Replace all weight-based interfaces in MBB with probability-based interfaces, and...

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

diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp
index 0b2495cc996e00b409c8a1be88a8d70b8f6391e2..54d92ad67a97de01e265185dc8f88ef19e68a0f1 100644 (file)
--- a/lib/CodeGen/BranchFolding.cpp
+++ b/lib/CodeGen/BranchFolding.cpp
@@ -1099,13 +1099,19 @@ void BranchFolder::setCommonTailEdgeWeights(MachineBasicBlock &TailMBB) {
   if (TailMBB.succ_size() <= 1)
     return;
 
-  auto MaxEdgeFreq = *std::max_element(EdgeFreqLs.begin(), EdgeFreqLs.end());
-  uint64_t Scale = MaxEdgeFreq.getFrequency() / UINT32_MAX + 1;
+  auto SumEdgeFreq =
+      std::accumulate(EdgeFreqLs.begin(), EdgeFreqLs.end(), BlockFrequency(0))
+          .getFrequency();
   auto EdgeFreq = EdgeFreqLs.begin();
 
-  for (auto SuccI = TailMBB.succ_begin(), SuccE = TailMBB.succ_end();
-       SuccI != SuccE; ++SuccI, ++EdgeFreq)
-    TailMBB.setSuccWeight(SuccI, EdgeFreq->getFrequency() / Scale);
+  if (SumEdgeFreq > 0) {
+    for (auto SuccI = TailMBB.succ_begin(), SuccE = TailMBB.succ_end();
+         SuccI != SuccE; ++SuccI, ++EdgeFreq) {
+      auto Prob = BranchProbability::getBranchProbability(
+          EdgeFreq->getFrequency(), SumEdgeFreq);
+      TailMBB.setSuccProbability(SuccI, Prob);
+    }
+  }
 }
 
 //===----------------------------------------------------------------------===//