Add inline stack streaming to binary sample profiles.

With this patch we can now read and write inline stacks in sample
profiles to the binary encoded profiles.

In a subsequent patch, I will add a string table to the binary encoding.
Right now function names are emitted as strings every time we find them.
This is too bloated and will produce large files in applications with
lots of inlining.

llvm-svn: 249861

include/llvm/ProfileData/SampleProfReader.h

@@ -157,6 +157,9 @@ protected:
   /// \brief Return true if we've reached the end of file.
   bool at_eof() const { return Data >= End; }
 
+  /// Read the contents of the given profile instance.
+  std::error_code readProfile(FunctionSamples &FProfile);
+
   /// \brief Points to the current location in the buffer.
   const uint8_t *Data;
 

lib/ProfileData/SampleProfReader.cpp

@@ -378,6 +378,83 @@ ErrorOr<StringRef> SampleProfileReaderBinary::readString() {
   return Str;
 }
 
+std::error_code
+SampleProfileReaderBinary::readProfile(FunctionSamples &FProfile) {
+  auto Val = readNumber<unsigned>();
+  if (std::error_code EC = Val.getError())
+    return EC;
+  FProfile.addTotalSamples(*Val);
+
+  Val = readNumber<unsigned>();
+  if (std::error_code EC = Val.getError())
+    return EC;
+  FProfile.addHeadSamples(*Val);
+
+  // Read the samples in the body.
+  auto NumRecords = readNumber<unsigned>();
+  if (std::error_code EC = NumRecords.getError())
+    return EC;
+
+  for (unsigned I = 0; I < *NumRecords; ++I) {
+    auto LineOffset = readNumber<uint64_t>();
+    if (std::error_code EC = LineOffset.getError())
+      return EC;
+
+    auto Discriminator = readNumber<uint64_t>();
+    if (std::error_code EC = Discriminator.getError())
+      return EC;
+
+    auto NumSamples = readNumber<uint64_t>();
+    if (std::error_code EC = NumSamples.getError())
+      return EC;
+
+    auto NumCalls = readNumber<unsigned>();
+    if (std::error_code EC = NumCalls.getError())
+      return EC;
+
+    for (unsigned J = 0; J < *NumCalls; ++J) {
+      auto CalledFunction(readString());
+      if (std::error_code EC = CalledFunction.getError())
+        return EC;
+
+      auto CalledFunctionSamples = readNumber<uint64_t>();
+      if (std::error_code EC = CalledFunctionSamples.getError())
+        return EC;
+
+      FProfile.addCalledTargetSamples(*LineOffset, *Discriminator,
+                                      *CalledFunction, *CalledFunctionSamples);
+    }
+
+    FProfile.addBodySamples(*LineOffset, *Discriminator, *NumSamples);
+  }
+
+  // Read all the samples for inlined function calls.
+  auto NumCallsites = readNumber<unsigned>();
+  if (std::error_code EC = NumCallsites.getError())
+    return EC;
+
+  for (unsigned J = 0; J < *NumCallsites; ++J) {
+    auto LineOffset = readNumber<uint64_t>();
+    if (std::error_code EC = LineOffset.getError())
+      return EC;
+
+    auto Discriminator = readNumber<uint64_t>();
+    if (std::error_code EC = Discriminator.getError())
+      return EC;
+
+    auto FName(readString());
+    if (std::error_code EC = FName.getError())
+      return EC;
+
+    FunctionSamples &CalleeProfile = FProfile.functionSamplesAt(
+        CallsiteLocation(*LineOffset, *Discriminator, *FName));
+    if (std::error_code EC = readProfile(CalleeProfile))
+      return EC;
+  }
+
+  return sampleprof_error::success;
+}
+
 std::error_code SampleProfileReaderBinary::read() {
   while (!at_eof()) {
     auto FName(readString());
@@ -387,53 +464,8 @@ std::error_code SampleProfileReaderBinary::read() {
     Profiles[*FName] = FunctionSamples();
     FunctionSamples &FProfile = Profiles[*FName];
 
-    auto Val = readNumber<unsigned>();
-    if (std::error_code EC = Val.getError())
+    if (std::error_code EC = readProfile(FProfile))
       return EC;
-    FProfile.addTotalSamples(*Val);
-
-    Val = readNumber<unsigned>();
-    if (std::error_code EC = Val.getError())
-      return EC;
-    FProfile.addHeadSamples(*Val);
-
-    // Read the samples in the body.
-    auto NumRecords = readNumber<unsigned>();
-    if (std::error_code EC = NumRecords.getError())
-      return EC;
-    for (unsigned I = 0; I < *NumRecords; ++I) {
-      auto LineOffset = readNumber<uint64_t>();
-      if (std::error_code EC = LineOffset.getError())
-        return EC;
-
-      auto Discriminator = readNumber<uint64_t>();
-      if (std::error_code EC = Discriminator.getError())
-        return EC;
-
-      auto NumSamples = readNumber<uint64_t>();
-      if (std::error_code EC = NumSamples.getError())
-        return EC;
-
-      auto NumCalls = readNumber<unsigned>();
-      if (std::error_code EC = NumCalls.getError())
-        return EC;
-
-      for (unsigned J = 0; J < *NumCalls; ++J) {
-        auto CalledFunction(readString());
-        if (std::error_code EC = CalledFunction.getError())
-          return EC;
-
-        auto CalledFunctionSamples = readNumber<uint64_t>();
-        if (std::error_code EC = CalledFunctionSamples.getError())
-          return EC;
-
-        FProfile.addCalledTargetSamples(*LineOffset, *Discriminator,
-                                        *CalledFunction,
-                                        *CalledFunctionSamples);
-      }
-
-      FProfile.addBodySamples(*LineOffset, *Discriminator, *NumSamples);
-    }
   }
 
   return sampleprof_error::success;

lib/ProfileData/SampleProfWriter.cpp

@@ -84,14 +84,13 @@ SampleProfileWriterBinary::SampleProfileWriterBinary(StringRef F,
 /// \returns true if the samples were written successfully, false otherwise.
 bool SampleProfileWriterBinary::write(StringRef FName,
                                       const FunctionSamples &S) {
-  if (S.empty())
-    return true;
-
   OS << FName;
   encodeULEB128(0, OS);
   encodeULEB128(S.getTotalSamples(), OS);
   encodeULEB128(S.getHeadSamples(), OS);
   encodeULEB128(S.getBodySamples().size(), OS);
+
+  // Emit all the body samples.
   for (const auto &I : S.getBodySamples()) {
     LineLocation Loc = I.first;
     const SampleRecord &Sample = I.second;
@@ -108,6 +107,16 @@ bool SampleProfileWriterBinary::write(StringRef FName,
     }
   }
 
+  // Recursively emit all the callsite samples.
+  encodeULEB128(S.getCallsiteSamples().size(), OS);
+  for (const auto &J : S.getCallsiteSamples()) {
+    CallsiteLocation Loc = J.first;
+    const FunctionSamples &CalleeSamples = J.second;
+    encodeULEB128(Loc.LineOffset, OS);
+    encodeULEB128(Loc.Discriminator, OS);
+    write(Loc.CalleeName, CalleeSamples);
+  }
+
   return true;
 }
 

test/tools/llvm-profdata/Inputs/inline-samples.afdo

@@ -0,0 +1,20 @@
+main:366846:0
+ 2.1: 60401
+ 4: 0
+ 3: 0
+ 0: 0
+ 2.3: 60401
+ 1: 0
+ 2.3: _Z3fool:246044
+  1.2: 39280
+  1.4: 46871
+  1: 60401
+  1.3: _Z3bari:0
+   1.2: 0
+   1.1: 0
+  1.8: _Z3bari:0
+   1.2: 0
+   1.1: 0
+  1.7: _Z3bari:99492
+   1.2: 46732
+   1.1: 52760

test/tools/llvm-profdata/inline-samples.test

@@ -0,0 +1,30 @@
+Tests for conversion between text and binary encoded sample profiles.
+
+1- Encode the original profile into binary form. All the tests below will use
+   the binary profile.
+RUN: llvm-profdata merge --sample %p/Inputs/inline-samples.afdo -o %t.profbin
+
+2- Show all functions. This profile has a single main() function with several
+   inlined callees.
+RUN: llvm-profdata show --sample %t.profbin | FileCheck %s --check-prefix=SHOW1
+SHOW1: Function: main: 366846, 0, 6 sampled lines
+SHOW1: line offset: 2, discriminator: 3, inlined callee: _Z3fool: 246044, 0, 3 sampled lines
+SHOW1:   line offset: 1, discriminator: 3, inlined callee: _Z3bari: 0, 0, 2 sampled lines
+SHOW1:   line offset: 1, discriminator: 8, inlined callee: _Z3bari: 0, 0, 2 sampled lines
+SHOW1:   line offset: 1, discriminator: 7, inlined callee: _Z3bari: 99492, 0, 2 sampled lines
+SHOW1:     line offset: 1, discriminator: 2, number of samples: 46732
+
+3- Convert the binary profile to text encoding and check that they are both
+   identical.
+RUN: llvm-profdata merge --sample %t.profbin --text -o - | llvm-profdata show --sample - -o %t-bintext
+RUN: llvm-profdata show --sample %p/Inputs/inline-samples.afdo -o %t-text
+RUN: diff %t-bintext %t-text
+
+4- Merge the binary and text encodings of the profile and check that the
+   counters have doubled.
+RUN: llvm-profdata merge --sample --text %t.profbin %p/Inputs/inline-samples.afdo -o - | FileCheck %s --check-prefix=MERGE1
+MERGE1: main:733692:0
+MERGE1: 2.3: 120802
+MERGE1: 2.3: _Z3fool:492088
+MERGE1: 1.7: _Z3bari:198984
+MERGE1: 1.1: 105520