[block-freq] Teach branch probability how to return the edge weight in between a BasicBlock and one of its successors.

IMHO At some point BasicBlock should be refactored along the lines of
MachineBasicBlock so that successors/weights are actually embedded within the
block. Now is not that time though.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197303 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 14 insertions, 0 deletions

diff --git a/include/llvm/Analysis/BranchProbabilityInfo.h b/include/llvm/Analysis/BranchProbabilityInfo.h
index 4ff7121728..fdad168ab1 100644
--- a/include/llvm/Analysis/BranchProbabilityInfo.h
+++ b/include/llvm/Analysis/BranchProbabilityInfo.h
@@ -16,6 +16,7 @@
 
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/Support/CFG.h"
 #include "llvm/InitializePasses.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/BranchProbability.h"
@@ -98,6 +99,9 @@ public:
   /// It is guaranteed to fall between 1 and UINT32_MAX.
   uint32_t getEdgeWeight(const BasicBlock *Src, const BasicBlock *Dst) const;
 
+  uint32_t getEdgeWeight(const BasicBlock *Src,
+                         succ_const_iterator Dst) const;
+
   /// \brief Set the raw edge weight for a given edge.
   ///
   /// This allows a pass to explicitly set the edge weight for an edge. It can
diff --git a/lib/Analysis/BranchProbabilityInfo.cpp b/lib/Analysis/BranchProbabilityInfo.cpp
index 86560ca33d..15491f072c 100644
--- a/lib/Analysis/BranchProbabilityInfo.cpp
+++ b/lib/Analysis/BranchProbabilityInfo.cpp
@@ -11,6 +11,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#define DEBUG_TYPE "branch-prob"
 #include "llvm/Analysis/BranchProbabilityInfo.h"
 #include "llvm/ADT/PostOrderIterator.h"
 #include "llvm/Analysis/LoopInfo.h"
@@ -483,6 +484,8 @@ void BranchProbabilityInfo::getAnalysisUsage(AnalysisUsage &AU) const {
 }
 
 bool BranchProbabilityInfo::runOnFunction(Function &F) {
+  DEBUG(dbgs() << "---- Branch Probability Info : " << F.getName()
+               << " ----\n\n");
   LastF = &F; // Store the last function we ran on for printing.
   LI = &getAnalysis<LoopInfo>();
   assert(PostDominatedByUnreachable.empty());
@@ -591,6 +594,13 @@ getEdgeWeight(const BasicBlock *Src, unsigned IndexInSuccessors) const {
   return DEFAULT_WEIGHT;
 }
 
+uint32_t
+BranchProbabilityInfo::
+getEdgeWeight(const BasicBlock *Src, succ_const_iterator Dst) const {
+  size_t index = std::distance(succ_begin(Src), Dst);
+  return getEdgeWeight(Src, index);
+}
+
 /// Get the raw edge weight calculated for the block pair. This returns the sum
 /// of all raw edge weights from Src to Dst.
 uint32_t BranchProbabilityInfo::