Temporarily revert r250345 to sort out bot failure.
[oota-llvm.git] / include / llvm / Support / BranchProbability.h
index f204777066e9be5b0dfd2b3eff63822884e512b7..98b2a3d7d9a2460c26ad964cf239d957faf3c81f 100644 (file)
 #define LLVM_SUPPORT_BRANCHPROBABILITY_H
 
 #include "llvm/Support/DataTypes.h"
-#include <algorithm>
 #include <cassert>
-#include <climits>
-#include <numeric>
 
 namespace llvm {
 
@@ -56,11 +53,6 @@ public:
   template <class ProbabilityList>
   static void normalizeProbabilities(ProbabilityList &Probs);
 
-  // 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; }
 
@@ -143,49 +135,6 @@ void BranchProbability::normalizeProbabilities(ProbabilityList &Probs) {
     Prob.N = (Prob.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