[compiler-rt] [llvm] [Memprof] Adds the option to collect AccessCountHistograms for memprof. (PR #94264)

[Teresa Johnson via llvm-commits]

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@@ -146,24 +146,35 @@ void SerializeStackToBuffer(const Vector<u64> &StackIds,
 // ---------- MIB Entry 0
 // Alloc Count
 // ...
+//       ---- AccessHistogram Entry 0
+//            ...
+//       ---- AccessHistogram Entry AccessHistogramSize - 1
 // ---------- MIB Entry 1
 // Alloc Count
 // ...
+//       ---- AccessHistogram Entry 0
+//            ...
+//       ---- AccessHistogram Entry AccessHistogramSize - 1
 // ----------
 void SerializeMIBInfoToBuffer(MIBMapTy &MIBMap, const Vector<u64> &StackIds,
                               const u64 ExpectedNumBytes, char *&Buffer) {
   char *Ptr = Buffer;
   const u64 NumEntries = StackIds.Size();
   Ptr = WriteBytes(NumEntries, Ptr);
-
   for (u64 i = 0; i < NumEntries; i++) {
     const u64 Key = StackIds[i];
     MIBMapTy::Handle h(&MIBMap, Key, /*remove=*/true, /*create=*/false);
     CHECK(h.exists());
     Ptr = WriteBytes(Key, Ptr);
     Ptr = WriteBytes((*h)->mib, Ptr);
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teresajohnson wrote:

Do we end up serializing out the AccessHistogram pointer unnecessarily?

https://github.com/llvm/llvm-project/pull/94264