//===- SampleProf.h - Sampling profiling format support ---------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// 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/DenseSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/MathExtras.h"
#include <algorithm>
#include <cstdint>
#include <list>
#include <map>
#include <set>
#include <sstream>
#include <string>
#include <system_error>
#include <unordered_map>
#include <utility>
namespace llvm {
class DILocation;
class raw_ostream;
const std::error_category &sampleprof_category();
enum class sampleprof_error {
success = 0,
bad_magic,
unsupported_version,
too_large,
truncated,
malformed,
unrecognized_format,
unsupported_writing_format,
truncated_name_table,
not_implemented,
counter_overflow,
ostream_seek_unsupported,
uncompress_failed,
zlib_unavailable,
hash_mismatch
};
inline std::error_code make_error_code(sampleprof_error E) {
return std::error_code(static_cast<int>(E), sampleprof_category());
}
inline sampleprof_error MergeResult(sampleprof_error &Accumulator,
sampleprof_error Result) {
// Prefer first error encountered as later errors may be secondary effects of
// the initial problem.
if (Accumulator == sampleprof_error::success &&
Result != sampleprof_error::success)
Accumulator = Result;
return Accumulator;
}
} // end namespace llvm
namespace std {
template <>
struct is_error_code_enum<llvm::sampleprof_error> : std::true_type {};
} // end namespace std
namespace llvm {
namespace sampleprof {
enum SampleProfileFormat {
SPF_None = 0,
SPF_Text = 0x1,
SPF_Compact_Binary = 0x2,
SPF_GCC = 0x3,
SPF_Ext_Binary = 0x4,
SPF_Binary = 0xff
};
static inline uint64_t SPMagic(SampleProfileFormat Format = SPF_Binary) {
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(Format);
}
/// Get the proper representation of a string according to whether the
/// current Format uses MD5 to represent the string.
static inline StringRef getRepInFormat(StringRef Name, bool UseMD5,
std::string &GUIDBuf) {
if (Name.empty() || !UseMD5)
return Name;
GUIDBuf = std::to_string(Function::getGUID(Name));
return GUIDBuf;
}
static inline uint64_t SPVersion() { return 103; }
// Section Type used by SampleProfileExtBinaryBaseReader and
// SampleProfileExtBinaryBaseWriter. Never change the existing
// value of enum. Only append new ones.
enum SecType {
SecInValid = 0,
SecProfSummary = 1,
SecNameTable = 2,
SecProfileSymbolList = 3,
SecFuncOffsetTable = 4,
SecFuncMetadata = 5,
SecCSNameTable = 6,
// marker for the first type of profile.
SecFuncProfileFirst = 32,
SecLBRProfile = SecFuncProfileFirst
};
static inline std::string getSecName(SecType Type) {
switch ((int)Type) { // Avoid -Wcovered-switch-default
case SecInValid:
return "InvalidSection";
case SecProfSummary:
return "ProfileSummarySection";
case SecNameTable:
return "NameTableSection";
case SecProfileSymbolList:
return "ProfileSymbolListSection";
case SecFuncOffsetTable:
return "FuncOffsetTableSection";
case SecFuncMetadata:
return "FunctionMetadata";
case SecCSNameTable:
return "CSNameTableSection";
case SecLBRProfile:
return "LBRProfileSection";
default:
return "UnknownSection";
}
}
// Entry type of section header table used by SampleProfileExtBinaryBaseReader
// and SampleProfileExtBinaryBaseWriter.
struct SecHdrTableEntry {
SecType Type;
uint64_t Flags;
uint64_t Offset;
uint64_t Size;
// The index indicating the location of the current entry in
// SectionHdrLayout table.
uint32_t LayoutIndex;
};
// Flags common for all sections are defined here. In SecHdrTableEntry::Flags,
// common flags will be saved in the lower 32bits and section specific flags
// will be saved in the higher 32 bits.
enum class SecCommonFlags : uint32_t {
SecFlagInValid = 0,
SecFlagCompress = (1 << 0),
// Indicate the section contains only profile without context.
SecFlagFlat = (1 << 1)
};
// Section specific flags are defined here.
// !!!Note: Everytime a new enum class is created here, please add
// a new check in verifySecFlag.
enum class SecNameTableFlags : uint32_t {
SecFlagInValid = 0,
SecFlagMD5Name = (1 << 0),
// Store MD5 in fixed length instead of ULEB128 so NameTable can be
// accessed like an array.
SecFlagFixedLengthMD5 = (1 << 1),
// Profile contains ".__uniq." suffix name. Compiler shouldn't strip
// the suffix when doing profile matching when seeing the flag.
SecFlagUniqSuffix = (1 << 2)
};
enum class SecProfSummaryFlags : uint32_t {
SecFlagInValid = 0,
/// SecFlagPartial means the profile is for common/shared code.
/// The common profile is usually merged from profiles collected
/// from running other targets.
SecFlagPartial = (1 << 0),
/// SecFlagContext means this is context-sensitive flat profile for
/// CSSPGO
SecFlagFullContext = (1 << 1),
/// SecFlagFSDiscriminator means this profile uses flow-sensitive
/// discriminators.
SecFlagFSDiscriminator = (1 << 2),
/// SecFlagIsPreInlined means this profile contains ShouldBeInlined
/// contexts thus this is CS preinliner computed.
SecFlagIsPreInlined = (1 << 4),
};
enum class SecFuncMetadataFlags : uint32_t {
SecFlagInvalid = 0,
SecFlagIsProbeBased = (1 << 0),
SecFlagHasAttribute = (1 << 1),
};
enum class SecFuncOffsetFlags : uint32_t {
SecFlagInvalid = 0,
// Store function offsets in an order of contexts. The order ensures that
// callee contexts of a given context laid out next to it.
SecFlagOrdered = (1 << 0),
};
// Verify section specific flag is used for the correct section.
template <class SecFlagType>
static inline void verifySecFlag(SecType Type, SecFlagType Flag) {
// No verification is needed for common flags.
if (std::is_same<SecCommonFlags, SecFlagType>())
return;
// Verification starts here for section specific flag.
bool IsFlagLegal = false;
switch (Type) {
case SecNameTable:
IsFlagLegal = std::is_same<SecNameTableFlags, SecFlagType>();
break;
case SecProfSummary:
IsFlagLegal = std::is_same<SecProfSummaryFlags, SecFlagType>();
break;
case SecFuncMetadata:
IsFlagLegal = std::is_same<SecFuncMetadataFlags, SecFlagType>();
break;
default:
case SecFuncOffsetTable:
IsFlagLegal = std::is_same<SecFuncOffsetFlags, SecFlagType>();
break;
}
if (!IsFlagLegal)
llvm_unreachable("Misuse of a flag in an incompatible section");
}
template <class SecFlagType>
static inline void addSecFlag(SecHdrTableEntry &Entry, SecFlagType Flag) {
verifySecFlag(Entry.Type, Flag);
auto FVal = static_cast<uint64_t>(Flag);
bool IsCommon = std::is_same<SecCommonFlags, SecFlagType>();
Entry.Flags |= IsCommon ? FVal : (FVal << 32);
}
template <class SecFlagType>
static inline void removeSecFlag(SecHdrTableEntry &Entry, SecFlagType Flag) {
verifySecFlag(Entry.Type, Flag);
auto FVal = static_cast<uint64_t>(Flag);
bool IsCommon = std::is_same<SecCommonFlags, SecFlagType>();
Entry.Flags &= ~(IsCommon ? FVal : (FVal << 32));
}
template <class SecFlagType>
static inline bool hasSecFlag(const SecHdrTableEntry &Entry, SecFlagType Flag) {
verifySecFlag(Entry.Type, Flag);
auto FVal = static_cast<uint64_t>(Flag);
bool IsCommon = std::is_same<SecCommonFlags, SecFlagType>();
return Entry.Flags & (IsCommon ? FVal : (FVal << 32));
}
/// 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(uint32_t L, uint32_t D) : LineOffset(L), Discriminator(D) {}
void print(raw_ostream &OS) const;
void dump() const;
bool operator<(const LineLocation &O) const {
return LineOffset < O.LineOffset ||
(LineOffset == O.LineOffset && Discriminator < O.Discriminator);
}
bool operator==(const LineLocation &O) const {
return LineOffset == O.LineOffset && Discriminator == O.Discriminator;
}
bool operator!=(const LineLocation &O) const {
return LineOffset != O.LineOffset || Discriminator != O.Discriminator;
}
uint32_t LineOffset;
uint32_t Discriminator;
};
struct LineLocationHash {
uint64_t operator()(const LineLocation &Loc) const {
return std::hash<std::uint64_t>{}((((uint64_t)Loc.LineOffset) << 32) |
Loc.Discriminator);
}
};
raw_ostream &operator<<(raw_ostream &OS, const LineLocation &Loc);
/// 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:
using CallTarget = std::pair<StringRef, uint64_t>;
struct CallTargetComparator {
bool operator()(const CallTarget &LHS, const CallTarget &RHS) const {
if (LHS.second != RHS.second)
return LHS.second > RHS.second;
return LHS.first < RHS.first;
}
};
using SortedCallTargetSet = std::set<CallTarget, CallTargetComparator>;
using CallTargetMap = StringMap<uint64_t>;
SampleRecord() = default;
/// Increment the number of samples for this record by \p S.
/// Optionally scale sample count \p S by \p Weight.
///
/// Sample counts accumulate using saturating arithmetic, to avoid wrapping
/// around unsigned integers.
sampleprof_error addSamples(uint64_t S, uint64_t Weight = 1) {
bool Overflowed;
NumSamples = SaturatingMultiplyAdd(S, Weight, NumSamples, &Overflowed);
return Overflowed ? sampleprof_error::counter_overflow
: sampleprof_error::success;
}
/// Decrease the number of samples for this record by \p S. Return the amout
/// of samples actually decreased.
uint64_t removeSamples(uint64_t S) {
if (S > NumSamples)
S = NumSamples;
NumSamples -= S;
return S;
}
/// Add called function \p F with samples \p S.
/// Optionally scale sample count \p S by \p Weight.
///
/// Sample counts accumulate using saturating arithmetic, to avoid wrapping
/// around unsigned integers.
sampleprof_error addCalledTarget(StringRef F, uint64_t S,
uint64_t Weight = 1) {
uint64_t &TargetSamples = CallTargets[F];
bool Overflowed;
TargetSamples =
SaturatingMultiplyAdd(S, Weight, TargetSamples, &Overflowed);
return Overflowed ? sampleprof_error::counter_overflow
: sampleprof_error::success;
}
/// Remove called function from the call target map. Return the target sample
/// count of the called function.
uint64_t removeCalledTarget(StringRef F) {
uint64_t Count = 0;
auto I = CallTargets.find(F);
if (I != CallTargets.end()) {
Count = I->second;
CallTargets.erase(I);
}
return Count;
}
/// Return true if this sample record contains function calls.
bool hasCalls() const { return !CallTargets.empty(); }
uint64_t getSamples() const { return NumSamples; }
const CallTargetMap &getCallTargets() const { return CallTargets; }
const SortedCallTargetSet getSortedCallTargets() const {
return SortCallTargets(CallTargets);
}
uint64_t getCallTargetSum() const {
uint64_t Sum = 0;
for (const auto &I : CallTargets)
Sum += I.second;
return Sum;
}
/// Sort call targets in descending order of call frequency.
static const SortedCallTargetSet SortCallTargets(const CallTargetMap &Targets) {
SortedCallTargetSet SortedTargets;
for (const auto &[Target, Frequency] : Targets) {
SortedTargets.emplace(Target, Frequency);
}
return SortedTargets;
}
/// Prorate call targets by a distribution factor.
static const CallTargetMap adjustCallTargets(const CallTargetMap &Targets,
float DistributionFactor) {
CallTargetMap AdjustedTargets;
for (const auto &[Target, Frequency] : Targets) {
AdjustedTargets[Target] = Frequency * DistributionFactor;
}
return AdjustedTargets;
}
/// Merge the samples in \p Other into this record.
/// Optionally scale sample counts by \p Weight.
sampleprof_error merge(const SampleRecord &Other, uint64_t Weight = 1);
void print(raw_ostream &OS, unsigned Indent) const;
void dump() const;
private:
uint64_t NumSamples = 0;
CallTargetMap CallTargets;
};
raw_ostream &operator<<(raw_ostream &OS, const SampleRecord &Sample);
// State of context associated with FunctionSamples
enum ContextStateMask {
UnknownContext = 0x0, // Profile without context
RawContext = 0x1, // Full context profile from input profile
SyntheticContext = 0x2, // Synthetic context created for context promotion
InlinedContext = 0x4, // Profile for context that is inlined into caller
MergedContext = 0x8 // Profile for context merged into base profile
};
// Attribute of context associated with FunctionSamples
enum ContextAttributeMask {
ContextNone = 0x0,
ContextWasInlined = 0x1, // Leaf of context was inlined in previous build
ContextShouldBeInlined = 0x2, // Leaf of context should be inlined
ContextDuplicatedIntoBase =
0x4, // Leaf of context is duplicated into the base profile
};
// Represents a context frame with function name and line location
struct SampleContextFrame {
StringRef FuncName;
LineLocation Location;
SampleContextFrame() : Location(0, 0) {}
SampleContextFrame(StringRef FuncName, LineLocation Location)
: FuncName(FuncName), Location(Location) {}
bool operator==(const SampleContextFrame &That) const {
return Location == That.Location && FuncName == That.FuncName;
}
bool operator!=(const SampleContextFrame &That) const {
return !(*this == That);
}
std::string toString(bool OutputLineLocation) const {
std::ostringstream OContextStr;
OContextStr << FuncName.str();
if (OutputLineLocation) {
OContextStr << ":" << Location.LineOffset;
if (Location.Discriminator)
OContextStr << "." << Location.Discriminator;
}
return OContextStr.str();
}
};
static inline hash_code hash_value(const SampleContextFrame &arg) {
return hash_combine(arg.FuncName, arg.Location.LineOffset,
arg.Location.Discriminator);
}
using SampleContextFrameVector = SmallVector<SampleContextFrame, 1>;
using SampleContextFrames = ArrayRef<SampleContextFrame>;
struct SampleContextFrameHash {
uint64_t operator()(const SampleContextFrameVector &S) const {
return hash_combine_range(S.begin(), S.end());
}
};
// Sample context for FunctionSamples. It consists of the calling context,
// the function name and context state. Internally sample context is represented
// using ArrayRef, which is also the input for constructing a `SampleContext`.
// It can accept and represent both full context string as well as context-less
// function name.
// For a CS profile, a full context vector can look like:
// `main:3 _Z5funcAi:1 _Z8funcLeafi`
// For a base CS profile without calling context, the context vector should only
// contain the leaf frame name.
// For a non-CS profile, the context vector should be empty.
class SampleContext {
public:
SampleContext() : State(UnknownContext), Attributes(ContextNone) {}
SampleContext(StringRef Name)
: Name(Name), State(UnknownContext), Attributes(ContextNone) {}
SampleContext(SampleContextFrames Context,
ContextStateMask CState = RawContext)
: Attributes(ContextNone) {
assert(!Context.empty() && "Context is empty");
setContext(Context, CState);
}
// Give a context string, decode and populate internal states like
// Function name, Calling context and context state. Example of input
// `ContextStr`: `[main:3 @ _Z5funcAi:1 @ _Z8funcLeafi]`
SampleContext(StringRef ContextStr,
std::list<SampleContextFrameVector> &CSNameTable,
ContextStateMask CState = RawContext)
: Attributes(ContextNone) {
assert(!ContextStr.empty());
// Note that `[]` wrapped input indicates a full context string, otherwise
// it's treated as context-less function name only.
bool HasContext = ContextStr.startswith("[");
if (!HasContext) {
State = UnknownContext;
Name = ContextStr;
} else {
CSNameTable.emplace_back();
SampleContextFrameVector &Context = CSNameTable.back();
createCtxVectorFromStr(ContextStr, Context);
setContext(Context, CState);
}
}
/// Create a context vector from a given context string and save it in
/// `Context`.
static void createCtxVectorFromStr(StringRef ContextStr,
SampleContextFrameVector &Context) {
// Remove encapsulating '[' and ']' if any
ContextStr = ContextStr.substr(1, ContextStr.size() - 2);
StringRef ContextRemain = ContextStr;
StringRef ChildContext;
StringRef CalleeName;
while (!ContextRemain.empty()) {
auto ContextSplit = ContextRemain.split(" @ ");
ChildContext = ContextSplit.first;
ContextRemain = ContextSplit.second;
LineLocation CallSiteLoc(0, 0);
decodeContextString(ChildContext, CalleeName, CallSiteLoc);
Context.emplace_back(CalleeName, CallSiteLoc);
}
}
// Decode context string for a frame to get function name and location.
// `ContextStr` is in the form of `FuncName:StartLine.Discriminator`.
static void decodeContextString(StringRef ContextStr, StringRef &FName,
LineLocation &LineLoc) {
// Get function name
auto EntrySplit = ContextStr.split(':');
FName = EntrySplit.first;
LineLoc = {0, 0};
if (!EntrySplit.second.empty()) {
// Get line offset, use signed int for getAsInteger so string will
// be parsed as signed.
int LineOffset = 0;
auto LocSplit = EntrySplit.second.split('.');
LocSplit.first.getAsInteger(10, LineOffset);
LineLoc.LineOffset = LineOffset;
// Get discriminator
if (!LocSplit.second.empty())
LocSplit.second.getAsInteger(10, LineLoc.Discriminator);
}
}
operator SampleContextFrames() const { return FullContext; }
bool hasAttribute(ContextAttributeMask A) { return Attributes & (uint32_t)A; }
void setAttribute(ContextAttributeMask A) { Attributes |= (uint32_t)A; }
uint32_t getAllAttributes() { return Attributes; }
void setAllAttributes(uint32_t A) { Attributes = A; }
bool hasState(ContextStateMask S) { return State & (uint32_t)S; }
void setState(ContextStateMask S) { State |= (uint32_t)S; }
void clearState(ContextStateMask S) { State &= (uint32_t)~S; }
bool hasContext() const { return State != UnknownContext; }
bool isBaseContext() const { return FullContext.size() == 1; }
StringRef getName() const { return Name; }
SampleContextFrames getContextFrames() const { return FullContext; }
static std::string getContextString(SampleContextFrames Context,
bool IncludeLeafLineLocation = false) {
std::ostringstream OContextStr;
for (uint32_t I = 0; I < Context.size(); I++) {
if (OContextStr.str().size()) {
OContextStr << " @ ";
}
OContextStr << Context[I].toString(I != Context.size() - 1 ||
IncludeLeafLineLocation);
}
return OContextStr.str();
}
std::string toString() const {
if (!hasContext())
return Name.str();
return getContextString(FullContext, false);
}
uint64_t getHashCode() const {
return hasContext() ? hash_value(getContextFrames())
: hash_value(getName());
}
/// Set the name of the function and clear the current context.
void setName(StringRef FunctionName) {
Name = FunctionName;
FullContext = SampleContextFrames();
State = UnknownContext;
}
void setContext(SampleContextFrames Context,
ContextStateMask CState = RawContext) {
assert(CState != UnknownContext);
FullContext = Context;
Name = Context.back().FuncName;
State = CState;
}
bool operator==(const SampleContext &That) const {
return State == That.State && Name == That.Name &&
FullContext == That.FullContext;
}
bool operator!=(const SampleContext &That) const { return !(*this == That); }
bool operator<(const SampleContext &That) const {
if (State != That.State)
return State < That.State;
if (!hasContext()) {
return Name < That.Name;
}
uint64_t I = 0;
while (I < std::min(FullContext.size(), That.FullContext.size())) {
auto &Context1 = FullContext[I];
auto &Context2 = That.FullContext[I];
auto V = Context1.FuncName.compare(Context2.FuncName);
if (V)
return V < 0;
if (Context1.Location != Context2.Location)
return Context1.Location < Context2.Location;
I++;
}
return FullContext.size() < That.FullContext.size();
}
struct Hash {
uint64_t operator()(const SampleContext &Context) const {
return Context.getHashCode();
}
};
bool IsPrefixOf(const SampleContext &That) const {
auto ThisContext = FullContext;
auto ThatContext = That.FullContext;
if (ThatContext.size() < ThisContext.size())
return false;
ThatContext = ThatContext.take_front(ThisContext.size());
// Compare Leaf frame first
if (ThisContext.back().FuncName != ThatContext.back().FuncName)
return false;
// Compare leading context
return ThisContext.drop_back() == ThatContext.drop_back();
}
private:
/// Mangled name of the function.
StringRef Name;
// Full context including calling context and leaf function name
SampleContextFrames FullContext;
// State of the associated sample profile
uint32_t State;
// Attribute of the associated sample profile
uint32_t Attributes;
};
static inline hash_code hash_value(const SampleContext &arg) {
return arg.hasContext() ? hash_value(arg.getContextFrames())
: hash_value(arg.getName());
}
class FunctionSamples;
class SampleProfileReaderItaniumRemapper;
using BodySampleMap = std::map<LineLocation, SampleRecord>;
// NOTE: Using a StringMap here makes parsed profiles consume around 17% more
// memory, which is *very* significant for large profiles.
using FunctionSamplesMap = std::map<std::string, FunctionSamples, std::less<>>;
using CallsiteSampleMap = std::map<LineLocation, FunctionSamplesMap>;
/// 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() = default;
void print(raw_ostream &OS = dbgs(), unsigned Indent = 0) const;
void dump() const;
sampleprof_error addTotalSamples(uint64_t Num, uint64_t Weight = 1) {
bool Overflowed;
TotalSamples =
SaturatingMultiplyAdd(Num, Weight, TotalSamples, &Overflowed);
return Overflowed ? sampleprof_error::counter_overflow
: sampleprof_error::success;
}
void removeTotalSamples(uint64_t Num) {
if (TotalSamples < Num)
TotalSamples = 0;
else
TotalSamples -= Num;
}
void setTotalSamples(uint64_t Num) { TotalSamples = Num; }
sampleprof_error addHeadSamples(uint64_t Num, uint64_t Weight = 1) {
bool Overflowed;
TotalHeadSamples =
SaturatingMultiplyAdd(Num, Weight, TotalHeadSamples, &Overflowed);
return Overflowed ? sampleprof_error::counter_overflow
: sampleprof_error::success;
}
sampleprof_error addBodySamples(uint32_t LineOffset, uint32_t Discriminator,
uint64_t Num, uint64_t Weight = 1) {
return BodySamples[LineLocation(LineOffset, Discriminator)].addSamples(
Num, Weight);
}
sampleprof_error addCalledTargetSamples(uint32_t LineOffset,
uint32_t Discriminator,
StringRef FName, uint64_t Num,
uint64_t Weight = 1) {
return BodySamples[LineLocation(LineOffset, Discriminator)].addCalledTarget(
FName, Num, Weight);
}
// Remove a call target and decrease the body sample correspondingly. Return
// the number of body samples actually decreased.
uint64_t removeCalledTargetAndBodySample(uint32_t LineOffset,
uint32_t Discriminator,
StringRef FName) {
uint64_t Count = 0;
auto I = BodySamples.find(LineLocation(LineOffset, Discriminator));
if (I != BodySamples.end()) {
Count = I->second.removeCalledTarget(FName);
Count = I->second.removeSamples(Count);
if (!I->second.getSamples())
BodySamples.erase(I);
}
return Count;
}
sampleprof_error addBodySamplesForProbe(uint32_t Index, uint64_t Num,
uint64_t Weight = 1) {
SampleRecord S;
S.addSamples(Num, Weight);
return BodySamples[LineLocation(Index, 0)].merge(S, Weight);
}
// Accumulate all call target samples to update the body samples.
void updateCallsiteSamples() {
for (auto &I : BodySamples) {
uint64_t TargetSamples = I.second.getCallTargetSum();
// It's possible that the body sample count can be greater than the call
// target sum. E.g, if some call targets are external targets, they won't
// be considered valid call targets, but the body sample count which is
// from lbr ranges can actually include them.
if (TargetSamples > I.second.getSamples())
I.second.addSamples(TargetSamples - I.second.getSamples());
}
}
// Accumulate all body samples to set total samples.
void updateTotalSamples() {
setTotalSamples(0);
for (const auto &I : BodySamples)
addTotalSamples(I.second.getSamples());
for (auto &I : CallsiteSamples) {
for (auto &CS : I.second) {
CS.second.updateTotalSamples();
addTotalSamples(CS.second.getTotalSamples());
}
}
}
// Set current context and all callee contexts to be synthetic.
void SetContextSynthetic() {
Context.setState(SyntheticContext);
for (auto &I : CallsiteSamples) {
for (auto &CS : I.second) {
CS.second.SetContextSynthetic();
}
}
}
/// Return the number of samples collected at the given location.
/// Each location is specified by \p LineOffset and \p Discriminator.
/// If the location is not found in profile, return error.
ErrorOr<uint64_t> findSamplesAt(uint32_t LineOffset,
uint32_t Discriminator) const {
const auto &ret = BodySamples.find(LineLocation(LineOffset, Discriminator));
if (ret == BodySamples.end())
return std::error_code();
return ret->second.getSamples();
}
/// Returns the call target map collected at a given location.
/// Each location is specified by \p LineOffset and \p Discriminator.
/// If the location is not found in profile, return error.
ErrorOr<SampleRecord::CallTargetMap>
findCallTargetMapAt(uint32_t LineOffset, uint32_t Discriminator) const {
const auto &ret = BodySamples.find(LineLocation(LineOffset, Discriminator));
if (ret == BodySamples.end())
return std::error_code();
return ret->second.getCallTargets();
}
/// Returns the call target map collected at a given location specified by \p
/// CallSite. If the location is not found in profile, return error.
ErrorOr<SampleRecord::CallTargetMap>
findCallTargetMapAt(const LineLocation &CallSite) const {
const auto &Ret = BodySamples.find(CallSite);
if (Ret == BodySamples.end())
return std::error_code();
return Ret->second.getCallTargets();
}
/// Return the function samples at the given callsite location.
FunctionSamplesMap &functionSamplesAt(const LineLocation &Loc) {
return CallsiteSamples[Loc];
}
/// Returns the FunctionSamplesMap at the given \p Loc.
const FunctionSamplesMap *
findFunctionSamplesMapAt(const LineLocation &Loc) const {
auto iter = CallsiteSamples.find(Loc);
if (iter == CallsiteSamples.end())
return nullptr;
return &iter->second;
}
/// Returns a pointer to FunctionSamples at the given callsite location
/// \p Loc with callee \p CalleeName. If no callsite can be found, relax
/// the restriction to return the FunctionSamples at callsite location
/// \p Loc with the maximum total sample count. If \p Remapper is not
/// nullptr, use \p Remapper to find FunctionSamples with equivalent name
/// as \p CalleeName.
const FunctionSamples *
findFunctionSamplesAt(const LineLocation &Loc, StringRef CalleeName,
SampleProfileReaderItaniumRemapper *Remapper) const;
bool empty() const { return TotalSamples == 0; }
/// Return the total number of samples collected inside the function.
uint64_t getTotalSamples() const { return TotalSamples; }
/// For top-level functions, return the total number of branch samples that
/// have the function as the branch target (or 0 otherwise). This is the raw
/// data fetched from the profile. This should be equivalent to the sample of
/// the first instruction of the symbol. But as we directly get this info for
/// raw profile without referring to potentially inaccurate debug info, this
/// gives more accurate profile data and is preferred for standalone symbols.
uint64_t getHeadSamples() const { return TotalHeadSamples; }
/// Return an estimate of the sample count of the function entry basic block.
/// The function can be either a standalone symbol or an inlined function.
/// For Context-Sensitive profiles, this will prefer returning the head
/// samples (i.e. getHeadSamples()), if non-zero. Otherwise it estimates from
/// the function body's samples or callsite samples.
uint64_t getHeadSamplesEstimate() const {
if (FunctionSamples::ProfileIsCS && getHeadSamples()) {
// For CS profile, if we already have more accurate head samples
// counted by branch sample from caller, use them as entry samples.
return getHeadSamples();
}
uint64_t Count = 0;
// Use either BodySamples or CallsiteSamples which ever has the smaller
// lineno.
if (!BodySamples.empty() &&
(CallsiteSamples.empty() ||
BodySamples.begin()->first < CallsiteSamples.begin()->first))
Count = BodySamples.begin()->second.getSamples();
else if (!CallsiteSamples.empty()) {
// An indirect callsite may be promoted to several inlined direct calls.
// We need to get the sum of them.
for (const auto &N_FS : CallsiteSamples.begin()->second)
Count += N_FS.second.getHeadSamplesEstimate();
}
// Return at least 1 if total sample is not 0.
return Count ? Count : TotalSamples > 0;
}
/// Return all the samples collected in the body of the function.
const BodySampleMap &getBodySamples() const { return BodySamples; }
/// Return all the callsite samples collected in the body of the function.
const CallsiteSampleMap &getCallsiteSamples() const {
return CallsiteSamples;
}
/// Return the maximum of sample counts in a function body. When SkipCallSite
/// is false, which is the default, the return count includes samples in the
/// inlined functions. When SkipCallSite is true, the return count only
/// considers the body samples.
uint64_t getMaxCountInside(bool SkipCallSite = false) const {
uint64_t MaxCount = 0;
for (const auto &L : getBodySamples())
MaxCount = std::max(MaxCount, L.second.getSamples());
if (SkipCallSite)
return MaxCount;
for (const auto &C : getCallsiteSamples())
for (const FunctionSamplesMap::value_type &F : C.second)
MaxCount = std::max(MaxCount, F.second.getMaxCountInside());
return MaxCount;
}
/// Merge the samples in \p Other into this one.
/// Optionally scale samples by \p Weight.
sampleprof_error merge(const FunctionSamples &Other, uint64_t Weight = 1) {
sampleprof_error Result = sampleprof_error::success;
if (!GUIDToFuncNameMap)
GUIDToFuncNameMap = Other.GUIDToFuncNameMap;
if (Context.getName().empty())
Context = Other.getContext();
if (FunctionHash == 0) {
// Set the function hash code for the target profile.
FunctionHash = Other.getFunctionHash();
} else if (FunctionHash != Other.getFunctionHash()) {
// The two profiles coming with different valid hash codes indicates
// either:
// 1. They are same-named static functions from different compilation
// units (without using -unique-internal-linkage-names), or
// 2. They are really the same function but from different compilations.
// Let's bail out in either case for now, which means one profile is
// dropped.
return sampleprof_error::hash_mismatch;
}
MergeResult(Result, addTotalSamples(Other.getTotalSamples(), Weight));
MergeResult(Result, addHeadSamples(Other.getHeadSamples(), Weight));
for (const auto &I : Other.getBodySamples()) {
const LineLocation &Loc = I.first;
const SampleRecord &Rec = I.second;
MergeResult(Result, BodySamples[Loc].merge(Rec, Weight));
}
for (const auto &I : Other.getCallsiteSamples()) {
const LineLocation &Loc = I.first;
FunctionSamplesMap &FSMap = functionSamplesAt(Loc);
for (const auto &Rec : I.second)
MergeResult(Result, FSMap[Rec.first].merge(Rec.second, Weight));
}
return Result;
}
/// Recursively traverses all children, if the total sample count of the
/// corresponding function is no less than \p Threshold, add its corresponding
/// GUID to \p S. Also traverse the BodySamples to add hot CallTarget's GUID
/// to \p S.
void findInlinedFunctions(DenseSet<GlobalValue::GUID> &S,
const StringMap<Function *> &SymbolMap,
uint64_t Threshold) const {
if (TotalSamples <= Threshold)
return;
auto isDeclaration = [](const Function *F) {
return !F || F->isDeclaration();
};
if (isDeclaration(SymbolMap.lookup(getFuncName()))) {
// Add to the import list only when it's defined out of module.
S.insert(getGUID(getName()));
}
// Import hot CallTargets, which may not be available in IR because full
// profile annotation cannot be done until backend compilation in ThinLTO.
for (const auto &BS : BodySamples)
for (const auto &TS : BS.second.getCallTargets())
if (TS.getValue() > Threshold) {
const Function *Callee = SymbolMap.lookup(getFuncName(TS.getKey()));
if (isDeclaration(Callee))
S.insert(getGUID(TS.getKey()));
}
for (const auto &CS : CallsiteSamples)
for (const auto &NameFS : CS.second)
NameFS.second.findInlinedFunctions(S, SymbolMap, Threshold);
}
/// Set the name of the function.
void setName(StringRef FunctionName) { Context.setName(FunctionName); }
/// Return the function name.
StringRef getName() const { return Context.getName(); }
/// Return the original function name.
StringRef getFuncName() const { return getFuncName(getName()); }
void setFunctionHash(uint64_t Hash) { FunctionHash = Hash; }
uint64_t getFunctionHash() const { return FunctionHash; }
/// Return the canonical name for a function, taking into account
/// suffix elision policy attributes.
static StringRef getCanonicalFnName(const Function &F) {
auto AttrName = "sample-profile-suffix-elision-policy";
auto Attr = F.getFnAttribute(AttrName).getValueAsString();
return getCanonicalFnName(F.getName(), Attr);
}
/// Name suffixes which canonicalization should handle to avoid
/// profile mismatch.
static constexpr const char *LLVMSuffix = ".llvm.";
static constexpr const char *PartSuffix = ".part.";
static constexpr const char *UniqSuffix = ".__uniq.";
static StringRef getCanonicalFnName(StringRef FnName,
StringRef Attr = "selected") {
// Note the sequence of the suffixes in the knownSuffixes array matters.
// If suffix "A" is appended after the suffix "B", "A" should be in front
// of "B" in knownSuffixes.
const char *knownSuffixes[] = {LLVMSuffix, PartSuffix, UniqSuffix};
if (Attr == "" || Attr == "all") {
return FnName.split('.').first;
} else if (Attr == "selected") {
StringRef Cand(FnName);
for (const auto &Suf : knownSuffixes) {
StringRef Suffix(Suf);
// If the profile contains ".__uniq." suffix, don't strip the
// suffix for names in the IR.
if (Suffix == UniqSuffix && FunctionSamples::HasUniqSuffix)
continue;
auto It = Cand.rfind(Suffix);
if (It == StringRef::npos)
continue;
auto Dit = Cand.rfind('.');
if (Dit == It + Suffix.size() - 1)
Cand = Cand.substr(0, It);
}
return Cand;
} else if (Attr == "none") {
return FnName;
} else {
assert(false && "internal error: unknown suffix elision policy");
}
return FnName;
}
/// Translate \p Name into its original name.
/// When profile doesn't use MD5, \p Name needs no translation.
/// When profile uses MD5, \p Name in current FunctionSamples
/// is actually GUID of the original function name. getFuncName will
/// translate \p Name in current FunctionSamples into its original name
/// by looking up in the function map GUIDToFuncNameMap.
/// If the original name doesn't exist in the map, return empty StringRef.
StringRef getFuncName(StringRef Name) const {
if (!UseMD5)
return Name;
assert(GUIDToFuncNameMap && "GUIDToFuncNameMap needs to be populated first");
return GUIDToFuncNameMap->lookup(std::stoull(Name.data()));
}
/// Returns the line offset to the start line of the subprogram.
/// We assume that a single function will not exceed 65535 LOC.
static unsigned getOffset(const DILocation *DIL);
/// Returns a unique call site identifier for a given debug location of a call
/// instruction. This is wrapper of two scenarios, the probe-based profile and
/// regular profile, to hide implementation details from the sample loader and
/// the context tracker.
static LineLocation getCallSiteIdentifier(const DILocation *DIL,
bool ProfileIsFS = false);
/// Returns a unique hash code for a combination of a callsite location and
/// the callee function name.
static uint64_t getCallSiteHash(StringRef CalleeName,
const LineLocation &Callsite);
/// Get the FunctionSamples of the inline instance where DIL originates
/// from.
///
/// The FunctionSamples of the instruction (Machine or IR) associated to
/// \p DIL is the inlined instance in which that instruction is coming from.
/// We traverse the inline stack of that instruction, and match it with the
/// tree nodes in the profile.
///
/// \returns the FunctionSamples pointer to the inlined instance.
/// If \p Remapper is not nullptr, it will be used to find matching
/// FunctionSamples with not exactly the same but equivalent name.
const FunctionSamples *findFunctionSamples(
const DILocation *DIL,
SampleProfileReaderItaniumRemapper *Remapper = nullptr) const;
static bool ProfileIsProbeBased;
static bool ProfileIsCS;
static bool ProfileIsPreInlined;
SampleContext &getContext() const { return Context; }
void setContext(const SampleContext &FContext) { Context = FContext; }
/// Whether the profile uses MD5 to represent string.
static bool UseMD5;
/// Whether the profile contains any ".__uniq." suffix in a name.
static bool HasUniqSuffix;
/// If this profile uses flow sensitive discriminators.
static bool ProfileIsFS;
/// GUIDToFuncNameMap saves the mapping from GUID to the symbol name, for
/// all the function symbols defined or declared in current module.
DenseMap<uint64_t, StringRef> *GUIDToFuncNameMap = nullptr;
// Assume the input \p Name is a name coming from FunctionSamples itself.
// If UseMD5 is true, the name is already a GUID and we
// don't want to return the GUID of GUID.
static uint64_t getGUID(StringRef Name) {
return UseMD5 ? std::stoull(Name.data()) : Function::getGUID(Name);
}
// Find all the names in the current FunctionSamples including names in
// all the inline instances and names of call targets.
void findAllNames(DenseSet<StringRef> &NameSet) const;
private:
/// CFG hash value for the function.
uint64_t FunctionHash = 0;
/// Calling context for function profile
mutable SampleContext Context;
/// 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.
uint64_t TotalSamples = 0;
/// 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.
uint64_t TotalHeadSamples = 0;
/// 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;
/// Map call sites to collected samples for the called function.
///
/// Each entry in this map corresponds to all the samples
/// collected for the inlined function call at the given
/// location. For example, given:
///
/// void foo() {
/// 1 bar();
/// ...
/// 8 baz();
/// }
///
/// If the bar() and baz() calls were inlined inside foo(), this
/// map will contain two entries. One for all the samples collected
/// in the call to bar() at line offset 1, the other for all the samples
/// collected in the call to baz() at line offset 8.
CallsiteSampleMap CallsiteSamples;
};
raw_ostream &operator<<(raw_ostream &OS, const FunctionSamples &FS);
using SampleProfileMap =
std::unordered_map<SampleContext, FunctionSamples, SampleContext::Hash>;
using NameFunctionSamples = std::pair<SampleContext, const FunctionSamples *>;
void sortFuncProfiles(const SampleProfileMap &ProfileMap,
std::vector<NameFunctionSamples> &SortedProfiles);
/// Sort a LocationT->SampleT map by LocationT.
///
/// It produces a sorted list of <LocationT, SampleT> records by ascending
/// order of LocationT.
template <class LocationT, class SampleT> class SampleSorter {
public:
using SamplesWithLoc = std::pair<const LocationT, SampleT>;
using SamplesWithLocList = SmallVector<const SamplesWithLoc *, 20>;
SampleSorter(const std::map<LocationT, SampleT> &Samples) {
for (const auto &I : Samples)
V.push_back(&I);
llvm::stable_sort(V, [](const SamplesWithLoc *A, const SamplesWithLoc *B) {
return A->first < B->first;
});
}
const SamplesWithLocList &get() const { return V; }
private:
SamplesWithLocList V;
};
/// SampleContextTrimmer impelements helper functions to trim, merge cold
/// context profiles. It also supports context profile canonicalization to make
/// sure ProfileMap's key is consistent with FunctionSample's name/context.
class SampleContextTrimmer {
public:
SampleContextTrimmer(SampleProfileMap &Profiles) : ProfileMap(Profiles){};
// Trim and merge cold context profile when requested. TrimBaseProfileOnly
// should only be effective when TrimColdContext is true. On top of
// TrimColdContext, TrimBaseProfileOnly can be used to specify to trim all
// cold profiles or only cold base profiles. Trimming base profiles only is
// mainly to honor the preinliner decsion. Note that when MergeColdContext is
// true, preinliner decsion is not honored anyway so TrimBaseProfileOnly will
// be ignored.
void trimAndMergeColdContextProfiles(uint64_t ColdCountThreshold,
bool TrimColdContext,
bool MergeColdContext,
uint32_t ColdContextFrameLength,
bool TrimBaseProfileOnly);
// Canonicalize context profile name and attributes.
void canonicalizeContextProfiles();
private:
SampleProfileMap &ProfileMap;
};
// CSProfileConverter converts a full context-sensitive flat sample profile into
// a nested context-sensitive sample profile.
class CSProfileConverter {
public:
CSProfileConverter(SampleProfileMap &Profiles);
void convertProfiles();
struct FrameNode {
FrameNode(StringRef FName = StringRef(),
FunctionSamples *FSamples = nullptr,
LineLocation CallLoc = {0, 0})
: FuncName(FName), FuncSamples(FSamples), CallSiteLoc(CallLoc){};
// Map line+discriminator location to child frame
std::map<uint64_t, FrameNode> AllChildFrames;
// Function name for current frame
StringRef FuncName;
// Function Samples for current frame
FunctionSamples *FuncSamples;
// Callsite location in parent context
LineLocation CallSiteLoc;
FrameNode *getOrCreateChildFrame(const LineLocation &CallSite,
StringRef CalleeName);
};
private:
// Nest all children profiles into the profile of Node.
void convertProfiles(FrameNode &Node);
FrameNode *getOrCreateContextPath(const SampleContext &Context);
SampleProfileMap &ProfileMap;
FrameNode RootFrame;
};
/// ProfileSymbolList records the list of function symbols shown up
/// in the binary used to generate the profile. It is useful to
/// to discriminate a function being so cold as not to shown up
/// in the profile and a function newly added.
class ProfileSymbolList {
public:
/// copy indicates whether we need to copy the underlying memory
/// for the input Name.
void add(StringRef Name, bool copy = false) {
if (!copy) {
Syms.insert(Name);
return;
}
Syms.insert(Name.copy(Allocator));
}
bool contains(StringRef Name) { return Syms.count(Name); }
void merge(const ProfileSymbolList &List) {
for (auto Sym : List.Syms)
add(Sym, true);
}
unsigned size() { return Syms.size(); }
void setToCompress(bool TC) { ToCompress = TC; }
bool toCompress() { return ToCompress; }
std::error_code read(const uint8_t *Data, uint64_t ListSize);
std::error_code write(raw_ostream &OS);
void dump(raw_ostream &OS = dbgs()) const;
private:
// Determine whether or not to compress the symbol list when
// writing it into profile. The variable is unused when the symbol
// list is read from an existing profile.
bool ToCompress = false;
DenseSet<StringRef> Syms;
BumpPtrAllocator Allocator;
};
} // end namespace sampleprof
using namespace sampleprof;
// Provide DenseMapInfo for SampleContext.
template <> struct DenseMapInfo<SampleContext> {
static inline SampleContext getEmptyKey() { return SampleContext(); }
static inline SampleContext getTombstoneKey() { return SampleContext("@"); }
static unsigned getHashValue(const SampleContext &Val) {
return Val.getHashCode();
}
static bool isEqual(const SampleContext &LHS, const SampleContext &RHS) {
return LHS == RHS;
}
};
// Prepend "__uniq" before the hash for tools like profilers to understand
// that this symbol is of internal linkage type. The "__uniq" is the
// pre-determined prefix that is used to tell tools that this symbol was
// created with -funique-internal-linakge-symbols and the tools can strip or
// keep the prefix as needed.
inline std::string getUniqueInternalLinkagePostfix(const StringRef &FName) {
llvm::MD5 Md5;
Md5.update(FName);
llvm::MD5::MD5Result R;
Md5.final(R);
SmallString<32> Str;
llvm::MD5::stringifyResult(R, Str);
// Convert MD5hash to Decimal. Demangler suffixes can either contain
// numbers or characters but not both.
llvm::APInt IntHash(128, Str.str(), 16);
return toString(IntHash, /* Radix = */ 10, /* Signed = */ false)
.insert(0, FunctionSamples::UniqSuffix);
}
} // end namespace llvm
#endif // LLVM_PROFILEDATA_SAMPLEPROF_H