| //===--- CGStmt.cpp - Emit LLVM Code from Statements ----------------------===// |
| // |
| // 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 contains code to emit Stmt nodes as LLVM code. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "CGDebugInfo.h" |
| #include "CGOpenMPRuntime.h" |
| #include "CodeGenFunction.h" |
| #include "CodeGenModule.h" |
| #include "TargetInfo.h" |
| #include "clang/AST/Attr.h" |
| #include "clang/AST/StmtVisitor.h" |
| #include "clang/Basic/Builtins.h" |
| #include "clang/Basic/PrettyStackTrace.h" |
| #include "clang/Basic/SourceManager.h" |
| #include "clang/Basic/TargetInfo.h" |
| #include "llvm/ADT/StringExtras.h" |
| #include "llvm/IR/DataLayout.h" |
| #include "llvm/IR/InlineAsm.h" |
| #include "llvm/IR/Intrinsics.h" |
| #include "llvm/IR/MDBuilder.h" |
| #include "llvm/Support/SaveAndRestore.h" |
| #include "llvm/Transforms/Scalar/LowerExpectIntrinsic.h" |
| |
| using namespace clang; |
| using namespace CodeGen; |
| |
| //===----------------------------------------------------------------------===// |
| // Statement Emission |
| //===----------------------------------------------------------------------===// |
| |
| void CodeGenFunction::EmitStopPoint(const Stmt *S) { |
| if (CGDebugInfo *DI = getDebugInfo()) { |
| SourceLocation Loc; |
| Loc = S->getBeginLoc(); |
| DI->EmitLocation(Builder, Loc); |
| |
| LastStopPoint = Loc; |
| } |
| } |
| |
| void CodeGenFunction::EmitStmt(const Stmt *S, ArrayRef<const Attr *> Attrs) { |
| assert(S && "Null statement?"); |
| PGO.setCurrentStmt(S); |
| |
| // These statements have their own debug info handling. |
| if (EmitSimpleStmt(S)) |
| return; |
| |
| // Check if we are generating unreachable code. |
| if (!HaveInsertPoint()) { |
| // If so, and the statement doesn't contain a label, then we do not need to |
| // generate actual code. This is safe because (1) the current point is |
| // unreachable, so we don't need to execute the code, and (2) we've already |
| // handled the statements which update internal data structures (like the |
| // local variable map) which could be used by subsequent statements. |
| if (!ContainsLabel(S)) { |
| // Verify that any decl statements were handled as simple, they may be in |
| // scope of subsequent reachable statements. |
| assert(!isa<DeclStmt>(*S) && "Unexpected DeclStmt!"); |
| return; |
| } |
| |
| // Otherwise, make a new block to hold the code. |
| EnsureInsertPoint(); |
| } |
| |
| // Generate a stoppoint if we are emitting debug info. |
| EmitStopPoint(S); |
| |
| // Ignore all OpenMP directives except for simd if OpenMP with Simd is |
| // enabled. |
| if (getLangOpts().OpenMP && getLangOpts().OpenMPSimd) { |
| if (const auto *D = dyn_cast<OMPExecutableDirective>(S)) { |
| EmitSimpleOMPExecutableDirective(*D); |
| return; |
| } |
| } |
| |
| switch (S->getStmtClass()) { |
| case Stmt::NoStmtClass: |
| case Stmt::CXXCatchStmtClass: |
| case Stmt::SEHExceptStmtClass: |
| case Stmt::SEHFinallyStmtClass: |
| case Stmt::MSDependentExistsStmtClass: |
| llvm_unreachable("invalid statement class to emit generically"); |
| case Stmt::NullStmtClass: |
| case Stmt::CompoundStmtClass: |
| case Stmt::DeclStmtClass: |
| case Stmt::LabelStmtClass: |
| case Stmt::AttributedStmtClass: |
| case Stmt::GotoStmtClass: |
| case Stmt::BreakStmtClass: |
| case Stmt::ContinueStmtClass: |
| case Stmt::DefaultStmtClass: |
| case Stmt::CaseStmtClass: |
| case Stmt::SEHLeaveStmtClass: |
| llvm_unreachable("should have emitted these statements as simple"); |
| |
| #define STMT(Type, Base) |
| #define ABSTRACT_STMT(Op) |
| #define EXPR(Type, Base) \ |
| case Stmt::Type##Class: |
| #include "clang/AST/StmtNodes.inc" |
| { |
| // Remember the block we came in on. |
| llvm::BasicBlock *incoming = Builder.GetInsertBlock(); |
| assert(incoming && "expression emission must have an insertion point"); |
| |
| EmitIgnoredExpr(cast<Expr>(S)); |
| |
| llvm::BasicBlock *outgoing = Builder.GetInsertBlock(); |
| assert(outgoing && "expression emission cleared block!"); |
| |
| // The expression emitters assume (reasonably!) that the insertion |
| // point is always set. To maintain that, the call-emission code |
| // for noreturn functions has to enter a new block with no |
| // predecessors. We want to kill that block and mark the current |
| // insertion point unreachable in the common case of a call like |
| // "exit();". Since expression emission doesn't otherwise create |
| // blocks with no predecessors, we can just test for that. |
| // However, we must be careful not to do this to our incoming |
| // block, because *statement* emission does sometimes create |
| // reachable blocks which will have no predecessors until later in |
| // the function. This occurs with, e.g., labels that are not |
| // reachable by fallthrough. |
| if (incoming != outgoing && outgoing->use_empty()) { |
| outgoing->eraseFromParent(); |
| Builder.ClearInsertionPoint(); |
| } |
| break; |
| } |
| |
| case Stmt::IndirectGotoStmtClass: |
| EmitIndirectGotoStmt(cast<IndirectGotoStmt>(*S)); break; |
| |
| case Stmt::IfStmtClass: EmitIfStmt(cast<IfStmt>(*S)); break; |
| case Stmt::WhileStmtClass: EmitWhileStmt(cast<WhileStmt>(*S), Attrs); break; |
| case Stmt::DoStmtClass: EmitDoStmt(cast<DoStmt>(*S), Attrs); break; |
| case Stmt::ForStmtClass: EmitForStmt(cast<ForStmt>(*S), Attrs); break; |
| |
| case Stmt::ReturnStmtClass: EmitReturnStmt(cast<ReturnStmt>(*S)); break; |
| |
| case Stmt::SwitchStmtClass: EmitSwitchStmt(cast<SwitchStmt>(*S)); break; |
| case Stmt::GCCAsmStmtClass: // Intentional fall-through. |
| case Stmt::MSAsmStmtClass: EmitAsmStmt(cast<AsmStmt>(*S)); break; |
| case Stmt::CoroutineBodyStmtClass: |
| EmitCoroutineBody(cast<CoroutineBodyStmt>(*S)); |
| break; |
| case Stmt::CoreturnStmtClass: |
| EmitCoreturnStmt(cast<CoreturnStmt>(*S)); |
| break; |
| case Stmt::CapturedStmtClass: { |
| const CapturedStmt *CS = cast<CapturedStmt>(S); |
| EmitCapturedStmt(*CS, CS->getCapturedRegionKind()); |
| } |
| break; |
| case Stmt::ObjCAtTryStmtClass: |
| EmitObjCAtTryStmt(cast<ObjCAtTryStmt>(*S)); |
| break; |
| case Stmt::ObjCAtCatchStmtClass: |
| llvm_unreachable( |
| "@catch statements should be handled by EmitObjCAtTryStmt"); |
| case Stmt::ObjCAtFinallyStmtClass: |
| llvm_unreachable( |
| "@finally statements should be handled by EmitObjCAtTryStmt"); |
| case Stmt::ObjCAtThrowStmtClass: |
| EmitObjCAtThrowStmt(cast<ObjCAtThrowStmt>(*S)); |
| break; |
| case Stmt::ObjCAtSynchronizedStmtClass: |
| EmitObjCAtSynchronizedStmt(cast<ObjCAtSynchronizedStmt>(*S)); |
| break; |
| case Stmt::ObjCForCollectionStmtClass: |
| EmitObjCForCollectionStmt(cast<ObjCForCollectionStmt>(*S)); |
| break; |
| case Stmt::ObjCAutoreleasePoolStmtClass: |
| EmitObjCAutoreleasePoolStmt(cast<ObjCAutoreleasePoolStmt>(*S)); |
| break; |
| |
| case Stmt::CXXTryStmtClass: |
| EmitCXXTryStmt(cast<CXXTryStmt>(*S)); |
| break; |
| case Stmt::CXXForRangeStmtClass: |
| EmitCXXForRangeStmt(cast<CXXForRangeStmt>(*S), Attrs); |
| break; |
| case Stmt::SEHTryStmtClass: |
| EmitSEHTryStmt(cast<SEHTryStmt>(*S)); |
| break; |
| case Stmt::OMPParallelDirectiveClass: |
| EmitOMPParallelDirective(cast<OMPParallelDirective>(*S)); |
| break; |
| case Stmt::OMPSimdDirectiveClass: |
| EmitOMPSimdDirective(cast<OMPSimdDirective>(*S)); |
| break; |
| case Stmt::OMPForDirectiveClass: |
| EmitOMPForDirective(cast<OMPForDirective>(*S)); |
| break; |
| case Stmt::OMPForSimdDirectiveClass: |
| EmitOMPForSimdDirective(cast<OMPForSimdDirective>(*S)); |
| break; |
| case Stmt::OMPSectionsDirectiveClass: |
| EmitOMPSectionsDirective(cast<OMPSectionsDirective>(*S)); |
| break; |
| case Stmt::OMPSectionDirectiveClass: |
| EmitOMPSectionDirective(cast<OMPSectionDirective>(*S)); |
| break; |
| case Stmt::OMPSingleDirectiveClass: |
| EmitOMPSingleDirective(cast<OMPSingleDirective>(*S)); |
| break; |
| case Stmt::OMPMasterDirectiveClass: |
| EmitOMPMasterDirective(cast<OMPMasterDirective>(*S)); |
| break; |
| case Stmt::OMPCriticalDirectiveClass: |
| EmitOMPCriticalDirective(cast<OMPCriticalDirective>(*S)); |
| break; |
| case Stmt::OMPParallelForDirectiveClass: |
| EmitOMPParallelForDirective(cast<OMPParallelForDirective>(*S)); |
| break; |
| case Stmt::OMPParallelForSimdDirectiveClass: |
| EmitOMPParallelForSimdDirective(cast<OMPParallelForSimdDirective>(*S)); |
| break; |
| case Stmt::OMPParallelMasterDirectiveClass: |
| EmitOMPParallelMasterDirective(cast<OMPParallelMasterDirective>(*S)); |
| break; |
| case Stmt::OMPParallelSectionsDirectiveClass: |
| EmitOMPParallelSectionsDirective(cast<OMPParallelSectionsDirective>(*S)); |
| break; |
| case Stmt::OMPTaskDirectiveClass: |
| EmitOMPTaskDirective(cast<OMPTaskDirective>(*S)); |
| break; |
| case Stmt::OMPTaskyieldDirectiveClass: |
| EmitOMPTaskyieldDirective(cast<OMPTaskyieldDirective>(*S)); |
| break; |
| case Stmt::OMPBarrierDirectiveClass: |
| EmitOMPBarrierDirective(cast<OMPBarrierDirective>(*S)); |
| break; |
| case Stmt::OMPTaskwaitDirectiveClass: |
| EmitOMPTaskwaitDirective(cast<OMPTaskwaitDirective>(*S)); |
| break; |
| case Stmt::OMPTaskgroupDirectiveClass: |
| EmitOMPTaskgroupDirective(cast<OMPTaskgroupDirective>(*S)); |
| break; |
| case Stmt::OMPFlushDirectiveClass: |
| EmitOMPFlushDirective(cast<OMPFlushDirective>(*S)); |
| break; |
| case Stmt::OMPDepobjDirectiveClass: |
| EmitOMPDepobjDirective(cast<OMPDepobjDirective>(*S)); |
| break; |
| case Stmt::OMPScanDirectiveClass: |
| EmitOMPScanDirective(cast<OMPScanDirective>(*S)); |
| break; |
| case Stmt::OMPOrderedDirectiveClass: |
| EmitOMPOrderedDirective(cast<OMPOrderedDirective>(*S)); |
| break; |
| case Stmt::OMPAtomicDirectiveClass: |
| EmitOMPAtomicDirective(cast<OMPAtomicDirective>(*S)); |
| break; |
| case Stmt::OMPTargetDirectiveClass: |
| EmitOMPTargetDirective(cast<OMPTargetDirective>(*S)); |
| break; |
| case Stmt::OMPTeamsDirectiveClass: |
| EmitOMPTeamsDirective(cast<OMPTeamsDirective>(*S)); |
| break; |
| case Stmt::OMPCancellationPointDirectiveClass: |
| EmitOMPCancellationPointDirective(cast<OMPCancellationPointDirective>(*S)); |
| break; |
| case Stmt::OMPCancelDirectiveClass: |
| EmitOMPCancelDirective(cast<OMPCancelDirective>(*S)); |
| break; |
| case Stmt::OMPTargetDataDirectiveClass: |
| EmitOMPTargetDataDirective(cast<OMPTargetDataDirective>(*S)); |
| break; |
| case Stmt::OMPTargetEnterDataDirectiveClass: |
| EmitOMPTargetEnterDataDirective(cast<OMPTargetEnterDataDirective>(*S)); |
| break; |
| case Stmt::OMPTargetExitDataDirectiveClass: |
| EmitOMPTargetExitDataDirective(cast<OMPTargetExitDataDirective>(*S)); |
| break; |
| case Stmt::OMPTargetParallelDirectiveClass: |
| EmitOMPTargetParallelDirective(cast<OMPTargetParallelDirective>(*S)); |
| break; |
| case Stmt::OMPTargetParallelForDirectiveClass: |
| EmitOMPTargetParallelForDirective(cast<OMPTargetParallelForDirective>(*S)); |
| break; |
| case Stmt::OMPTaskLoopDirectiveClass: |
| EmitOMPTaskLoopDirective(cast<OMPTaskLoopDirective>(*S)); |
| break; |
| case Stmt::OMPTaskLoopSimdDirectiveClass: |
| EmitOMPTaskLoopSimdDirective(cast<OMPTaskLoopSimdDirective>(*S)); |
| break; |
| case Stmt::OMPMasterTaskLoopDirectiveClass: |
| EmitOMPMasterTaskLoopDirective(cast<OMPMasterTaskLoopDirective>(*S)); |
| break; |
| case Stmt::OMPMasterTaskLoopSimdDirectiveClass: |
| EmitOMPMasterTaskLoopSimdDirective( |
| cast<OMPMasterTaskLoopSimdDirective>(*S)); |
| break; |
| case Stmt::OMPParallelMasterTaskLoopDirectiveClass: |
| EmitOMPParallelMasterTaskLoopDirective( |
| cast<OMPParallelMasterTaskLoopDirective>(*S)); |
| break; |
| case Stmt::OMPParallelMasterTaskLoopSimdDirectiveClass: |
| EmitOMPParallelMasterTaskLoopSimdDirective( |
| cast<OMPParallelMasterTaskLoopSimdDirective>(*S)); |
| break; |
| case Stmt::OMPDistributeDirectiveClass: |
| EmitOMPDistributeDirective(cast<OMPDistributeDirective>(*S)); |
| break; |
| case Stmt::OMPTargetUpdateDirectiveClass: |
| EmitOMPTargetUpdateDirective(cast<OMPTargetUpdateDirective>(*S)); |
| break; |
| case Stmt::OMPDistributeParallelForDirectiveClass: |
| EmitOMPDistributeParallelForDirective( |
| cast<OMPDistributeParallelForDirective>(*S)); |
| break; |
| case Stmt::OMPDistributeParallelForSimdDirectiveClass: |
| EmitOMPDistributeParallelForSimdDirective( |
| cast<OMPDistributeParallelForSimdDirective>(*S)); |
| break; |
| case Stmt::OMPDistributeSimdDirectiveClass: |
| EmitOMPDistributeSimdDirective(cast<OMPDistributeSimdDirective>(*S)); |
| break; |
| case Stmt::OMPTargetParallelForSimdDirectiveClass: |
| EmitOMPTargetParallelForSimdDirective( |
| cast<OMPTargetParallelForSimdDirective>(*S)); |
| break; |
| case Stmt::OMPTargetSimdDirectiveClass: |
| EmitOMPTargetSimdDirective(cast<OMPTargetSimdDirective>(*S)); |
| break; |
| case Stmt::OMPTeamsDistributeDirectiveClass: |
| EmitOMPTeamsDistributeDirective(cast<OMPTeamsDistributeDirective>(*S)); |
| break; |
| case Stmt::OMPTeamsDistributeSimdDirectiveClass: |
| EmitOMPTeamsDistributeSimdDirective( |
| cast<OMPTeamsDistributeSimdDirective>(*S)); |
| break; |
| case Stmt::OMPTeamsDistributeParallelForSimdDirectiveClass: |
| EmitOMPTeamsDistributeParallelForSimdDirective( |
| cast<OMPTeamsDistributeParallelForSimdDirective>(*S)); |
| break; |
| case Stmt::OMPTeamsDistributeParallelForDirectiveClass: |
| EmitOMPTeamsDistributeParallelForDirective( |
| cast<OMPTeamsDistributeParallelForDirective>(*S)); |
| break; |
| case Stmt::OMPTargetTeamsDirectiveClass: |
| EmitOMPTargetTeamsDirective(cast<OMPTargetTeamsDirective>(*S)); |
| break; |
| case Stmt::OMPTargetTeamsDistributeDirectiveClass: |
| EmitOMPTargetTeamsDistributeDirective( |
| cast<OMPTargetTeamsDistributeDirective>(*S)); |
| break; |
| case Stmt::OMPTargetTeamsDistributeParallelForDirectiveClass: |
| EmitOMPTargetTeamsDistributeParallelForDirective( |
| cast<OMPTargetTeamsDistributeParallelForDirective>(*S)); |
| break; |
| case Stmt::OMPTargetTeamsDistributeParallelForSimdDirectiveClass: |
| EmitOMPTargetTeamsDistributeParallelForSimdDirective( |
| cast<OMPTargetTeamsDistributeParallelForSimdDirective>(*S)); |
| break; |
| case Stmt::OMPTargetTeamsDistributeSimdDirectiveClass: |
| EmitOMPTargetTeamsDistributeSimdDirective( |
| cast<OMPTargetTeamsDistributeSimdDirective>(*S)); |
| break; |
| } |
| } |
| |
| bool CodeGenFunction::EmitSimpleStmt(const Stmt *S) { |
| switch (S->getStmtClass()) { |
| default: return false; |
| case Stmt::NullStmtClass: break; |
| case Stmt::CompoundStmtClass: EmitCompoundStmt(cast<CompoundStmt>(*S)); break; |
| case Stmt::DeclStmtClass: EmitDeclStmt(cast<DeclStmt>(*S)); break; |
| case Stmt::LabelStmtClass: EmitLabelStmt(cast<LabelStmt>(*S)); break; |
| case Stmt::AttributedStmtClass: |
| EmitAttributedStmt(cast<AttributedStmt>(*S)); break; |
| case Stmt::GotoStmtClass: EmitGotoStmt(cast<GotoStmt>(*S)); break; |
| case Stmt::BreakStmtClass: EmitBreakStmt(cast<BreakStmt>(*S)); break; |
| case Stmt::ContinueStmtClass: EmitContinueStmt(cast<ContinueStmt>(*S)); break; |
| case Stmt::DefaultStmtClass: EmitDefaultStmt(cast<DefaultStmt>(*S)); break; |
| case Stmt::CaseStmtClass: EmitCaseStmt(cast<CaseStmt>(*S)); break; |
| case Stmt::SEHLeaveStmtClass: EmitSEHLeaveStmt(cast<SEHLeaveStmt>(*S)); break; |
| } |
| |
| return true; |
| } |
| |
| /// EmitCompoundStmt - Emit a compound statement {..} node. If GetLast is true, |
| /// this captures the expression result of the last sub-statement and returns it |
| /// (for use by the statement expression extension). |
| Address CodeGenFunction::EmitCompoundStmt(const CompoundStmt &S, bool GetLast, |
| AggValueSlot AggSlot) { |
| PrettyStackTraceLoc CrashInfo(getContext().getSourceManager(),S.getLBracLoc(), |
| "LLVM IR generation of compound statement ('{}')"); |
| |
| // Keep track of the current cleanup stack depth, including debug scopes. |
| LexicalScope Scope(*this, S.getSourceRange()); |
| |
| return EmitCompoundStmtWithoutScope(S, GetLast, AggSlot); |
| } |
| |
| Address |
| CodeGenFunction::EmitCompoundStmtWithoutScope(const CompoundStmt &S, |
| bool GetLast, |
| AggValueSlot AggSlot) { |
| |
| const Stmt *ExprResult = S.getStmtExprResult(); |
| assert((!GetLast || (GetLast && ExprResult)) && |
| "If GetLast is true then the CompoundStmt must have a StmtExprResult"); |
| |
| Address RetAlloca = Address::invalid(); |
| |
| for (auto *CurStmt : S.body()) { |
| if (GetLast && ExprResult == CurStmt) { |
| // We have to special case labels here. They are statements, but when put |
| // at the end of a statement expression, they yield the value of their |
| // subexpression. Handle this by walking through all labels we encounter, |
| // emitting them before we evaluate the subexpr. |
| // Similar issues arise for attributed statements. |
| while (!isa<Expr>(ExprResult)) { |
| if (const auto *LS = dyn_cast<LabelStmt>(ExprResult)) { |
| EmitLabel(LS->getDecl()); |
| ExprResult = LS->getSubStmt(); |
| } else if (const auto *AS = dyn_cast<AttributedStmt>(ExprResult)) { |
| // FIXME: Update this if we ever have attributes that affect the |
| // semantics of an expression. |
| ExprResult = AS->getSubStmt(); |
| } else { |
| llvm_unreachable("unknown value statement"); |
| } |
| } |
| |
| EnsureInsertPoint(); |
| |
| const Expr *E = cast<Expr>(ExprResult); |
| QualType ExprTy = E->getType(); |
| if (hasAggregateEvaluationKind(ExprTy)) { |
| EmitAggExpr(E, AggSlot); |
| } else { |
| // We can't return an RValue here because there might be cleanups at |
| // the end of the StmtExpr. Because of that, we have to emit the result |
| // here into a temporary alloca. |
| RetAlloca = CreateMemTemp(ExprTy); |
| EmitAnyExprToMem(E, RetAlloca, Qualifiers(), |
| /*IsInit*/ false); |
| } |
| } else { |
| EmitStmt(CurStmt); |
| } |
| } |
| |
| return RetAlloca; |
| } |
| |
| void CodeGenFunction::SimplifyForwardingBlocks(llvm::BasicBlock *BB) { |
| llvm::BranchInst *BI = dyn_cast<llvm::BranchInst>(BB->getTerminator()); |
| |
| // If there is a cleanup stack, then we it isn't worth trying to |
| // simplify this block (we would need to remove it from the scope map |
| // and cleanup entry). |
| if (!EHStack.empty()) |
| return; |
| |
| // Can only simplify direct branches. |
| if (!BI || !BI->isUnconditional()) |
| return; |
| |
| // Can only simplify empty blocks. |
| if (BI->getIterator() != BB->begin()) |
| return; |
| |
| BB->replaceAllUsesWith(BI->getSuccessor(0)); |
| BI->eraseFromParent(); |
| BB->eraseFromParent(); |
| } |
| |
| void CodeGenFunction::EmitBlock(llvm::BasicBlock *BB, bool IsFinished) { |
| llvm::BasicBlock *CurBB = Builder.GetInsertBlock(); |
| |
| // Fall out of the current block (if necessary). |
| EmitBranch(BB); |
| |
| if (IsFinished && BB->use_empty()) { |
| delete BB; |
| return; |
| } |
| |
| // Place the block after the current block, if possible, or else at |
| // the end of the function. |
| if (CurBB && CurBB->getParent()) |
| CurFn->getBasicBlockList().insertAfter(CurBB->getIterator(), BB); |
| else |
| CurFn->getBasicBlockList().push_back(BB); |
| Builder.SetInsertPoint(BB); |
| } |
| |
| void CodeGenFunction::EmitBranch(llvm::BasicBlock *Target) { |
| // Emit a branch from the current block to the target one if this |
| // was a real block. If this was just a fall-through block after a |
| // terminator, don't emit it. |
| llvm::BasicBlock *CurBB = Builder.GetInsertBlock(); |
| |
| if (!CurBB || CurBB->getTerminator()) { |
| // If there is no insert point or the previous block is already |
| // terminated, don't touch it. |
| } else { |
| // Otherwise, create a fall-through branch. |
| Builder.CreateBr(Target); |
| } |
| |
| Builder.ClearInsertionPoint(); |
| } |
| |
| void CodeGenFunction::EmitBlockAfterUses(llvm::BasicBlock *block) { |
| bool inserted = false; |
| for (llvm::User *u : block->users()) { |
| if (llvm::Instruction *insn = dyn_cast<llvm::Instruction>(u)) { |
| CurFn->getBasicBlockList().insertAfter(insn->getParent()->getIterator(), |
| block); |
| inserted = true; |
| break; |
| } |
| } |
| |
| if (!inserted) |
| CurFn->getBasicBlockList().push_back(block); |
| |
| Builder.SetInsertPoint(block); |
| } |
| |
| CodeGenFunction::JumpDest |
| CodeGenFunction::getJumpDestForLabel(const LabelDecl *D) { |
| JumpDest &Dest = LabelMap[D]; |
| if (Dest.isValid()) return Dest; |
| |
| // Create, but don't insert, the new block. |
| Dest = JumpDest(createBasicBlock(D->getName()), |
| EHScopeStack::stable_iterator::invalid(), |
| NextCleanupDestIndex++); |
| return Dest; |
| } |
| |
| void CodeGenFunction::EmitLabel(const LabelDecl *D) { |
| // Add this label to the current lexical scope if we're within any |
| // normal cleanups. Jumps "in" to this label --- when permitted by |
| // the language --- may need to be routed around such cleanups. |
| if (EHStack.hasNormalCleanups() && CurLexicalScope) |
| CurLexicalScope->addLabel(D); |
| |
| JumpDest &Dest = LabelMap[D]; |
| |
| // If we didn't need a forward reference to this label, just go |
| // ahead and create a destination at the current scope. |
| if (!Dest.isValid()) { |
| Dest = getJumpDestInCurrentScope(D->getName()); |
| |
| // Otherwise, we need to give this label a target depth and remove |
| // it from the branch-fixups list. |
| } else { |
| assert(!Dest.getScopeDepth().isValid() && "already emitted label!"); |
| Dest.setScopeDepth(EHStack.stable_begin()); |
| ResolveBranchFixups(Dest.getBlock()); |
| } |
| |
| EmitBlock(Dest.getBlock()); |
| |
| // Emit debug info for labels. |
| if (CGDebugInfo *DI = getDebugInfo()) { |
| if (CGM.getCodeGenOpts().hasReducedDebugInfo()) { |
| DI->setLocation(D->getLocation()); |
| DI->EmitLabel(D, Builder); |
| } |
| } |
| |
| incrementProfileCounter(D->getStmt()); |
| } |
| |
| /// Change the cleanup scope of the labels in this lexical scope to |
| /// match the scope of the enclosing context. |
| void CodeGenFunction::LexicalScope::rescopeLabels() { |
| assert(!Labels.empty()); |
| EHScopeStack::stable_iterator innermostScope |
| = CGF.EHStack.getInnermostNormalCleanup(); |
| |
| // Change the scope depth of all the labels. |
| for (SmallVectorImpl<const LabelDecl*>::const_iterator |
| i = Labels.begin(), e = Labels.end(); i != e; ++i) { |
| assert(CGF.LabelMap.count(*i)); |
| JumpDest &dest = CGF.LabelMap.find(*i)->second; |
| assert(dest.getScopeDepth().isValid()); |
| assert(innermostScope.encloses(dest.getScopeDepth())); |
| dest.setScopeDepth(innermostScope); |
| } |
| |
| // Reparent the labels if the new scope also has cleanups. |
| if (innermostScope != EHScopeStack::stable_end() && ParentScope) { |
| ParentScope->Labels.append(Labels.begin(), Labels.end()); |
| } |
| } |
| |
| |
| void CodeGenFunction::EmitLabelStmt(const LabelStmt &S) { |
| EmitLabel(S.getDecl()); |
| EmitStmt(S.getSubStmt()); |
| } |
| |
| void CodeGenFunction::EmitAttributedStmt(const AttributedStmt &S) { |
| bool nomerge = false; |
| for (const auto *A : S.getAttrs()) |
| if (A->getKind() == attr::NoMerge) { |
| nomerge = true; |
| break; |
| } |
| SaveAndRestore<bool> save_nomerge(InNoMergeAttributedStmt, nomerge); |
| EmitStmt(S.getSubStmt(), S.getAttrs()); |
| } |
| |
| void CodeGenFunction::EmitGotoStmt(const GotoStmt &S) { |
| // If this code is reachable then emit a stop point (if generating |
| // debug info). We have to do this ourselves because we are on the |
| // "simple" statement path. |
| if (HaveInsertPoint()) |
| EmitStopPoint(&S); |
| |
| EmitBranchThroughCleanup(getJumpDestForLabel(S.getLabel())); |
| } |
| |
| |
| void CodeGenFunction::EmitIndirectGotoStmt(const IndirectGotoStmt &S) { |
| if (const LabelDecl *Target = S.getConstantTarget()) { |
| EmitBranchThroughCleanup(getJumpDestForLabel(Target)); |
| return; |
| } |
| |
| // Ensure that we have an i8* for our PHI node. |
| llvm::Value *V = Builder.CreateBitCast(EmitScalarExpr(S.getTarget()), |
| Int8PtrTy, "addr"); |
| llvm::BasicBlock *CurBB = Builder.GetInsertBlock(); |
| |
| // Get the basic block for the indirect goto. |
| llvm::BasicBlock *IndGotoBB = GetIndirectGotoBlock(); |
| |
| // The first instruction in the block has to be the PHI for the switch dest, |
| // add an entry for this branch. |
| cast<llvm::PHINode>(IndGotoBB->begin())->addIncoming(V, CurBB); |
| |
| EmitBranch(IndGotoBB); |
| } |
| static Optional<std::pair<uint32_t, uint32_t>> |
| getLikelihoodWeights(const IfStmt &If) { |
| switch (Stmt::getLikelihood(If.getThen(), If.getElse())) { |
| case Stmt::LH_Unlikely: |
| return std::pair<uint32_t, uint32_t>(llvm::UnlikelyBranchWeight, |
| llvm::LikelyBranchWeight); |
| case Stmt::LH_None: |
| return None; |
| case Stmt::LH_Likely: |
| return std::pair<uint32_t, uint32_t>(llvm::LikelyBranchWeight, |
| llvm::UnlikelyBranchWeight); |
| } |
| llvm_unreachable("Unknown Likelihood"); |
| } |
| |
| void CodeGenFunction::EmitIfStmt(const IfStmt &S) { |
| // C99 6.8.4.1: The first substatement is executed if the expression compares |
| // unequal to 0. The condition must be a scalar type. |
| LexicalScope ConditionScope(*this, S.getCond()->getSourceRange()); |
| |
| if (S.getInit()) |
| EmitStmt(S.getInit()); |
| |
| if (S.getConditionVariable()) |
| EmitDecl(*S.getConditionVariable()); |
| |
| // If the condition constant folds and can be elided, try to avoid emitting |
| // the condition and the dead arm of the if/else. |
| bool CondConstant; |
| if (ConstantFoldsToSimpleInteger(S.getCond(), CondConstant, |
| S.isConstexpr())) { |
| // Figure out which block (then or else) is executed. |
| const Stmt *Executed = S.getThen(); |
| const Stmt *Skipped = S.getElse(); |
| if (!CondConstant) // Condition false? |
| std::swap(Executed, Skipped); |
| |
| // If the skipped block has no labels in it, just emit the executed block. |
| // This avoids emitting dead code and simplifies the CFG substantially. |
| if (S.isConstexpr() || !ContainsLabel(Skipped)) { |
| if (CondConstant) |
| incrementProfileCounter(&S); |
| if (Executed) { |
| RunCleanupsScope ExecutedScope(*this); |
| EmitStmt(Executed); |
| } |
| return; |
| } |
| } |
| |
| // Otherwise, the condition did not fold, or we couldn't elide it. Just emit |
| // the conditional branch. |
| llvm::BasicBlock *ThenBlock = createBasicBlock("if.then"); |
| llvm::BasicBlock *ContBlock = createBasicBlock("if.end"); |
| llvm::BasicBlock *ElseBlock = ContBlock; |
| if (S.getElse()) |
| ElseBlock = createBasicBlock("if.else"); |
| |
| // Prefer the PGO based weights over the likelihood attribute. |
| // When the build isn't optimized the metadata isn't used, so don't generate |
| // it. |
| llvm::MDNode *Weights = nullptr; |
| uint64_t Count = getProfileCount(S.getThen()); |
| if (!Count && CGM.getCodeGenOpts().OptimizationLevel) { |
| Optional<std::pair<uint32_t, uint32_t>> LHW = getLikelihoodWeights(S); |
| if (LHW) { |
| llvm::MDBuilder MDHelper(CGM.getLLVMContext()); |
| Weights = MDHelper.createBranchWeights(LHW->first, LHW->second); |
| } |
| } |
| |
| EmitBranchOnBoolExpr(S.getCond(), ThenBlock, ElseBlock, Count, Weights); |
| |
| // Emit the 'then' code. |
| EmitBlock(ThenBlock); |
| incrementProfileCounter(&S); |
| { |
| RunCleanupsScope ThenScope(*this); |
| EmitStmt(S.getThen()); |
| } |
| EmitBranch(ContBlock); |
| |
| // Emit the 'else' code if present. |
| if (const Stmt *Else = S.getElse()) { |
| { |
| // There is no need to emit line number for an unconditional branch. |
| auto NL = ApplyDebugLocation::CreateEmpty(*this); |
| EmitBlock(ElseBlock); |
| } |
| { |
| RunCleanupsScope ElseScope(*this); |
| EmitStmt(Else); |
| } |
| { |
| // There is no need to emit line number for an unconditional branch. |
| auto NL = ApplyDebugLocation::CreateEmpty(*this); |
| EmitBranch(ContBlock); |
| } |
| } |
| |
| // Emit the continuation block for code after the if. |
| EmitBlock(ContBlock, true); |
| } |
| |
| void CodeGenFunction::EmitWhileStmt(const WhileStmt &S, |
| ArrayRef<const Attr *> WhileAttrs) { |
| // Emit the header for the loop, which will also become |
| // the continue target. |
| JumpDest LoopHeader = getJumpDestInCurrentScope("while.cond"); |
| EmitBlock(LoopHeader.getBlock()); |
| |
| const SourceRange &R = S.getSourceRange(); |
| LoopStack.push(LoopHeader.getBlock(), CGM.getContext(), CGM.getCodeGenOpts(), |
| WhileAttrs, SourceLocToDebugLoc(R.getBegin()), |
| SourceLocToDebugLoc(R.getEnd())); |
| |
| // Create an exit block for when the condition fails, which will |
| // also become the break target. |
| JumpDest LoopExit = getJumpDestInCurrentScope("while.end"); |
| |
| // Store the blocks to use for break and continue. |
| BreakContinueStack.push_back(BreakContinue(LoopExit, LoopHeader)); |
| |
| // C++ [stmt.while]p2: |
| // When the condition of a while statement is a declaration, the |
| // scope of the variable that is declared extends from its point |
| // of declaration (3.3.2) to the end of the while statement. |
| // [...] |
| // The object created in a condition is destroyed and created |
| // with each iteration of the loop. |
| RunCleanupsScope ConditionScope(*this); |
| |
| if (S.getConditionVariable()) |
| EmitDecl(*S.getConditionVariable()); |
| |
| // Evaluate the conditional in the while header. C99 6.8.5.1: The |
| // evaluation of the controlling expression takes place before each |
| // execution of the loop body. |
| llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond()); |
| |
| // while(1) is common, avoid extra exit blocks. Be sure |
| // to correctly handle break/continue though. |
| bool EmitBoolCondBranch = true; |
| if (llvm::ConstantInt *C = dyn_cast<llvm::ConstantInt>(BoolCondVal)) |
| if (C->isOne()) |
| EmitBoolCondBranch = false; |
| |
| // As long as the condition is true, go to the loop body. |
| llvm::BasicBlock *LoopBody = createBasicBlock("while.body"); |
| if (EmitBoolCondBranch) { |
| llvm::BasicBlock *ExitBlock = LoopExit.getBlock(); |
| if (ConditionScope.requiresCleanups()) |
| ExitBlock = createBasicBlock("while.exit"); |
| Builder.CreateCondBr( |
| BoolCondVal, LoopBody, ExitBlock, |
| createProfileWeightsForLoop(S.getCond(), getProfileCount(S.getBody()))); |
| |
| if (ExitBlock != LoopExit.getBlock()) { |
| EmitBlock(ExitBlock); |
| EmitBranchThroughCleanup(LoopExit); |
| } |
| } |
| |
| // Emit the loop body. We have to emit this in a cleanup scope |
| // because it might be a singleton DeclStmt. |
| { |
| RunCleanupsScope BodyScope(*this); |
| EmitBlock(LoopBody); |
| incrementProfileCounter(&S); |
| EmitStmt(S.getBody()); |
| } |
| |
| BreakContinueStack.pop_back(); |
| |
| // Immediately force cleanup. |
| ConditionScope.ForceCleanup(); |
| |
| EmitStopPoint(&S); |
| // Branch to the loop header again. |
| EmitBranch(LoopHeader.getBlock()); |
| |
| LoopStack.pop(); |
| |
| // Emit the exit block. |
| EmitBlock(LoopExit.getBlock(), true); |
| |
| // The LoopHeader typically is just a branch if we skipped emitting |
| // a branch, try to erase it. |
| if (!EmitBoolCondBranch) |
| SimplifyForwardingBlocks(LoopHeader.getBlock()); |
| } |
| |
| void CodeGenFunction::EmitDoStmt(const DoStmt &S, |
| ArrayRef<const Attr *> DoAttrs) { |
| JumpDest LoopExit = getJumpDestInCurrentScope("do.end"); |
| JumpDest LoopCond = getJumpDestInCurrentScope("do.cond"); |
| |
| uint64_t ParentCount = getCurrentProfileCount(); |
| |
| // Store the blocks to use for break and continue. |
| BreakContinueStack.push_back(BreakContinue(LoopExit, LoopCond)); |
| |
| // Emit the body of the loop. |
| llvm::BasicBlock *LoopBody = createBasicBlock("do.body"); |
| |
| EmitBlockWithFallThrough(LoopBody, &S); |
| { |
| RunCleanupsScope BodyScope(*this); |
| EmitStmt(S.getBody()); |
| } |
| |
| EmitBlock(LoopCond.getBlock()); |
| |
| const SourceRange &R = S.getSourceRange(); |
| LoopStack.push(LoopBody, CGM.getContext(), CGM.getCodeGenOpts(), DoAttrs, |
| SourceLocToDebugLoc(R.getBegin()), |
| SourceLocToDebugLoc(R.getEnd())); |
| |
| // C99 6.8.5.2: "The evaluation of the controlling expression takes place |
| // after each execution of the loop body." |
| |
| // Evaluate the conditional in the while header. |
| // C99 6.8.5p2/p4: The first substatement is executed if the expression |
| // compares unequal to 0. The condition must be a scalar type. |
| llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond()); |
| |
| BreakContinueStack.pop_back(); |
| |
| // "do {} while (0)" is common in macros, avoid extra blocks. Be sure |
| // to correctly handle break/continue though. |
| bool EmitBoolCondBranch = true; |
| if (llvm::ConstantInt *C = dyn_cast<llvm::ConstantInt>(BoolCondVal)) |
| if (C->isZero()) |
| EmitBoolCondBranch = false; |
| |
| // As long as the condition is true, iterate the loop. |
| if (EmitBoolCondBranch) { |
| uint64_t BackedgeCount = getProfileCount(S.getBody()) - ParentCount; |
| Builder.CreateCondBr( |
| BoolCondVal, LoopBody, LoopExit.getBlock(), |
| createProfileWeightsForLoop(S.getCond(), BackedgeCount)); |
| } |
| |
| LoopStack.pop(); |
| |
| // Emit the exit block. |
| EmitBlock(LoopExit.getBlock()); |
| |
| // The DoCond block typically is just a branch if we skipped |
| // emitting a branch, try to erase it. |
| if (!EmitBoolCondBranch) |
| SimplifyForwardingBlocks(LoopCond.getBlock()); |
| } |
| |
| void CodeGenFunction::EmitForStmt(const ForStmt &S, |
| ArrayRef<const Attr *> ForAttrs) { |
| JumpDest LoopExit = getJumpDestInCurrentScope("for.end"); |
| |
| LexicalScope ForScope(*this, S.getSourceRange()); |
| |
| // Evaluate the first part before the loop. |
| if (S.getInit()) |
| EmitStmt(S.getInit()); |
| |
| // Start the loop with a block that tests the condition. |
| // If there's an increment, the continue scope will be overwritten |
| // later. |
| JumpDest Continue = getJumpDestInCurrentScope("for.cond"); |
| llvm::BasicBlock *CondBlock = Continue.getBlock(); |
| EmitBlock(CondBlock); |
| |
| const SourceRange &R = S.getSourceRange(); |
| LoopStack.push(CondBlock, CGM.getContext(), CGM.getCodeGenOpts(), ForAttrs, |
| SourceLocToDebugLoc(R.getBegin()), |
| SourceLocToDebugLoc(R.getEnd())); |
| |
| // If the for loop doesn't have an increment we can just use the |
| // condition as the continue block. Otherwise we'll need to create |
| // a block for it (in the current scope, i.e. in the scope of the |
| // condition), and that we will become our continue block. |
| if (S.getInc()) |
| Continue = getJumpDestInCurrentScope("for.inc"); |
| |
| // Store the blocks to use for break and continue. |
| BreakContinueStack.push_back(BreakContinue(LoopExit, Continue)); |
| |
| // Create a cleanup scope for the condition variable cleanups. |
| LexicalScope ConditionScope(*this, S.getSourceRange()); |
| |
| if (S.getCond()) { |
| // If the for statement has a condition scope, emit the local variable |
| // declaration. |
| if (S.getConditionVariable()) { |
| EmitDecl(*S.getConditionVariable()); |
| } |
| |
| llvm::BasicBlock *ExitBlock = LoopExit.getBlock(); |
| // If there are any cleanups between here and the loop-exit scope, |
| // create a block to stage a loop exit along. |
| if (ForScope.requiresCleanups()) |
| ExitBlock = createBasicBlock("for.cond.cleanup"); |
| |
| // As long as the condition is true, iterate the loop. |
| llvm::BasicBlock *ForBody = createBasicBlock("for.body"); |
| |
| // C99 6.8.5p2/p4: The first substatement is executed if the expression |
| // compares unequal to 0. The condition must be a scalar type. |
| llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond()); |
| Builder.CreateCondBr( |
| BoolCondVal, ForBody, ExitBlock, |
| createProfileWeightsForLoop(S.getCond(), getProfileCount(S.getBody()))); |
| |
| if (ExitBlock != LoopExit.getBlock()) { |
| EmitBlock(ExitBlock); |
| EmitBranchThroughCleanup(LoopExit); |
| } |
| |
| EmitBlock(ForBody); |
| } else { |
| // Treat it as a non-zero constant. Don't even create a new block for the |
| // body, just fall into it. |
| } |
| incrementProfileCounter(&S); |
| |
| { |
| // Create a separate cleanup scope for the body, in case it is not |
| // a compound statement. |
| RunCleanupsScope BodyScope(*this); |
| EmitStmt(S.getBody()); |
| } |
| |
| // If there is an increment, emit it next. |
| if (S.getInc()) { |
| EmitBlock(Continue.getBlock()); |
| EmitStmt(S.getInc()); |
| } |
| |
| BreakContinueStack.pop_back(); |
| |
| ConditionScope.ForceCleanup(); |
| |
| EmitStopPoint(&S); |
| EmitBranch(CondBlock); |
| |
| ForScope.ForceCleanup(); |
| |
| LoopStack.pop(); |
| |
| // Emit the fall-through block. |
| EmitBlock(LoopExit.getBlock(), true); |
| } |
| |
| void |
| CodeGenFunction::EmitCXXForRangeStmt(const CXXForRangeStmt &S, |
| ArrayRef<const Attr *> ForAttrs) { |
| JumpDest LoopExit = getJumpDestInCurrentScope("for.end"); |
| |
| LexicalScope ForScope(*this, S.getSourceRange()); |
| |
| // Evaluate the first pieces before the loop. |
| if (S.getInit()) |
| EmitStmt(S.getInit()); |
| EmitStmt(S.getRangeStmt()); |
| EmitStmt(S.getBeginStmt()); |
| EmitStmt(S.getEndStmt()); |
| |
| // Start the loop with a block that tests the condition. |
| // If there's an increment, the continue scope will be overwritten |
| // later. |
| llvm::BasicBlock *CondBlock = createBasicBlock("for.cond"); |
| EmitBlock(CondBlock); |
| |
| const SourceRange &R = S.getSourceRange(); |
| LoopStack.push(CondBlock, CGM.getContext(), CGM.getCodeGenOpts(), ForAttrs, |
| SourceLocToDebugLoc(R.getBegin()), |
| SourceLocToDebugLoc(R.getEnd())); |
| |
| // If there are any cleanups between here and the loop-exit scope, |
| // create a block to stage a loop exit along. |
| llvm::BasicBlock *ExitBlock = LoopExit.getBlock(); |
| if (ForScope.requiresCleanups()) |
| ExitBlock = createBasicBlock("for.cond.cleanup"); |
| |
| // The loop body, consisting of the specified body and the loop variable. |
| llvm::BasicBlock *ForBody = createBasicBlock("for.body"); |
| |
| // The body is executed if the expression, contextually converted |
| // to bool, is true. |
| llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond()); |
| Builder.CreateCondBr( |
| BoolCondVal, ForBody, ExitBlock, |
| createProfileWeightsForLoop(S.getCond(), getProfileCount(S.getBody()))); |
| |
| if (ExitBlock != LoopExit.getBlock()) { |
| EmitBlock(ExitBlock); |
| EmitBranchThroughCleanup(LoopExit); |
| } |
| |
| EmitBlock(ForBody); |
| incrementProfileCounter(&S); |
| |
| // Create a block for the increment. In case of a 'continue', we jump there. |
| JumpDest Continue = getJumpDestInCurrentScope("for.inc"); |
| |
| // Store the blocks to use for break and continue. |
| BreakContinueStack.push_back(BreakContinue(LoopExit, Continue)); |
| |
| { |
| // Create a separate cleanup scope for the loop variable and body. |
| LexicalScope BodyScope(*this, S.getSourceRange()); |
| EmitStmt(S.getLoopVarStmt()); |
| EmitStmt(S.getBody()); |
| } |
| |
| EmitStopPoint(&S); |
| // If there is an increment, emit it next. |
| EmitBlock(Continue.getBlock()); |
| EmitStmt(S.getInc()); |
| |
| BreakContinueStack.pop_back(); |
| |
| EmitBranch(CondBlock); |
| |
| ForScope.ForceCleanup(); |
| |
| LoopStack.pop(); |
| |
| // Emit the fall-through block. |
| EmitBlock(LoopExit.getBlock(), true); |
| } |
| |
| void CodeGenFunction::EmitReturnOfRValue(RValue RV, QualType Ty) { |
| if (RV.isScalar()) { |
| Builder.CreateStore(RV.getScalarVal(), ReturnValue); |
| } else if (RV.isAggregate()) { |
| LValue Dest = MakeAddrLValue(ReturnValue, Ty); |
| LValue Src = MakeAddrLValue(RV.getAggregateAddress(), Ty); |
| EmitAggregateCopy(Dest, Src, Ty, getOverlapForReturnValue()); |
| } else { |
| EmitStoreOfComplex(RV.getComplexVal(), MakeAddrLValue(ReturnValue, Ty), |
| /*init*/ true); |
| } |
| EmitBranchThroughCleanup(ReturnBlock); |
| } |
| |
| namespace { |
| // RAII struct used to save and restore a return statment's result expression. |
| struct SaveRetExprRAII { |
| SaveRetExprRAII(const Expr *RetExpr, CodeGenFunction &CGF) |
| : OldRetExpr(CGF.RetExpr), CGF(CGF) { |
| CGF.RetExpr = RetExpr; |
| } |
| ~SaveRetExprRAII() { CGF.RetExpr = OldRetExpr; } |
| const Expr *OldRetExpr; |
| CodeGenFunction &CGF; |
| }; |
| } // namespace |
| |
| /// EmitReturnStmt - Note that due to GCC extensions, this can have an operand |
| /// if the function returns void, or may be missing one if the function returns |
| /// non-void. Fun stuff :). |
| void CodeGenFunction::EmitReturnStmt(const ReturnStmt &S) { |
| if (requiresReturnValueCheck()) { |
| llvm::Constant *SLoc = EmitCheckSourceLocation(S.getBeginLoc()); |
| auto *SLocPtr = |
| new llvm::GlobalVariable(CGM.getModule(), SLoc->getType(), false, |
| llvm::GlobalVariable::PrivateLinkage, SLoc); |
| SLocPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); |
| CGM.getSanitizerMetadata()->disableSanitizerForGlobal(SLocPtr); |
| assert(ReturnLocation.isValid() && "No valid return location"); |
| Builder.CreateStore(Builder.CreateBitCast(SLocPtr, Int8PtrTy), |
| ReturnLocation); |
| } |
| |
| // Returning from an outlined SEH helper is UB, and we already warn on it. |
| if (IsOutlinedSEHHelper) { |
| Builder.CreateUnreachable(); |
| Builder.ClearInsertionPoint(); |
| } |
| |
| // Emit the result value, even if unused, to evaluate the side effects. |
| const Expr *RV = S.getRetValue(); |
| |
| // Record the result expression of the return statement. The recorded |
| // expression is used to determine whether a block capture's lifetime should |
| // end at the end of the full expression as opposed to the end of the scope |
| // enclosing the block expression. |
| // |
| // This permits a small, easily-implemented exception to our over-conservative |
| // rules about not jumping to statements following block literals with |
| // non-trivial cleanups. |
| SaveRetExprRAII SaveRetExpr(RV, *this); |
| |
| RunCleanupsScope cleanupScope(*this); |
| if (const auto *EWC = dyn_cast_or_null<ExprWithCleanups>(RV)) |
| RV = EWC->getSubExpr(); |
| // FIXME: Clean this up by using an LValue for ReturnTemp, |
| // EmitStoreThroughLValue, and EmitAnyExpr. |
| // Check if the NRVO candidate was not globalized in OpenMP mode. |
| if (getLangOpts().ElideConstructors && S.getNRVOCandidate() && |
| S.getNRVOCandidate()->isNRVOVariable() && |
| (!getLangOpts().OpenMP || |
| !CGM.getOpenMPRuntime() |
| .getAddressOfLocalVariable(*this, S.getNRVOCandidate()) |
| .isValid())) { |
| // Apply the named return value optimization for this return statement, |
| // which means doing nothing: the appropriate result has already been |
| // constructed into the NRVO variable. |
| |
| // If there is an NRVO flag for this variable, set it to 1 into indicate |
| // that the cleanup code should not destroy the variable. |
| if (llvm::Value *NRVOFlag = NRVOFlags[S.getNRVOCandidate()]) |
| Builder.CreateFlagStore(Builder.getTrue(), NRVOFlag); |
| } else if (!ReturnValue.isValid() || (RV && RV->getType()->isVoidType())) { |
| // Make sure not to return anything, but evaluate the expression |
| // for side effects. |
| if (RV) |
| EmitAnyExpr(RV); |
| } else if (!RV) { |
| // Do nothing (return value is left uninitialized) |
| } else if (FnRetTy->isReferenceType()) { |
| // If this function returns a reference, take the address of the expression |
| // rather than the value. |
| RValue Result = EmitReferenceBindingToExpr(RV); |
| Builder.CreateStore(Result.getScalarVal(), ReturnValue); |
| } else { |
| switch (getEvaluationKind(RV->getType())) { |
| case TEK_Scalar: |
| Builder.CreateStore(EmitScalarExpr(RV), ReturnValue); |
| break; |
| case TEK_Complex: |
| EmitComplexExprIntoLValue(RV, MakeAddrLValue(ReturnValue, RV->getType()), |
| /*isInit*/ true); |
| break; |
| case TEK_Aggregate: |
| EmitAggExpr(RV, AggValueSlot::forAddr( |
| ReturnValue, Qualifiers(), |
| AggValueSlot::IsDestructed, |
| AggValueSlot::DoesNotNeedGCBarriers, |
| AggValueSlot::IsNotAliased, |
| getOverlapForReturnValue())); |
| break; |
| } |
| } |
| |
| ++NumReturnExprs; |
| if (!RV || RV->isEvaluatable(getContext())) |
| ++NumSimpleReturnExprs; |
| |
| cleanupScope.ForceCleanup(); |
| EmitBranchThroughCleanup(ReturnBlock); |
| } |
| |
| void CodeGenFunction::EmitDeclStmt(const DeclStmt &S) { |
| // As long as debug info is modeled with instructions, we have to ensure we |
| // have a place to insert here and write the stop point here. |
| if (HaveInsertPoint()) |
| EmitStopPoint(&S); |
| |
| for (const auto *I : S.decls()) |
| EmitDecl(*I); |
| } |
| |
| void CodeGenFunction::EmitBreakStmt(const BreakStmt &S) { |
| assert(!BreakContinueStack.empty() && "break stmt not in a loop or switch!"); |
| |
| // If this code is reachable then emit a stop point (if generating |
| // debug info). We have to do this ourselves because we are on the |
| // "simple" statement path. |
| if (HaveInsertPoint()) |
| EmitStopPoint(&S); |
| |
| EmitBranchThroughCleanup(BreakContinueStack.back().BreakBlock); |
| } |
| |
| void CodeGenFunction::EmitContinueStmt(const ContinueStmt &S) { |
| assert(!BreakContinueStack.empty() && "continue stmt not in a loop!"); |
| |
| // If this code is reachable then emit a stop point (if generating |
| // debug info). We have to do this ourselves because we are on the |
| // "simple" statement path. |
| if (HaveInsertPoint()) |
| EmitStopPoint(&S); |
| |
| EmitBranchThroughCleanup(BreakContinueStack.back().ContinueBlock); |
| } |
| |
| /// EmitCaseStmtRange - If case statement range is not too big then |
| /// add multiple cases to switch instruction, one for each value within |
| /// the range. If range is too big then emit "if" condition check. |
| void CodeGenFunction::EmitCaseStmtRange(const CaseStmt &S) { |
| assert(S.getRHS() && "Expected RHS value in CaseStmt"); |
| |
| llvm::APSInt LHS = S.getLHS()->EvaluateKnownConstInt(getContext()); |
| llvm::APSInt RHS = S.getRHS()->EvaluateKnownConstInt(getContext()); |
| |
| // Emit the code for this case. We do this first to make sure it is |
| // properly chained from our predecessor before generating the |
| // switch machinery to enter this block. |
| llvm::BasicBlock *CaseDest = createBasicBlock("sw.bb"); |
| EmitBlockWithFallThrough(CaseDest, &S); |
| EmitStmt(S.getSubStmt()); |
| |
| // If range is empty, do nothing. |
| if (LHS.isSigned() ? RHS.slt(LHS) : RHS.ult(LHS)) |
| return; |
| |
| llvm::APInt Range = RHS - LHS; |
| // FIXME: parameters such as this should not be hardcoded. |
| if (Range.ult(llvm::APInt(Range.getBitWidth(), 64))) { |
| // Range is small enough to add multiple switch instruction cases. |
| uint64_t Total = getProfileCount(&S); |
| unsigned NCases = Range.getZExtValue() + 1; |
| // We only have one region counter for the entire set of cases here, so we |
| // need to divide the weights evenly between the generated cases, ensuring |
| // that the total weight is preserved. E.g., a weight of 5 over three cases |
| // will be distributed as weights of 2, 2, and 1. |
| uint64_t Weight = Total / NCases, Rem = Total % NCases; |
| for (unsigned I = 0; I != NCases; ++I) { |
| if (SwitchWeights) |
| SwitchWeights->push_back(Weight + (Rem ? 1 : 0)); |
| if (Rem) |
| Rem--; |
| SwitchInsn->addCase(Builder.getInt(LHS), CaseDest); |
| ++LHS; |
| } |
| return; |
| } |
| |
| // The range is too big. Emit "if" condition into a new block, |
| // making sure to save and restore the current insertion point. |
| llvm::BasicBlock *RestoreBB = Builder.GetInsertBlock(); |
| |
| // Push this test onto the chain of range checks (which terminates |
| // in the default basic block). The switch's default will be changed |
| // to the top of this chain after switch emission is complete. |
| llvm::BasicBlock *FalseDest = CaseRangeBlock; |
| CaseRangeBlock = createBasicBlock("sw.caserange"); |
| |
| CurFn->getBasicBlockList().push_back(CaseRangeBlock); |
| Builder.SetInsertPoint(CaseRangeBlock); |
| |
| // Emit range check. |
| llvm::Value *Diff = |
| Builder.CreateSub(SwitchInsn->getCondition(), Builder.getInt(LHS)); |
| llvm::Value *Cond = |
| Builder.CreateICmpULE(Diff, Builder.getInt(Range), "inbounds"); |
| |
| llvm::MDNode *Weights = nullptr; |
| if (SwitchWeights) { |
| uint64_t ThisCount = getProfileCount(&S); |
| uint64_t DefaultCount = (*SwitchWeights)[0]; |
| Weights = createProfileWeights(ThisCount, DefaultCount); |
| |
| // Since we're chaining the switch default through each large case range, we |
| // need to update the weight for the default, ie, the first case, to include |
| // this case. |
| (*SwitchWeights)[0] += ThisCount; |
| } |
| Builder.CreateCondBr(Cond, CaseDest, FalseDest, Weights); |
| |
| // Restore the appropriate insertion point. |
| if (RestoreBB) |
| Builder.SetInsertPoint(RestoreBB); |
| else |
| Builder.ClearInsertionPoint(); |
| } |
| |
| void CodeGenFunction::EmitCaseStmt(const CaseStmt &S) { |
| // If there is no enclosing switch instance that we're aware of, then this |
| // case statement and its block can be elided. This situation only happens |
| // when we've constant-folded the switch, are emitting the constant case, |
| // and part of the constant case includes another case statement. For |
| // instance: switch (4) { case 4: do { case 5: } while (1); } |
| if (!SwitchInsn) { |
| EmitStmt(S.getSubStmt()); |
| return; |
| } |
| |
| // Handle case ranges. |
| if (S.getRHS()) { |
| EmitCaseStmtRange(S); |
| return; |
| } |
| |
| llvm::ConstantInt *CaseVal = |
| Builder.getInt(S.getLHS()->EvaluateKnownConstInt(getContext())); |
| |
| // If the body of the case is just a 'break', try to not emit an empty block. |
| // If we're profiling or we're not optimizing, leave the block in for better |
| // debug and coverage analysis. |
| if (!CGM.getCodeGenOpts().hasProfileClangInstr() && |
| CGM.getCodeGenOpts().OptimizationLevel > 0 && |
| isa<BreakStmt>(S.getSubStmt())) { |
| JumpDest Block = BreakContinueStack.back().BreakBlock; |
| |
| // Only do this optimization if there are no cleanups that need emitting. |
| if (isObviouslyBranchWithoutCleanups(Block)) { |
| if (SwitchWeights) |
| SwitchWeights->push_back(getProfileCount(&S)); |
| SwitchInsn->addCase(CaseVal, Block.getBlock()); |
| |
| // If there was a fallthrough into this case, make sure to redirect it to |
| // the end of the switch as well. |
| if (Builder.GetInsertBlock()) { |
| Builder.CreateBr(Block.getBlock()); |
| Builder.ClearInsertionPoint(); |
| } |
| return; |
| } |
| } |
| |
| llvm::BasicBlock *CaseDest = createBasicBlock("sw.bb"); |
| EmitBlockWithFallThrough(CaseDest, &S); |
| if (SwitchWeights) |
| SwitchWeights->push_back(getProfileCount(&S)); |
| SwitchInsn->addCase(CaseVal, CaseDest); |
| |
| // Recursively emitting the statement is acceptable, but is not wonderful for |
| // code where we have many case statements nested together, i.e.: |
| // case 1: |
| // case 2: |
| // case 3: etc. |
| // Handling this recursively will create a new block for each case statement |
| // that falls through to the next case which is IR intensive. It also causes |
| // deep recursion which can run into stack depth limitations. Handle |
| // sequential non-range case statements specially. |
| const CaseStmt *CurCase = &S; |
| const CaseStmt *NextCase = dyn_cast<CaseStmt>(S.getSubStmt()); |
| |
| // Otherwise, iteratively add consecutive cases to this switch stmt. |
| while (NextCase && NextCase->getRHS() == nullptr) { |
| CurCase = NextCase; |
| llvm::ConstantInt *CaseVal = |
| Builder.getInt(CurCase->getLHS()->EvaluateKnownConstInt(getContext())); |
| |
| if (SwitchWeights) |
| SwitchWeights->push_back(getProfileCount(NextCase)); |
| if (CGM.getCodeGenOpts().hasProfileClangInstr()) { |
| CaseDest = createBasicBlock("sw.bb"); |
| EmitBlockWithFallThrough(CaseDest, &S); |
| } |
| |
| SwitchInsn->addCase(CaseVal, CaseDest); |
| NextCase = dyn_cast<CaseStmt>(CurCase->getSubStmt()); |
| } |
| |
| // Normal default recursion for non-cases. |
| EmitStmt(CurCase->getSubStmt()); |
| } |
| |
| void CodeGenFunction::EmitDefaultStmt(const DefaultStmt &S) { |
| // If there is no enclosing switch instance that we're aware of, then this |
| // default statement can be elided. This situation only happens when we've |
| // constant-folded the switch. |
| if (!SwitchInsn) { |
| EmitStmt(S.getSubStmt()); |
| return; |
| } |
| |
| llvm::BasicBlock *DefaultBlock = SwitchInsn->getDefaultDest(); |
| assert(DefaultBlock->empty() && |
| "EmitDefaultStmt: Default block already defined?"); |
| |
| EmitBlockWithFallThrough(DefaultBlock, &S); |
| |
| EmitStmt(S.getSubStmt()); |
| } |
| |
| /// CollectStatementsForCase - Given the body of a 'switch' statement and a |
| /// constant value that is being switched on, see if we can dead code eliminate |
| /// the body of the switch to a simple series of statements to emit. Basically, |
| /// on a switch (5) we want to find these statements: |
| /// case 5: |
| /// printf(...); <-- |
| /// ++i; <-- |
| /// break; |
| /// |
| /// and add them to the ResultStmts vector. If it is unsafe to do this |
| /// transformation (for example, one of the elided statements contains a label |
| /// that might be jumped to), return CSFC_Failure. If we handled it and 'S' |
| /// should include statements after it (e.g. the printf() line is a substmt of |
| /// the case) then return CSFC_FallThrough. If we handled it and found a break |
| /// statement, then return CSFC_Success. |
| /// |
| /// If Case is non-null, then we are looking for the specified case, checking |
| /// that nothing we jump over contains labels. If Case is null, then we found |
| /// the case and are looking for the break. |
| /// |
| /// If the recursive walk actually finds our Case, then we set FoundCase to |
| /// true. |
| /// |
| enum CSFC_Result { CSFC_Failure, CSFC_FallThrough, CSFC_Success }; |
| static CSFC_Result CollectStatementsForCase(const Stmt *S, |
| const SwitchCase *Case, |
| bool &FoundCase, |
| SmallVectorImpl<const Stmt*> &ResultStmts) { |
| // If this is a null statement, just succeed. |
| if (!S) |
| return Case ? CSFC_Success : CSFC_FallThrough; |
| |
| // If this is the switchcase (case 4: or default) that we're looking for, then |
| // we're in business. Just add the substatement. |
| if (const SwitchCase *SC = dyn_cast<SwitchCase>(S)) { |
| if (S == Case) { |
| FoundCase = true; |
| return CollectStatementsForCase(SC->getSubStmt(), nullptr, FoundCase, |
| ResultStmts); |
| } |
| |
| // Otherwise, this is some other case or default statement, just ignore it. |
| return CollectStatementsForCase(SC->getSubStmt(), Case, FoundCase, |
| ResultStmts); |
| } |
| |
| // If we are in the live part of the code and we found our break statement, |
| // return a success! |
| if (!Case && isa<BreakStmt>(S)) |
| return CSFC_Success; |
| |
| // If this is a switch statement, then it might contain the SwitchCase, the |
| // break, or neither. |
| if (const CompoundStmt *CS = dyn_cast<CompoundStmt>(S)) { |
| // Handle this as two cases: we might be looking for the SwitchCase (if so |
| // the skipped statements must be skippable) or we might already have it. |
| CompoundStmt::const_body_iterator I = CS->body_begin(), E = CS->body_end(); |
| bool StartedInLiveCode = FoundCase; |
| unsigned StartSize = ResultStmts.size(); |
| |
| // If we've not found the case yet, scan through looking for it. |
| if (Case) { |
| // Keep track of whether we see a skipped declaration. The code could be |
| // using the declaration even if it is skipped, so we can't optimize out |
| // the decl if the kept statements might refer to it. |
| bool HadSkippedDecl = false; |
| |
| // If we're looking for the case, just see if we can skip each of the |
| // substatements. |
| for (; Case && I != E; ++I) { |
| HadSkippedDecl |= CodeGenFunction::mightAddDeclToScope(*I); |
| |
| switch (CollectStatementsForCase(*I, Case, FoundCase, ResultStmts)) { |
| case CSFC_Failure: return CSFC_Failure; |
| case CSFC_Success: |
| // A successful result means that either 1) that the statement doesn't |
| // have the case and is skippable, or 2) does contain the case value |
| // and also contains the break to exit the switch. In the later case, |
| // we just verify the rest of the statements are elidable. |
| if (FoundCase) { |
| // If we found the case and skipped declarations, we can't do the |
| // optimization. |
| if (HadSkippedDecl) |
| return CSFC_Failure; |
| |
| for (++I; I != E; ++I) |
| if (CodeGenFunction::ContainsLabel(*I, true)) |
| return CSFC_Failure; |
| return CSFC_Success; |
| } |
| break; |
| case CSFC_FallThrough: |
| // If we have a fallthrough condition, then we must have found the |
| // case started to include statements. Consider the rest of the |
| // statements in the compound statement as candidates for inclusion. |
| assert(FoundCase && "Didn't find case but returned fallthrough?"); |
| // We recursively found Case, so we're not looking for it anymore. |
| Case = nullptr; |
| |
| // If we found the case and skipped declarations, we can't do the |
| // optimization. |
| if (HadSkippedDecl) |
| return CSFC_Failure; |
| break; |
| } |
| } |
| |
| if (!FoundCase) |
| return CSFC_Success; |
| |
| assert(!HadSkippedDecl && "fallthrough after skipping decl"); |
| } |
| |
| // If we have statements in our range, then we know that the statements are |
| // live and need to be added to the set of statements we're tracking. |
| bool AnyDecls = false; |
| for (; I != E; ++I) { |
| AnyDecls |= CodeGenFunction::mightAddDeclToScope(*I); |
| |
| switch (CollectStatementsForCase(*I, nullptr, FoundCase, ResultStmts)) { |
| case CSFC_Failure: return CSFC_Failure; |
| case CSFC_FallThrough: |
| // A fallthrough result means that the statement was simple and just |
| // included in ResultStmt, keep adding them afterwards. |
| break; |
| case CSFC_Success: |
| // A successful result means that we found the break statement and |
| // stopped statement inclusion. We just ensure that any leftover stmts |
| // are skippable and return success ourselves. |
| for (++I; I != E; ++I) |
| if (CodeGenFunction::ContainsLabel(*I, true)) |
| return CSFC_Failure; |
| return CSFC_Success; |
| } |
| } |
| |
| // If we're about to fall out of a scope without hitting a 'break;', we |
| // can't perform the optimization if there were any decls in that scope |
| // (we'd lose their end-of-lifetime). |
| if (AnyDecls) { |
| // If the entire compound statement was live, there's one more thing we |
| // can try before giving up: emit the whole thing as a single statement. |
| // We can do that unless the statement contains a 'break;'. |
| // FIXME: Such a break must be at the end of a construct within this one. |
| // We could emit this by just ignoring the BreakStmts entirely. |
| if (StartedInLiveCode && !CodeGenFunction::containsBreak(S)) { |
| ResultStmts.resize(StartSize); |
| ResultStmts.push_back(S); |
| } else { |
| return CSFC_Failure; |
| } |
| } |
| |
| return CSFC_FallThrough; |
| } |
| |
| // Okay, this is some other statement that we don't handle explicitly, like a |
| // for statement or increment etc. If we are skipping over this statement, |
| // just verify it doesn't have labels, which would make it invalid to elide. |
| if (Case) { |
| if (CodeGenFunction::ContainsLabel(S, true)) |
| return CSFC_Failure; |
| return CSFC_Success; |
| } |
| |
| // Otherwise, we want to include this statement. Everything is cool with that |
| // so long as it doesn't contain a break out of the switch we're in. |
| if (CodeGenFunction::containsBreak(S)) return CSFC_Failure; |
| |
| // Otherwise, everything is great. Include the statement and tell the caller |
| // that we fall through and include the next statement as well. |
| ResultStmts.push_back(S); |
| return CSFC_FallThrough; |
| } |
| |
| /// FindCaseStatementsForValue - Find the case statement being jumped to and |
| /// then invoke CollectStatementsForCase to find the list of statements to emit |
| /// for a switch on constant. See the comment above CollectStatementsForCase |
| /// for more details. |
| static bool FindCaseStatementsForValue(const SwitchStmt &S, |
| const llvm::APSInt &ConstantCondValue, |
| SmallVectorImpl<const Stmt*> &ResultStmts, |
| ASTContext &C, |
| const SwitchCase *&ResultCase) { |
| // First step, find the switch case that is being branched to. We can do this |
| // efficiently by scanning the SwitchCase list. |
| const SwitchCase *Case = S.getSwitchCaseList(); |
| const DefaultStmt *DefaultCase = nullptr; |
| |
| for (; Case; Case = Case->getNextSwitchCase()) { |
| // It's either a default or case. Just remember the default statement in |
| // case we're not jumping to any numbered cases. |
| if (const DefaultStmt *DS = dyn_cast<DefaultStmt>(Case)) { |
| DefaultCase = DS; |
| continue; |
| } |
| |
| // Check to see if this case is the one we're looking for. |
| const CaseStmt *CS = cast<CaseStmt>(Case); |
| // Don't handle case ranges yet. |
| if (CS->getRHS()) return false; |
| |
| // If we found our case, remember it as 'case'. |
| if (CS->getLHS()->EvaluateKnownConstInt(C) == ConstantCondValue) |
| break; |
| } |
| |
| // If we didn't find a matching case, we use a default if it exists, or we |
| // elide the whole switch body! |
| if (!Case) { |
| // It is safe to elide the body of the switch if it doesn't contain labels |
| // etc. If it is safe, return successfully with an empty ResultStmts list. |
| if (!DefaultCase) |
| return !CodeGenFunction::ContainsLabel(&S); |
| Case = DefaultCase; |
| } |
| |
| // Ok, we know which case is being jumped to, try to collect all the |
| // statements that follow it. This can fail for a variety of reasons. Also, |
| // check to see that the recursive walk actually found our case statement. |
| // Insane cases like this can fail to find it in the recursive walk since we |
| // don't handle every stmt kind: |
| // switch (4) { |
| // while (1) { |
| // case 4: ... |
| bool FoundCase = false; |
| ResultCase = Case; |
| return CollectStatementsForCase(S.getBody(), Case, FoundCase, |
| ResultStmts) != CSFC_Failure && |
| FoundCase; |
| } |
| |
| void CodeGenFunction::EmitSwitchStmt(const SwitchStmt &S) { |
| // Handle nested switch statements. |
| llvm::SwitchInst *SavedSwitchInsn = SwitchInsn; |
| SmallVector<uint64_t, 16> *SavedSwitchWeights = SwitchWeights; |
| llvm::BasicBlock *SavedCRBlock = CaseRangeBlock; |
| |
| // See if we can constant fold the condition of the switch and therefore only |
| // emit the live case statement (if any) of the switch. |
| llvm::APSInt ConstantCondValue; |
| if (ConstantFoldsToSimpleInteger(S.getCond(), ConstantCondValue)) { |
| SmallVector<const Stmt*, 4> CaseStmts; |
| const SwitchCase *Case = nullptr; |
| if (FindCaseStatementsForValue(S, ConstantCondValue, CaseStmts, |
| getContext(), Case)) { |
| if (Case) |
| incrementProfileCounter(Case); |
| RunCleanupsScope ExecutedScope(*this); |
| |
| if (S.getInit()) |
| EmitStmt(S.getInit()); |
| |
| // Emit the condition variable if needed inside the entire cleanup scope |
| // used by this special case for constant folded switches. |
| if (S.getConditionVariable()) |
| EmitDecl(*S.getConditionVariable()); |
| |
| // At this point, we are no longer "within" a switch instance, so |
| // we can temporarily enforce this to ensure that any embedded case |
| // statements are not emitted. |
| SwitchInsn = nullptr; |
| |
| // Okay, we can dead code eliminate everything except this case. Emit the |
| // specified series of statements and we're good. |
| for (unsigned i = 0, e = CaseStmts.size(); i != e; ++i) |
| EmitStmt(CaseStmts[i]); |
| incrementProfileCounter(&S); |
| |
| // Now we want to restore the saved switch instance so that nested |
| // switches continue to function properly |
| SwitchInsn = SavedSwitchInsn; |
| |
| return; |
| } |
| } |
| |
| JumpDest SwitchExit = getJumpDestInCurrentScope("sw.epilog"); |
| |
| RunCleanupsScope ConditionScope(*this); |
| |
| if (S.getInit()) |
| EmitStmt(S.getInit()); |
| |
| if (S.getConditionVariable()) |
| EmitDecl(*S.getConditionVariable()); |
| llvm::Value *CondV = EmitScalarExpr(S.getCond()); |
| |
| // Create basic block to hold stuff that comes after switch |
| // statement. We also need to create a default block now so that |
| // explicit case ranges tests can have a place to jump to on |
| // failure. |
| llvm::BasicBlock *DefaultBlock = createBasicBlock("sw.default"); |
| SwitchInsn = Builder.CreateSwitch(CondV, DefaultBlock); |
| if (PGO.haveRegionCounts()) { |
| // Walk the SwitchCase list to find how many there are. |
| uint64_t DefaultCount = 0; |
| unsigned NumCases = 0; |
| for (const SwitchCase *Case = S.getSwitchCaseList(); |
| Case; |
| Case = Case->getNextSwitchCase()) { |
| if (isa<DefaultStmt>(Case)) |
| DefaultCount = getProfileCount(Case); |
| NumCases += 1; |
| } |
| SwitchWeights = new SmallVector<uint64_t, 16>(); |
| SwitchWeights->reserve(NumCases); |
| // The default needs to be first. We store the edge count, so we already |
| // know the right weight. |
| SwitchWeights->push_back(DefaultCount); |
| } |
| CaseRangeBlock = DefaultBlock; |
| |
| // Clear the insertion point to indicate we are in unreachable code. |
| Builder.ClearInsertionPoint(); |
| |
| // All break statements jump to NextBlock. If BreakContinueStack is non-empty |
| // then reuse last ContinueBlock. |
| JumpDest OuterContinue; |
| if (!BreakContinueStack.empty()) |
| OuterContinue = BreakContinueStack.back().ContinueBlock; |
| |
| BreakContinueStack.push_back(BreakContinue(SwitchExit, OuterContinue)); |
| |
| // Emit switch body. |
| EmitStmt(S.getBody()); |
| |
| BreakContinueStack.pop_back(); |
| |
| // Update the default block in case explicit case range tests have |
| // been chained on top. |
| SwitchInsn->setDefaultDest(CaseRangeBlock); |
| |
| // If a default was never emitted: |
| if (!DefaultBlock->getParent()) { |
| // If we have cleanups, emit the default block so that there's a |
| // place to jump through the cleanups from. |
| if (ConditionScope.requiresCleanups()) { |
| EmitBlock(DefaultBlock); |
| |
| // Otherwise, just forward the default block to the switch end. |
| } else { |
| DefaultBlock->replaceAllUsesWith(SwitchExit.getBlock()); |
| delete DefaultBlock; |
| } |
| } |
| |
| ConditionScope.ForceCleanup(); |
| |
| // Emit continuation. |
| EmitBlock(SwitchExit.getBlock(), true); |
| incrementProfileCounter(&S); |
| |
| // If the switch has a condition wrapped by __builtin_unpredictable, |
| // create metadata that specifies that the switch is unpredictable. |
| // Don't bother if not optimizing because that metadata would not be used. |
| auto *Call = dyn_cast<CallExpr>(S.getCond()); |
| if (Call && CGM.getCodeGenOpts().OptimizationLevel != 0) { |
| auto *FD = dyn_cast_or_null<FunctionDecl>(Call->getCalleeDecl()); |
| if (FD && FD->getBuiltinID() == Builtin::BI__builtin_unpredictable) { |
| llvm::MDBuilder MDHelper(getLLVMContext()); |
| SwitchInsn->setMetadata(llvm::LLVMContext::MD_unpredictable, |
| MDHelper.createUnpredictable()); |
| } |
| } |
| |
| if (SwitchWeights) { |
| assert(SwitchWeights->size() == 1 + SwitchInsn->getNumCases() && |
| "switch weights do not match switch cases"); |
| // If there's only one jump destination there's no sense weighting it. |
| if (SwitchWeights->size() > 1) |
| SwitchInsn->setMetadata(llvm::LLVMContext::MD_prof, |
| createProfileWeights(*SwitchWeights)); |
| delete SwitchWeights; |
| } |
| SwitchInsn = SavedSwitchInsn; |
| SwitchWeights = SavedSwitchWeights; |
| CaseRangeBlock = SavedCRBlock; |
| } |
| |
| static std::string |
| SimplifyConstraint(const char *Constraint, const TargetInfo &Target, |
| SmallVectorImpl<TargetInfo::ConstraintInfo> *OutCons=nullptr) { |
| std::string Result; |
| |
| while (*Constraint) { |
| switch (*Constraint) { |
| default: |
| Result += Target.convertConstraint(Constraint); |
| break; |
| // Ignore these |
| case '*': |
| case '?': |
| case '!': |
| case '=': // Will see this and the following in mult-alt constraints. |
| case '+': |
| break; |
| case '#': // Ignore the rest of the constraint alternative. |
| while (Constraint[1] && Constraint[1] != ',') |
| Constraint++; |
| break; |
| case '&': |
| case '%': |
| Result += *Constraint; |
| while (Constraint[1] && Constraint[1] == *Constraint) |
| Constraint++; |
| break; |
| case ',': |
| Result += "|"; |
| break; |
| case 'g': |
| Result += "imr"; |
| break; |
| case '[': { |
| assert(OutCons && |
| "Must pass output names to constraints with a symbolic name"); |
| unsigned Index; |
| bool result = Target.resolveSymbolicName(Constraint, *OutCons, Index); |
| assert(result && "Could not resolve symbolic name"); (void)result; |
| Result += llvm::utostr(Index); |
| break; |
| } |
| } |
| |
| Constraint++; |
| } |
| |
| return Result; |
| } |
| |
| /// AddVariableConstraints - Look at AsmExpr and if it is a variable declared |
| /// as using a particular register add that as a constraint that will be used |
| /// in this asm stmt. |
| static std::string |
| AddVariableConstraints(const std::string &Constraint, const Expr &AsmExpr, |
| const TargetInfo &Target, CodeGenModule &CGM, |
| const AsmStmt &Stmt, const bool EarlyClobber) { |
| const DeclRefExpr *AsmDeclRef = dyn_cast<DeclRefExpr>(&AsmExpr); |
| if (!AsmDeclRef) |
| return Constraint; |
| const ValueDecl &Value = *AsmDeclRef->getDecl(); |
| const VarDecl *Variable = dyn_cast<VarDecl>(&Value); |
| if (!Variable) |
| return Constraint; |
| if (Variable->getStorageClass() != SC_Register) |
| return Constraint; |
| AsmLabelAttr *Attr = Variable->getAttr<AsmLabelAttr>(); |
| if (!Attr) |
| return Constraint; |
| StringRef Register = Attr->getLabel(); |
| assert(Target.isValidGCCRegisterName(Register)); |
| // We're using validateOutputConstraint here because we only care if |
| // this is a register constraint. |
| TargetInfo::ConstraintInfo Info(Constraint, ""); |
| if (Target.validateOutputConstraint(Info) && |
| !Info.allowsRegister()) { |
| CGM.ErrorUnsupported(&Stmt, "__asm__"); |
| return Constraint; |
| } |
| // Canonicalize the register here before returning it. |
| Register = Target.getNormalizedGCCRegisterName(Register); |
| return (EarlyClobber ? "&{" : "{") + Register.str() + "}"; |
| } |
| |
| llvm::Value* |
| CodeGenFunction::EmitAsmInputLValue(const TargetInfo::ConstraintInfo &Info, |
| LValue InputValue, QualType InputType, |
| std::string &ConstraintStr, |
| SourceLocation Loc) { |
| llvm::Value *Arg; |
| if (Info.allowsRegister() || !Info.allowsMemory()) { |
| if (CodeGenFunction::hasScalarEvaluationKind(InputType)) { |
| Arg = EmitLoadOfLValue(InputValue, Loc).getScalarVal(); |
| } else { |
| llvm::Type *Ty = ConvertType(InputType); |
| uint64_t Size = CGM.getDataLayout().getTypeSizeInBits(Ty); |
| if (Size <= 64 && llvm::isPowerOf2_64(Size)) { |
| Ty = llvm::IntegerType::get(getLLVMContext(), Size); |
| Ty = llvm::PointerType::getUnqual(Ty); |
| |
| Arg = Builder.CreateLoad( |
| Builder.CreateBitCast(InputValue.getAddress(*this), Ty)); |
| } else { |
| Arg = InputValue.getPointer(*this); |
| ConstraintStr += '*'; |
| } |
| } |
| } else { |
| Arg = InputValue.getPointer(*this); |
| ConstraintStr += '*'; |
| } |
| |
| return Arg; |
| } |
| |
| llvm::Value* CodeGenFunction::EmitAsmInput( |
| const TargetInfo::ConstraintInfo &Info, |
| const Expr *InputExpr, |
| std::string &ConstraintStr) { |
| // If this can't be a register or memory, i.e., has to be a constant |
| // (immediate or symbolic), try to emit it as such. |
| if (!Info.allowsRegister() && !Info.allowsMemory()) { |
| if (Info.requiresImmediateConstant()) { |
| Expr::EvalResult EVResult; |
| InputExpr->EvaluateAsRValue(EVResult, getContext(), true); |
| |
| llvm::APSInt IntResult; |
| if (EVResult.Val.toIntegralConstant(IntResult, InputExpr->getType(), |
| getContext())) |
| return llvm::ConstantInt::get(getLLVMContext(), IntResult); |
| } |
| |
| Expr::EvalResult Result; |
| if (InputExpr->EvaluateAsInt(Result, getContext())) |
| return llvm::ConstantInt::get(getLLVMContext(), Result.Val.getInt()); |
| } |
| |
| if (Info.allowsRegister() || !Info.allowsMemory()) |
| if (CodeGenFunction::hasScalarEvaluationKind(InputExpr->getType())) |
| return EmitScalarExpr(InputExpr); |
| if (InputExpr->getStmtClass() == Expr::CXXThisExprClass) |
| return EmitScalarExpr(InputExpr); |
| InputExpr = InputExpr->IgnoreParenNoopCasts(getContext()); |
| LValue Dest = EmitLValue(InputExpr); |
| return EmitAsmInputLValue(Info, Dest, InputExpr->getType(), ConstraintStr, |
| InputExpr->getExprLoc()); |
| } |
| |
| /// getAsmSrcLocInfo - Return the !srcloc metadata node to attach to an inline |
| /// asm call instruction. The !srcloc MDNode contains a list of constant |
| /// integers which are the source locations of the start of each line in the |
| /// asm. |
| static llvm::MDNode *getAsmSrcLocInfo(const StringLiteral *Str, |
| CodeGenFunction &CGF) { |
| SmallVector<llvm::Metadata *, 8> Locs; |
| // Add the location of the first line to the MDNode. |
| Locs.push_back(llvm::ConstantAsMetadata::get(llvm::ConstantInt::get( |
| CGF.Int32Ty, Str->getBeginLoc().getRawEncoding()))); |
| StringRef StrVal = Str->getString(); |
| if (!StrVal.empty()) { |
| const SourceManager &SM = CGF.CGM.getContext().getSourceManager(); |
| const LangOptions &LangOpts = CGF.CGM.getLangOpts(); |
| unsigned StartToken = 0; |
| unsigned ByteOffset = 0; |
| |
| // Add the location of the start of each subsequent line of the asm to the |
| // MDNode. |
| for (unsigned i = 0, e = StrVal.size() - 1; i != e; ++i) { |
| if (StrVal[i] != '\n') continue; |
| SourceLocation LineLoc = Str->getLocationOfByte( |
| i + 1, SM, LangOpts, CGF.getTarget(), &StartToken, &ByteOffset); |
| Locs.push_back(llvm::ConstantAsMetadata::get( |
| llvm::ConstantInt::get(CGF.Int32Ty, LineLoc.getRawEncoding()))); |
| } |
| } |
| |
| return llvm::MDNode::get(CGF.getLLVMContext(), Locs); |
| } |
| |
| static void UpdateAsmCallInst(llvm::CallBase &Result, bool HasSideEffect, |
| bool ReadOnly, bool ReadNone, bool NoMerge, |
| const AsmStmt &S, |
| const std::vector<llvm::Type *> &ResultRegTypes, |
| CodeGenFunction &CGF, |
| std::vector<llvm::Value *> &RegResults) { |
| Result.addAttribute(llvm::AttributeList::FunctionIndex, |
| llvm::Attribute::NoUnwind); |
| if (NoMerge) |
| Result.addAttribute(llvm::AttributeList::FunctionIndex, |
| llvm::Attribute::NoMerge); |
| // Attach readnone and readonly attributes. |
| if (!HasSideEffect) { |
| if (ReadNone) |
| Result.addAttribute(llvm::AttributeList::FunctionIndex, |
| llvm::Attribute::ReadNone); |
| else if (ReadOnly) |
| Result.addAttribute(llvm::AttributeList::FunctionIndex, |
| llvm::Attribute::ReadOnly); |
| } |
| |
| // Slap the source location of the inline asm into a !srcloc metadata on the |
| // call. |
| if (const auto *gccAsmStmt = dyn_cast<GCCAsmStmt>(&S)) |
| Result.setMetadata("srcloc", |
| getAsmSrcLocInfo(gccAsmStmt->getAsmString(), CGF)); |
| else { |
| // At least put the line number on MS inline asm blobs. |
| llvm::Constant *Loc = llvm::ConstantInt::get(CGF.Int32Ty, |
| S.getAsmLoc().getRawEncoding()); |
| Result.setMetadata("srcloc", |
| llvm::MDNode::get(CGF.getLLVMContext(), |
| llvm::ConstantAsMetadata::get(Loc))); |
| } |
| |
| if (CGF.getLangOpts().assumeFunctionsAreConvergent()) |
| // Conservatively, mark all inline asm blocks in CUDA or OpenCL as |
| // convergent (meaning, they may call an intrinsically convergent op, such |
| // as bar.sync, and so can't have certain optimizations applied around |
| // them). |
| Result.addAttribute(llvm::AttributeList::FunctionIndex, |
| llvm::Attribute::Convergent); |
| // Extract all of the register value results from the asm. |
| if (ResultRegTypes.size() == 1) { |
| RegResults.push_back(&Result); |
| } else { |
| for (unsigned i = 0, e = ResultRegTypes.size(); i != e; ++i) { |
| llvm::Value *Tmp = CGF.Builder.CreateExtractValue(&Result, i, "asmresult"); |
| RegResults.push_back(Tmp); |
| } |
| } |
| } |
| |
| void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) { |
| // Assemble the final asm string. |
| std::string AsmString = S.generateAsmString(getContext()); |
| |
| // Get all the output and input constraints together. |
| SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; |
| SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; |
| |
| for (unsigned i = 0, e = S.getNumOutputs(); i != e; i++) { |
| StringRef Name; |
| if (const GCCAsmStmt *GAS = dyn_cast<GCCAsmStmt>(&S)) |
| Name = GAS->getOutputName(i); |
| TargetInfo::ConstraintInfo Info(S.getOutputConstraint(i), Name); |
| bool IsValid = getTarget().validateOutputConstraint(Info); (void)IsValid; |
| assert(IsValid && "Failed to parse output constraint"); |
| OutputConstraintInfos.push_back(Info); |
| } |
| |
| for (unsigned i = 0, e = S.getNumInputs(); i != e; i++) { |
| StringRef Name; |
| if (const GCCAsmStmt *GAS = dyn_cast<GCCAsmStmt>(&S)) |
| Name = GAS->getInputName(i); |
| TargetInfo::ConstraintInfo Info(S.getInputConstraint(i), Name); |
| bool IsValid = |
| getTarget().validateInputConstraint(OutputConstraintInfos, Info); |
| assert(IsValid && "Failed to parse input constraint"); (void)IsValid; |
| InputConstraintInfos.push_back(Info); |
| } |
| |
| std::string Constraints; |
| |
| std::vector<LValue> ResultRegDests; |
| std::vector<QualType> ResultRegQualTys; |
| std::vector<llvm::Type *> ResultRegTypes; |
| std::vector<llvm::Type *> ResultTruncRegTypes; |
| std::vector<llvm::Type *> ArgTypes; |
| std::vector<llvm::Value*> Args; |
| llvm::BitVector ResultTypeRequiresCast; |
| |
| // Keep track of inout constraints. |
| std::string InOutConstraints; |
| std::vector<llvm::Value*> InOutArgs; |
| std::vector<llvm::Type*> InOutArgTypes; |
| |
| // Keep track of out constraints for tied input operand. |
| std::vector<std::string> OutputConstraints; |
| |
| // An inline asm can be marked readonly if it meets the following conditions: |
| // - it doesn't have any sideeffects |
| // - it doesn't clobber memory |
| // - it doesn't return a value by-reference |
| // It can be marked readnone if it doesn't have any input memory constraints |
| // in addition to meeting the conditions listed above. |
| bool ReadOnly = true, ReadNone = true; |
| |
| for (unsigned i = 0, e = S.getNumOutputs(); i != e; i++) { |
| TargetInfo::ConstraintInfo &Info = OutputConstraintInfos[i]; |
| |
| // Simplify the output constraint. |
| std::string OutputConstraint(S.getOutputConstraint(i)); |
| OutputConstraint = SimplifyConstraint(OutputConstraint.c_str() + 1, |
| getTarget(), &OutputConstraintInfos); |
| |
| const Expr *OutExpr = S.getOutputExpr(i); |
| OutExpr = OutExpr->IgnoreParenNoopCasts(getContext()); |
| |
| OutputConstraint = AddVariableConstraints(OutputConstraint, *OutExpr, |
| getTarget(), CGM, S, |
| Info.earlyClobber()); |
| OutputConstraints.push_back(OutputConstraint); |
| LValue Dest = EmitLValue(OutExpr); |
| if (!Constraints.empty()) |
| Constraints += ','; |
| |
| // If this is a register output, then make the inline asm return it |
| // by-value. If this is a memory result, return the value by-reference. |
| bool isScalarizableAggregate = |
| hasAggregateEvaluationKind(OutExpr->getType()); |
| if (!Info.allowsMemory() && (hasScalarEvaluationKind(OutExpr->getType()) || |
| isScalarizableAggregate)) { |
| Constraints += "=" + OutputConstraint; |
| ResultRegQualTys.push_back(OutExpr->getType()); |
| ResultRegDests.push_back(Dest); |
| ResultTruncRegTypes.push_back(ConvertTypeForMem(OutExpr->getType())); |
| if (Info.allowsRegister() && isScalarizableAggregate) { |
| ResultTypeRequiresCast.push_back(true); |
| unsigned Size = getContext().getTypeSize(OutExpr->getType()); |
| llvm::Type *ConvTy = llvm::IntegerType::get(getLLVMContext(), Size); |
| ResultRegTypes.push_back(ConvTy); |
| } else { |
| ResultTypeRequiresCast.push_back(false); |
| ResultRegTypes.push_back(ResultTruncRegTypes.back()); |
| } |
| // If this output is tied to an input, and if the input is larger, then |
| // we need to set the actual result type of the inline asm node to be the |
| // same as the input type. |
| if (Info.hasMatchingInput()) { |
| unsigned InputNo; |
| for (InputNo = 0; InputNo != S.getNumInputs(); ++InputNo) { |
| TargetInfo::ConstraintInfo &Input = InputConstraintInfos[InputNo]; |
| if (Input.hasTiedOperand() && Input.getTiedOperand() == i) |
| break; |
| } |
| assert(InputNo != S.getNumInputs() && "Didn't find matching input!"); |
| |
| QualType InputTy = S.getInputExpr(InputNo)->getType(); |
| QualType OutputType = OutExpr->getType(); |
| |
| uint64_t InputSize = getContext().getTypeSize(InputTy); |
| if (getContext().getTypeSize(OutputType) < InputSize) { |
| // Form the asm to return the value as a larger integer or fp type. |
| ResultRegTypes.back() = ConvertType(InputTy); |
| } |
| } |
| if (llvm::Type* AdjTy = |
| getTargetHooks().adjustInlineAsmType(*this, OutputConstraint, |
| ResultRegTypes.back())) |
| ResultRegTypes.back() = AdjTy; |
| else { |
| CGM.getDiags().Report(S.getAsmLoc(), |
| diag::err_asm_invalid_type_in_input) |
| << OutExpr->getType() << OutputConstraint; |
| } |
| |
| // Update largest vector width for any vector types. |
| if (auto *VT = dyn_cast<llvm::VectorType>(ResultRegTypes.back())) |
| LargestVectorWidth = |
| std::max((uint64_t)LargestVectorWidth, |
| VT->getPrimitiveSizeInBits().getKnownMinSize()); |
| } else { |
| ArgTypes.push_back(Dest.getAddress(*this).getType()); |
| Args.push_back(Dest.getPointer(*this)); |
| Constraints += "=*"; |
| Constraints += OutputConstraint; |
| ReadOnly = ReadNone = false; |
| } |
| |
| if (Info.isReadWrite()) { |
| InOutConstraints += ','; |
| |
| const Expr *InputExpr = S.getOutputExpr(i); |
| llvm::Value *Arg = EmitAsmInputLValue(Info, Dest, InputExpr->getType(), |
| InOutConstraints, |
| InputExpr->getExprLoc()); |
| |
| if (llvm::Type* AdjTy = |
| getTargetHooks().adjustInlineAsmType(*this, OutputConstraint, |
| Arg->getType())) |
| Arg = Builder.CreateBitCast(Arg, AdjTy); |
| |
| // Update largest vector width for any vector types. |
| if (auto *VT = dyn_cast<llvm::VectorType>(Arg->getType())) |
| LargestVectorWidth = |
| std::max((uint64_t)LargestVectorWidth, |
| VT->getPrimitiveSizeInBits().getKnownMinSize()); |
| if (Info.allowsRegister()) |
| InOutConstraints += llvm::utostr(i); |
| else |
| InOutConstraints += OutputConstraint; |
| |
| InOutArgTypes.push_back(Arg->getType()); |
| InOutArgs.push_back(Arg); |
| } |
| } |
| |
| // If this is a Microsoft-style asm blob, store the return registers (EAX:EDX) |
| // to the return value slot. Only do this when returning in registers. |
| if (isa<MSAsmStmt>(&S)) { |
| const ABIArgInfo &RetAI = CurFnInfo->getReturnInfo(); |
| if (RetAI.isDirect() || RetAI.isExtend()) { |
| // Make a fake lvalue for the return value slot. |
| LValue ReturnSlot = MakeAddrLValue(ReturnValue, FnRetTy); |
| CGM.getTargetCodeGenInfo().addReturnRegisterOutputs( |
| *this, ReturnSlot, Constraints, ResultRegTypes, ResultTruncRegTypes, |
| ResultRegDests, AsmString, S.getNumOutputs()); |
| SawAsmBlock = true; |
| } |
| } |
| |
| for (unsigned i = 0, e = S.getNumInputs(); i != e; i++) { |
| const Expr *InputExpr = S.getInputExpr(i); |
| |
| TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; |
| |
| if (Info.allowsMemory()) |
| ReadNone = false; |
| |
| if (!Constraints.empty()) |
| Constraints += ','; |
| |
| // Simplify the input constraint. |
| std::string InputConstraint(S.getInputConstraint(i)); |
| InputConstraint = SimplifyConstraint(InputConstraint.c_str(), getTarget(), |
| &OutputConstraintInfos); |
| |
| InputConstraint = AddVariableConstraints( |
| InputConstraint, *InputExpr->IgnoreParenNoopCasts(getContext()), |
| getTarget(), CGM, S, false /* No EarlyClobber */); |
| |
| std::string ReplaceConstraint (InputConstraint); |
| llvm::Value *Arg = EmitAsmInput(Info, InputExpr, Constraints); |
| |
| // If this input argument is tied to a larger output result, extend the |
| // input to be the same size as the output. The LLVM backend wants to see |
| // the input and output of a matching constraint be the same size. Note |
| // that GCC does not define what the top bits are here. We use zext because |
| // that is usually cheaper, but LLVM IR should really get an anyext someday. |
| if (Info.hasTiedOperand()) { |
| unsigned Output = Info.getTiedOperand(); |
| QualType OutputType = S.getOutputExpr(Output)->getType(); |
| QualType InputTy = InputExpr->getType(); |
| |
| if (getContext().getTypeSize(OutputType) > |
| getContext().getTypeSize(InputTy)) { |
| // Use ptrtoint as appropriate so that we can do our extension. |
| if (isa<llvm::PointerType>(Arg->getType())) |
| Arg = Builder.CreatePtrToInt(Arg, IntPtrTy); |
| llvm::Type *OutputTy = ConvertType(OutputType); |
| if (isa<llvm::IntegerType>(OutputTy)) |
| Arg = Builder.CreateZExt(Arg, OutputTy); |
| else if (isa<llvm::PointerType>(OutputTy)) |
| Arg = Builder.CreateZExt(Arg, IntPtrTy); |
| else { |
| assert(OutputTy->isFloatingPointTy() && "Unexpected output type"); |
| Arg = Builder.CreateFPExt(Arg, OutputTy); |
| } |
| } |
| // Deal with the tied operands' constraint code in adjustInlineAsmType. |
| ReplaceConstraint = OutputConstraints[Output]; |
| } |
| if (llvm::Type* AdjTy = |
| getTargetHooks().adjustInlineAsmType(*this, ReplaceConstraint, |
| Arg->getType())) |
| Arg = Builder.CreateBitCast(Arg, AdjTy); |
| else |
| CGM.getDiags().Report(S.getAsmLoc(), diag::err_asm_invalid_type_in_input) |
| << InputExpr->getType() << InputConstraint; |
| |
| // Update largest vector width for any vector types. |
| if (auto *VT = dyn_cast<llvm::VectorType>(Arg->getType())) |
| LargestVectorWidth = |
| std::max((uint64_t)LargestVectorWidth, |
| VT->getPrimitiveSizeInBits().getKnownMinSize()); |
| |
| ArgTypes.push_back(Arg->getType()); |
| Args.push_back(Arg); |
| Constraints += InputConstraint; |
| } |
| |
| // Labels |
| SmallVector<llvm::BasicBlock *, 16> Transfer; |
| llvm::BasicBlock *Fallthrough = nullptr; |
| bool IsGCCAsmGoto = false; |
| if (const auto *GS = dyn_cast<GCCAsmStmt>(&S)) { |
| IsGCCAsmGoto = GS->isAsmGoto(); |
| if (IsGCCAsmGoto) { |
| for (const auto *E : GS->labels()) { |
| JumpDest Dest = getJumpDestForLabel(E->getLabel()); |
| Transfer.push_back(Dest.getBlock()); |
| llvm::BlockAddress *BA = |
| llvm::BlockAddress::get(CurFn, Dest.getBlock()); |
| Args.push_back(BA); |
| ArgTypes.push_back(BA->getType()); |
| if (!Constraints.empty()) |
| Constraints += ','; |
| Constraints += 'X'; |
| } |
| Fallthrough = createBasicBlock("asm.fallthrough"); |
| } |
| } |
| |
| // Append the "input" part of inout constraints last. |
| for (unsigned i = 0, e = InOutArgs.size(); i != e; i++) { |
| ArgTypes.push_back(InOutArgTypes[i]); |
| Args.push_back(InOutArgs[i]); |
| } |
| Constraints += InOutConstraints; |
| |
| // Clobbers |
| for (unsigned i = 0, e = S.getNumClobbers(); i != e; i++) { |
| StringRef Clobber = S.getClobber(i); |
| |
| if (Clobber == "memory") |
| ReadOnly = ReadNone = false; |
| else if (Clobber != "cc") { |
| Clobber = getTarget().getNormalizedGCCRegisterName(Clobber); |
| if (CGM.getCodeGenOpts().StackClashProtector && |
| getTarget().isSPRegName(Clobber)) { |
| CGM.getDiags().Report(S.getAsmLoc(), |
| diag::warn_stack_clash_protection_inline_asm); |
| } |
| } |
| |
| if (!Constraints.empty()) |
| Constraints += ','; |
| |
| Constraints += "~{"; |
| Constraints += Clobber; |
| Constraints += '}'; |
| } |
| |
| // Add machine specific clobbers |
| std::string MachineClobbers = getTarget().getClobbers(); |
| if (!MachineClobbers.empty()) { |
| if (!Constraints.empty()) |
| Constraints += ','; |
| Constraints += MachineClobbers; |
| } |
| |
| llvm::Type *ResultType; |
| if (ResultRegTypes.empty()) |
| ResultType = VoidTy; |
| else if (ResultRegTypes.size() == 1) |
| ResultType = ResultRegTypes[0]; |
| else |
| ResultType = llvm::StructType::get(getLLVMContext(), ResultRegTypes); |
| |
| llvm::FunctionType *FTy = |
| llvm::FunctionType::get(ResultType, ArgTypes, false); |
| |
| bool HasSideEffect = S.isVolatile() || S.getNumOutputs() == 0; |
| llvm::InlineAsm::AsmDialect AsmDialect = isa<MSAsmStmt>(&S) ? |
| llvm::InlineAsm::AD_Intel : llvm::InlineAsm::AD_ATT; |
| llvm::InlineAsm *IA = |
| llvm::InlineAsm::get(FTy, AsmString, Constraints, HasSideEffect, |
| /* IsAlignStack */ false, AsmDialect); |
| std::vector<llvm::Value*> RegResults; |
| if (IsGCCAsmGoto) { |
| llvm::CallBrInst *Result = |
| Builder.CreateCallBr(IA, Fallthrough, Transfer, Args); |
| EmitBlock(Fallthrough); |
| UpdateAsmCallInst(cast<llvm::CallBase>(*Result), HasSideEffect, ReadOnly, |
| ReadNone, InNoMergeAttributedStmt, S, ResultRegTypes, |
| *this, RegResults); |
| } else { |
| llvm::CallInst *Result = |
| Builder.CreateCall(IA, Args, getBundlesForFunclet(IA)); |
| UpdateAsmCallInst(cast<llvm::CallBase>(*Result), HasSideEffect, ReadOnly, |
| ReadNone, InNoMergeAttributedStmt, S, ResultRegTypes, |
| *this, RegResults); |
| } |
| |
| assert(RegResults.size() == ResultRegTypes.size()); |
| assert(RegResults.size() == ResultTruncRegTypes.size()); |
| assert(RegResults.size() == ResultRegDests.size()); |
| // ResultRegDests can be also populated by addReturnRegisterOutputs() above, |
| // in which case its size may grow. |
| assert(ResultTypeRequiresCast.size() <= ResultRegDests.size()); |
| for (unsigned i = 0, e = RegResults.size(); i != e; ++i) { |
| llvm::Value *Tmp = RegResults[i]; |
| |
| // If the result type of the LLVM IR asm doesn't match the result type of |
| // the expression, do the conversion. |
| if (ResultRegTypes[i] != ResultTruncRegTypes[i]) { |
| llvm::Type *TruncTy = ResultTruncRegTypes[i]; |
| |
| // Truncate the integer result to the right size, note that TruncTy can be |
| // a pointer. |
| if (TruncTy->isFloatingPointTy()) |
| Tmp = Builder.CreateFPTrunc(Tmp, TruncTy); |
| else if (TruncTy->isPointerTy() && Tmp->getType()->isIntegerTy()) { |
| uint64_t ResSize = CGM.getDataLayout().getTypeSizeInBits(TruncTy); |
| Tmp = Builder.CreateTrunc(Tmp, |
| llvm::IntegerType::get(getLLVMContext(), (unsigned)ResSize)); |
| Tmp = Builder.CreateIntToPtr(Tmp, TruncTy); |
| } else if (Tmp->getType()->isPointerTy() && TruncTy->isIntegerTy()) { |
| uint64_t TmpSize =CGM.getDataLayout().getTypeSizeInBits(Tmp->getType()); |
| Tmp = Builder.CreatePtrToInt(Tmp, |
| llvm::IntegerType::get(getLLVMContext(), (unsigned)TmpSize)); |
| Tmp = Builder.CreateTrunc(Tmp, TruncTy); |
| } else if (TruncTy->isIntegerTy()) { |
| Tmp = Builder.CreateZExtOrTrunc(Tmp, TruncTy); |
| } else if (TruncTy->isVectorTy()) { |
| Tmp = Builder.CreateBitCast(Tmp, TruncTy); |
| } |
| } |
| |
| LValue Dest = ResultRegDests[i]; |
| // ResultTypeRequiresCast elements correspond to the first |
| // ResultTypeRequiresCast.size() elements of RegResults. |
| if ((i < ResultTypeRequiresCast.size()) && ResultTypeRequiresCast[i]) { |
| unsigned Size = getContext().getTypeSize(ResultRegQualTys[i]); |
| Address A = Builder.CreateBitCast(Dest.getAddress(*this), |
| ResultRegTypes[i]->getPointerTo()); |
| QualType Ty = getContext().getIntTypeForBitwidth(Size, /*Signed*/ false); |
| if (Ty.isNull()) { |
| const Expr *OutExpr = S.getOutputExpr(i); |
| CGM.Error( |
| OutExpr->getExprLoc(), |
| "impossible constraint in asm: can't store value into a register"); |
| return; |
| } |
| Dest = MakeAddrLValue(A, Ty); |
| } |
| EmitStoreThroughLValue(RValue::get(Tmp), Dest); |
| } |
| } |
| |
| LValue CodeGenFunction::InitCapturedStruct(const CapturedStmt &S) { |
| const RecordDecl *RD = S.getCapturedRecordDecl(); |
| QualType RecordTy = getContext().getRecordType(RD); |
| |
| // Initialize the captured struct. |
| LValue SlotLV = |
| MakeAddrLValue(CreateMemTemp(RecordTy, "agg.captured"), RecordTy); |
| |
| RecordDecl::field_iterator CurField = RD->field_begin(); |
| for (CapturedStmt::const_capture_init_iterator I = S.capture_init_begin(), |
| E = S.capture_init_end(); |
| I != E; ++I, ++CurField) { |
| LValue LV = EmitLValueForFieldInitialization(SlotLV, *CurField); |
| if (CurField->hasCapturedVLAType()) { |
| EmitLambdaVLACapture(CurField->getCapturedVLAType(), LV); |
| } else { |
| EmitInitializerForField(*CurField, LV, *I); |
| } |
| } |
| |
| return SlotLV; |
| } |
| |
| /// Generate an outlined function for the body of a CapturedStmt, store any |
| /// captured variables into the captured struct, and call the outlined function. |
| llvm::Function * |
| CodeGenFunction::EmitCapturedStmt(const CapturedStmt &S, CapturedRegionKind K) { |
| LValue CapStruct = InitCapturedStruct(S); |
| |
| // Emit the CapturedDecl |
| CodeGenFunction CGF(CGM, true); |
| CGCapturedStmtRAII CapInfoRAII(CGF, new CGCapturedStmtInfo(S, K)); |
| llvm::Function *F = CGF.GenerateCapturedStmtFunction(S); |
| delete CGF.CapturedStmtInfo; |
| |
| // Emit call to the helper function. |
| EmitCallOrInvoke(F, CapStruct.getPointer(*this)); |
| |
| return F; |
| } |
| |
| Address CodeGenFunction::GenerateCapturedStmtArgument(const CapturedStmt &S) { |
| LValue CapStruct = InitCapturedStruct(S); |
| return CapStruct.getAddress(*this); |
| } |
| |
| /// Creates the outlined function for a CapturedStmt. |
| llvm::Function * |
| CodeGenFunction::GenerateCapturedStmtFunction(const CapturedStmt &S) { |
| assert(CapturedStmtInfo && |
| "CapturedStmtInfo should be set when generating the captured function"); |
| const CapturedDecl *CD = S.getCapturedDecl(); |
| const RecordDecl *RD = S.getCapturedRecordDecl(); |
| SourceLocation Loc = S.getBeginLoc(); |
| assert(CD->hasBody() && "missing CapturedDecl body"); |
| |
| // Build the argument list. |
| ASTContext &Ctx = CGM.getContext(); |
| FunctionArgList Args; |
| Args.append(CD->param_begin(), CD->param_end()); |
| |
| // Create the function declaration. |
| const CGFunctionInfo &FuncInfo = |
| CGM.getTypes().arrangeBuiltinFunctionDeclaration(Ctx.VoidTy, Args); |
| llvm::FunctionType *FuncLLVMTy = CGM.getTypes().GetFunctionType(FuncInfo); |
| |
| llvm::Function *F = |
| llvm::Function::Create(FuncLLVMTy, llvm::GlobalValue::InternalLinkage, |
| CapturedStmtInfo->getHelperName(), &CGM.getModule()); |
| CGM.SetInternalFunctionAttributes(CD, F, FuncInfo); |
| if (CD->isNothrow()) |
| F->addFnAttr(llvm::Attribute::NoUnwind); |
| |
| // Generate the function. |
| StartFunction(CD, Ctx.VoidTy, F, FuncInfo, Args, CD->getLocation(), |
| CD->getBody()->getBeginLoc()); |
| // Set the context parameter in CapturedStmtInfo. |
| Address DeclPtr = GetAddrOfLocalVar(CD->getContextParam()); |
| CapturedStmtInfo->setContextValue(Builder.CreateLoad(DeclPtr)); |
| |
| // Initialize variable-length arrays. |
| LValue Base = MakeNaturalAlignAddrLValue(CapturedStmtInfo->getContextValue(), |
| Ctx.getTagDeclType(RD)); |
| for (auto *FD : RD->fields()) { |
| if (FD->hasCapturedVLAType()) { |
| auto *ExprArg = |
| EmitLoadOfLValue(EmitLValueForField(Base, FD), S.getBeginLoc()) |
| .getScalarVal(); |
| auto VAT = FD->getCapturedVLAType(); |
| VLASizeMap[VAT->getSizeExpr()] = ExprArg; |
| } |
| } |
| |
| // If 'this' is captured, load it into CXXThisValue. |
| if (CapturedStmtInfo->isCXXThisExprCaptured()) { |
| FieldDecl *FD = CapturedStmtInfo->getThisFieldDecl(); |
| LValue ThisLValue = EmitLValueForField(Base, FD); |
| CXXThisValue = EmitLoadOfLValue(ThisLValue, Loc).getScalarVal(); |
| } |
| |
| PGO.assignRegionCounters(GlobalDecl(CD), F); |
| CapturedStmtInfo->EmitBody(*this, CD->getBody()); |
| FinishFunction(CD->getBodyRBrace()); |
| |
| return F; |
| } |