llvm-project/clang/lib/CodeGen/CodeGenPGO.h
Saleem Abdulrasool 10a4972a8d revert SVN r265702, r265640
Revert the two changes to thread CodeGenOptions into the TargetInfo allocation
and to fix the layering violation by moving CodeGenOptions into Basic.
Code Generation is arguably not particularly "basic".  This addresses Richard's
post-commit review comments.  This change purely does the mechanical revert and
will be followed up with an alternate approach to thread the desired information
into TargetInfo.

llvm-svn: 265806
2016-04-08 16:52:00 +00:00

125 lines
4.5 KiB
C++

//===--- CodeGenPGO.h - PGO Instrumentation for LLVM CodeGen ----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Instrumentation-based profile-guided optimization
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_LIB_CODEGEN_CODEGENPGO_H
#define LLVM_CLANG_LIB_CODEGEN_CODEGENPGO_H
#include "CGBuilder.h"
#include "CodeGenModule.h"
#include "CodeGenTypes.h"
#include "clang/Frontend/CodeGenOptions.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ProfileData/InstrProfReader.h"
#include "llvm/Support/MemoryBuffer.h"
#include <array>
#include <memory>
namespace clang {
namespace CodeGen {
/// Per-function PGO state.
class CodeGenPGO {
private:
CodeGenModule &CGM;
std::string FuncName;
llvm::GlobalVariable *FuncNameVar;
std::array <unsigned, llvm::IPVK_Last + 1> NumValueSites;
unsigned NumRegionCounters;
uint64_t FunctionHash;
std::unique_ptr<llvm::DenseMap<const Stmt *, unsigned>> RegionCounterMap;
std::unique_ptr<llvm::DenseMap<const Stmt *, uint64_t>> StmtCountMap;
std::unique_ptr<llvm::InstrProfRecord> ProfRecord;
std::vector<uint64_t> RegionCounts;
uint64_t CurrentRegionCount;
/// \brief A flag that is set to true when this function doesn't need
/// to have coverage mapping data.
bool SkipCoverageMapping;
public:
CodeGenPGO(CodeGenModule &CGM)
: CGM(CGM), NumValueSites({{0}}), NumRegionCounters(0),
FunctionHash(0), CurrentRegionCount(0), SkipCoverageMapping(false) {}
/// Whether or not we have PGO region data for the current function. This is
/// false both when we have no data at all and when our data has been
/// discarded.
bool haveRegionCounts() const { return !RegionCounts.empty(); }
/// Return the counter value of the current region.
uint64_t getCurrentRegionCount() const { return CurrentRegionCount; }
/// Set the counter value for the current region. This is used to keep track
/// of changes to the most recent counter from control flow and non-local
/// exits.
void setCurrentRegionCount(uint64_t Count) { CurrentRegionCount = Count; }
/// Check if an execution count is known for a given statement. If so, return
/// true and put the value in Count; else return false.
Optional<uint64_t> getStmtCount(const Stmt *S) {
if (!StmtCountMap)
return None;
auto I = StmtCountMap->find(S);
if (I == StmtCountMap->end())
return None;
return I->second;
}
/// If the execution count for the current statement is known, record that
/// as the current count.
void setCurrentStmt(const Stmt *S) {
if (auto Count = getStmtCount(S))
setCurrentRegionCount(*Count);
}
/// Assign counters to regions and configure them for PGO of a given
/// function. Does nothing if instrumentation is not enabled and either
/// generates global variables or associates PGO data with each of the
/// counters depending on whether we are generating or using instrumentation.
void assignRegionCounters(GlobalDecl GD, llvm::Function *Fn);
/// Emit a coverage mapping range with a counter zero
/// for an unused declaration.
void emitEmptyCounterMapping(const Decl *D, StringRef FuncName,
llvm::GlobalValue::LinkageTypes Linkage);
// Insert instrumentation or attach profile metadata at value sites
void valueProfile(CGBuilderTy &Builder, uint32_t ValueKind,
llvm::Instruction *ValueSite, llvm::Value *ValuePtr);
private:
void setFuncName(llvm::Function *Fn);
void setFuncName(StringRef Name, llvm::GlobalValue::LinkageTypes Linkage);
void mapRegionCounters(const Decl *D);
void computeRegionCounts(const Decl *D);
void applyFunctionAttributes(llvm::IndexedInstrProfReader *PGOReader,
llvm::Function *Fn);
void loadRegionCounts(llvm::IndexedInstrProfReader *PGOReader,
bool IsInMainFile);
void emitCounterRegionMapping(const Decl *D);
public:
void emitCounterIncrement(CGBuilderTy &Builder, const Stmt *S);
/// Return the region count for the counter at the given index.
uint64_t getRegionCount(const Stmt *S) {
if (!RegionCounterMap)
return 0;
if (!haveRegionCounts())
return 0;
return RegionCounts[(*RegionCounterMap)[S]];
}
};
} // end namespace CodeGen
} // end namespace clang
#endif