void normalizeProbabilities(ProbabilityIter Begin,
                                      ProbabilityIter End);
 
-  // Normalize a list of weights by scaling them down so that the sum of them
-  // doesn't exceed UINT32_MAX.
-  template <class WeightListIter>
-  static void normalizeEdgeWeights(WeightListIter Begin, WeightListIter End);
-
   uint32_t getNumerator() const { return N; }
   static uint32_t getDenominator() { return D; }
 
@@ -219,49 +214,6 @@ void BranchProbability::normalizeProbabilities(ProbabilityIter Begin,
     I->N = (I->N * uint64_t(D) + Sum / 2) / Sum;
 }
 
-template <class WeightListIter>
-void BranchProbability::normalizeEdgeWeights(WeightListIter Begin,
-                                             WeightListIter End) {
-  // First we compute the sum with 64-bits of precision.
-  uint64_t Sum = std::accumulate(Begin, End, uint64_t(0));
-
-  if (Sum > UINT32_MAX) {
-    // Compute the scale necessary to cause the weights to fit, and re-sum with
-    // that scale applied.
-    assert(Sum / UINT32_MAX < UINT32_MAX &&
-           "The sum of weights exceeds UINT32_MAX^2!");
-    uint32_t Scale = Sum / UINT32_MAX + 1;
-    for (auto I = Begin; I != End; ++I)
-      *I /= Scale;
-    Sum = std::accumulate(Begin, End, uint64_t(0));
-  }
-
-  // Eliminate zero weights.
-  auto ZeroWeightNum = std::count(Begin, End, 0u);
-  if (ZeroWeightNum > 0) {
-    // If all weights are zeros, replace them by 1.
-    if (Sum == 0)
-      std::fill(Begin, End, 1u);
-    else {
-      // We are converting zeros into ones, and here we need to make sure that
-      // after this the sum won't exceed UINT32_MAX.
-      if (Sum + ZeroWeightNum > UINT32_MAX) {
-        for (auto I = Begin; I != End; ++I)
-          *I /= 2;
-        ZeroWeightNum = std::count(Begin, End, 0u);
-        Sum = std::accumulate(Begin, End, uint64_t(0));
-      }
-      // Scale up non-zero weights and turn zero weights into ones.
-      uint64_t ScalingFactor = (UINT32_MAX - ZeroWeightNum) / Sum;
-      assert(ScalingFactor >= 1);
-      if (ScalingFactor > 1)
-        for (auto I = Begin; I != End; ++I)
-          *I *= ScalingFactor;
-      std::replace(Begin, End, 0u, 1u);
-    }
-  }
-}
-
 }
 
 #endif