[memprof] Use CSId to construct MemProfRecord (#88362)

We are in the process of referring to call stacks with CallStackId in
IndexedMemProfRecord and IndexedAllocationInfo instead of holding call
stacks inline (both in memory and the serialized format).  Doing so
deduplicates call stacks and reduces the MemProf profile file size.

Before we can eliminate the two fields holding call stacks inline:

- IndexedAllocationInfo::CallStack
- IndexedMemProfRecord::CallSites

we need to eliminate all the read operations on them.

This patch is a step toward that direction.  Specifically, we
eliminate the read operations in the context of MemProfReader and
RawMemProfReader.  A subsequent patch will eliminate the read
operations during the serialization.

1 files changed, 85 insertions, 0 deletions

diff --git a/llvm/unittests/ProfileData/MemProfTest.cpp b/llvm/unittests/ProfileData/MemProfTest.cpp
index 9cf3074..ab9227e9 100644
--- a/llvm/unittests/ProfileData/MemProfTest.cpp
+++ b/llvm/unittests/ProfileData/MemProfTest.cpp
@@ -21,9 +21,11 @@ using ::llvm::DILineInfo;
 using ::llvm::DILineInfoSpecifier;
 using ::llvm::DILocal;
 using ::llvm::StringRef;
+using ::llvm::memprof::CallStackId;
 using ::llvm::memprof::CallStackMap;
 using ::llvm::memprof::Frame;
 using ::llvm::memprof::FrameId;
+using ::llvm::memprof::IndexedAllocationInfo;
 using ::llvm::memprof::IndexedMemProfRecord;
 using ::llvm::memprof::MemInfoBlock;
 using ::llvm::memprof::MemProfReader;
@@ -36,6 +38,7 @@ using ::llvm::memprof::SegmentEntry;
 using ::llvm::object::SectionedAddress;
 using ::llvm::symbolize::SymbolizableModule;
 using ::testing::Return;
+using ::testing::SizeIs;
 
 class MockSymbolizer : public SymbolizableModule {
 public:
@@ -432,4 +435,86 @@ TEST(MemProf, BaseMemProfReader) {
   EXPECT_THAT(Records[0].AllocSites[0].CallStack[1],
               FrameContains("bar", 10U, 2U, false));
 }
+
+TEST(MemProf, IndexedMemProfRecordToMemProfRecord) {
+  // Verify that MemProfRecord can be constructed from IndexedMemProfRecord with
+  // CallStackIds only.
+
+  llvm::DenseMap<FrameId, Frame> FrameIdMap;
+  Frame F1(1, 0, 0, false);
+  Frame F2(2, 0, 0, false);
+  Frame F3(3, 0, 0, false);
+  Frame F4(4, 0, 0, false);
+  FrameIdMap.insert({F1.hash(), F1});
+  FrameIdMap.insert({F2.hash(), F2});
+  FrameIdMap.insert({F3.hash(), F3});
+  FrameIdMap.insert({F4.hash(), F4});
+
+  llvm::DenseMap<CallStackId, llvm::SmallVector<FrameId>> CallStackIdMap;
+  llvm::SmallVector<FrameId> CS1 = {F1.hash(), F2.hash()};
+  llvm::SmallVector<FrameId> CS2 = {F1.hash(), F3.hash()};
+  llvm::SmallVector<FrameId> CS3 = {F2.hash(), F3.hash()};
+  llvm::SmallVector<FrameId> CS4 = {F2.hash(), F4.hash()};
+  CallStackIdMap.insert({llvm::memprof::hashCallStack(CS1), CS1});
+  CallStackIdMap.insert({llvm::memprof::hashCallStack(CS2), CS2});
+  CallStackIdMap.insert({llvm::memprof::hashCallStack(CS3), CS3});
+  CallStackIdMap.insert({llvm::memprof::hashCallStack(CS4), CS4});
+
+  IndexedMemProfRecord IndexedRecord;
+  IndexedAllocationInfo AI;
+  AI.CSId = llvm::memprof::hashCallStack(CS1);
+  IndexedRecord.AllocSites.push_back(AI);
+  AI.CSId = llvm::memprof::hashCallStack(CS2);
+  IndexedRecord.AllocSites.push_back(AI);
+  IndexedRecord.CallSiteIds.push_back(llvm::memprof::hashCallStack(CS3));
+  IndexedRecord.CallSiteIds.push_back(llvm::memprof::hashCallStack(CS4));
+
+  bool CSIdMissing = false;
+  bool FrameIdMissing = false;
+
+  auto Callback = [&](CallStackId CSId) -> llvm::SmallVector<Frame> {
+    llvm::SmallVector<Frame> CallStack;
+    llvm::SmallVector<FrameId> FrameIds;
+
+    auto Iter = CallStackIdMap.find(CSId);
+    if (Iter == CallStackIdMap.end())
+      CSIdMissing = true;
+    else
+      FrameIds = Iter->second;
+
+    for (FrameId Id : FrameIds) {
+      Frame F(0, 0, 0, false);
+      auto Iter = FrameIdMap.find(Id);
+      if (Iter == FrameIdMap.end())
+        FrameIdMissing = true;
+      else
+        F = Iter->second;
+      CallStack.push_back(F);
+    }
+
+    return CallStack;
+  };
+
+  MemProfRecord Record = IndexedRecord.toMemProfRecord(Callback);
+
+  // Make sure that all lookups are successful.
+  ASSERT_FALSE(CSIdMissing);
+  ASSERT_FALSE(FrameIdMissing);
+
+  // Verify the contents of Record.
+  ASSERT_THAT(Record.AllocSites, SizeIs(2));
+  ASSERT_THAT(Record.AllocSites[0].CallStack, SizeIs(2));
+  EXPECT_EQ(Record.AllocSites[0].CallStack[0].hash(), F1.hash());
+  EXPECT_EQ(Record.AllocSites[0].CallStack[1].hash(), F2.hash());
+  ASSERT_THAT(Record.AllocSites[1].CallStack, SizeIs(2));
+  EXPECT_EQ(Record.AllocSites[1].CallStack[0].hash(), F1.hash());
+  EXPECT_EQ(Record.AllocSites[1].CallStack[1].hash(), F3.hash());
+  ASSERT_THAT(Record.CallSites, SizeIs(2));
+  ASSERT_THAT(Record.CallSites[0], SizeIs(2));
+  EXPECT_EQ(Record.CallSites[0][0].hash(), F2.hash());
+  EXPECT_EQ(Record.CallSites[0][1].hash(), F3.hash());
+  ASSERT_THAT(Record.CallSites[1], SizeIs(2));
+  EXPECT_EQ(Record.CallSites[1][0].hash(), F2.hash());
+  EXPECT_EQ(Record.CallSites[1][1].hash(), F4.hash());
+}
 } // namespace