Re-land "[ThinLTO] Add call edges' relative block frequency to per-module summary."

It was reverted after buildbot regressions.

Original commit message:

This allows relative block frequency of call edges to be passed
to the thinlink stage where it will be used to compute synthetic
entry counts of functions.

llvm-svn: 323460
This commit is contained in:
Easwaran Raman
2018-01-25 19:27:17 +00:00
parent 7e9453d583
commit c73cec84c9
7 changed files with 93 additions and 31 deletions

View File

@@ -86,6 +86,9 @@ static cl::opt<unsigned>
cl::desc("Number of metadatas above which we emit an index "
"to enable lazy-loading"));
cl::opt<bool> WriteRelBFToSummary(
"write-relbf-to-summary", cl::Hidden, cl::init(false),
cl::desc("Write relative block frequency to function summary "));
namespace {
/// These are manifest constants used by the bitcode writer. They do not need to
@@ -3378,11 +3381,15 @@ void ModuleBitcodeWriterBase::writePerModuleFunctionSummaryRecord(
NameVals.push_back(getValueId(ECI.first));
if (HasProfileData)
NameVals.push_back(static_cast<uint8_t>(ECI.second.Hotness));
else if (WriteRelBFToSummary)
NameVals.push_back(ECI.second.RelBlockFreq);
}
unsigned FSAbbrev = (HasProfileData ? FSCallsProfileAbbrev : FSCallsAbbrev);
unsigned Code =
(HasProfileData ? bitc::FS_PERMODULE_PROFILE : bitc::FS_PERMODULE);
(HasProfileData ? bitc::FS_PERMODULE_PROFILE
: (WriteRelBFToSummary ? bitc::FS_PERMODULE_RELBF
: bitc::FS_PERMODULE));
// Emit the finished record.
Stream.EmitRecord(Code, NameVals, FSAbbrev);
@@ -3448,21 +3455,8 @@ void ModuleBitcodeWriterBase::writePerModuleGlobalValueSummary() {
ArrayRef<uint64_t>{GVI.second, GVI.first});
}
// Abbrev for FS_PERMODULE.
auto Abbv = std::make_shared<BitCodeAbbrev>();
Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE));
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // flags
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // instcount
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // fflags
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numrefs
// numrefs x valueid, n x (valueid)
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
unsigned FSCallsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
// Abbrev for FS_PERMODULE_PROFILE.
Abbv = std::make_shared<BitCodeAbbrev>();
auto Abbv = std::make_shared<BitCodeAbbrev>();
Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_PROFILE));
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // flags
@@ -3474,6 +3468,22 @@ void ModuleBitcodeWriterBase::writePerModuleGlobalValueSummary() {
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
unsigned FSCallsProfileAbbrev = Stream.EmitAbbrev(std::move(Abbv));
// Abbrev for FS_PERMODULE or FS_PERMODULE_RELBF.
Abbv = std::make_shared<BitCodeAbbrev>();
if (WriteRelBFToSummary)
Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_RELBF));
else
Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE));
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // flags
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // instcount
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // fflags
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numrefs
// numrefs x valueid, n x (valueid [, rel_block_freq])
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
unsigned FSCallsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
// Abbrev for FS_PERMODULE_GLOBALVAR_INIT_REFS.
Abbv = std::make_shared<BitCodeAbbrev>();
Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS));
@@ -3675,7 +3685,8 @@ void IndexBitcodeWriter::writeCombinedGlobalValueSummary() {
bool HasProfileData = false;
for (auto &EI : FS->calls()) {
HasProfileData |= EI.second.Hotness != CalleeInfo::HotnessType::Unknown;
HasProfileData |=
EI.second.getHotness() != CalleeInfo::HotnessType::Unknown;
if (HasProfileData)
break;
}