Include already promoted counts when computing SUM for VP.

Summary: When computing the SUM for indirect call promotion, if the callsite is already promoted in the profile, it will be promoted before ICP. In the current implementation, ICP only sees remaining counts in SUM. This may cause extra indirect call targets being promoted. This patch updates the SUM to include the counts already promoted earlier. This way we do not end up promoting too many indirect call targets.

Reviewers: tejohnson

Reviewed By: tejohnson

Subscribers: llvm-commits, sanjoy

Differential Revision: https://reviews.llvm.org/D38763

llvm-svn: 317502

1 files changed, 12 insertions, 14 deletions

diff --git a/llvm/lib/Transforms/IPO/SampleProfile.cpp b/llvm/lib/Transforms/IPO/SampleProfile.cpp
index 34414f96cca..8930e9b2b95 100644
--- a/llvm/lib/Transforms/IPO/SampleProfile.cpp
+++ b/llvm/lib/Transforms/IPO/SampleProfile.cpp
@@ -1182,24 +1182,20 @@ void SampleProfileLoader::buildEdges(Function &F) {
   }
 }
 
-/// Sorts the CallTargetMap \p M by count in descending order and stores the
-/// sorted result in \p Sorted. Returns the total counts.
-static uint64_t SortCallTargets(SmallVector<InstrProfValueData, 2> &Sorted,
-                                const SampleRecord::CallTargetMap &M) {
-  Sorted.clear();
-  uint64_t Sum = 0;
-  for (auto I = M.begin(); I != M.end(); ++I) {
-    Sum += I->getValue();
-    Sorted.push_back({Function::getGUID(I->getKey()), I->getValue()});
-  }
-  std::sort(Sorted.begin(), Sorted.end(),
+/// Returns the sorted CallTargetMap \p M by count in descending order.
+static SmallVector<InstrProfValueData, 2> SortCallTargets(
+    const SampleRecord::CallTargetMap &M) {
+  SmallVector<InstrProfValueData, 2> R;
+  for (auto I = M.begin(); I != M.end(); ++I)
+    R.push_back({Function::getGUID(I->getKey()), I->getValue()});
+  std::sort(R.begin(), R.end(),
             [](const InstrProfValueData &L, const InstrProfValueData &R) {
               if (L.Count == R.Count)
                 return L.Value > R.Value;
               else
                 return L.Count > R.Count;
             });
-  return Sum;
+  return R;
 }
 
 /// \brief Propagate weights into edges
@@ -1292,8 +1288,10 @@ void SampleProfileLoader::propagateWeights(Function &F) {
           auto T = FS->findCallTargetMapAt(LineOffset, Discriminator);
           if (!T || T.get().empty())
             continue;
-          SmallVector<InstrProfValueData, 2> SortedCallTargets;
-          uint64_t Sum = SortCallTargets(SortedCallTargets, T.get());
+          SmallVector<InstrProfValueData, 2> SortedCallTargets =
+              SortCallTargets(T.get());
+          uint64_t Sum;
+          findIndirectCallFunctionSamples(I, Sum);
           annotateValueSite(*I.getParent()->getParent()->getParent(), I,
                             SortedCallTargets, Sum, IPVK_IndirectCallTarget,
                             SortedCallTargets.size());