xref: /freebsd-src/contrib/llvm-project/clang/lib/CodeGen/CodeGenPGO.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
10b57cec5SDimitry Andric //===--- CodeGenPGO.h - PGO Instrumentation for LLVM CodeGen ----*- C++ -*-===//
20b57cec5SDimitry Andric //
30b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
40b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
50b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
60b57cec5SDimitry Andric //
70b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
80b57cec5SDimitry Andric //
90b57cec5SDimitry Andric // Instrumentation-based profile-guided optimization
100b57cec5SDimitry Andric //
110b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
120b57cec5SDimitry Andric 
130b57cec5SDimitry Andric #ifndef LLVM_CLANG_LIB_CODEGEN_CODEGENPGO_H
140b57cec5SDimitry Andric #define LLVM_CLANG_LIB_CODEGEN_CODEGENPGO_H
150b57cec5SDimitry Andric 
160b57cec5SDimitry Andric #include "CGBuilder.h"
170b57cec5SDimitry Andric #include "CodeGenModule.h"
180b57cec5SDimitry Andric #include "CodeGenTypes.h"
19*0fca6ea1SDimitry Andric #include "MCDCState.h"
200b57cec5SDimitry Andric #include "llvm/ProfileData/InstrProfReader.h"
210b57cec5SDimitry Andric #include <array>
220b57cec5SDimitry Andric #include <memory>
23bdd1243dSDimitry Andric #include <optional>
240b57cec5SDimitry Andric 
250b57cec5SDimitry Andric namespace clang {
260b57cec5SDimitry Andric namespace CodeGen {
270b57cec5SDimitry Andric 
280b57cec5SDimitry Andric /// Per-function PGO state.
290b57cec5SDimitry Andric class CodeGenPGO {
300b57cec5SDimitry Andric private:
310b57cec5SDimitry Andric   CodeGenModule &CGM;
320b57cec5SDimitry Andric   std::string FuncName;
330b57cec5SDimitry Andric   llvm::GlobalVariable *FuncNameVar;
340b57cec5SDimitry Andric 
350b57cec5SDimitry Andric   std::array <unsigned, llvm::IPVK_Last + 1> NumValueSites;
360b57cec5SDimitry Andric   unsigned NumRegionCounters;
370b57cec5SDimitry Andric   uint64_t FunctionHash;
380b57cec5SDimitry Andric   std::unique_ptr<llvm::DenseMap<const Stmt *, unsigned>> RegionCounterMap;
390b57cec5SDimitry Andric   std::unique_ptr<llvm::DenseMap<const Stmt *, uint64_t>> StmtCountMap;
400b57cec5SDimitry Andric   std::unique_ptr<llvm::InstrProfRecord> ProfRecord;
41*0fca6ea1SDimitry Andric   std::unique_ptr<MCDC::State> RegionMCDCState;
420b57cec5SDimitry Andric   std::vector<uint64_t> RegionCounts;
430b57cec5SDimitry Andric   uint64_t CurrentRegionCount;
440b57cec5SDimitry Andric 
450b57cec5SDimitry Andric public:
465ffd83dbSDimitry Andric   CodeGenPGO(CodeGenModule &CGModule)
475ffd83dbSDimitry Andric       : CGM(CGModule), FuncNameVar(nullptr), NumValueSites({{0}}),
48*0fca6ea1SDimitry Andric         NumRegionCounters(0), FunctionHash(0), CurrentRegionCount(0) {}
490b57cec5SDimitry Andric 
500b57cec5SDimitry Andric   /// Whether or not we have PGO region data for the current function. This is
510b57cec5SDimitry Andric   /// false both when we have no data at all and when our data has been
520b57cec5SDimitry Andric   /// discarded.
530b57cec5SDimitry Andric   bool haveRegionCounts() const { return !RegionCounts.empty(); }
540b57cec5SDimitry Andric 
550b57cec5SDimitry Andric   /// Return the counter value of the current region.
560b57cec5SDimitry Andric   uint64_t getCurrentRegionCount() const { return CurrentRegionCount; }
570b57cec5SDimitry Andric 
580b57cec5SDimitry Andric   /// Set the counter value for the current region. This is used to keep track
590b57cec5SDimitry Andric   /// of changes to the most recent counter from control flow and non-local
600b57cec5SDimitry Andric   /// exits.
610b57cec5SDimitry Andric   void setCurrentRegionCount(uint64_t Count) { CurrentRegionCount = Count; }
620b57cec5SDimitry Andric 
630b57cec5SDimitry Andric   /// Check if an execution count is known for a given statement. If so, return
640b57cec5SDimitry Andric   /// true and put the value in Count; else return false.
65bdd1243dSDimitry Andric   std::optional<uint64_t> getStmtCount(const Stmt *S) const {
660b57cec5SDimitry Andric     if (!StmtCountMap)
67bdd1243dSDimitry Andric       return std::nullopt;
680b57cec5SDimitry Andric     auto I = StmtCountMap->find(S);
690b57cec5SDimitry Andric     if (I == StmtCountMap->end())
70bdd1243dSDimitry Andric       return std::nullopt;
710b57cec5SDimitry Andric     return I->second;
720b57cec5SDimitry Andric   }
730b57cec5SDimitry Andric 
740b57cec5SDimitry Andric   /// If the execution count for the current statement is known, record that
750b57cec5SDimitry Andric   /// as the current count.
760b57cec5SDimitry Andric   void setCurrentStmt(const Stmt *S) {
770b57cec5SDimitry Andric     if (auto Count = getStmtCount(S))
780b57cec5SDimitry Andric       setCurrentRegionCount(*Count);
790b57cec5SDimitry Andric   }
800b57cec5SDimitry Andric 
810b57cec5SDimitry Andric   /// Assign counters to regions and configure them for PGO of a given
820b57cec5SDimitry Andric   /// function. Does nothing if instrumentation is not enabled and either
830b57cec5SDimitry Andric   /// generates global variables or associates PGO data with each of the
840b57cec5SDimitry Andric   /// counters depending on whether we are generating or using instrumentation.
850b57cec5SDimitry Andric   void assignRegionCounters(GlobalDecl GD, llvm::Function *Fn);
860b57cec5SDimitry Andric   /// Emit a coverage mapping range with a counter zero
870b57cec5SDimitry Andric   /// for an unused declaration.
880b57cec5SDimitry Andric   void emitEmptyCounterMapping(const Decl *D, StringRef FuncName,
890b57cec5SDimitry Andric                                llvm::GlobalValue::LinkageTypes Linkage);
900b57cec5SDimitry Andric   // Insert instrumentation or attach profile metadata at value sites
910b57cec5SDimitry Andric   void valueProfile(CGBuilderTy &Builder, uint32_t ValueKind,
920b57cec5SDimitry Andric                     llvm::Instruction *ValueSite, llvm::Value *ValuePtr);
93fe6060f1SDimitry Andric 
94fe6060f1SDimitry Andric   // Set a module flag indicating if value profiling is enabled.
95fe6060f1SDimitry Andric   void setValueProfilingFlag(llvm::Module &M);
96fe6060f1SDimitry Andric 
97*0fca6ea1SDimitry Andric   void setProfileVersion(llvm::Module &M);
98*0fca6ea1SDimitry Andric 
990b57cec5SDimitry Andric private:
1000b57cec5SDimitry Andric   void setFuncName(llvm::Function *Fn);
1010b57cec5SDimitry Andric   void setFuncName(StringRef Name, llvm::GlobalValue::LinkageTypes Linkage);
1020b57cec5SDimitry Andric   void mapRegionCounters(const Decl *D);
1030b57cec5SDimitry Andric   void computeRegionCounts(const Decl *D);
1040b57cec5SDimitry Andric   void applyFunctionAttributes(llvm::IndexedInstrProfReader *PGOReader,
1050b57cec5SDimitry Andric                                llvm::Function *Fn);
1060b57cec5SDimitry Andric   void loadRegionCounts(llvm::IndexedInstrProfReader *PGOReader,
1070b57cec5SDimitry Andric                         bool IsInMainFile);
1080b57cec5SDimitry Andric   bool skipRegionMappingForDecl(const Decl *D);
1090b57cec5SDimitry Andric   void emitCounterRegionMapping(const Decl *D);
1101db9f3b2SDimitry Andric   bool canEmitMCDCCoverage(const CGBuilderTy &Builder);
1110b57cec5SDimitry Andric 
1120b57cec5SDimitry Andric public:
113*0fca6ea1SDimitry Andric   void emitCounterSetOrIncrement(CGBuilderTy &Builder, const Stmt *S,
1140b57cec5SDimitry Andric                                  llvm::Value *StepV);
1151db9f3b2SDimitry Andric   void emitMCDCTestVectorBitmapUpdate(CGBuilderTy &Builder, const Expr *S,
116*0fca6ea1SDimitry Andric                                       Address MCDCCondBitmapAddr,
117*0fca6ea1SDimitry Andric                                       CodeGenFunction &CGF);
1181db9f3b2SDimitry Andric   void emitMCDCParameters(CGBuilderTy &Builder);
1191db9f3b2SDimitry Andric   void emitMCDCCondBitmapReset(CGBuilderTy &Builder, const Expr *S,
1201db9f3b2SDimitry Andric                                Address MCDCCondBitmapAddr);
1211db9f3b2SDimitry Andric   void emitMCDCCondBitmapUpdate(CGBuilderTy &Builder, const Expr *S,
122*0fca6ea1SDimitry Andric                                 Address MCDCCondBitmapAddr, llvm::Value *Val,
123*0fca6ea1SDimitry Andric                                 CodeGenFunction &CGF);
1240b57cec5SDimitry Andric 
1250b57cec5SDimitry Andric   /// Return the region count for the counter at the given index.
1260b57cec5SDimitry Andric   uint64_t getRegionCount(const Stmt *S) {
1270b57cec5SDimitry Andric     if (!RegionCounterMap)
1280b57cec5SDimitry Andric       return 0;
1290b57cec5SDimitry Andric     if (!haveRegionCounts())
1300b57cec5SDimitry Andric       return 0;
13106c3fb27SDimitry Andric     // With profiles from a differing version of clang we can have mismatched
13206c3fb27SDimitry Andric     // decl counts. Don't crash in such a case.
13306c3fb27SDimitry Andric     auto Index = (*RegionCounterMap)[S];
13406c3fb27SDimitry Andric     if (Index >= RegionCounts.size())
13506c3fb27SDimitry Andric       return 0;
13606c3fb27SDimitry Andric     return RegionCounts[Index];
1370b57cec5SDimitry Andric   }
1380b57cec5SDimitry Andric };
1390b57cec5SDimitry Andric 
1400b57cec5SDimitry Andric }  // end namespace CodeGen
1410b57cec5SDimitry Andric }  // end namespace clang
1420b57cec5SDimitry Andric 
1430b57cec5SDimitry Andric #endif
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