llvm-6502/include/llvm/ProfileData/SampleProf.h
2015-05-12 22:03:00 +00:00

250 lines
8.6 KiB
C++

//=-- SampleProf.h - Sampling profiling format support --------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains common definitions used in the reading and writing of
// sample profile data.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_PROFILEDATA_SAMPLEPROF_H_
#define LLVM_PROFILEDATA_SAMPLEPROF_H_
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include <system_error>
namespace llvm {
const std::error_category &sampleprof_category();
enum class sampleprof_error {
success = 0,
bad_magic,
unsupported_version,
too_large,
truncated,
malformed,
unrecognized_format
};
inline std::error_code make_error_code(sampleprof_error E) {
return std::error_code(static_cast<int>(E), sampleprof_category());
}
} // end namespace llvm
namespace std {
template <>
struct is_error_code_enum<llvm::sampleprof_error> : std::true_type {};
}
namespace llvm {
namespace sampleprof {
static inline uint64_t SPMagic() {
return uint64_t('S') << (64 - 8) | uint64_t('P') << (64 - 16) |
uint64_t('R') << (64 - 24) | uint64_t('O') << (64 - 32) |
uint64_t('F') << (64 - 40) | uint64_t('4') << (64 - 48) |
uint64_t('2') << (64 - 56) | uint64_t(0xff);
}
static inline uint64_t SPVersion() { return 100; }
/// Represents the relative location of an instruction.
///
/// Instruction locations are specified by the line offset from the
/// beginning of the function (marked by the line where the function
/// header is) and the discriminator value within that line.
///
/// The discriminator value is useful to distinguish instructions
/// that are on the same line but belong to different basic blocks
/// (e.g., the two post-increment instructions in "if (p) x++; else y++;").
struct LineLocation {
LineLocation(int L, unsigned D) : LineOffset(L), Discriminator(D) {}
int LineOffset;
unsigned Discriminator;
};
} // End namespace sampleprof
template <> struct DenseMapInfo<sampleprof::LineLocation> {
typedef DenseMapInfo<int> OffsetInfo;
typedef DenseMapInfo<unsigned> DiscriminatorInfo;
static inline sampleprof::LineLocation getEmptyKey() {
return sampleprof::LineLocation(OffsetInfo::getEmptyKey(),
DiscriminatorInfo::getEmptyKey());
}
static inline sampleprof::LineLocation getTombstoneKey() {
return sampleprof::LineLocation(OffsetInfo::getTombstoneKey(),
DiscriminatorInfo::getTombstoneKey());
}
static inline unsigned getHashValue(sampleprof::LineLocation Val) {
return DenseMapInfo<std::pair<int, unsigned>>::getHashValue(
std::pair<int, unsigned>(Val.LineOffset, Val.Discriminator));
}
static inline bool isEqual(sampleprof::LineLocation LHS,
sampleprof::LineLocation RHS) {
return LHS.LineOffset == RHS.LineOffset &&
LHS.Discriminator == RHS.Discriminator;
}
};
namespace sampleprof {
/// Representation of a single sample record.
///
/// A sample record is represented by a positive integer value, which
/// indicates how frequently was the associated line location executed.
///
/// Additionally, if the associated location contains a function call,
/// the record will hold a list of all the possible called targets. For
/// direct calls, this will be the exact function being invoked. For
/// indirect calls (function pointers, virtual table dispatch), this
/// will be a list of one or more functions.
class SampleRecord {
public:
typedef StringMap<unsigned> CallTargetMap;
SampleRecord() : NumSamples(0), CallTargets() {}
/// Increment the number of samples for this record by \p S.
///
/// Sample counts accumulate using saturating arithmetic, to avoid wrapping
/// around unsigned integers.
void addSamples(unsigned S) {
if (NumSamples <= std::numeric_limits<unsigned>::max() - S)
NumSamples += S;
else
NumSamples = std::numeric_limits<unsigned>::max();
}
/// Add called function \p F with samples \p S.
///
/// Sample counts accumulate using saturating arithmetic, to avoid wrapping
/// around unsigned integers.
void addCalledTarget(StringRef F, unsigned S) {
unsigned &TargetSamples = CallTargets[F];
if (TargetSamples <= std::numeric_limits<unsigned>::max() - S)
TargetSamples += S;
else
TargetSamples = std::numeric_limits<unsigned>::max();
}
/// Return true if this sample record contains function calls.
bool hasCalls() const { return CallTargets.size() > 0; }
unsigned getSamples() const { return NumSamples; }
const CallTargetMap &getCallTargets() const { return CallTargets; }
/// Merge the samples in \p Other into this record.
void merge(const SampleRecord &Other) {
addSamples(Other.getSamples());
for (const auto &I : Other.getCallTargets())
addCalledTarget(I.first(), I.second);
}
private:
unsigned NumSamples;
CallTargetMap CallTargets;
};
typedef DenseMap<LineLocation, SampleRecord> BodySampleMap;
/// Representation of the samples collected for a function.
///
/// This data structure contains all the collected samples for the body
/// of a function. Each sample corresponds to a LineLocation instance
/// within the body of the function.
class FunctionSamples {
public:
FunctionSamples() : TotalSamples(0), TotalHeadSamples(0) {}
void print(raw_ostream &OS = dbgs());
void addTotalSamples(unsigned Num) { TotalSamples += Num; }
void addHeadSamples(unsigned Num) { TotalHeadSamples += Num; }
void addBodySamples(int LineOffset, unsigned Discriminator, unsigned Num) {
assert(LineOffset >= 0);
// When dealing with instruction weights, we use the value
// zero to indicate the absence of a sample. If we read an
// actual zero from the profile file, use the value 1 to
// avoid the confusion later on.
if (Num == 0)
Num = 1;
BodySamples[LineLocation(LineOffset, Discriminator)].addSamples(Num);
}
void addCalledTargetSamples(int LineOffset, unsigned Discriminator,
std::string FName, unsigned Num) {
assert(LineOffset >= 0);
BodySamples[LineLocation(LineOffset, Discriminator)].addCalledTarget(FName,
Num);
}
/// Return the sample record at the given location.
/// Each location is specified by \p LineOffset and \p Discriminator.
SampleRecord &sampleRecordAt(const LineLocation &Loc) {
return BodySamples[Loc];
}
/// Return the number of samples collected at the given location.
/// Each location is specified by \p LineOffset and \p Discriminator.
unsigned samplesAt(int LineOffset, unsigned Discriminator) {
return sampleRecordAt(LineLocation(LineOffset, Discriminator)).getSamples();
}
bool empty() const { return BodySamples.empty(); }
/// Return the total number of samples collected inside the function.
unsigned getTotalSamples() const { return TotalSamples; }
/// Return the total number of samples collected at the head of the
/// function.
unsigned getHeadSamples() const { return TotalHeadSamples; }
/// Return all the samples collected in the body of the function.
const BodySampleMap &getBodySamples() const { return BodySamples; }
/// Merge the samples in \p Other into this one.
void merge(const FunctionSamples &Other) {
addTotalSamples(Other.getTotalSamples());
addHeadSamples(Other.getHeadSamples());
for (const auto &I : Other.getBodySamples()) {
const LineLocation &Loc = I.first;
const SampleRecord &Rec = I.second;
sampleRecordAt(Loc).merge(Rec);
}
}
private:
/// Total number of samples collected inside this function.
///
/// Samples are cumulative, they include all the samples collected
/// inside this function and all its inlined callees.
unsigned TotalSamples;
/// Total number of samples collected at the head of the function.
/// This is an approximation of the number of calls made to this function
/// at runtime.
unsigned TotalHeadSamples;
/// Map instruction locations to collected samples.
///
/// Each entry in this map contains the number of samples
/// collected at the corresponding line offset. All line locations
/// are an offset from the start of the function.
BodySampleMap BodySamples;
};
} // End namespace sampleprof
} // End namespace llvm
#endif // LLVM_PROFILEDATA_SAMPLEPROF_H_