| //===--- CodeGenPGO.cpp - PGO Instrumentation for LLVM CodeGen --*- 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 |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Instrumentation-based profile-guided optimization |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "CodeGenPGO.h" |
| #include "CodeGenFunction.h" |
| #include "CoverageMappingGen.h" |
| #include "clang/AST/RecursiveASTVisitor.h" |
| #include "clang/AST/StmtVisitor.h" |
| #include "llvm/IR/Intrinsics.h" |
| #include "llvm/IR/MDBuilder.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Support/Endian.h" |
| #include "llvm/Support/FileSystem.h" |
| #include "llvm/Support/MD5.h" |
| #include <optional> |
| |
| namespace llvm { |
| extern cl::opt<bool> EnableSingleByteCoverage; |
| } // namespace llvm |
| |
| static llvm::cl::opt<bool> |
| EnableValueProfiling("enable-value-profiling", |
| llvm::cl::desc("Enable value profiling"), |
| llvm::cl::Hidden, llvm::cl::init(false)); |
| |
| extern llvm::cl::opt<bool> SystemHeadersCoverage; |
| |
| using namespace clang; |
| using namespace CodeGen; |
| |
| void CodeGenPGO::setFuncName(StringRef Name, |
| llvm::GlobalValue::LinkageTypes Linkage) { |
| llvm::IndexedInstrProfReader *PGOReader = CGM.getPGOReader(); |
| FuncName = llvm::getPGOFuncName( |
| Name, Linkage, CGM.getCodeGenOpts().MainFileName, |
| PGOReader ? PGOReader->getVersion() : llvm::IndexedInstrProf::Version); |
| |
| // If we're generating a profile, create a variable for the name. |
| if (CGM.getCodeGenOpts().hasProfileClangInstr()) |
| FuncNameVar = llvm::createPGOFuncNameVar(CGM.getModule(), Linkage, FuncName); |
| } |
| |
| void CodeGenPGO::setFuncName(llvm::Function *Fn) { |
| setFuncName(Fn->getName(), Fn->getLinkage()); |
| // Create PGOFuncName meta data. |
| llvm::createPGOFuncNameMetadata(*Fn, FuncName); |
| } |
| |
| /// The version of the PGO hash algorithm. |
| enum PGOHashVersion : unsigned { |
| PGO_HASH_V1, |
| PGO_HASH_V2, |
| PGO_HASH_V3, |
| |
| // Keep this set to the latest hash version. |
| PGO_HASH_LATEST = PGO_HASH_V3 |
| }; |
| |
| namespace { |
| /// Stable hasher for PGO region counters. |
| /// |
| /// PGOHash produces a stable hash of a given function's control flow. |
| /// |
| /// Changing the output of this hash will invalidate all previously generated |
| /// profiles -- i.e., don't do it. |
| /// |
| /// \note When this hash does eventually change (years?), we still need to |
| /// support old hashes. We'll need to pull in the version number from the |
| /// profile data format and use the matching hash function. |
| class PGOHash { |
| uint64_t Working; |
| unsigned Count; |
| PGOHashVersion HashVersion; |
| llvm::MD5 MD5; |
| |
| static const int NumBitsPerType = 6; |
| static const unsigned NumTypesPerWord = sizeof(uint64_t) * 8 / NumBitsPerType; |
| static const unsigned TooBig = 1u << NumBitsPerType; |
| |
| public: |
| /// Hash values for AST nodes. |
| /// |
| /// Distinct values for AST nodes that have region counters attached. |
| /// |
| /// These values must be stable. All new members must be added at the end, |
| /// and no members should be removed. Changing the enumeration value for an |
| /// AST node will affect the hash of every function that contains that node. |
| enum HashType : unsigned char { |
| None = 0, |
| LabelStmt = 1, |
| WhileStmt, |
| DoStmt, |
| ForStmt, |
| CXXForRangeStmt, |
| ObjCForCollectionStmt, |
| SwitchStmt, |
| CaseStmt, |
| DefaultStmt, |
| IfStmt, |
| CXXTryStmt, |
| CXXCatchStmt, |
| ConditionalOperator, |
| BinaryOperatorLAnd, |
| BinaryOperatorLOr, |
| BinaryConditionalOperator, |
| // The preceding values are available with PGO_HASH_V1. |
| |
| EndOfScope, |
| IfThenBranch, |
| IfElseBranch, |
| GotoStmt, |
| IndirectGotoStmt, |
| BreakStmt, |
| ContinueStmt, |
| ReturnStmt, |
| ThrowExpr, |
| UnaryOperatorLNot, |
| BinaryOperatorLT, |
| BinaryOperatorGT, |
| BinaryOperatorLE, |
| BinaryOperatorGE, |
| BinaryOperatorEQ, |
| BinaryOperatorNE, |
| // The preceding values are available since PGO_HASH_V2. |
| |
| // Keep this last. It's for the static assert that follows. |
| LastHashType |
| }; |
| static_assert(LastHashType <= TooBig, "Too many types in HashType"); |
| |
| PGOHash(PGOHashVersion HashVersion) |
| : Working(0), Count(0), HashVersion(HashVersion) {} |
| void combine(HashType Type); |
| uint64_t finalize(); |
| PGOHashVersion getHashVersion() const { return HashVersion; } |
| }; |
| const int PGOHash::NumBitsPerType; |
| const unsigned PGOHash::NumTypesPerWord; |
| const unsigned PGOHash::TooBig; |
| |
| /// Get the PGO hash version used in the given indexed profile. |
| static PGOHashVersion getPGOHashVersion(llvm::IndexedInstrProfReader *PGOReader, |
| CodeGenModule &CGM) { |
| if (PGOReader->getVersion() <= 4) |
| return PGO_HASH_V1; |
| if (PGOReader->getVersion() <= 5) |
| return PGO_HASH_V2; |
| return PGO_HASH_V3; |
| } |
| |
| /// A RecursiveASTVisitor that fills a map of statements to PGO counters. |
| struct MapRegionCounters : public RecursiveASTVisitor<MapRegionCounters> { |
| using Base = RecursiveASTVisitor<MapRegionCounters>; |
| |
| /// The next counter value to assign. |
| unsigned NextCounter; |
| /// The function hash. |
| PGOHash Hash; |
| /// The map of statements to counters. |
| llvm::DenseMap<const Stmt *, unsigned> &CounterMap; |
| /// The next bitmap byte index to assign. |
| unsigned NextMCDCBitmapIdx; |
| /// The state of MC/DC Coverage in this function. |
| MCDC::State &MCDCState; |
| /// Maximum number of supported MC/DC conditions in a boolean expression. |
| unsigned MCDCMaxCond; |
| /// The profile version. |
| uint64_t ProfileVersion; |
| /// Diagnostics Engine used to report warnings. |
| DiagnosticsEngine &Diag; |
| |
| MapRegionCounters(PGOHashVersion HashVersion, uint64_t ProfileVersion, |
| llvm::DenseMap<const Stmt *, unsigned> &CounterMap, |
| MCDC::State &MCDCState, unsigned MCDCMaxCond, |
| DiagnosticsEngine &Diag) |
| : NextCounter(0), Hash(HashVersion), CounterMap(CounterMap), |
| NextMCDCBitmapIdx(0), MCDCState(MCDCState), MCDCMaxCond(MCDCMaxCond), |
| ProfileVersion(ProfileVersion), Diag(Diag) {} |
| |
| // Blocks and lambdas are handled as separate functions, so we need not |
| // traverse them in the parent context. |
| bool TraverseBlockExpr(BlockExpr *BE) { return true; } |
| bool TraverseLambdaExpr(LambdaExpr *LE) { |
| // Traverse the captures, but not the body. |
| for (auto C : zip(LE->captures(), LE->capture_inits())) |
| TraverseLambdaCapture(LE, &std::get<0>(C), std::get<1>(C)); |
| return true; |
| } |
| bool TraverseCapturedStmt(CapturedStmt *CS) { return true; } |
| |
| bool VisitDecl(const Decl *D) { |
| switch (D->getKind()) { |
| default: |
| break; |
| case Decl::Function: |
| case Decl::CXXMethod: |
| case Decl::CXXConstructor: |
| case Decl::CXXDestructor: |
| case Decl::CXXConversion: |
| case Decl::ObjCMethod: |
| case Decl::Block: |
| case Decl::Captured: |
| CounterMap[D->getBody()] = NextCounter++; |
| break; |
| } |
| return true; |
| } |
| |
| /// If \p S gets a fresh counter, update the counter mappings. Return the |
| /// V1 hash of \p S. |
| PGOHash::HashType updateCounterMappings(Stmt *S) { |
| auto Type = getHashType(PGO_HASH_V1, S); |
| if (Type != PGOHash::None) |
| CounterMap[S] = NextCounter++; |
| return Type; |
| } |
| |
| /// The following stacks are used with dataTraverseStmtPre() and |
| /// dataTraverseStmtPost() to track the depth of nested logical operators in a |
| /// boolean expression in a function. The ultimate purpose is to keep track |
| /// of the number of leaf-level conditions in the boolean expression so that a |
| /// profile bitmap can be allocated based on that number. |
| /// |
| /// The stacks are also used to find error cases and notify the user. A |
| /// standard logical operator nest for a boolean expression could be in a form |
| /// similar to this: "x = a && b && c && (d || f)" |
| unsigned NumCond = 0; |
| bool SplitNestedLogicalOp = false; |
| SmallVector<const Stmt *, 16> NonLogOpStack; |
| SmallVector<const BinaryOperator *, 16> LogOpStack; |
| |
| // Hook: dataTraverseStmtPre() is invoked prior to visiting an AST Stmt node. |
| bool dataTraverseStmtPre(Stmt *S) { |
| /// If MC/DC is not enabled, MCDCMaxCond will be set to 0. Do nothing. |
| if (MCDCMaxCond == 0) |
| return true; |
| |
| /// At the top of the logical operator nest, reset the number of conditions, |
| /// also forget previously seen split nesting cases. |
| if (LogOpStack.empty()) { |
| NumCond = 0; |
| SplitNestedLogicalOp = false; |
| } |
| |
| if (const Expr *E = dyn_cast<Expr>(S)) { |
| const BinaryOperator *BinOp = dyn_cast<BinaryOperator>(E->IgnoreParens()); |
| if (BinOp && BinOp->isLogicalOp()) { |
| /// Check for "split-nested" logical operators. This happens when a new |
| /// boolean expression logical-op nest is encountered within an existing |
| /// boolean expression, separated by a non-logical operator. For |
| /// example, in "x = (a && b && c && foo(d && f))", the "d && f" case |
| /// starts a new boolean expression that is separated from the other |
| /// conditions by the operator foo(). Split-nested cases are not |
| /// supported by MC/DC. |
| SplitNestedLogicalOp = SplitNestedLogicalOp || !NonLogOpStack.empty(); |
| |
| LogOpStack.push_back(BinOp); |
| return true; |
| } |
| } |
| |
| /// Keep track of non-logical operators. These are OK as long as we don't |
| /// encounter a new logical operator after seeing one. |
| if (!LogOpStack.empty()) |
| NonLogOpStack.push_back(S); |
| |
| return true; |
| } |
| |
| // Hook: dataTraverseStmtPost() is invoked by the AST visitor after visiting |
| // an AST Stmt node. MC/DC will use it to to signal when the top of a |
| // logical operation (boolean expression) nest is encountered. |
| bool dataTraverseStmtPost(Stmt *S) { |
| /// If MC/DC is not enabled, MCDCMaxCond will be set to 0. Do nothing. |
| if (MCDCMaxCond == 0) |
| return true; |
| |
| if (const Expr *E = dyn_cast<Expr>(S)) { |
| const BinaryOperator *BinOp = dyn_cast<BinaryOperator>(E->IgnoreParens()); |
| if (BinOp && BinOp->isLogicalOp()) { |
| assert(LogOpStack.back() == BinOp); |
| LogOpStack.pop_back(); |
| |
| /// At the top of logical operator nest: |
| if (LogOpStack.empty()) { |
| /// Was the "split-nested" logical operator case encountered? |
| if (SplitNestedLogicalOp) { |
| unsigned DiagID = Diag.getCustomDiagID( |
| DiagnosticsEngine::Warning, |
| "unsupported MC/DC boolean expression; " |
| "contains an operation with a nested boolean expression. " |
| "Expression will not be covered"); |
| Diag.Report(S->getBeginLoc(), DiagID); |
| return true; |
| } |
| |
| /// Was the maximum number of conditions encountered? |
| if (NumCond > MCDCMaxCond) { |
| unsigned DiagID = Diag.getCustomDiagID( |
| DiagnosticsEngine::Warning, |
| "unsupported MC/DC boolean expression; " |
| "number of conditions (%0) exceeds max (%1). " |
| "Expression will not be covered"); |
| Diag.Report(S->getBeginLoc(), DiagID) << NumCond << MCDCMaxCond; |
| return true; |
| } |
| |
| // Otherwise, allocate the number of bytes required for the bitmap |
| // based on the number of conditions. Must be at least 1-byte long. |
| MCDCState.DecisionByStmt[BinOp].BitmapIdx = NextMCDCBitmapIdx; |
| unsigned SizeInBits = std::max<unsigned>(1L << NumCond, CHAR_BIT); |
| NextMCDCBitmapIdx += SizeInBits / CHAR_BIT; |
| } |
| return true; |
| } |
| } |
| |
| if (!LogOpStack.empty()) |
| NonLogOpStack.pop_back(); |
| |
| return true; |
| } |
| |
| /// The RHS of all logical operators gets a fresh counter in order to count |
| /// how many times the RHS evaluates to true or false, depending on the |
| /// semantics of the operator. This is only valid for ">= v7" of the profile |
| /// version so that we facilitate backward compatibility. In addition, in |
| /// order to use MC/DC, count the number of total LHS and RHS conditions. |
| bool VisitBinaryOperator(BinaryOperator *S) { |
| if (S->isLogicalOp()) { |
| if (CodeGenFunction::isInstrumentedCondition(S->getLHS())) |
| NumCond++; |
| |
| if (CodeGenFunction::isInstrumentedCondition(S->getRHS())) { |
| if (ProfileVersion >= llvm::IndexedInstrProf::Version7) |
| CounterMap[S->getRHS()] = NextCounter++; |
| |
| NumCond++; |
| } |
| } |
| return Base::VisitBinaryOperator(S); |
| } |
| |
| bool VisitConditionalOperator(ConditionalOperator *S) { |
| if (llvm::EnableSingleByteCoverage && S->getTrueExpr()) |
| CounterMap[S->getTrueExpr()] = NextCounter++; |
| if (llvm::EnableSingleByteCoverage && S->getFalseExpr()) |
| CounterMap[S->getFalseExpr()] = NextCounter++; |
| return Base::VisitConditionalOperator(S); |
| } |
| |
| /// Include \p S in the function hash. |
| bool VisitStmt(Stmt *S) { |
| auto Type = updateCounterMappings(S); |
| if (Hash.getHashVersion() != PGO_HASH_V1) |
| Type = getHashType(Hash.getHashVersion(), S); |
| if (Type != PGOHash::None) |
| Hash.combine(Type); |
| return true; |
| } |
| |
| bool TraverseIfStmt(IfStmt *If) { |
| // If we used the V1 hash, use the default traversal. |
| if (Hash.getHashVersion() == PGO_HASH_V1) |
| return Base::TraverseIfStmt(If); |
| |
| // When single byte coverage mode is enabled, add a counter to then and |
| // else. |
| bool NoSingleByteCoverage = !llvm::EnableSingleByteCoverage; |
| for (Stmt *CS : If->children()) { |
| if (!CS || NoSingleByteCoverage) |
| continue; |
| if (CS == If->getThen()) |
| CounterMap[If->getThen()] = NextCounter++; |
| else if (CS == If->getElse()) |
| CounterMap[If->getElse()] = NextCounter++; |
| } |
| |
| // Otherwise, keep track of which branch we're in while traversing. |
| VisitStmt(If); |
| |
| for (Stmt *CS : If->children()) { |
| if (!CS) |
| continue; |
| if (CS == If->getThen()) |
| Hash.combine(PGOHash::IfThenBranch); |
| else if (CS == If->getElse()) |
| Hash.combine(PGOHash::IfElseBranch); |
| TraverseStmt(CS); |
| } |
| Hash.combine(PGOHash::EndOfScope); |
| return true; |
| } |
| |
| bool TraverseWhileStmt(WhileStmt *While) { |
| // When single byte coverage mode is enabled, add a counter to condition and |
| // body. |
| bool NoSingleByteCoverage = !llvm::EnableSingleByteCoverage; |
| for (Stmt *CS : While->children()) { |
| if (!CS || NoSingleByteCoverage) |
| continue; |
| if (CS == While->getCond()) |
| CounterMap[While->getCond()] = NextCounter++; |
| else if (CS == While->getBody()) |
| CounterMap[While->getBody()] = NextCounter++; |
| } |
| |
| Base::TraverseWhileStmt(While); |
| if (Hash.getHashVersion() != PGO_HASH_V1) |
| Hash.combine(PGOHash::EndOfScope); |
| return true; |
| } |
| |
| bool TraverseDoStmt(DoStmt *Do) { |
| // When single byte coverage mode is enabled, add a counter to condition and |
| // body. |
| bool NoSingleByteCoverage = !llvm::EnableSingleByteCoverage; |
| for (Stmt *CS : Do->children()) { |
| if (!CS || NoSingleByteCoverage) |
| continue; |
| if (CS == Do->getCond()) |
| CounterMap[Do->getCond()] = NextCounter++; |
| else if (CS == Do->getBody()) |
| CounterMap[Do->getBody()] = NextCounter++; |
| } |
| |
| Base::TraverseDoStmt(Do); |
| if (Hash.getHashVersion() != PGO_HASH_V1) |
| Hash.combine(PGOHash::EndOfScope); |
| return true; |
| } |
| |
| bool TraverseForStmt(ForStmt *For) { |
| // When single byte coverage mode is enabled, add a counter to condition, |
| // increment and body. |
| bool NoSingleByteCoverage = !llvm::EnableSingleByteCoverage; |
| for (Stmt *CS : For->children()) { |
| if (!CS || NoSingleByteCoverage) |
| continue; |
| if (CS == For->getCond()) |
| CounterMap[For->getCond()] = NextCounter++; |
| else if (CS == For->getInc()) |
| CounterMap[For->getInc()] = NextCounter++; |
| else if (CS == For->getBody()) |
| CounterMap[For->getBody()] = NextCounter++; |
| } |
| |
| Base::TraverseForStmt(For); |
| if (Hash.getHashVersion() != PGO_HASH_V1) |
| Hash.combine(PGOHash::EndOfScope); |
| return true; |
| } |
| |
| bool TraverseCXXForRangeStmt(CXXForRangeStmt *ForRange) { |
| // When single byte coverage mode is enabled, add a counter to body. |
| bool NoSingleByteCoverage = !llvm::EnableSingleByteCoverage; |
| for (Stmt *CS : ForRange->children()) { |
| if (!CS || NoSingleByteCoverage) |
| continue; |
| if (CS == ForRange->getBody()) |
| CounterMap[ForRange->getBody()] = NextCounter++; |
| } |
| |
| Base::TraverseCXXForRangeStmt(ForRange); |
| if (Hash.getHashVersion() != PGO_HASH_V1) |
| Hash.combine(PGOHash::EndOfScope); |
| return true; |
| } |
| |
| // If the statement type \p N is nestable, and its nesting impacts profile |
| // stability, define a custom traversal which tracks the end of the statement |
| // in the hash (provided we're not using the V1 hash). |
| #define DEFINE_NESTABLE_TRAVERSAL(N) \ |
| bool Traverse##N(N *S) { \ |
| Base::Traverse##N(S); \ |
| if (Hash.getHashVersion() != PGO_HASH_V1) \ |
| Hash.combine(PGOHash::EndOfScope); \ |
| return true; \ |
| } |
| |
| DEFINE_NESTABLE_TRAVERSAL(ObjCForCollectionStmt) |
| DEFINE_NESTABLE_TRAVERSAL(CXXTryStmt) |
| DEFINE_NESTABLE_TRAVERSAL(CXXCatchStmt) |
| |
| /// Get version \p HashVersion of the PGO hash for \p S. |
| PGOHash::HashType getHashType(PGOHashVersion HashVersion, const Stmt *S) { |
| switch (S->getStmtClass()) { |
| default: |
| break; |
| case Stmt::LabelStmtClass: |
| return PGOHash::LabelStmt; |
| case Stmt::WhileStmtClass: |
| return PGOHash::WhileStmt; |
| case Stmt::DoStmtClass: |
| return PGOHash::DoStmt; |
| case Stmt::ForStmtClass: |
| return PGOHash::ForStmt; |
| case Stmt::CXXForRangeStmtClass: |
| return PGOHash::CXXForRangeStmt; |
| case Stmt::ObjCForCollectionStmtClass: |
| return PGOHash::ObjCForCollectionStmt; |
| case Stmt::SwitchStmtClass: |
| return PGOHash::SwitchStmt; |
| case Stmt::CaseStmtClass: |
| return PGOHash::CaseStmt; |
| case Stmt::DefaultStmtClass: |
| return PGOHash::DefaultStmt; |
| case Stmt::IfStmtClass: |
| return PGOHash::IfStmt; |
| case Stmt::CXXTryStmtClass: |
| return PGOHash::CXXTryStmt; |
| case Stmt::CXXCatchStmtClass: |
| return PGOHash::CXXCatchStmt; |
| case Stmt::ConditionalOperatorClass: |
| return PGOHash::ConditionalOperator; |
| case Stmt::BinaryConditionalOperatorClass: |
| return PGOHash::BinaryConditionalOperator; |
| case Stmt::BinaryOperatorClass: { |
| const BinaryOperator *BO = cast<BinaryOperator>(S); |
| if (BO->getOpcode() == BO_LAnd) |
| return PGOHash::BinaryOperatorLAnd; |
| if (BO->getOpcode() == BO_LOr) |
| return PGOHash::BinaryOperatorLOr; |
| if (HashVersion >= PGO_HASH_V2) { |
| switch (BO->getOpcode()) { |
| default: |
| break; |
| case BO_LT: |
| return PGOHash::BinaryOperatorLT; |
| case BO_GT: |
| return PGOHash::BinaryOperatorGT; |
| case BO_LE: |
| return PGOHash::BinaryOperatorLE; |
| case BO_GE: |
| return PGOHash::BinaryOperatorGE; |
| case BO_EQ: |
| return PGOHash::BinaryOperatorEQ; |
| case BO_NE: |
| return PGOHash::BinaryOperatorNE; |
| } |
| } |
| break; |
| } |
| } |
| |
| if (HashVersion >= PGO_HASH_V2) { |
| switch (S->getStmtClass()) { |
| default: |
| break; |
| case Stmt::GotoStmtClass: |
| return PGOHash::GotoStmt; |
| case Stmt::IndirectGotoStmtClass: |
| return PGOHash::IndirectGotoStmt; |
| case Stmt::BreakStmtClass: |
| return PGOHash::BreakStmt; |
| case Stmt::ContinueStmtClass: |
| return PGOHash::ContinueStmt; |
| case Stmt::ReturnStmtClass: |
| return PGOHash::ReturnStmt; |
| case Stmt::CXXThrowExprClass: |
| return PGOHash::ThrowExpr; |
| case Stmt::UnaryOperatorClass: { |
| const UnaryOperator *UO = cast<UnaryOperator>(S); |
| if (UO->getOpcode() == UO_LNot) |
| return PGOHash::UnaryOperatorLNot; |
| break; |
| } |
| } |
| } |
| |
| return PGOHash::None; |
| } |
| }; |
| |
| /// A StmtVisitor that propagates the raw counts through the AST and |
| /// records the count at statements where the value may change. |
| struct ComputeRegionCounts : public ConstStmtVisitor<ComputeRegionCounts> { |
| /// PGO state. |
| CodeGenPGO &PGO; |
| |
| /// A flag that is set when the current count should be recorded on the |
| /// next statement, such as at the exit of a loop. |
| bool RecordNextStmtCount; |
| |
| /// The count at the current location in the traversal. |
| uint64_t CurrentCount; |
| |
| /// The map of statements to count values. |
| llvm::DenseMap<const Stmt *, uint64_t> &CountMap; |
| |
| /// BreakContinueStack - Keep counts of breaks and continues inside loops. |
| struct BreakContinue { |
| uint64_t BreakCount = 0; |
| uint64_t ContinueCount = 0; |
| BreakContinue() = default; |
| }; |
| SmallVector<BreakContinue, 8> BreakContinueStack; |
| |
| ComputeRegionCounts(llvm::DenseMap<const Stmt *, uint64_t> &CountMap, |
| CodeGenPGO &PGO) |
| : PGO(PGO), RecordNextStmtCount(false), CountMap(CountMap) {} |
| |
| void RecordStmtCount(const Stmt *S) { |
| if (RecordNextStmtCount) { |
| CountMap[S] = CurrentCount; |
| RecordNextStmtCount = false; |
| } |
| } |
| |
| /// Set and return the current count. |
| uint64_t setCount(uint64_t Count) { |
| CurrentCount = Count; |
| return Count; |
| } |
| |
| void VisitStmt(const Stmt *S) { |
| RecordStmtCount(S); |
| for (const Stmt *Child : S->children()) |
| if (Child) |
| this->Visit(Child); |
| } |
| |
| void VisitFunctionDecl(const FunctionDecl *D) { |
| // Counter tracks entry to the function body. |
| uint64_t BodyCount = setCount(PGO.getRegionCount(D->getBody())); |
| CountMap[D->getBody()] = BodyCount; |
| Visit(D->getBody()); |
| } |
| |
| // Skip lambda expressions. We visit these as FunctionDecls when we're |
| // generating them and aren't interested in the body when generating a |
| // parent context. |
| void VisitLambdaExpr(const LambdaExpr *LE) {} |
| |
| void VisitCapturedDecl(const CapturedDecl *D) { |
| // Counter tracks entry to the capture body. |
| uint64_t BodyCount = setCount(PGO.getRegionCount(D->getBody())); |
| CountMap[D->getBody()] = BodyCount; |
| Visit(D->getBody()); |
| } |
| |
| void VisitObjCMethodDecl(const ObjCMethodDecl *D) { |
| // Counter tracks entry to the method body. |
| uint64_t BodyCount = setCount(PGO.getRegionCount(D->getBody())); |
| CountMap[D->getBody()] = BodyCount; |
| Visit(D->getBody()); |
| } |
| |
| void VisitBlockDecl(const BlockDecl *D) { |
| // Counter tracks entry to the block body. |
| uint64_t BodyCount = setCount(PGO.getRegionCount(D->getBody())); |
| CountMap[D->getBody()] = BodyCount; |
| Visit(D->getBody()); |
| } |
| |
| void VisitReturnStmt(const ReturnStmt *S) { |
| RecordStmtCount(S); |
| if (S->getRetValue()) |
| Visit(S->getRetValue()); |
| CurrentCount = 0; |
| RecordNextStmtCount = true; |
| } |
| |
| void VisitCXXThrowExpr(const CXXThrowExpr *E) { |
| RecordStmtCount(E); |
| if (E->getSubExpr()) |
| Visit(E->getSubExpr()); |
| CurrentCount = 0; |
| RecordNextStmtCount = true; |
| } |
| |
| void VisitGotoStmt(const GotoStmt *S) { |
| RecordStmtCount(S); |
| CurrentCount = 0; |
| RecordNextStmtCount = true; |
| } |
| |
| void VisitLabelStmt(const LabelStmt *S) { |
| RecordNextStmtCount = false; |
| // Counter tracks the block following the label. |
| uint64_t BlockCount = setCount(PGO.getRegionCount(S)); |
| CountMap[S] = BlockCount; |
| Visit(S->getSubStmt()); |
| } |
| |
| void VisitBreakStmt(const BreakStmt *S) { |
| RecordStmtCount(S); |
| assert(!BreakContinueStack.empty() && "break not in a loop or switch!"); |
| BreakContinueStack.back().BreakCount += CurrentCount; |
| CurrentCount = 0; |
| RecordNextStmtCount = true; |
| } |
| |
| void VisitContinueStmt(const ContinueStmt *S) { |
| RecordStmtCount(S); |
| assert(!BreakContinueStack.empty() && "continue stmt not in a loop!"); |
| BreakContinueStack.back().ContinueCount += CurrentCount; |
| CurrentCount = 0; |
| RecordNextStmtCount = true; |
| } |
| |
| void VisitWhileStmt(const WhileStmt *S) { |
| RecordStmtCount(S); |
| uint64_t ParentCount = CurrentCount; |
| |
| BreakContinueStack.push_back(BreakContinue()); |
| // Visit the body region first so the break/continue adjustments can be |
| // included when visiting the condition. |
| uint64_t BodyCount = setCount(PGO.getRegionCount(S)); |
| CountMap[S->getBody()] = CurrentCount; |
| Visit(S->getBody()); |
| uint64_t BackedgeCount = CurrentCount; |
| |
| // ...then go back and propagate counts through the condition. The count |
| // at the start of the condition is the sum of the incoming edges, |
| // the backedge from the end of the loop body, and the edges from |
| // continue statements. |
| BreakContinue BC = BreakContinueStack.pop_back_val(); |
| uint64_t CondCount = |
| setCount(ParentCount + BackedgeCount + BC.ContinueCount); |
| CountMap[S->getCond()] = CondCount; |
| Visit(S->getCond()); |
| setCount(BC.BreakCount + CondCount - BodyCount); |
| RecordNextStmtCount = true; |
| } |
| |
| void VisitDoStmt(const DoStmt *S) { |
| RecordStmtCount(S); |
| uint64_t LoopCount = PGO.getRegionCount(S); |
| |
| BreakContinueStack.push_back(BreakContinue()); |
| // The count doesn't include the fallthrough from the parent scope. Add it. |
| uint64_t BodyCount = setCount(LoopCount + CurrentCount); |
| CountMap[S->getBody()] = BodyCount; |
| Visit(S->getBody()); |
| uint64_t BackedgeCount = CurrentCount; |
| |
| BreakContinue BC = BreakContinueStack.pop_back_val(); |
| // The count at the start of the condition is equal to the count at the |
| // end of the body, plus any continues. |
| uint64_t CondCount = setCount(BackedgeCount + BC.ContinueCount); |
| CountMap[S->getCond()] = CondCount; |
| Visit(S->getCond()); |
| setCount(BC.BreakCount + CondCount - LoopCount); |
| RecordNextStmtCount = true; |
| } |
| |
| void VisitForStmt(const ForStmt *S) { |
| RecordStmtCount(S); |
| if (S->getInit()) |
| Visit(S->getInit()); |
| |
| uint64_t ParentCount = CurrentCount; |
| |
| BreakContinueStack.push_back(BreakContinue()); |
| // Visit the body region first. (This is basically the same as a while |
| // loop; see further comments in VisitWhileStmt.) |
| uint64_t BodyCount = setCount(PGO.getRegionCount(S)); |
| CountMap[S->getBody()] = BodyCount; |
| Visit(S->getBody()); |
| uint64_t BackedgeCount = CurrentCount; |
| BreakContinue BC = BreakContinueStack.pop_back_val(); |
| |
| // The increment is essentially part of the body but it needs to include |
| // the count for all the continue statements. |
| if (S->getInc()) { |
| uint64_t IncCount = setCount(BackedgeCount + BC.ContinueCount); |
| CountMap[S->getInc()] = IncCount; |
| Visit(S->getInc()); |
| } |
| |
| // ...then go back and propagate counts through the condition. |
| uint64_t CondCount = |
| setCount(ParentCount + BackedgeCount + BC.ContinueCount); |
| if (S->getCond()) { |
| CountMap[S->getCond()] = CondCount; |
| Visit(S->getCond()); |
| } |
| setCount(BC.BreakCount + CondCount - BodyCount); |
| RecordNextStmtCount = true; |
| } |
| |
| void VisitCXXForRangeStmt(const CXXForRangeStmt *S) { |
| RecordStmtCount(S); |
| if (S->getInit()) |
| Visit(S->getInit()); |
| Visit(S->getLoopVarStmt()); |
| Visit(S->getRangeStmt()); |
| Visit(S->getBeginStmt()); |
| Visit(S->getEndStmt()); |
| |
| uint64_t ParentCount = CurrentCount; |
| BreakContinueStack.push_back(BreakContinue()); |
| // Visit the body region first. (This is basically the same as a while |
| // loop; see further comments in VisitWhileStmt.) |
| uint64_t BodyCount = setCount(PGO.getRegionCount(S)); |
| CountMap[S->getBody()] = BodyCount; |
| Visit(S->getBody()); |
| uint64_t BackedgeCount = CurrentCount; |
| BreakContinue BC = BreakContinueStack.pop_back_val(); |
| |
| // The increment is essentially part of the body but it needs to include |
| // the count for all the continue statements. |
| uint64_t IncCount = setCount(BackedgeCount + BC.ContinueCount); |
| CountMap[S->getInc()] = IncCount; |
| Visit(S->getInc()); |
| |
| // ...then go back and propagate counts through the condition. |
| uint64_t CondCount = |
| setCount(ParentCount + BackedgeCount + BC.ContinueCount); |
| CountMap[S->getCond()] = CondCount; |
| Visit(S->getCond()); |
| setCount(BC.BreakCount + CondCount - BodyCount); |
| RecordNextStmtCount = true; |
| } |
| |
| void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S) { |
| RecordStmtCount(S); |
| Visit(S->getElement()); |
| uint64_t ParentCount = CurrentCount; |
| BreakContinueStack.push_back(BreakContinue()); |
| // Counter tracks the body of the loop. |
| uint64_t BodyCount = setCount(PGO.getRegionCount(S)); |
| CountMap[S->getBody()] = BodyCount; |
| Visit(S->getBody()); |
| uint64_t BackedgeCount = CurrentCount; |
| BreakContinue BC = BreakContinueStack.pop_back_val(); |
| |
| setCount(BC.BreakCount + ParentCount + BackedgeCount + BC.ContinueCount - |
| BodyCount); |
| RecordNextStmtCount = true; |
| } |
| |
| void VisitSwitchStmt(const SwitchStmt *S) { |
| RecordStmtCount(S); |
| if (S->getInit()) |
| Visit(S->getInit()); |
| Visit(S->getCond()); |
| CurrentCount = 0; |
| BreakContinueStack.push_back(BreakContinue()); |
| Visit(S->getBody()); |
| // If the switch is inside a loop, add the continue counts. |
| BreakContinue BC = BreakContinueStack.pop_back_val(); |
| if (!BreakContinueStack.empty()) |
| BreakContinueStack.back().ContinueCount += BC.ContinueCount; |
| // Counter tracks the exit block of the switch. |
| setCount(PGO.getRegionCount(S)); |
| RecordNextStmtCount = true; |
| } |
| |
| void VisitSwitchCase(const SwitchCase *S) { |
| RecordNextStmtCount = false; |
| // Counter for this particular case. This counts only jumps from the |
| // switch header and does not include fallthrough from the case before |
| // this one. |
| uint64_t CaseCount = PGO.getRegionCount(S); |
| setCount(CurrentCount + CaseCount); |
| // We need the count without fallthrough in the mapping, so it's more useful |
| // for branch probabilities. |
| CountMap[S] = CaseCount; |
| RecordNextStmtCount = true; |
| Visit(S->getSubStmt()); |
| } |
| |
| void VisitIfStmt(const IfStmt *S) { |
| RecordStmtCount(S); |
| |
| if (S->isConsteval()) { |
| const Stmt *Stm = S->isNegatedConsteval() ? S->getThen() : S->getElse(); |
| if (Stm) |
| Visit(Stm); |
| return; |
| } |
| |
| uint64_t ParentCount = CurrentCount; |
| if (S->getInit()) |
| Visit(S->getInit()); |
| Visit(S->getCond()); |
| |
| // Counter tracks the "then" part of an if statement. The count for |
| // the "else" part, if it exists, will be calculated from this counter. |
| uint64_t ThenCount = setCount(PGO.getRegionCount(S)); |
| CountMap[S->getThen()] = ThenCount; |
| Visit(S->getThen()); |
| uint64_t OutCount = CurrentCount; |
| |
| uint64_t ElseCount = ParentCount - ThenCount; |
| if (S->getElse()) { |
| setCount(ElseCount); |
| CountMap[S->getElse()] = ElseCount; |
| Visit(S->getElse()); |
| OutCount += CurrentCount; |
| } else |
| OutCount += ElseCount; |
| setCount(OutCount); |
| RecordNextStmtCount = true; |
| } |
| |
| void VisitCXXTryStmt(const CXXTryStmt *S) { |
| RecordStmtCount(S); |
| Visit(S->getTryBlock()); |
| for (unsigned I = 0, E = S->getNumHandlers(); I < E; ++I) |
| Visit(S->getHandler(I)); |
| // Counter tracks the continuation block of the try statement. |
| setCount(PGO.getRegionCount(S)); |
| RecordNextStmtCount = true; |
| } |
| |
| void VisitCXXCatchStmt(const CXXCatchStmt *S) { |
| RecordNextStmtCount = false; |
| // Counter tracks the catch statement's handler block. |
| uint64_t CatchCount = setCount(PGO.getRegionCount(S)); |
| CountMap[S] = CatchCount; |
| Visit(S->getHandlerBlock()); |
| } |
| |
| void VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) { |
| RecordStmtCount(E); |
| uint64_t ParentCount = CurrentCount; |
| Visit(E->getCond()); |
| |
| // Counter tracks the "true" part of a conditional operator. The |
| // count in the "false" part will be calculated from this counter. |
| uint64_t TrueCount = setCount(PGO.getRegionCount(E)); |
| CountMap[E->getTrueExpr()] = TrueCount; |
| Visit(E->getTrueExpr()); |
| uint64_t OutCount = CurrentCount; |
| |
| uint64_t FalseCount = setCount(ParentCount - TrueCount); |
| CountMap[E->getFalseExpr()] = FalseCount; |
| Visit(E->getFalseExpr()); |
| OutCount += CurrentCount; |
| |
| setCount(OutCount); |
| RecordNextStmtCount = true; |
| } |
| |
| void VisitBinLAnd(const BinaryOperator *E) { |
| RecordStmtCount(E); |
| uint64_t ParentCount = CurrentCount; |
| Visit(E->getLHS()); |
| // Counter tracks the right hand side of a logical and operator. |
| uint64_t RHSCount = setCount(PGO.getRegionCount(E)); |
| CountMap[E->getRHS()] = RHSCount; |
| Visit(E->getRHS()); |
| setCount(ParentCount + RHSCount - CurrentCount); |
| RecordNextStmtCount = true; |
| } |
| |
| void VisitBinLOr(const BinaryOperator *E) { |
| RecordStmtCount(E); |
| uint64_t ParentCount = CurrentCount; |
| Visit(E->getLHS()); |
| // Counter tracks the right hand side of a logical or operator. |
| uint64_t RHSCount = setCount(PGO.getRegionCount(E)); |
| CountMap[E->getRHS()] = RHSCount; |
| Visit(E->getRHS()); |
| setCount(ParentCount + RHSCount - CurrentCount); |
| RecordNextStmtCount = true; |
| } |
| }; |
| } // end anonymous namespace |
| |
| void PGOHash::combine(HashType Type) { |
| // Check that we never combine 0 and only have six bits. |
| assert(Type && "Hash is invalid: unexpected type 0"); |
| assert(unsigned(Type) < TooBig && "Hash is invalid: too many types"); |
| |
| // Pass through MD5 if enough work has built up. |
| if (Count && Count % NumTypesPerWord == 0) { |
| using namespace llvm::support; |
| uint64_t Swapped = |
| endian::byte_swap<uint64_t, llvm::endianness::little>(Working); |
| MD5.update(llvm::ArrayRef((uint8_t *)&Swapped, sizeof(Swapped))); |
| Working = 0; |
| } |
| |
| // Accumulate the current type. |
| ++Count; |
| Working = Working << NumBitsPerType | Type; |
| } |
| |
| uint64_t PGOHash::finalize() { |
| // Use Working as the hash directly if we never used MD5. |
| if (Count <= NumTypesPerWord) |
| // No need to byte swap here, since none of the math was endian-dependent. |
| // This number will be byte-swapped as required on endianness transitions, |
| // so we will see the same value on the other side. |
| return Working; |
| |
| // Check for remaining work in Working. |
| if (Working) { |
| // Keep the buggy behavior from v1 and v2 for backward-compatibility. This |
| // is buggy because it converts a uint64_t into an array of uint8_t. |
| if (HashVersion < PGO_HASH_V3) { |
| MD5.update({(uint8_t)Working}); |
| } else { |
| using namespace llvm::support; |
| uint64_t Swapped = |
| endian::byte_swap<uint64_t, llvm::endianness::little>(Working); |
| MD5.update(llvm::ArrayRef((uint8_t *)&Swapped, sizeof(Swapped))); |
| } |
| } |
| |
| // Finalize the MD5 and return the hash. |
| llvm::MD5::MD5Result Result; |
| MD5.final(Result); |
| return Result.low(); |
| } |
| |
| void CodeGenPGO::assignRegionCounters(GlobalDecl GD, llvm::Function *Fn) { |
| const Decl *D = GD.getDecl(); |
| if (!D->hasBody()) |
| return; |
| |
| // Skip CUDA/HIP kernel launch stub functions. |
| if (CGM.getLangOpts().CUDA && !CGM.getLangOpts().CUDAIsDevice && |
| D->hasAttr<CUDAGlobalAttr>()) |
| return; |
| |
| bool InstrumentRegions = CGM.getCodeGenOpts().hasProfileClangInstr(); |
| llvm::IndexedInstrProfReader *PGOReader = CGM.getPGOReader(); |
| if (!InstrumentRegions && !PGOReader) |
| return; |
| if (D->isImplicit()) |
| return; |
| // Constructors and destructors may be represented by several functions in IR. |
| // If so, instrument only base variant, others are implemented by delegation |
| // to the base one, it would be counted twice otherwise. |
| if (CGM.getTarget().getCXXABI().hasConstructorVariants()) { |
| if (const auto *CCD = dyn_cast<CXXConstructorDecl>(D)) |
| if (GD.getCtorType() != Ctor_Base && |
| CodeGenFunction::IsConstructorDelegationValid(CCD)) |
| return; |
| } |
| if (isa<CXXDestructorDecl>(D) && GD.getDtorType() != Dtor_Base) |
| return; |
| |
| CGM.ClearUnusedCoverageMapping(D); |
| if (Fn->hasFnAttribute(llvm::Attribute::NoProfile)) |
| return; |
| if (Fn->hasFnAttribute(llvm::Attribute::SkipProfile)) |
| return; |
| |
| setFuncName(Fn); |
| |
| mapRegionCounters(D); |
| if (CGM.getCodeGenOpts().CoverageMapping) |
| emitCounterRegionMapping(D); |
| if (PGOReader) { |
| SourceManager &SM = CGM.getContext().getSourceManager(); |
| loadRegionCounts(PGOReader, SM.isInMainFile(D->getLocation())); |
| computeRegionCounts(D); |
| applyFunctionAttributes(PGOReader, Fn); |
| } |
| } |
| |
| void CodeGenPGO::mapRegionCounters(const Decl *D) { |
| // Use the latest hash version when inserting instrumentation, but use the |
| // version in the indexed profile if we're reading PGO data. |
| PGOHashVersion HashVersion = PGO_HASH_LATEST; |
| uint64_t ProfileVersion = llvm::IndexedInstrProf::Version; |
| if (auto *PGOReader = CGM.getPGOReader()) { |
| HashVersion = getPGOHashVersion(PGOReader, CGM); |
| ProfileVersion = PGOReader->getVersion(); |
| } |
| |
| // If MC/DC is enabled, set the MaxConditions to a preset value. Otherwise, |
| // set it to zero. This value impacts the number of conditions accepted in a |
| // given boolean expression, which impacts the size of the bitmap used to |
| // track test vector execution for that boolean expression. Because the |
| // bitmap scales exponentially (2^n) based on the number of conditions seen, |
| // the maximum value is hard-coded at 6 conditions, which is more than enough |
| // for most embedded applications. Setting a maximum value prevents the |
| // bitmap footprint from growing too large without the user's knowledge. In |
| // the future, this value could be adjusted with a command-line option. |
| unsigned MCDCMaxConditions = (CGM.getCodeGenOpts().MCDCCoverage) ? 6 : 0; |
| |
| RegionCounterMap.reset(new llvm::DenseMap<const Stmt *, unsigned>); |
| RegionMCDCState.reset(new MCDC::State); |
| MapRegionCounters Walker(HashVersion, ProfileVersion, *RegionCounterMap, |
| *RegionMCDCState, MCDCMaxConditions, CGM.getDiags()); |
| if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D)) |
| Walker.TraverseDecl(const_cast<FunctionDecl *>(FD)); |
| else if (const ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(D)) |
| Walker.TraverseDecl(const_cast<ObjCMethodDecl *>(MD)); |
| else if (const BlockDecl *BD = dyn_cast_or_null<BlockDecl>(D)) |
| Walker.TraverseDecl(const_cast<BlockDecl *>(BD)); |
| else if (const CapturedDecl *CD = dyn_cast_or_null<CapturedDecl>(D)) |
| Walker.TraverseDecl(const_cast<CapturedDecl *>(CD)); |
| assert(Walker.NextCounter > 0 && "no entry counter mapped for decl"); |
| NumRegionCounters = Walker.NextCounter; |
| RegionMCDCState->BitmapBytes = Walker.NextMCDCBitmapIdx; |
| FunctionHash = Walker.Hash.finalize(); |
| } |
| |
| bool CodeGenPGO::skipRegionMappingForDecl(const Decl *D) { |
| if (!D->getBody()) |
| return true; |
| |
| // Skip host-only functions in the CUDA device compilation and device-only |
| // functions in the host compilation. Just roughly filter them out based on |
| // the function attributes. If there are effectively host-only or device-only |
| // ones, their coverage mapping may still be generated. |
| if (CGM.getLangOpts().CUDA && |
| ((CGM.getLangOpts().CUDAIsDevice && !D->hasAttr<CUDADeviceAttr>() && |
| !D->hasAttr<CUDAGlobalAttr>()) || |
| (!CGM.getLangOpts().CUDAIsDevice && |
| (D->hasAttr<CUDAGlobalAttr>() || |
| (!D->hasAttr<CUDAHostAttr>() && D->hasAttr<CUDADeviceAttr>()))))) |
| return true; |
| |
| // Don't map the functions in system headers. |
| const auto &SM = CGM.getContext().getSourceManager(); |
| auto Loc = D->getBody()->getBeginLoc(); |
| return !SystemHeadersCoverage && SM.isInSystemHeader(Loc); |
| } |
| |
| void CodeGenPGO::emitCounterRegionMapping(const Decl *D) { |
| if (skipRegionMappingForDecl(D)) |
| return; |
| |
| std::string CoverageMapping; |
| llvm::raw_string_ostream OS(CoverageMapping); |
| RegionMCDCState->BranchByStmt.clear(); |
| CoverageMappingGen MappingGen( |
| *CGM.getCoverageMapping(), CGM.getContext().getSourceManager(), |
| CGM.getLangOpts(), RegionCounterMap.get(), RegionMCDCState.get()); |
| MappingGen.emitCounterMapping(D, OS); |
| OS.flush(); |
| |
| if (CoverageMapping.empty()) |
| return; |
| |
| CGM.getCoverageMapping()->addFunctionMappingRecord( |
| FuncNameVar, FuncName, FunctionHash, CoverageMapping); |
| } |
| |
| void |
| CodeGenPGO::emitEmptyCounterMapping(const Decl *D, StringRef Name, |
| llvm::GlobalValue::LinkageTypes Linkage) { |
| if (skipRegionMappingForDecl(D)) |
| return; |
| |
| std::string CoverageMapping; |
| llvm::raw_string_ostream OS(CoverageMapping); |
| CoverageMappingGen MappingGen(*CGM.getCoverageMapping(), |
| CGM.getContext().getSourceManager(), |
| CGM.getLangOpts()); |
| MappingGen.emitEmptyMapping(D, OS); |
| OS.flush(); |
| |
| if (CoverageMapping.empty()) |
| return; |
| |
| setFuncName(Name, Linkage); |
| CGM.getCoverageMapping()->addFunctionMappingRecord( |
| FuncNameVar, FuncName, FunctionHash, CoverageMapping, false); |
| } |
| |
| void CodeGenPGO::computeRegionCounts(const Decl *D) { |
| StmtCountMap.reset(new llvm::DenseMap<const Stmt *, uint64_t>); |
| ComputeRegionCounts Walker(*StmtCountMap, *this); |
| if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D)) |
| Walker.VisitFunctionDecl(FD); |
| else if (const ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(D)) |
| Walker.VisitObjCMethodDecl(MD); |
| else if (const BlockDecl *BD = dyn_cast_or_null<BlockDecl>(D)) |
| Walker.VisitBlockDecl(BD); |
| else if (const CapturedDecl *CD = dyn_cast_or_null<CapturedDecl>(D)) |
| Walker.VisitCapturedDecl(const_cast<CapturedDecl *>(CD)); |
| } |
| |
| void |
| CodeGenPGO::applyFunctionAttributes(llvm::IndexedInstrProfReader *PGOReader, |
| llvm::Function *Fn) { |
| if (!haveRegionCounts()) |
| return; |
| |
| uint64_t FunctionCount = getRegionCount(nullptr); |
| Fn->setEntryCount(FunctionCount); |
| } |
| |
| void CodeGenPGO::emitCounterSetOrIncrement(CGBuilderTy &Builder, const Stmt *S, |
| llvm::Value *StepV) { |
| if (!RegionCounterMap || !Builder.GetInsertBlock()) |
| return; |
| |
| unsigned Counter = (*RegionCounterMap)[S]; |
| |
| llvm::Value *Args[] = {FuncNameVar, |
| Builder.getInt64(FunctionHash), |
| Builder.getInt32(NumRegionCounters), |
| Builder.getInt32(Counter), StepV}; |
| |
| if (llvm::EnableSingleByteCoverage) |
| Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::instrprof_cover), |
| ArrayRef(Args, 4)); |
| else { |
| if (!StepV) |
| Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::instrprof_increment), |
| ArrayRef(Args, 4)); |
| else |
| Builder.CreateCall( |
| CGM.getIntrinsic(llvm::Intrinsic::instrprof_increment_step), |
| ArrayRef(Args)); |
| } |
| } |
| |
| bool CodeGenPGO::canEmitMCDCCoverage(const CGBuilderTy &Builder) { |
| return (CGM.getCodeGenOpts().hasProfileClangInstr() && |
| CGM.getCodeGenOpts().MCDCCoverage && Builder.GetInsertBlock()); |
| } |
| |
| void CodeGenPGO::emitMCDCParameters(CGBuilderTy &Builder) { |
| if (!canEmitMCDCCoverage(Builder) || !RegionMCDCState) |
| return; |
| |
| auto *I8PtrTy = llvm::PointerType::getUnqual(CGM.getLLVMContext()); |
| |
| // Emit intrinsic representing MCDC bitmap parameters at function entry. |
| // This is used by the instrumentation pass, but it isn't actually lowered to |
| // anything. |
| llvm::Value *Args[3] = {llvm::ConstantExpr::getBitCast(FuncNameVar, I8PtrTy), |
| Builder.getInt64(FunctionHash), |
| Builder.getInt32(RegionMCDCState->BitmapBytes)}; |
| Builder.CreateCall( |
| CGM.getIntrinsic(llvm::Intrinsic::instrprof_mcdc_parameters), Args); |
| } |
| |
| void CodeGenPGO::emitMCDCTestVectorBitmapUpdate(CGBuilderTy &Builder, |
| const Expr *S, |
| Address MCDCCondBitmapAddr, |
| CodeGenFunction &CGF) { |
| if (!canEmitMCDCCoverage(Builder) || !RegionMCDCState) |
| return; |
| |
| S = S->IgnoreParens(); |
| |
| auto DecisionStateIter = RegionMCDCState->DecisionByStmt.find(S); |
| if (DecisionStateIter == RegionMCDCState->DecisionByStmt.end()) |
| return; |
| |
| // Extract the offset of the global bitmap associated with this expression. |
| unsigned MCDCTestVectorBitmapOffset = DecisionStateIter->second.BitmapIdx; |
| auto *I8PtrTy = llvm::PointerType::getUnqual(CGM.getLLVMContext()); |
| |
| // Emit intrinsic responsible for updating the global bitmap corresponding to |
| // a boolean expression. The index being set is based on the value loaded |
| // from a pointer to a dedicated temporary value on the stack that is itself |
| // updated via emitMCDCCondBitmapReset() and emitMCDCCondBitmapUpdate(). The |
| // index represents an executed test vector. |
| llvm::Value *Args[5] = {llvm::ConstantExpr::getBitCast(FuncNameVar, I8PtrTy), |
| Builder.getInt64(FunctionHash), |
| Builder.getInt32(RegionMCDCState->BitmapBytes), |
| Builder.getInt32(MCDCTestVectorBitmapOffset), |
| MCDCCondBitmapAddr.emitRawPointer(CGF)}; |
| Builder.CreateCall( |
| CGM.getIntrinsic(llvm::Intrinsic::instrprof_mcdc_tvbitmap_update), Args); |
| } |
| |
| void CodeGenPGO::emitMCDCCondBitmapReset(CGBuilderTy &Builder, const Expr *S, |
| Address MCDCCondBitmapAddr) { |
| if (!canEmitMCDCCoverage(Builder) || !RegionMCDCState) |
| return; |
| |
| S = S->IgnoreParens(); |
| |
| if (!RegionMCDCState->DecisionByStmt.contains(S)) |
| return; |
| |
| // Emit intrinsic that resets a dedicated temporary value on the stack to 0. |
| Builder.CreateStore(Builder.getInt32(0), MCDCCondBitmapAddr); |
| } |
| |
| void CodeGenPGO::emitMCDCCondBitmapUpdate(CGBuilderTy &Builder, const Expr *S, |
| Address MCDCCondBitmapAddr, |
| llvm::Value *Val, |
| CodeGenFunction &CGF) { |
| if (!canEmitMCDCCoverage(Builder) || !RegionMCDCState) |
| return; |
| |
| // Even though, for simplicity, parentheses and unary logical-NOT operators |
| // are considered part of their underlying condition for both MC/DC and |
| // branch coverage, the condition IDs themselves are assigned and tracked |
| // using the underlying condition itself. This is done solely for |
| // consistency since parentheses and logical-NOTs are ignored when checking |
| // whether the condition is actually an instrumentable condition. This can |
| // also make debugging a bit easier. |
| S = CodeGenFunction::stripCond(S); |
| |
| auto BranchStateIter = RegionMCDCState->BranchByStmt.find(S); |
| if (BranchStateIter == RegionMCDCState->BranchByStmt.end()) |
| return; |
| |
| // Extract the ID of the condition we are setting in the bitmap. |
| const auto &Branch = BranchStateIter->second; |
| assert(Branch.ID >= 0 && "Condition has no ID!"); |
| |
| auto *I8PtrTy = llvm::PointerType::getUnqual(CGM.getLLVMContext()); |
| |
| // Emit intrinsic that updates a dedicated temporary value on the stack after |
| // a condition is evaluated. After the set of conditions has been updated, |
| // the resulting value is used to update the boolean expression's bitmap. |
| llvm::Value *Args[5] = {llvm::ConstantExpr::getBitCast(FuncNameVar, I8PtrTy), |
| Builder.getInt64(FunctionHash), |
| Builder.getInt32(Branch.ID), |
| MCDCCondBitmapAddr.emitRawPointer(CGF), Val}; |
| Builder.CreateCall( |
| CGM.getIntrinsic(llvm::Intrinsic::instrprof_mcdc_condbitmap_update), |
| Args); |
| } |
| |
| void CodeGenPGO::setValueProfilingFlag(llvm::Module &M) { |
| if (CGM.getCodeGenOpts().hasProfileClangInstr()) |
| M.addModuleFlag(llvm::Module::Warning, "EnableValueProfiling", |
| uint32_t(EnableValueProfiling)); |
| } |
| |
| void CodeGenPGO::setProfileVersion(llvm::Module &M) { |
| if (CGM.getCodeGenOpts().hasProfileClangInstr() && |
| llvm::EnableSingleByteCoverage) { |
| const StringRef VarName(INSTR_PROF_QUOTE(INSTR_PROF_RAW_VERSION_VAR)); |
| llvm::Type *IntTy64 = llvm::Type::getInt64Ty(M.getContext()); |
| uint64_t ProfileVersion = |
| (INSTR_PROF_RAW_VERSION | VARIANT_MASK_BYTE_COVERAGE); |
| |
| auto IRLevelVersionVariable = new llvm::GlobalVariable( |
| M, IntTy64, true, llvm::GlobalValue::WeakAnyLinkage, |
| llvm::Constant::getIntegerValue(IntTy64, |
| llvm::APInt(64, ProfileVersion)), |
| VarName); |
| |
| IRLevelVersionVariable->setVisibility(llvm::GlobalValue::DefaultVisibility); |
| llvm::Triple TT(M.getTargetTriple()); |
| if (TT.supportsCOMDAT()) { |
| IRLevelVersionVariable->setLinkage(llvm::GlobalValue::ExternalLinkage); |
| IRLevelVersionVariable->setComdat(M.getOrInsertComdat(VarName)); |
| } |
| IRLevelVersionVariable->setDSOLocal(true); |
| } |
| } |
| |
| // This method either inserts a call to the profile run-time during |
| // instrumentation or puts profile data into metadata for PGO use. |
| void CodeGenPGO::valueProfile(CGBuilderTy &Builder, uint32_t ValueKind, |
| llvm::Instruction *ValueSite, llvm::Value *ValuePtr) { |
| |
| if (!EnableValueProfiling) |
| return; |
| |
| if (!ValuePtr || !ValueSite || !Builder.GetInsertBlock()) |
| return; |
| |
| if (isa<llvm::Constant>(ValuePtr)) |
| return; |
| |
| bool InstrumentValueSites = CGM.getCodeGenOpts().hasProfileClangInstr(); |
| if (InstrumentValueSites && RegionCounterMap) { |
| auto BuilderInsertPoint = Builder.saveIP(); |
| Builder.SetInsertPoint(ValueSite); |
| llvm::Value *Args[5] = { |
| FuncNameVar, |
| Builder.getInt64(FunctionHash), |
| Builder.CreatePtrToInt(ValuePtr, Builder.getInt64Ty()), |
| Builder.getInt32(ValueKind), |
| Builder.getInt32(NumValueSites[ValueKind]++) |
| }; |
| Builder.CreateCall( |
| CGM.getIntrinsic(llvm::Intrinsic::instrprof_value_profile), Args); |
| Builder.restoreIP(BuilderInsertPoint); |
| return; |
| } |
| |
| llvm::IndexedInstrProfReader *PGOReader = CGM.getPGOReader(); |
| if (PGOReader && haveRegionCounts()) { |
| // We record the top most called three functions at each call site. |
| // Profile metadata contains "VP" string identifying this metadata |
| // as value profiling data, then a uint32_t value for the value profiling |
| // kind, a uint64_t value for the total number of times the call is |
| // executed, followed by the function hash and execution count (uint64_t) |
| // pairs for each function. |
| if (NumValueSites[ValueKind] >= ProfRecord->getNumValueSites(ValueKind)) |
| return; |
| |
| llvm::annotateValueSite(CGM.getModule(), *ValueSite, *ProfRecord, |
| (llvm::InstrProfValueKind)ValueKind, |
| NumValueSites[ValueKind]); |
| |
| NumValueSites[ValueKind]++; |
| } |
| } |
| |
| void CodeGenPGO::loadRegionCounts(llvm::IndexedInstrProfReader *PGOReader, |
| bool IsInMainFile) { |
| CGM.getPGOStats().addVisited(IsInMainFile); |
| RegionCounts.clear(); |
| llvm::Expected<llvm::InstrProfRecord> RecordExpected = |
| PGOReader->getInstrProfRecord(FuncName, FunctionHash); |
| if (auto E = RecordExpected.takeError()) { |
| auto IPE = std::get<0>(llvm::InstrProfError::take(std::move(E))); |
| if (IPE == llvm::instrprof_error::unknown_function) |
| CGM.getPGOStats().addMissing(IsInMainFile); |
| else if (IPE == llvm::instrprof_error::hash_mismatch) |
| CGM.getPGOStats().addMismatched(IsInMainFile); |
| else if (IPE == llvm::instrprof_error::malformed) |
| // TODO: Consider a more specific warning for this case. |
| CGM.getPGOStats().addMismatched(IsInMainFile); |
| return; |
| } |
| ProfRecord = |
| std::make_unique<llvm::InstrProfRecord>(std::move(RecordExpected.get())); |
| RegionCounts = ProfRecord->Counts; |
| } |
| |
| /// Calculate what to divide by to scale weights. |
| /// |
| /// Given the maximum weight, calculate a divisor that will scale all the |
| /// weights to strictly less than UINT32_MAX. |
| static uint64_t calculateWeightScale(uint64_t MaxWeight) { |
| return MaxWeight < UINT32_MAX ? 1 : MaxWeight / UINT32_MAX + 1; |
| } |
| |
| /// Scale an individual branch weight (and add 1). |
| /// |
| /// Scale a 64-bit weight down to 32-bits using \c Scale. |
| /// |
| /// According to Laplace's Rule of Succession, it is better to compute the |
| /// weight based on the count plus 1, so universally add 1 to the value. |
| /// |
| /// \pre \c Scale was calculated by \a calculateWeightScale() with a weight no |
| /// greater than \c Weight. |
| static uint32_t scaleBranchWeight(uint64_t Weight, uint64_t Scale) { |
| assert(Scale && "scale by 0?"); |
| uint64_t Scaled = Weight / Scale + 1; |
| assert(Scaled <= UINT32_MAX && "overflow 32-bits"); |
| return Scaled; |
| } |
| |
| llvm::MDNode *CodeGenFunction::createProfileWeights(uint64_t TrueCount, |
| uint64_t FalseCount) const { |
| // Check for empty weights. |
| if (!TrueCount && !FalseCount) |
| return nullptr; |
| |
| // Calculate how to scale down to 32-bits. |
| uint64_t Scale = calculateWeightScale(std::max(TrueCount, FalseCount)); |
| |
| llvm::MDBuilder MDHelper(CGM.getLLVMContext()); |
| return MDHelper.createBranchWeights(scaleBranchWeight(TrueCount, Scale), |
| scaleBranchWeight(FalseCount, Scale)); |
| } |
| |
| llvm::MDNode * |
| CodeGenFunction::createProfileWeights(ArrayRef<uint64_t> Weights) const { |
| // We need at least two elements to create meaningful weights. |
| if (Weights.size() < 2) |
| return nullptr; |
| |
| // Check for empty weights. |
| uint64_t MaxWeight = *std::max_element(Weights.begin(), Weights.end()); |
| if (MaxWeight == 0) |
| return nullptr; |
| |
| // Calculate how to scale down to 32-bits. |
| uint64_t Scale = calculateWeightScale(MaxWeight); |
| |
| SmallVector<uint32_t, 16> ScaledWeights; |
| ScaledWeights.reserve(Weights.size()); |
| for (uint64_t W : Weights) |
| ScaledWeights.push_back(scaleBranchWeight(W, Scale)); |
| |
| llvm::MDBuilder MDHelper(CGM.getLLVMContext()); |
| return MDHelper.createBranchWeights(ScaledWeights); |
| } |
| |
| llvm::MDNode * |
| CodeGenFunction::createProfileWeightsForLoop(const Stmt *Cond, |
| uint64_t LoopCount) const { |
| if (!PGO.haveRegionCounts()) |
| return nullptr; |
| std::optional<uint64_t> CondCount = PGO.getStmtCount(Cond); |
| if (!CondCount || *CondCount == 0) |
| return nullptr; |
| return createProfileWeights(LoopCount, |
| std::max(*CondCount, LoopCount) - LoopCount); |
| } |
