[PATCH] D90980: [BranchProbabilityInfo] Simplify getEdgeProbability (NFC)

[Kazu Hirata via Phabricator via llvm-commits]

kazu created this revision.
kazu added reviewers: MaskRay, yrouban.
Herald added subscribers: llvm-commits, hiraditya.
Herald added a project: LLVM.
kazu requested review of this revision.

The patch simplifies BranchProbabilityInfo::getEdgeProbability by
handling two cases separately, depending on whether we have edge
probabilities.

- If we have edge probabilities, then add up probabilities for successors being equal to Dst.

- Otherwise, return the number of ocurrences divided by the total number of successors.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D90980

Files:
  llvm/lib/Analysis/BranchProbabilityInfo.cpp


Index: llvm/lib/Analysis/BranchProbabilityInfo.cpp
===================================================================
--- llvm/lib/Analysis/BranchProbabilityInfo.cpp
+++ llvm/lib/Analysis/BranchProbabilityInfo.cpp
@@ -1114,19 +1114,15 @@
 BranchProbability
 BranchProbabilityInfo::getEdgeProbability(const BasicBlock *Src,
                                           const BasicBlock *Dst) const {
+  if (!Probs.count(std::make_pair(Src, 0)))
+    return BranchProbability(llvm::count(successors(Src), Dst), succ_size(Src));
+
   auto Prob = BranchProbability::getZero();
-  bool FoundProb = false;
-  uint32_t EdgeCount = 0;
   for (const_succ_iterator I = succ_begin(Src), E = succ_end(Src); I != E; ++I)
-    if (*I == Dst) {
-      ++EdgeCount;
-      auto MapI = Probs.find(std::make_pair(Src, I.getSuccessorIndex()));
-      if (MapI != Probs.end()) {
-        FoundProb = true;
-        Prob += MapI->second;
-      }
-    }
-  return FoundProb ? Prob : BranchProbability(EdgeCount, succ_size(Src));
+    if (*I == Dst)
+      Prob += Probs.find(std::make_pair(Src, I.getSuccessorIndex()))->second;
+
+  return Prob;
 }
 
 /// Set the edge probability for all edges at once.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D90980.303565.patch
Type: text/x-patch
Size: 1182 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20201106/54ed45a8/attachment.bin>