Include already promoted counts when computing SUM for VP.

[danielcdh]

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.

[tejohnson]

LGTM
Sorry, completely missed this one earlier.

lib/Transforms/IPO/SampleProfile.cpp

for (auto &BI : F) {
     for (succ_iterator SI = succ_begin(B1), SE = succ_end(B1); SI != SE; ++SI) {
       BasicBlock *B2 = *SI;
       if (Visited.insert(B2).second)
         Successors[B1].push_back(B2);
     }
   }
 }
 
-/// 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(
+  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
 ///
 /// The following rules are applied to every block BB in the CFG:
 ///
 /// - If BB has a single predecessor/successor, then the weight
 ///   of that edge is the weight of the block.
if (BlockWeights[BB]) {
           uint32_t Discriminator = DIL->getBaseDiscriminator();
 
           const FunctionSamples *FS = findFunctionSamples(I);
           if (!FS)
             continue;
           auto T = FS->findCallTargetMapAt(LineOffset, Discriminator);
           if (!T || T.get().size() == 0)
             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());
         } else if (!dyn_cast<IntrinsicInst>(&I)) {
           SmallVector<uint32_t, 1> Weights;
           Weights.push_back(BlockWeights[BB]);
           I.setMetadata(LLVMContext::MD_prof, MDB.createBranchWeights(Weights));
         }

test/Transforms/SampleProfile/indirect-call.ll

 !1 = !DIFile(filename: "test.cc", directory: "/")
 !2 = !{i32 2, !"Debug Info Version", i32 3}
 !3 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 3, unit: !0)
 !4 = !DILocation(line: 4, scope: !3)
 !5 = !DILocation(line: 6, scope: !3)
 ; CHECK: ![[PROF]] = !{!"VP", i32 0, i64 3457, i64 9191153033785521275, i64 2059, i64 -1069303473483922844, i64 1398}
 ; CHECK: ![[BR1]] = !{!"branch_weights", i32 4000, i32 4000}
 ; CHECK: ![[BR2]] = !{!"branch_weights", i32 3000, i32 1000}
-; CHECK: ![[VP]] = !{!"VP", i32 0, i64 1000, i64 -6391416044382067764, i64 1000}
+; CHECK: ![[VP]] = !{!"VP", i32 0, i64 8000, i64 -6391416044382067764, i64 1000}
 !6 = distinct !DISubprogram(name: "test_inline", scope: !1, file: !1, line: 6, unit: !0)
 !7 = !DILocation(line: 7, scope: !6)
 !8 = distinct !DISubprogram(name: "test_inline_strip", scope: !1, file: !1, line: 8, unit: !0)
 !9 = !DILocation(line: 9, scope: !8)
 !10 = distinct !DISubprogram(name: "test_inline_strip_conflict", scope: !1, file: !1, line: 10, unit: !0)
 !11 = !DILocation(line: 11, scope: !10)
 !12 = distinct !DISubprogram(name: "test_noinline", scope: !1, file: !1, line: 12, unit: !0)
 !13 = !DILocation(line: 13, scope: !12)