[MemProf] Merge all callee guids for indirect call VP metadata

llvm/lib/Transforms/Instrumentation/MemProfUse.cpp

@@ -528,35 +528,50 @@ static void handleCallSite(
     Module &M, std::set<std::vector<uint64_t>> &MatchedCallSites,
     OptimizationRemarkEmitter &ORE) {
   auto &Ctx = M.getContext();
+  // Set of Callee GUIDs to attach to indirect calls. We accumulate all of them
+  // to support cases where the instuction's inlined frames match multiple call
+  // site entries, which can happen if the profile was collected from a binary
+  // where this instruction was eventually inlined into multiple callers.
+  SetVector<GlobalValue::GUID> CalleeGuids;
+  bool CallsiteMDAdded = false;
   for (const auto &CallSiteEntry : CallSiteEntries) {
     // If we found and thus matched all frames on the call, create and
     // attach call stack metadata.
     if (stackFrameIncludesInlinedCallStack(CallSiteEntry.Frames,
                                            InlinedCallStack)) {
       NumOfMemProfMatchedCallSites++;
-      addCallsiteMetadata(I, InlinedCallStack, Ctx);
-
-      // Try to attach indirect call metadata if possible.
-      if (!CalledFunction)
-        addVPMetadata(M, I, CallSiteEntry.CalleeGuids);
-
       // Only need to find one with a matching call stack and add a single
       // callsite metadata.
-
-      // Accumulate call site matching information upon request.
-      if (ClPrintMemProfMatchInfo) {
-        std::vector<uint64_t> CallStack;
-        append_range(CallStack, InlinedCallStack);
-        MatchedCallSites.insert(std::move(CallStack));
+      if (!CallsiteMDAdded) {
+        addCallsiteMetadata(I, InlinedCallStack, Ctx);
+
+        // Accumulate call site matching information upon request.
+        if (ClPrintMemProfMatchInfo) {
+          std::vector<uint64_t> CallStack;
+          append_range(CallStack, InlinedCallStack);
+          MatchedCallSites.insert(std::move(CallStack));
+        }
+        ORE.emit(OptimizationRemark(DEBUG_TYPE, "MemProfUse", &I)
+                 << ore::NV("CallSite", &I) << " in function "
+                 << ore::NV("Caller", I.getFunction())
+                 << " matched callsite with frame count "
+                 << ore::NV("Frames", InlinedCallStack.size()));
+
+        // If this is a direct call, we're done.
+        if (CalledFunction)
+          break;
+        CallsiteMDAdded = true;
       }
-      ORE.emit(OptimizationRemark(DEBUG_TYPE, "MemProfUse", &I)
-               << ore::NV("CallSite", &I) << " in function "
-               << ore::NV("Caller", I.getFunction())
-               << " matched callsite with frame count "
-               << ore::NV("Frames", InlinedCallStack.size()));
-      break;
+
+      assert(!CalledFunction && "Didn't expect direct call");
+
+      // Collect Callee GUIDs from all matching CallSiteEntries.
+      CalleeGuids.insert(CallSiteEntry.CalleeGuids.begin(),
+                         CallSiteEntry.CalleeGuids.end());
     }
   }
+  // Try to attach indirect call metadata if possible.
+  addVPMetadata(M, I, CalleeGuids.getArrayRef());
 }
 
 static void readMemprof(Module &M, Function &F,

llvm/test/Transforms/PGOProfile/memprof_annotate_indirect_call.test

@@ -18,6 +18,18 @@ HeapProfileRecords:
       - Frames:
           - { Function: _Z3barv, LineOffset: 3, Column: 5, IsInlineFrame: false }
         CalleeGuids:   [0x123456789abcdef0, 0x23456789abcdef01]
+      # The next 2 sets of frames simulates the case where this function was
+      # eventually inlined into multiple callers. We would have propagated the
+      # resulting frames and callee guids here for matching with they not yet
+      # inlined bar. We should aggregate all callee guids into the metadata.
+      - Frames:
+          - { Function: _Z3barv, LineOffset: 3, Column: 5, IsInlineFrame: true }
+          - { Function: _Z3foov, LineOffset: 1, Column: 6, IsInlineFrame: false }
+        CalleeGuids:   [0x1234, 0x2345]
+      - Frames:
+          - { Function: _Z3barv, LineOffset: 3, Column: 5, IsInlineFrame: true }
+          - { Function: _Z3foov, LineOffset: 10, Column: 7, IsInlineFrame: false }
+        CalleeGuids:   [0x3456, 0x4567]
 ...
 
 ;--- basic.ll
@@ -31,7 +43,7 @@ entry:
   ret void
 }
 
-; CHECK-ENABLE: !6 = !{!"VP", i32 0, i64 2, i64 1311768467463790320, i64 1, i64 2541551405711093505, i64 1}
+; CHECK-ENABLE: !6 = !{!"VP", i32 0, i64 6, i64 13398, i64 1, i64 17767, i64 1, i64 4660, i64 1, i64 9029, i64 1, i64 1311768467463790320, i64 1, i64 2541551405711093505, i64 1}
 
 !llvm.module.flags = !{!2, !3}