Refactor synthetic profile count computation. NFC.

Summary:
Instead of using two separate callbacks to return the entry count and the
relative block frequency, use a single callback to return callsite
count. This would allow better supporting hybrid mode in the future as
the count of callsite need not always be derived from entry count (as in
sample PGO).

Reviewers: davidxl

Subscribers: mehdi_amini, steven_wu, dexonsmith, dang, llvm-commits

Differential Revision: https://reviews.llvm.org/D56464

llvm-svn: 350755

1 files changed, 10 insertions, 19 deletions

diff --git a/llvm/lib/Analysis/SyntheticCountsUtils.cpp b/llvm/lib/Analysis/SyntheticCountsUtils.cpp
index 386396bcff3..c2d7bb11a4c 100644
--- a/llvm/lib/Analysis/SyntheticCountsUtils.cpp
+++ b/llvm/lib/Analysis/SyntheticCountsUtils.cpp
@@ -26,8 +26,7 @@ using namespace llvm;
 // Given an SCC, propagate entry counts along the edge of the SCC nodes.
 template <typename CallGraphType>
 void SyntheticCountsUtils<CallGraphType>::propagateFromSCC(
-    const SccTy &SCC, GetRelBBFreqTy GetRelBBFreq, GetCountTy GetCount,
-    AddCountTy AddCount) {
+    const SccTy &SCC, GetProfCountTy GetProfCount, AddCountTy AddCount) {
 
   DenseSet<NodeRef> SCCNodes;
   SmallVector<std::pair<NodeRef, EdgeRef>, 8> SCCEdges, NonSCCEdges;
@@ -54,17 +53,13 @@ void SyntheticCountsUtils<CallGraphType>::propagateFromSCC(
   // This ensures that the order of
   // traversal of nodes within the SCC doesn't affect the final result.
 
-  DenseMap<NodeRef, uint64_t> AdditionalCounts;
+  DenseMap<NodeRef, Scaled64> AdditionalCounts;
   for (auto &E : SCCEdges) {
-    auto OptRelFreq = GetRelBBFreq(E.second);
-    if (!OptRelFreq)
+    auto OptProfCount = GetProfCount(E.first, E.second);
+    if (!OptProfCount)
       continue;
-    Scaled64 RelFreq = OptRelFreq.getValue();
-    auto Caller = E.first;
     auto Callee = CGT::edge_dest(E.second);
-    RelFreq *= Scaled64(GetCount(Caller), 0);
-    uint64_t AdditionalCount = RelFreq.toInt<uint64_t>();
-    AdditionalCounts[Callee] += AdditionalCount;
+    AdditionalCounts[Callee] += OptProfCount.getValue();
   }
 
   // Update the counts for the nodes in the SCC.
@@ -73,14 +68,11 @@ void SyntheticCountsUtils<CallGraphType>::propagateFromSCC(
 
   // Now update the counts for nodes outside the SCC.
   for (auto &E : NonSCCEdges) {
-    auto OptRelFreq = GetRelBBFreq(E.second);
-    if (!OptRelFreq)
+    auto OptProfCount = GetProfCount(E.first, E.second);
+    if (!OptProfCount)
       continue;
-    Scaled64 RelFreq = OptRelFreq.getValue();
-    auto Caller = E.first;
     auto Callee = CGT::edge_dest(E.second);
-    RelFreq *= Scaled64(GetCount(Caller), 0);
-    AddCount(Callee, RelFreq.toInt<uint64_t>());
+    AddCount(Callee, OptProfCount.getValue());
   }
 }
 
@@ -94,8 +86,7 @@ void SyntheticCountsUtils<CallGraphType>::propagateFromSCC(
 
 template <typename CallGraphType>
 void SyntheticCountsUtils<CallGraphType>::propagate(const CallGraphType &CG,
-                                                    GetRelBBFreqTy GetRelBBFreq,
-                                                    GetCountTy GetCount,
+                                                    GetProfCountTy GetProfCount,
                                                     AddCountTy AddCount) {
   std::vector<SccTy> SCCs;
 
@@ -107,7 +98,7 @@ void SyntheticCountsUtils<CallGraphType>::propagate(const CallGraphType &CG,
   // The scc iterator returns the scc in bottom-up order, so reverse the SCCs
   // and call propagateFromSCC.
   for (auto &SCC : reverse(SCCs))
-    propagateFromSCC(SCC, GetRelBBFreq, GetCount, AddCount);
+    propagateFromSCC(SCC, GetProfCount, AddCount);
 }
 
 template class llvm::SyntheticCountsUtils<const CallGraph *>;