[SampleFDO] Add a new compact binary format for sample profile.

Name table occupies a big chunk of size in current binary format sample profile.
In order to reduce its size, the patch changes the sample writer/reader to
save/restore MD5Hash of names in the name table. Sample annotation phase will
also use MD5Hash of name to query samples accordingly.

Experiment shows compact binary format can reduce the size of sample profile by
2/3 compared with binary format generally.

Differential Revision: https://reviews.llvm.org/D47955

llvm-svn: 334447

1 files changed, 10 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/IPO/SampleProfile.cpp b/llvm/lib/Transforms/IPO/SampleProfile.cpp
index 1c53a82cf8a..357a7d1148c 100644
--- a/llvm/lib/Transforms/IPO/SampleProfile.cpp
+++ b/llvm/lib/Transforms/IPO/SampleProfile.cpp
@@ -638,6 +638,8 @@ SampleProfileLoader::findCalleeFunctionSamples(const Instruction &Inst) const {
   if (FS == nullptr)
     return nullptr;
 
+  std::string CalleeGUID;
+  CalleeName = getRepInFormat(CalleeName, Reader->getFormat(), CalleeGUID);
   return FS->findFunctionSamplesAt(LineLocation(FunctionSamples::getOffset(DIL),
                                                 DIL->getBaseDiscriminator()),
                                    CalleeName);
@@ -753,6 +755,7 @@ bool SampleProfileLoader::inlineHotFunctions(
     Function &F, DenseSet<GlobalValue::GUID> &InlinedGUIDs) {
   DenseSet<Instruction *> PromotedInsns;
   bool Changed = false;
+  bool isCompact = (Reader->getFormat() == SPF_Compact_Binary);
   while (true) {
     bool LocalChanged = false;
     SmallVector<Instruction *, 10> CIS;
@@ -784,7 +787,8 @@ bool SampleProfileLoader::inlineHotFunctions(
         for (const auto *FS : findIndirectCallFunctionSamples(*I, Sum)) {
           if (IsThinLTOPreLink) {
             FS->findInlinedFunctions(InlinedGUIDs, F.getParent(),
-                                     PSI->getOrCompHotCountThreshold());
+                                     PSI->getOrCompHotCountThreshold(),
+                                     isCompact);
             continue;
           }
           auto CalleeFunctionName = FS->getName();
@@ -793,7 +797,9 @@ bool SampleProfileLoader::inlineHotFunctions(
           // clone the caller first, and inline the cloned caller if it is
           // recursive. As llvm does not inline recursive calls, we will
           // simply ignore it instead of handling it explicitly.
-          if (CalleeFunctionName == F.getName())
+          std::string FGUID;
+          auto Fname = getRepInFormat(F.getName(), Reader->getFormat(), FGUID);
+          if (CalleeFunctionName == Fname)
             continue;
 
           const char *Reason = "Callee function not available";
@@ -823,7 +829,8 @@ bool SampleProfileLoader::inlineHotFunctions(
           LocalChanged = true;
       } else if (IsThinLTOPreLink) {
         findCalleeFunctionSamples(*I)->findInlinedFunctions(
-            InlinedGUIDs, F.getParent(), PSI->getOrCompHotCountThreshold());
+            InlinedGUIDs, F.getParent(), PSI->getOrCompHotCountThreshold(),
+            isCompact);
       }
     }
     if (LocalChanged) {