llvm-6502/lib/ProfileData/InstrProfWriter.cpp

160 lines
5.0 KiB
C++
Raw Normal View History

//=-- InstrProfWriter.cpp - Instrumented profiling writer -------------------=//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains support for writing profiling data for clang's
// instrumentation based PGO and coverage.
//
//===----------------------------------------------------------------------===//
#include "llvm/ProfileData/InstrProfWriter.h"
#include "InstrProfIndexed.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/EndianStream.h"
#include "llvm/Support/OnDiskHashTable.h"
using namespace llvm;
namespace {
class InstrProfRecordTrait {
public:
typedef StringRef key_type;
typedef StringRef key_type_ref;
typedef const InstrProfWriter::CounterData *const data_type;
typedef const InstrProfWriter::CounterData *const data_type_ref;
typedef uint64_t hash_value_type;
typedef uint64_t offset_type;
static hash_value_type ComputeHash(key_type_ref K) {
return IndexedInstrProf::ComputeHash(IndexedInstrProf::HashType, K);
}
static std::pair<offset_type, offset_type>
EmitKeyDataLength(raw_ostream &Out, key_type_ref K, data_type_ref V) {
using namespace llvm::support;
endian::Writer<little> LE(Out);
offset_type N = K.size();
LE.write<offset_type>(N);
offset_type M = 0;
for (const auto &Counts : *V)
M += (2 + Counts.second.size()) * sizeof(uint64_t);
LE.write<offset_type>(M);
return std::make_pair(N, M);
}
static void EmitKey(raw_ostream &Out, key_type_ref K, offset_type N){
Out.write(K.data(), N);
}
static void EmitData(raw_ostream &Out, key_type_ref, data_type_ref V,
offset_type) {
using namespace llvm::support;
endian::Writer<little> LE(Out);
for (const auto &Counts : *V) {
LE.write<uint64_t>(Counts.first);
LE.write<uint64_t>(Counts.second.size());
for (uint64_t I : Counts.second)
LE.write<uint64_t>(I);
}
}
};
}
std::error_code
InstrProfWriter::addFunctionCounts(StringRef FunctionName,
uint64_t FunctionHash,
ArrayRef<uint64_t> Counters) {
auto &CounterData = FunctionData[FunctionName];
auto Where = CounterData.find(FunctionHash);
if (Where == CounterData.end()) {
// We've never seen a function with this name and hash, add it.
CounterData[FunctionHash] = Counters;
// We keep track of the max function count as we go for simplicity.
if (Counters[0] > MaxFunctionCount)
MaxFunctionCount = Counters[0];
return instrprof_error::success;
}
// We're updating a function we've seen before.
auto &FoundCounters = Where->second;
// If the number of counters doesn't match we either have bad data or a hash
// collision.
if (FoundCounters.size() != Counters.size())
return instrprof_error::count_mismatch;
for (size_t I = 0, E = Counters.size(); I < E; ++I) {
if (FoundCounters[I] + Counters[I] < FoundCounters[I])
return instrprof_error::counter_overflow;
FoundCounters[I] += Counters[I];
}
// We keep track of the max function count as we go for simplicity.
if (FoundCounters[0] > MaxFunctionCount)
MaxFunctionCount = FoundCounters[0];
return instrprof_error::success;
}
std::pair<uint64_t, uint64_t> InstrProfWriter::writeImpl(raw_ostream &OS) {
OnDiskChainedHashTableGenerator<InstrProfRecordTrait> Generator;
// Populate the hash table generator.
for (const auto &I : FunctionData)
Generator.insert(I.getKey(), &I.getValue());
using namespace llvm::support;
endian::Writer<little> LE(OS);
// Write the header.
LE.write<uint64_t>(IndexedInstrProf::Magic);
LE.write<uint64_t>(IndexedInstrProf::Version);
LE.write<uint64_t>(MaxFunctionCount);
LE.write<uint64_t>(static_cast<uint64_t>(IndexedInstrProf::HashType));
// Save a space to write the hash table start location.
uint64_t HashTableStartLoc = OS.tell();
LE.write<uint64_t>(0);
// Write the hash table.
uint64_t HashTableStart = Generator.Emit(OS);
return std::make_pair(HashTableStartLoc, HashTableStart);
}
void InstrProfWriter::write(raw_fd_ostream &OS) {
// Write the hash table.
auto TableStart = writeImpl(OS);
// Go back and fill in the hash table start.
using namespace support;
OS.seek(TableStart.first);
endian::Writer<little>(OS).write<uint64_t>(TableStart.second);
}
std::unique_ptr<MemoryBuffer> InstrProfWriter::writeBuffer() {
std::string Data;
llvm::raw_string_ostream OS(Data);
// Write the hash table.
auto TableStart = writeImpl(OS);
OS.flush();
// Go back and fill in the hash table start.
using namespace support;
uint64_t Bytes = endian::byte_swap<uint64_t, little>(TableStart.second);
Data.replace(TableStart.first, sizeof(uint64_t), (const char *)&Bytes,
sizeof(uint64_t));
// Return this in an aligned memory buffer.
return MemoryBuffer::getMemBufferCopy(Data);
}