Revert r254348: "Replace all weight-based interfaces in MBB with probability-based...

[oota-llvm.git] / lib / CodeGen / BranchFolding.cpp

diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp
index ba21d9cc9d55391ac2bcef43b9147b5f106346fb..0b2495cc996e00b409c8a1be88a8d70b8f6391e2 100644 (file)
--- a/lib/CodeGen/BranchFolding.cpp
+++ b/lib/CodeGen/BranchFolding.cpp
@@ -1099,16 +1099,13 @@ void BranchFolder::setCommonTailEdgeWeights(MachineBasicBlock &TailMBB) {
   if (TailMBB.succ_size() <= 1)
     return;
 
-  auto SumEdgeFreq =
-      std::accumulate(EdgeFreqLs.begin(), EdgeFreqLs.end(), BlockFrequency(0))
-          .getFrequency();
+  auto MaxEdgeFreq = *std::max_element(EdgeFreqLs.begin(), EdgeFreqLs.end());
+  uint64_t Scale = MaxEdgeFreq.getFrequency() / UINT32_MAX + 1;
   auto EdgeFreq = EdgeFreqLs.begin();
 
   for (auto SuccI = TailMBB.succ_begin(), SuccE = TailMBB.succ_end();
        SuccI != SuccE; ++SuccI, ++EdgeFreq)
-    TailMBB.setSuccProbability(
-        SuccI, BranchProbability::getBranchProbability(EdgeFreq->getFrequency(),
-                                                       SumEdgeFreq));
+    TailMBB.setSuccWeight(SuccI, EdgeFreq->getFrequency() / Scale);
 }
 
 //===----------------------------------------------------------------------===//