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IR: Function summary extensions for whole-program devirtualization pass.

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The summary information includes all uses of llvm.type.test and
llvm.type.checked.load intrinsics that can be used to devirtualize calls,
including any constant arguments for virtual constant propagation.

Differential Revision: https://reviews.llvm.org/D29734

llvm-svn: 294795
This commit is contained in:
Peter Collingbourne
2017-02-10 22:29:38 +00:00
parent 03ab8a366e
commit be9ffaacfa
8 changed files with 426 additions and 35 deletions
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49
llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
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@@ -3368,6 +3368,49 @@ void IndexBitcodeWriter::writeModStrings() {
Stream.ExitBlock();
}
/// Write the function type metadata related records that need to appear before
/// a function summary entry (whether per-module or combined).
static void writeFunctionTypeMetadataRecords(BitstreamWriter &Stream,
FunctionSummary *FS) {
if (!FS->type_tests().empty())
Stream.EmitRecord(bitc::FS_TYPE_TESTS, FS->type_tests());
SmallVector<uint64_t, 64> Record;
auto WriteVFuncIdVec = [&](uint64_t Ty,
ArrayRef<FunctionSummary::VFuncId> VFs) {
if (VFs.empty())
return;
Record.clear();
for (auto &VF : VFs) {
Record.push_back(VF.GUID);
Record.push_back(VF.Offset);
}
Stream.EmitRecord(Ty, Record);
};
WriteVFuncIdVec(bitc::FS_TYPE_TEST_ASSUME_VCALLS,
FS->type_test_assume_vcalls());
WriteVFuncIdVec(bitc::FS_TYPE_CHECKED_LOAD_VCALLS,
FS->type_checked_load_vcalls());
auto WriteConstVCallVec = [&](uint64_t Ty,
ArrayRef<FunctionSummary::ConstVCall> VCs) {
for (auto &VC : VCs) {
Record.clear();
Record.push_back(VC.VFunc.GUID);
Record.push_back(VC.VFunc.Offset);
Record.insert(Record.end(), VC.Args.begin(), VC.Args.end());
Stream.EmitRecord(Ty, Record);
}
};
WriteConstVCallVec(bitc::FS_TYPE_TEST_ASSUME_CONST_VCALL,
FS->type_test_assume_const_vcalls());
WriteConstVCallVec(bitc::FS_TYPE_CHECKED_LOAD_CONST_VCALL,
FS->type_checked_load_const_vcalls());
}
// Helper to emit a single function summary record.
void ModuleBitcodeWriter::writePerModuleFunctionSummaryRecord(
SmallVector<uint64_t, 64> &NameVals, GlobalValueSummary *Summary,
@@ -3376,8 +3419,7 @@ void ModuleBitcodeWriter::writePerModuleFunctionSummaryRecord(
NameVals.push_back(ValueID);
FunctionSummary *FS = cast<FunctionSummary>(Summary);
if (!FS->type_tests().empty())
Stream.EmitRecord(bitc::FS_TYPE_TESTS, FS->type_tests());
writeFunctionTypeMetadataRecords(Stream, FS);
NameVals.push_back(getEncodedGVSummaryFlags(FS->flags()));
NameVals.push_back(FS->instCount());
@@ -3637,8 +3679,7 @@ void IndexBitcodeWriter::writeCombinedGlobalValueSummary() {
}
auto *FS = cast<FunctionSummary>(S);
if (!FS->type_tests().empty())
Stream.EmitRecord(bitc::FS_TYPE_TESTS, FS->type_tests());
writeFunctionTypeMetadataRecords(Stream, FS);
NameVals.push_back(ValueId);
NameVals.push_back(Index.getModuleId(FS->modulePath()));