[SampleFDO] Add indexing for function profiles so they can be loaded on demand

in ExtBinary format

Currently for Text, Binary and ExtBinary format profiles, when we compile a
module with samplefdo, even if there is no function showing up in the profile,
we have to load all the function profiles from the profile input. That is a
waste of compile time.

CompactBinary format profile has already had the support of loading function
profiles on demand. In this patch, we add the support to load profile on
demand for ExtBinary format. It will work no matter the sections in ExtBinary
format profile are compressed or not. Experiment shows it reduces the time to
compile a server benchmark by 30%.

When profile remapping and loading function profiles on demand are both used,
extra work needs to be done so that the loading on demand process will take
the name remapping into consideration. It will be addressed in a follow-up
patch.

Differential Revision: https://reviews.llvm.org/D68601

llvm-svn: 374233

1 files changed, 28 insertions, 8 deletions

diff --git a/llvm/unittests/ProfileData/SampleProfTest.cpp b/llvm/unittests/ProfileData/SampleProfTest.cpp
index dd5ded5bc9b..59ed19d292e 100644
--- a/llvm/unittests/ProfileData/SampleProfTest.cpp
+++ b/llvm/unittests/ProfileData/SampleProfTest.cpp
@@ -54,7 +54,7 @@ struct SampleProfTest : ::testing::Test {
     auto ReaderOrErr = SampleProfileReader::create(Profile, Context);
     ASSERT_TRUE(NoError(ReaderOrErr.getError()));
     Reader = std::move(ReaderOrErr.get());
-    Reader->collectFuncsToUse(M);
+    Reader->collectFuncsFrom(M);
   }
 
   void testRoundTrip(SampleProfileFormat Format, bool Remap) {
@@ -86,6 +86,13 @@ struct SampleProfTest : ::testing::Test {
     BarSamples.addCalledTargetSamples(1, 0, MconstructName, 1000);
     BarSamples.addCalledTargetSamples(1, 0, StringviewName, 437);
 
+    StringRef BazName("_Z3bazi");
+    FunctionSamples BazSamples;
+    BazSamples.setName(BazName);
+    BazSamples.addTotalSamples(12557);
+    BazSamples.addHeadSamples(1257);
+    BazSamples.addBodySamples(1, 0, 12557);
+
     Module M("my_module", Context);
     FunctionType *fn_type =
         FunctionType::get(Type::getVoidTy(Context), {}, false);
@@ -95,6 +102,7 @@ struct SampleProfTest : ::testing::Test {
     StringMap<FunctionSamples> Profiles;
     Profiles[FooName] = std::move(FooSamples);
     Profiles[BarName] = std::move(BarSamples);
+    Profiles[BazName] = std::move(BazSamples);
 
     ProfileSymbolList List;
     if (Format == SampleProfileFormat::SPF_Ext_Binary) {
@@ -137,8 +145,6 @@ struct SampleProfTest : ::testing::Test {
       ASSERT_TRUE(NoError(EC));
     }
 
-    ASSERT_EQ(2u, Reader->getProfiles().size());
-
     FunctionSamples *ReadFooSamples = Reader->getSamplesFor(FooName);
     ASSERT_TRUE(ReadFooSamples != nullptr);
     if (Format != SampleProfileFormat::SPF_Compact_Binary) {
@@ -158,6 +164,20 @@ struct SampleProfTest : ::testing::Test {
         ReadBarSamples->findCallTargetMapAt(1, 0);
     ASSERT_FALSE(CTMap.getError());
 
+    // Because _Z3bazi is not defined in module M, expect _Z3bazi's profile
+    // is not loaded when the profile is ExtBinary or Compact format because
+    // these formats support loading function profiles on demand.
+    FunctionSamples *ReadBazSamples = Reader->getSamplesFor(BazName);
+    if (Format == SampleProfileFormat::SPF_Ext_Binary ||
+        Format == SampleProfileFormat::SPF_Compact_Binary) {
+      ASSERT_TRUE(ReadBazSamples == nullptr);
+      ASSERT_EQ(2u, Reader->getProfiles().size());
+    } else {
+      ASSERT_TRUE(ReadBazSamples != nullptr);
+      ASSERT_EQ(12557u, ReadBazSamples->getTotalSamples());
+      ASSERT_EQ(3u, Reader->getProfiles().size());
+    }
+
     std::string MconstructGUID;
     StringRef MconstructRep =
         getRepInFormat(MconstructName, Format, MconstructGUID);
@@ -169,9 +189,9 @@ struct SampleProfTest : ::testing::Test {
 
     auto VerifySummary = [](ProfileSummary &Summary) mutable {
       ASSERT_EQ(ProfileSummary::PSK_Sample, Summary.getKind());
-      ASSERT_EQ(123603u, Summary.getTotalCount());
-      ASSERT_EQ(6u, Summary.getNumCounts());
-      ASSERT_EQ(2u, Summary.getNumFunctions());
+      ASSERT_EQ(136160u, Summary.getTotalCount());
+      ASSERT_EQ(7u, Summary.getNumCounts());
+      ASSERT_EQ(3u, Summary.getNumFunctions());
       ASSERT_EQ(1437u, Summary.getMaxFunctionCount());
       ASSERT_EQ(60351u, Summary.getMaxCount());
 
@@ -188,8 +208,8 @@ struct SampleProfTest : ::testing::Test {
       Cutoff = 990000;
       auto NinetyNinePerc = find_if(Details, Predicate);
       ASSERT_EQ(60000u, EightyPerc->MinCount);
-      ASSERT_EQ(60000u, NinetyPerc->MinCount);
-      ASSERT_EQ(60000u, NinetyFivePerc->MinCount);
+      ASSERT_EQ(12557u, NinetyPerc->MinCount);
+      ASSERT_EQ(12557u, NinetyFivePerc->MinCount);
       ASSERT_EQ(610u, NinetyNinePerc->MinCount);
     };