1 //===--- CGStmt.cpp - Emit LLVM Code from Statements ----------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This contains code to emit Stmt nodes as LLVM code. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "CGDebugInfo.h" 14 #include "CodeGenFunction.h" 15 #include "CodeGenModule.h" 16 #include "TargetInfo.h" 17 #include "clang/AST/Attr.h" 18 #include "clang/AST/StmtVisitor.h" 19 #include "clang/Basic/Builtins.h" 20 #include "clang/Basic/PrettyStackTrace.h" 21 #include "clang/Basic/SourceManager.h" 22 #include "clang/Basic/TargetInfo.h" 23 #include "llvm/ADT/StringExtras.h" 24 #include "llvm/IR/DataLayout.h" 25 #include "llvm/IR/InlineAsm.h" 26 #include "llvm/IR/Intrinsics.h" 27 #include "llvm/IR/MDBuilder.h" 28 29 using namespace clang; 30 using namespace CodeGen; 31 32 //===----------------------------------------------------------------------===// 33 // Statement Emission 34 //===----------------------------------------------------------------------===// 35 36 void CodeGenFunction::EmitStopPoint(const Stmt *S) { 37 if (CGDebugInfo *DI = getDebugInfo()) { 38 SourceLocation Loc; 39 Loc = S->getBeginLoc(); 40 DI->EmitLocation(Builder, Loc); 41 42 LastStopPoint = Loc; 43 } 44 } 45 46 void CodeGenFunction::EmitStmt(const Stmt *S, ArrayRef<const Attr *> Attrs) { 47 assert(S && "Null statement?"); 48 PGO.setCurrentStmt(S); 49 50 // These statements have their own debug info handling. 51 if (EmitSimpleStmt(S)) 52 return; 53 54 // Check if we are generating unreachable code. 55 if (!HaveInsertPoint()) { 56 // If so, and the statement doesn't contain a label, then we do not need to 57 // generate actual code. This is safe because (1) the current point is 58 // unreachable, so we don't need to execute the code, and (2) we've already 59 // handled the statements which update internal data structures (like the 60 // local variable map) which could be used by subsequent statements. 61 if (!ContainsLabel(S)) { 62 // Verify that any decl statements were handled as simple, they may be in 63 // scope of subsequent reachable statements. 64 assert(!isa<DeclStmt>(*S) && "Unexpected DeclStmt!"); 65 return; 66 } 67 68 // Otherwise, make a new block to hold the code. 69 EnsureInsertPoint(); 70 } 71 72 // Generate a stoppoint if we are emitting debug info. 73 EmitStopPoint(S); 74 75 // Ignore all OpenMP directives except for simd if OpenMP with Simd is 76 // enabled. 77 if (getLangOpts().OpenMP && getLangOpts().OpenMPSimd) { 78 if (const auto *D = dyn_cast<OMPExecutableDirective>(S)) { 79 EmitSimpleOMPExecutableDirective(*D); 80 return; 81 } 82 } 83 84 switch (S->getStmtClass()) { 85 case Stmt::NoStmtClass: 86 case Stmt::CXXCatchStmtClass: 87 case Stmt::SEHExceptStmtClass: 88 case Stmt::SEHFinallyStmtClass: 89 case Stmt::MSDependentExistsStmtClass: 90 llvm_unreachable("invalid statement class to emit generically"); 91 case Stmt::NullStmtClass: 92 case Stmt::CompoundStmtClass: 93 case Stmt::DeclStmtClass: 94 case Stmt::LabelStmtClass: 95 case Stmt::AttributedStmtClass: 96 case Stmt::GotoStmtClass: 97 case Stmt::BreakStmtClass: 98 case Stmt::ContinueStmtClass: 99 case Stmt::DefaultStmtClass: 100 case Stmt::CaseStmtClass: 101 case Stmt::SEHLeaveStmtClass: 102 llvm_unreachable("should have emitted these statements as simple"); 103 104 #define STMT(Type, Base) 105 #define ABSTRACT_STMT(Op) 106 #define EXPR(Type, Base) \ 107 case Stmt::Type##Class: 108 #include "clang/AST/StmtNodes.inc" 109 { 110 // Remember the block we came in on. 111 llvm::BasicBlock *incoming = Builder.GetInsertBlock(); 112 assert(incoming && "expression emission must have an insertion point"); 113 114 EmitIgnoredExpr(cast<Expr>(S)); 115 116 llvm::BasicBlock *outgoing = Builder.GetInsertBlock(); 117 assert(outgoing && "expression emission cleared block!"); 118 119 // The expression emitters assume (reasonably!) that the insertion 120 // point is always set. To maintain that, the call-emission code 121 // for noreturn functions has to enter a new block with no 122 // predecessors. We want to kill that block and mark the current 123 // insertion point unreachable in the common case of a call like 124 // "exit();". Since expression emission doesn't otherwise create 125 // blocks with no predecessors, we can just test for that. 126 // However, we must be careful not to do this to our incoming 127 // block, because *statement* emission does sometimes create 128 // reachable blocks which will have no predecessors until later in 129 // the function. This occurs with, e.g., labels that are not 130 // reachable by fallthrough. 131 if (incoming != outgoing && outgoing->use_empty()) { 132 outgoing->eraseFromParent(); 133 Builder.ClearInsertionPoint(); 134 } 135 break; 136 } 137 138 case Stmt::IndirectGotoStmtClass: 139 EmitIndirectGotoStmt(cast<IndirectGotoStmt>(*S)); break; 140 141 case Stmt::IfStmtClass: EmitIfStmt(cast<IfStmt>(*S)); break; 142 case Stmt::WhileStmtClass: EmitWhileStmt(cast<WhileStmt>(*S), Attrs); break; 143 case Stmt::DoStmtClass: EmitDoStmt(cast<DoStmt>(*S), Attrs); break; 144 case Stmt::ForStmtClass: EmitForStmt(cast<ForStmt>(*S), Attrs); break; 145 146 case Stmt::ReturnStmtClass: EmitReturnStmt(cast<ReturnStmt>(*S)); break; 147 148 case Stmt::SwitchStmtClass: EmitSwitchStmt(cast<SwitchStmt>(*S)); break; 149 case Stmt::GCCAsmStmtClass: // Intentional fall-through. 150 case Stmt::MSAsmStmtClass: EmitAsmStmt(cast<AsmStmt>(*S)); break; 151 case Stmt::CoroutineBodyStmtClass: 152 EmitCoroutineBody(cast<CoroutineBodyStmt>(*S)); 153 break; 154 case Stmt::CoreturnStmtClass: 155 EmitCoreturnStmt(cast<CoreturnStmt>(*S)); 156 break; 157 case Stmt::CapturedStmtClass: { 158 const CapturedStmt *CS = cast<CapturedStmt>(S); 159 EmitCapturedStmt(*CS, CS->getCapturedRegionKind()); 160 } 161 break; 162 case Stmt::ObjCAtTryStmtClass: 163 EmitObjCAtTryStmt(cast<ObjCAtTryStmt>(*S)); 164 break; 165 case Stmt::ObjCAtCatchStmtClass: 166 llvm_unreachable( 167 "@catch statements should be handled by EmitObjCAtTryStmt"); 168 case Stmt::ObjCAtFinallyStmtClass: 169 llvm_unreachable( 170 "@finally statements should be handled by EmitObjCAtTryStmt"); 171 case Stmt::ObjCAtThrowStmtClass: 172 EmitObjCAtThrowStmt(cast<ObjCAtThrowStmt>(*S)); 173 break; 174 case Stmt::ObjCAtSynchronizedStmtClass: 175 EmitObjCAtSynchronizedStmt(cast<ObjCAtSynchronizedStmt>(*S)); 176 break; 177 case Stmt::ObjCForCollectionStmtClass: 178 EmitObjCForCollectionStmt(cast<ObjCForCollectionStmt>(*S)); 179 break; 180 case Stmt::ObjCAutoreleasePoolStmtClass: 181 EmitObjCAutoreleasePoolStmt(cast<ObjCAutoreleasePoolStmt>(*S)); 182 break; 183 184 case Stmt::CXXTryStmtClass: 185 EmitCXXTryStmt(cast<CXXTryStmt>(*S)); 186 break; 187 case Stmt::CXXForRangeStmtClass: 188 EmitCXXForRangeStmt(cast<CXXForRangeStmt>(*S), Attrs); 189 break; 190 case Stmt::SEHTryStmtClass: 191 EmitSEHTryStmt(cast<SEHTryStmt>(*S)); 192 break; 193 case Stmt::OMPParallelDirectiveClass: 194 EmitOMPParallelDirective(cast<OMPParallelDirective>(*S)); 195 break; 196 case Stmt::OMPSimdDirectiveClass: 197 EmitOMPSimdDirective(cast<OMPSimdDirective>(*S)); 198 break; 199 case Stmt::OMPForDirectiveClass: 200 EmitOMPForDirective(cast<OMPForDirective>(*S)); 201 break; 202 case Stmt::OMPForSimdDirectiveClass: 203 EmitOMPForSimdDirective(cast<OMPForSimdDirective>(*S)); 204 break; 205 case Stmt::OMPSectionsDirectiveClass: 206 EmitOMPSectionsDirective(cast<OMPSectionsDirective>(*S)); 207 break; 208 case Stmt::OMPSectionDirectiveClass: 209 EmitOMPSectionDirective(cast<OMPSectionDirective>(*S)); 210 break; 211 case Stmt::OMPSingleDirectiveClass: 212 EmitOMPSingleDirective(cast<OMPSingleDirective>(*S)); 213 break; 214 case Stmt::OMPMasterDirectiveClass: 215 EmitOMPMasterDirective(cast<OMPMasterDirective>(*S)); 216 break; 217 case Stmt::OMPCriticalDirectiveClass: 218 EmitOMPCriticalDirective(cast<OMPCriticalDirective>(*S)); 219 break; 220 case Stmt::OMPParallelForDirectiveClass: 221 EmitOMPParallelForDirective(cast<OMPParallelForDirective>(*S)); 222 break; 223 case Stmt::OMPParallelForSimdDirectiveClass: 224 EmitOMPParallelForSimdDirective(cast<OMPParallelForSimdDirective>(*S)); 225 break; 226 case Stmt::OMPParallelMasterDirectiveClass: 227 EmitOMPParallelMasterDirective(cast<OMPParallelMasterDirective>(*S)); 228 break; 229 case Stmt::OMPParallelSectionsDirectiveClass: 230 EmitOMPParallelSectionsDirective(cast<OMPParallelSectionsDirective>(*S)); 231 break; 232 case Stmt::OMPTaskDirectiveClass: 233 EmitOMPTaskDirective(cast<OMPTaskDirective>(*S)); 234 break; 235 case Stmt::OMPTaskyieldDirectiveClass: 236 EmitOMPTaskyieldDirective(cast<OMPTaskyieldDirective>(*S)); 237 break; 238 case Stmt::OMPBarrierDirectiveClass: 239 EmitOMPBarrierDirective(cast<OMPBarrierDirective>(*S)); 240 break; 241 case Stmt::OMPTaskwaitDirectiveClass: 242 EmitOMPTaskwaitDirective(cast<OMPTaskwaitDirective>(*S)); 243 break; 244 case Stmt::OMPTaskgroupDirectiveClass: 245 EmitOMPTaskgroupDirective(cast<OMPTaskgroupDirective>(*S)); 246 break; 247 case Stmt::OMPFlushDirectiveClass: 248 EmitOMPFlushDirective(cast<OMPFlushDirective>(*S)); 249 break; 250 case Stmt::OMPDepobjDirectiveClass: 251 EmitOMPDepobjDirective(cast<OMPDepobjDirective>(*S)); 252 break; 253 case Stmt::OMPScanDirectiveClass: 254 llvm_unreachable("Scan directive not supported yet."); 255 break; 256 case Stmt::OMPOrderedDirectiveClass: 257 EmitOMPOrderedDirective(cast<OMPOrderedDirective>(*S)); 258 break; 259 case Stmt::OMPAtomicDirectiveClass: 260 EmitOMPAtomicDirective(cast<OMPAtomicDirective>(*S)); 261 break; 262 case Stmt::OMPTargetDirectiveClass: 263 EmitOMPTargetDirective(cast<OMPTargetDirective>(*S)); 264 break; 265 case Stmt::OMPTeamsDirectiveClass: 266 EmitOMPTeamsDirective(cast<OMPTeamsDirective>(*S)); 267 break; 268 case Stmt::OMPCancellationPointDirectiveClass: 269 EmitOMPCancellationPointDirective(cast<OMPCancellationPointDirective>(*S)); 270 break; 271 case Stmt::OMPCancelDirectiveClass: 272 EmitOMPCancelDirective(cast<OMPCancelDirective>(*S)); 273 break; 274 case Stmt::OMPTargetDataDirectiveClass: 275 EmitOMPTargetDataDirective(cast<OMPTargetDataDirective>(*S)); 276 break; 277 case Stmt::OMPTargetEnterDataDirectiveClass: 278 EmitOMPTargetEnterDataDirective(cast<OMPTargetEnterDataDirective>(*S)); 279 break; 280 case Stmt::OMPTargetExitDataDirectiveClass: 281 EmitOMPTargetExitDataDirective(cast<OMPTargetExitDataDirective>(*S)); 282 break; 283 case Stmt::OMPTargetParallelDirectiveClass: 284 EmitOMPTargetParallelDirective(cast<OMPTargetParallelDirective>(*S)); 285 break; 286 case Stmt::OMPTargetParallelForDirectiveClass: 287 EmitOMPTargetParallelForDirective(cast<OMPTargetParallelForDirective>(*S)); 288 break; 289 case Stmt::OMPTaskLoopDirectiveClass: 290 EmitOMPTaskLoopDirective(cast<OMPTaskLoopDirective>(*S)); 291 break; 292 case Stmt::OMPTaskLoopSimdDirectiveClass: 293 EmitOMPTaskLoopSimdDirective(cast<OMPTaskLoopSimdDirective>(*S)); 294 break; 295 case Stmt::OMPMasterTaskLoopDirectiveClass: 296 EmitOMPMasterTaskLoopDirective(cast<OMPMasterTaskLoopDirective>(*S)); 297 break; 298 case Stmt::OMPMasterTaskLoopSimdDirectiveClass: 299 EmitOMPMasterTaskLoopSimdDirective( 300 cast<OMPMasterTaskLoopSimdDirective>(*S)); 301 break; 302 case Stmt::OMPParallelMasterTaskLoopDirectiveClass: 303 EmitOMPParallelMasterTaskLoopDirective( 304 cast<OMPParallelMasterTaskLoopDirective>(*S)); 305 break; 306 case Stmt::OMPParallelMasterTaskLoopSimdDirectiveClass: 307 EmitOMPParallelMasterTaskLoopSimdDirective( 308 cast<OMPParallelMasterTaskLoopSimdDirective>(*S)); 309 break; 310 case Stmt::OMPDistributeDirectiveClass: 311 EmitOMPDistributeDirective(cast<OMPDistributeDirective>(*S)); 312 break; 313 case Stmt::OMPTargetUpdateDirectiveClass: 314 EmitOMPTargetUpdateDirective(cast<OMPTargetUpdateDirective>(*S)); 315 break; 316 case Stmt::OMPDistributeParallelForDirectiveClass: 317 EmitOMPDistributeParallelForDirective( 318 cast<OMPDistributeParallelForDirective>(*S)); 319 break; 320 case Stmt::OMPDistributeParallelForSimdDirectiveClass: 321 EmitOMPDistributeParallelForSimdDirective( 322 cast<OMPDistributeParallelForSimdDirective>(*S)); 323 break; 324 case Stmt::OMPDistributeSimdDirectiveClass: 325 EmitOMPDistributeSimdDirective(cast<OMPDistributeSimdDirective>(*S)); 326 break; 327 case Stmt::OMPTargetParallelForSimdDirectiveClass: 328 EmitOMPTargetParallelForSimdDirective( 329 cast<OMPTargetParallelForSimdDirective>(*S)); 330 break; 331 case Stmt::OMPTargetSimdDirectiveClass: 332 EmitOMPTargetSimdDirective(cast<OMPTargetSimdDirective>(*S)); 333 break; 334 case Stmt::OMPTeamsDistributeDirectiveClass: 335 EmitOMPTeamsDistributeDirective(cast<OMPTeamsDistributeDirective>(*S)); 336 break; 337 case Stmt::OMPTeamsDistributeSimdDirectiveClass: 338 EmitOMPTeamsDistributeSimdDirective( 339 cast<OMPTeamsDistributeSimdDirective>(*S)); 340 break; 341 case Stmt::OMPTeamsDistributeParallelForSimdDirectiveClass: 342 EmitOMPTeamsDistributeParallelForSimdDirective( 343 cast<OMPTeamsDistributeParallelForSimdDirective>(*S)); 344 break; 345 case Stmt::OMPTeamsDistributeParallelForDirectiveClass: 346 EmitOMPTeamsDistributeParallelForDirective( 347 cast<OMPTeamsDistributeParallelForDirective>(*S)); 348 break; 349 case Stmt::OMPTargetTeamsDirectiveClass: 350 EmitOMPTargetTeamsDirective(cast<OMPTargetTeamsDirective>(*S)); 351 break; 352 case Stmt::OMPTargetTeamsDistributeDirectiveClass: 353 EmitOMPTargetTeamsDistributeDirective( 354 cast<OMPTargetTeamsDistributeDirective>(*S)); 355 break; 356 case Stmt::OMPTargetTeamsDistributeParallelForDirectiveClass: 357 EmitOMPTargetTeamsDistributeParallelForDirective( 358 cast<OMPTargetTeamsDistributeParallelForDirective>(*S)); 359 break; 360 case Stmt::OMPTargetTeamsDistributeParallelForSimdDirectiveClass: 361 EmitOMPTargetTeamsDistributeParallelForSimdDirective( 362 cast<OMPTargetTeamsDistributeParallelForSimdDirective>(*S)); 363 break; 364 case Stmt::OMPTargetTeamsDistributeSimdDirectiveClass: 365 EmitOMPTargetTeamsDistributeSimdDirective( 366 cast<OMPTargetTeamsDistributeSimdDirective>(*S)); 367 break; 368 } 369 } 370 371 bool CodeGenFunction::EmitSimpleStmt(const Stmt *S) { 372 switch (S->getStmtClass()) { 373 default: return false; 374 case Stmt::NullStmtClass: break; 375 case Stmt::CompoundStmtClass: EmitCompoundStmt(cast<CompoundStmt>(*S)); break; 376 case Stmt::DeclStmtClass: EmitDeclStmt(cast<DeclStmt>(*S)); break; 377 case Stmt::LabelStmtClass: EmitLabelStmt(cast<LabelStmt>(*S)); break; 378 case Stmt::AttributedStmtClass: 379 EmitAttributedStmt(cast<AttributedStmt>(*S)); break; 380 case Stmt::GotoStmtClass: EmitGotoStmt(cast<GotoStmt>(*S)); break; 381 case Stmt::BreakStmtClass: EmitBreakStmt(cast<BreakStmt>(*S)); break; 382 case Stmt::ContinueStmtClass: EmitContinueStmt(cast<ContinueStmt>(*S)); break; 383 case Stmt::DefaultStmtClass: EmitDefaultStmt(cast<DefaultStmt>(*S)); break; 384 case Stmt::CaseStmtClass: EmitCaseStmt(cast<CaseStmt>(*S)); break; 385 case Stmt::SEHLeaveStmtClass: EmitSEHLeaveStmt(cast<SEHLeaveStmt>(*S)); break; 386 } 387 388 return true; 389 } 390 391 /// EmitCompoundStmt - Emit a compound statement {..} node. If GetLast is true, 392 /// this captures the expression result of the last sub-statement and returns it 393 /// (for use by the statement expression extension). 394 Address CodeGenFunction::EmitCompoundStmt(const CompoundStmt &S, bool GetLast, 395 AggValueSlot AggSlot) { 396 PrettyStackTraceLoc CrashInfo(getContext().getSourceManager(),S.getLBracLoc(), 397 "LLVM IR generation of compound statement ('{}')"); 398 399 // Keep track of the current cleanup stack depth, including debug scopes. 400 LexicalScope Scope(*this, S.getSourceRange()); 401 402 return EmitCompoundStmtWithoutScope(S, GetLast, AggSlot); 403 } 404 405 Address 406 CodeGenFunction::EmitCompoundStmtWithoutScope(const CompoundStmt &S, 407 bool GetLast, 408 AggValueSlot AggSlot) { 409 410 const Stmt *ExprResult = S.getStmtExprResult(); 411 assert((!GetLast || (GetLast && ExprResult)) && 412 "If GetLast is true then the CompoundStmt must have a StmtExprResult"); 413 414 Address RetAlloca = Address::invalid(); 415 416 for (auto *CurStmt : S.body()) { 417 if (GetLast && ExprResult == CurStmt) { 418 // We have to special case labels here. They are statements, but when put 419 // at the end of a statement expression, they yield the value of their 420 // subexpression. Handle this by walking through all labels we encounter, 421 // emitting them before we evaluate the subexpr. 422 // Similar issues arise for attributed statements. 423 while (!isa<Expr>(ExprResult)) { 424 if (const auto *LS = dyn_cast<LabelStmt>(ExprResult)) { 425 EmitLabel(LS->getDecl()); 426 ExprResult = LS->getSubStmt(); 427 } else if (const auto *AS = dyn_cast<AttributedStmt>(ExprResult)) { 428 // FIXME: Update this if we ever have attributes that affect the 429 // semantics of an expression. 430 ExprResult = AS->getSubStmt(); 431 } else { 432 llvm_unreachable("unknown value statement"); 433 } 434 } 435 436 EnsureInsertPoint(); 437 438 const Expr *E = cast<Expr>(ExprResult); 439 QualType ExprTy = E->getType(); 440 if (hasAggregateEvaluationKind(ExprTy)) { 441 EmitAggExpr(E, AggSlot); 442 } else { 443 // We can't return an RValue here because there might be cleanups at 444 // the end of the StmtExpr. Because of that, we have to emit the result 445 // here into a temporary alloca. 446 RetAlloca = CreateMemTemp(ExprTy); 447 EmitAnyExprToMem(E, RetAlloca, Qualifiers(), 448 /*IsInit*/ false); 449 } 450 } else { 451 EmitStmt(CurStmt); 452 } 453 } 454 455 return RetAlloca; 456 } 457 458 void CodeGenFunction::SimplifyForwardingBlocks(llvm::BasicBlock *BB) { 459 llvm::BranchInst *BI = dyn_cast<llvm::BranchInst>(BB->getTerminator()); 460 461 // If there is a cleanup stack, then we it isn't worth trying to 462 // simplify this block (we would need to remove it from the scope map 463 // and cleanup entry). 464 if (!EHStack.empty()) 465 return; 466 467 // Can only simplify direct branches. 468 if (!BI || !BI->isUnconditional()) 469 return; 470 471 // Can only simplify empty blocks. 472 if (BI->getIterator() != BB->begin()) 473 return; 474 475 BB->replaceAllUsesWith(BI->getSuccessor(0)); 476 BI->eraseFromParent(); 477 BB->eraseFromParent(); 478 } 479 480 void CodeGenFunction::EmitBlock(llvm::BasicBlock *BB, bool IsFinished) { 481 llvm::BasicBlock *CurBB = Builder.GetInsertBlock(); 482 483 // Fall out of the current block (if necessary). 484 EmitBranch(BB); 485 486 if (IsFinished && BB->use_empty()) { 487 delete BB; 488 return; 489 } 490 491 // Place the block after the current block, if possible, or else at 492 // the end of the function. 493 if (CurBB && CurBB->getParent()) 494 CurFn->getBasicBlockList().insertAfter(CurBB->getIterator(), BB); 495 else 496 CurFn->getBasicBlockList().push_back(BB); 497 Builder.SetInsertPoint(BB); 498 } 499 500 void CodeGenFunction::EmitBranch(llvm::BasicBlock *Target) { 501 // Emit a branch from the current block to the target one if this 502 // was a real block. If this was just a fall-through block after a 503 // terminator, don't emit it. 504 llvm::BasicBlock *CurBB = Builder.GetInsertBlock(); 505 506 if (!CurBB || CurBB->getTerminator()) { 507 // If there is no insert point or the previous block is already 508 // terminated, don't touch it. 509 } else { 510 // Otherwise, create a fall-through branch. 511 Builder.CreateBr(Target); 512 } 513 514 Builder.ClearInsertionPoint(); 515 } 516 517 void CodeGenFunction::EmitBlockAfterUses(llvm::BasicBlock *block) { 518 bool inserted = false; 519 for (llvm::User *u : block->users()) { 520 if (llvm::Instruction *insn = dyn_cast<llvm::Instruction>(u)) { 521 CurFn->getBasicBlockList().insertAfter(insn->getParent()->getIterator(), 522 block); 523 inserted = true; 524 break; 525 } 526 } 527 528 if (!inserted) 529 CurFn->getBasicBlockList().push_back(block); 530 531 Builder.SetInsertPoint(block); 532 } 533 534 CodeGenFunction::JumpDest 535 CodeGenFunction::getJumpDestForLabel(const LabelDecl *D) { 536 JumpDest &Dest = LabelMap[D]; 537 if (Dest.isValid()) return Dest; 538 539 // Create, but don't insert, the new block. 540 Dest = JumpDest(createBasicBlock(D->getName()), 541 EHScopeStack::stable_iterator::invalid(), 542 NextCleanupDestIndex++); 543 return Dest; 544 } 545 546 void CodeGenFunction::EmitLabel(const LabelDecl *D) { 547 // Add this label to the current lexical scope if we're within any 548 // normal cleanups. Jumps "in" to this label --- when permitted by 549 // the language --- may need to be routed around such cleanups. 550 if (EHStack.hasNormalCleanups() && CurLexicalScope) 551 CurLexicalScope->addLabel(D); 552 553 JumpDest &Dest = LabelMap[D]; 554 555 // If we didn't need a forward reference to this label, just go 556 // ahead and create a destination at the current scope. 557 if (!Dest.isValid()) { 558 Dest = getJumpDestInCurrentScope(D->getName()); 559 560 // Otherwise, we need to give this label a target depth and remove 561 // it from the branch-fixups list. 562 } else { 563 assert(!Dest.getScopeDepth().isValid() && "already emitted label!"); 564 Dest.setScopeDepth(EHStack.stable_begin()); 565 ResolveBranchFixups(Dest.getBlock()); 566 } 567 568 EmitBlock(Dest.getBlock()); 569 570 // Emit debug info for labels. 571 if (CGDebugInfo *DI = getDebugInfo()) { 572 if (CGM.getCodeGenOpts().hasReducedDebugInfo()) { 573 DI->setLocation(D->getLocation()); 574 DI->EmitLabel(D, Builder); 575 } 576 } 577 578 incrementProfileCounter(D->getStmt()); 579 } 580 581 /// Change the cleanup scope of the labels in this lexical scope to 582 /// match the scope of the enclosing context. 583 void CodeGenFunction::LexicalScope::rescopeLabels() { 584 assert(!Labels.empty()); 585 EHScopeStack::stable_iterator innermostScope 586 = CGF.EHStack.getInnermostNormalCleanup(); 587 588 // Change the scope depth of all the labels. 589 for (SmallVectorImpl<const LabelDecl*>::const_iterator 590 i = Labels.begin(), e = Labels.end(); i != e; ++i) { 591 assert(CGF.LabelMap.count(*i)); 592 JumpDest &dest = CGF.LabelMap.find(*i)->second; 593 assert(dest.getScopeDepth().isValid()); 594 assert(innermostScope.encloses(dest.getScopeDepth())); 595 dest.setScopeDepth(innermostScope); 596 } 597 598 // Reparent the labels if the new scope also has cleanups. 599 if (innermostScope != EHScopeStack::stable_end() && ParentScope) { 600 ParentScope->Labels.append(Labels.begin(), Labels.end()); 601 } 602 } 603 604 605 void CodeGenFunction::EmitLabelStmt(const LabelStmt &S) { 606 EmitLabel(S.getDecl()); 607 EmitStmt(S.getSubStmt()); 608 } 609 610 void CodeGenFunction::EmitAttributedStmt(const AttributedStmt &S) { 611 EmitStmt(S.getSubStmt(), S.getAttrs()); 612 } 613 614 void CodeGenFunction::EmitGotoStmt(const GotoStmt &S) { 615 // If this code is reachable then emit a stop point (if generating 616 // debug info). We have to do this ourselves because we are on the 617 // "simple" statement path. 618 if (HaveInsertPoint()) 619 EmitStopPoint(&S); 620 621 EmitBranchThroughCleanup(getJumpDestForLabel(S.getLabel())); 622 } 623 624 625 void CodeGenFunction::EmitIndirectGotoStmt(const IndirectGotoStmt &S) { 626 if (const LabelDecl *Target = S.getConstantTarget()) { 627 EmitBranchThroughCleanup(getJumpDestForLabel(Target)); 628 return; 629 } 630 631 // Ensure that we have an i8* for our PHI node. 632 llvm::Value *V = Builder.CreateBitCast(EmitScalarExpr(S.getTarget()), 633 Int8PtrTy, "addr"); 634 llvm::BasicBlock *CurBB = Builder.GetInsertBlock(); 635 636 // Get the basic block for the indirect goto. 637 llvm::BasicBlock *IndGotoBB = GetIndirectGotoBlock(); 638 639 // The first instruction in the block has to be the PHI for the switch dest, 640 // add an entry for this branch. 641 cast<llvm::PHINode>(IndGotoBB->begin())->addIncoming(V, CurBB); 642 643 EmitBranch(IndGotoBB); 644 } 645 646 void CodeGenFunction::EmitIfStmt(const IfStmt &S) { 647 // C99 6.8.4.1: The first substatement is executed if the expression compares 648 // unequal to 0. The condition must be a scalar type. 649 LexicalScope ConditionScope(*this, S.getCond()->getSourceRange()); 650 651 if (S.getInit()) 652 EmitStmt(S.getInit()); 653 654 if (S.getConditionVariable()) 655 EmitDecl(*S.getConditionVariable()); 656 657 // If the condition constant folds and can be elided, try to avoid emitting 658 // the condition and the dead arm of the if/else. 659 bool CondConstant; 660 if (ConstantFoldsToSimpleInteger(S.getCond(), CondConstant, 661 S.isConstexpr())) { 662 // Figure out which block (then or else) is executed. 663 const Stmt *Executed = S.getThen(); 664 const Stmt *Skipped = S.getElse(); 665 if (!CondConstant) // Condition false? 666 std::swap(Executed, Skipped); 667 668 // If the skipped block has no labels in it, just emit the executed block. 669 // This avoids emitting dead code and simplifies the CFG substantially. 670 if (S.isConstexpr() || !ContainsLabel(Skipped)) { 671 if (CondConstant) 672 incrementProfileCounter(&S); 673 if (Executed) { 674 RunCleanupsScope ExecutedScope(*this); 675 EmitStmt(Executed); 676 } 677 return; 678 } 679 } 680 681 // Otherwise, the condition did not fold, or we couldn't elide it. Just emit 682 // the conditional branch. 683 llvm::BasicBlock *ThenBlock = createBasicBlock("if.then"); 684 llvm::BasicBlock *ContBlock = createBasicBlock("if.end"); 685 llvm::BasicBlock *ElseBlock = ContBlock; 686 if (S.getElse()) 687 ElseBlock = createBasicBlock("if.else"); 688 689 EmitBranchOnBoolExpr(S.getCond(), ThenBlock, ElseBlock, 690 getProfileCount(S.getThen())); 691 692 // Emit the 'then' code. 693 EmitBlock(ThenBlock); 694 incrementProfileCounter(&S); 695 { 696 RunCleanupsScope ThenScope(*this); 697 EmitStmt(S.getThen()); 698 } 699 EmitBranch(ContBlock); 700 701 // Emit the 'else' code if present. 702 if (const Stmt *Else = S.getElse()) { 703 { 704 // There is no need to emit line number for an unconditional branch. 705 auto NL = ApplyDebugLocation::CreateEmpty(*this); 706 EmitBlock(ElseBlock); 707 } 708 { 709 RunCleanupsScope ElseScope(*this); 710 EmitStmt(Else); 711 } 712 { 713 // There is no need to emit line number for an unconditional branch. 714 auto NL = ApplyDebugLocation::CreateEmpty(*this); 715 EmitBranch(ContBlock); 716 } 717 } 718 719 // Emit the continuation block for code after the if. 720 EmitBlock(ContBlock, true); 721 } 722 723 void CodeGenFunction::EmitWhileStmt(const WhileStmt &S, 724 ArrayRef<const Attr *> WhileAttrs) { 725 // Emit the header for the loop, which will also become 726 // the continue target. 727 JumpDest LoopHeader = getJumpDestInCurrentScope("while.cond"); 728 EmitBlock(LoopHeader.getBlock()); 729 730 const SourceRange &R = S.getSourceRange(); 731 LoopStack.push(LoopHeader.getBlock(), CGM.getContext(), CGM.getCodeGenOpts(), 732 WhileAttrs, SourceLocToDebugLoc(R.getBegin()), 733 SourceLocToDebugLoc(R.getEnd())); 734 735 // Create an exit block for when the condition fails, which will 736 // also become the break target. 737 JumpDest LoopExit = getJumpDestInCurrentScope("while.end"); 738 739 // Store the blocks to use for break and continue. 740 BreakContinueStack.push_back(BreakContinue(LoopExit, LoopHeader)); 741 742 // C++ [stmt.while]p2: 743 // When the condition of a while statement is a declaration, the 744 // scope of the variable that is declared extends from its point 745 // of declaration (3.3.2) to the end of the while statement. 746 // [...] 747 // The object created in a condition is destroyed and created 748 // with each iteration of the loop. 749 RunCleanupsScope ConditionScope(*this); 750 751 if (S.getConditionVariable()) 752 EmitDecl(*S.getConditionVariable()); 753 754 // Evaluate the conditional in the while header. C99 6.8.5.1: The 755 // evaluation of the controlling expression takes place before each 756 // execution of the loop body. 757 llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond()); 758 759 // while(1) is common, avoid extra exit blocks. Be sure 760 // to correctly handle break/continue though. 761 bool EmitBoolCondBranch = true; 762 if (llvm::ConstantInt *C = dyn_cast<llvm::ConstantInt>(BoolCondVal)) 763 if (C->isOne()) 764 EmitBoolCondBranch = false; 765 766 // As long as the condition is true, go to the loop body. 767 llvm::BasicBlock *LoopBody = createBasicBlock("while.body"); 768 if (EmitBoolCondBranch) { 769 llvm::BasicBlock *ExitBlock = LoopExit.getBlock(); 770 if (ConditionScope.requiresCleanups()) 771 ExitBlock = createBasicBlock("while.exit"); 772 Builder.CreateCondBr( 773 BoolCondVal, LoopBody, ExitBlock, 774 createProfileWeightsForLoop(S.getCond(), getProfileCount(S.getBody()))); 775 776 if (ExitBlock != LoopExit.getBlock()) { 777 EmitBlock(ExitBlock); 778 EmitBranchThroughCleanup(LoopExit); 779 } 780 } 781 782 // Emit the loop body. We have to emit this in a cleanup scope 783 // because it might be a singleton DeclStmt. 784 { 785 RunCleanupsScope BodyScope(*this); 786 EmitBlock(LoopBody); 787 incrementProfileCounter(&S); 788 EmitStmt(S.getBody()); 789 } 790 791 BreakContinueStack.pop_back(); 792 793 // Immediately force cleanup. 794 ConditionScope.ForceCleanup(); 795 796 EmitStopPoint(&S); 797 // Branch to the loop header again. 798 EmitBranch(LoopHeader.getBlock()); 799 800 LoopStack.pop(); 801 802 // Emit the exit block. 803 EmitBlock(LoopExit.getBlock(), true); 804 805 // The LoopHeader typically is just a branch if we skipped emitting 806 // a branch, try to erase it. 807 if (!EmitBoolCondBranch) 808 SimplifyForwardingBlocks(LoopHeader.getBlock()); 809 } 810 811 void CodeGenFunction::EmitDoStmt(const DoStmt &S, 812 ArrayRef<const Attr *> DoAttrs) { 813 JumpDest LoopExit = getJumpDestInCurrentScope("do.end"); 814 JumpDest LoopCond = getJumpDestInCurrentScope("do.cond"); 815 816 uint64_t ParentCount = getCurrentProfileCount(); 817 818 // Store the blocks to use for break and continue. 819 BreakContinueStack.push_back(BreakContinue(LoopExit, LoopCond)); 820 821 // Emit the body of the loop. 822 llvm::BasicBlock *LoopBody = createBasicBlock("do.body"); 823 824 EmitBlockWithFallThrough(LoopBody, &S); 825 { 826 RunCleanupsScope BodyScope(*this); 827 EmitStmt(S.getBody()); 828 } 829 830 EmitBlock(LoopCond.getBlock()); 831 832 const SourceRange &R = S.getSourceRange(); 833 LoopStack.push(LoopBody, CGM.getContext(), CGM.getCodeGenOpts(), DoAttrs, 834 SourceLocToDebugLoc(R.getBegin()), 835 SourceLocToDebugLoc(R.getEnd())); 836 837 // C99 6.8.5.2: "The evaluation of the controlling expression takes place 838 // after each execution of the loop body." 839 840 // Evaluate the conditional in the while header. 841 // C99 6.8.5p2/p4: The first substatement is executed if the expression 842 // compares unequal to 0. The condition must be a scalar type. 843 llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond()); 844 845 BreakContinueStack.pop_back(); 846 847 // "do {} while (0)" is common in macros, avoid extra blocks. Be sure 848 // to correctly handle break/continue though. 849 bool EmitBoolCondBranch = true; 850 if (llvm::ConstantInt *C = dyn_cast<llvm::ConstantInt>(BoolCondVal)) 851 if (C->isZero()) 852 EmitBoolCondBranch = false; 853 854 // As long as the condition is true, iterate the loop. 855 if (EmitBoolCondBranch) { 856 uint64_t BackedgeCount = getProfileCount(S.getBody()) - ParentCount; 857 Builder.CreateCondBr( 858 BoolCondVal, LoopBody, LoopExit.getBlock(), 859 createProfileWeightsForLoop(S.getCond(), BackedgeCount)); 860 } 861 862 LoopStack.pop(); 863 864 // Emit the exit block. 865 EmitBlock(LoopExit.getBlock()); 866 867 // The DoCond block typically is just a branch if we skipped 868 // emitting a branch, try to erase it. 869 if (!EmitBoolCondBranch) 870 SimplifyForwardingBlocks(LoopCond.getBlock()); 871 } 872 873 void CodeGenFunction::EmitForStmt(const ForStmt &S, 874 ArrayRef<const Attr *> ForAttrs) { 875 JumpDest LoopExit = getJumpDestInCurrentScope("for.end"); 876 877 LexicalScope ForScope(*this, S.getSourceRange()); 878 879 // Evaluate the first part before the loop. 880 if (S.getInit()) 881 EmitStmt(S.getInit()); 882 883 // Start the loop with a block that tests the condition. 884 // If there's an increment, the continue scope will be overwritten 885 // later. 886 JumpDest Continue = getJumpDestInCurrentScope("for.cond"); 887 llvm::BasicBlock *CondBlock = Continue.getBlock(); 888 EmitBlock(CondBlock); 889 890 const SourceRange &R = S.getSourceRange(); 891 LoopStack.push(CondBlock, CGM.getContext(), CGM.getCodeGenOpts(), ForAttrs, 892 SourceLocToDebugLoc(R.getBegin()), 893 SourceLocToDebugLoc(R.getEnd())); 894 895 // If the for loop doesn't have an increment we can just use the 896 // condition as the continue block. Otherwise we'll need to create 897 // a block for it (in the current scope, i.e. in the scope of the 898 // condition), and that we will become our continue block. 899 if (S.getInc()) 900 Continue = getJumpDestInCurrentScope("for.inc"); 901 902 // Store the blocks to use for break and continue. 903 BreakContinueStack.push_back(BreakContinue(LoopExit, Continue)); 904 905 // Create a cleanup scope for the condition variable cleanups. 906 LexicalScope ConditionScope(*this, S.getSourceRange()); 907 908 if (S.getCond()) { 909 // If the for statement has a condition scope, emit the local variable 910 // declaration. 911 if (S.getConditionVariable()) { 912 EmitDecl(*S.getConditionVariable()); 913 } 914 915 llvm::BasicBlock *ExitBlock = LoopExit.getBlock(); 916 // If there are any cleanups between here and the loop-exit scope, 917 // create a block to stage a loop exit along. 918 if (ForScope.requiresCleanups()) 919 ExitBlock = createBasicBlock("for.cond.cleanup"); 920 921 // As long as the condition is true, iterate the loop. 922 llvm::BasicBlock *ForBody = createBasicBlock("for.body"); 923 924 // C99 6.8.5p2/p4: The first substatement is executed if the expression 925 // compares unequal to 0. The condition must be a scalar type. 926 llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond()); 927 Builder.CreateCondBr( 928 BoolCondVal, ForBody, ExitBlock, 929 createProfileWeightsForLoop(S.getCond(), getProfileCount(S.getBody()))); 930 931 if (ExitBlock != LoopExit.getBlock()) { 932 EmitBlock(ExitBlock); 933 EmitBranchThroughCleanup(LoopExit); 934 } 935 936 EmitBlock(ForBody); 937 } else { 938 // Treat it as a non-zero constant. Don't even create a new block for the 939 // body, just fall into it. 940 } 941 incrementProfileCounter(&S); 942 943 { 944 // Create a separate cleanup scope for the body, in case it is not 945 // a compound statement. 946 RunCleanupsScope BodyScope(*this); 947 EmitStmt(S.getBody()); 948 } 949 950 // If there is an increment, emit it next. 951 if (S.getInc()) { 952 EmitBlock(Continue.getBlock()); 953 EmitStmt(S.getInc()); 954 } 955 956 BreakContinueStack.pop_back(); 957 958 ConditionScope.ForceCleanup(); 959 960 EmitStopPoint(&S); 961 EmitBranch(CondBlock); 962 963 ForScope.ForceCleanup(); 964 965 LoopStack.pop(); 966 967 // Emit the fall-through block. 968 EmitBlock(LoopExit.getBlock(), true); 969 } 970 971 void 972 CodeGenFunction::EmitCXXForRangeStmt(const CXXForRangeStmt &S, 973 ArrayRef<const Attr *> ForAttrs) { 974 JumpDest LoopExit = getJumpDestInCurrentScope("for.end"); 975 976 LexicalScope ForScope(*this, S.getSourceRange()); 977 978 // Evaluate the first pieces before the loop. 979 if (S.getInit()) 980 EmitStmt(S.getInit()); 981 EmitStmt(S.getRangeStmt()); 982 EmitStmt(S.getBeginStmt()); 983 EmitStmt(S.getEndStmt()); 984 985 // Start the loop with a block that tests the condition. 986 // If there's an increment, the continue scope will be overwritten 987 // later. 988 llvm::BasicBlock *CondBlock = createBasicBlock("for.cond"); 989 EmitBlock(CondBlock); 990 991 const SourceRange &R = S.getSourceRange(); 992 LoopStack.push(CondBlock, CGM.getContext(), CGM.getCodeGenOpts(), ForAttrs, 993 SourceLocToDebugLoc(R.getBegin()), 994 SourceLocToDebugLoc(R.getEnd())); 995 996 // If there are any cleanups between here and the loop-exit scope, 997 // create a block to stage a loop exit along. 998 llvm::BasicBlock *ExitBlock = LoopExit.getBlock(); 999 if (ForScope.requiresCleanups()) 1000 ExitBlock = createBasicBlock("for.cond.cleanup"); 1001 1002 // The loop body, consisting of the specified body and the loop variable. 1003 llvm::BasicBlock *ForBody = createBasicBlock("for.body"); 1004 1005 // The body is executed if the expression, contextually converted 1006 // to bool, is true. 1007 llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond()); 1008 Builder.CreateCondBr( 1009 BoolCondVal, ForBody, ExitBlock, 1010 createProfileWeightsForLoop(S.getCond(), getProfileCount(S.getBody()))); 1011 1012 if (ExitBlock != LoopExit.getBlock()) { 1013 EmitBlock(ExitBlock); 1014 EmitBranchThroughCleanup(LoopExit); 1015 } 1016 1017 EmitBlock(ForBody); 1018 incrementProfileCounter(&S); 1019 1020 // Create a block for the increment. In case of a 'continue', we jump there. 1021 JumpDest Continue = getJumpDestInCurrentScope("for.inc"); 1022 1023 // Store the blocks to use for break and continue. 1024 BreakContinueStack.push_back(BreakContinue(LoopExit, Continue)); 1025 1026 { 1027 // Create a separate cleanup scope for the loop variable and body. 1028 LexicalScope BodyScope(*this, S.getSourceRange()); 1029 EmitStmt(S.getLoopVarStmt()); 1030 EmitStmt(S.getBody()); 1031 } 1032 1033 EmitStopPoint(&S); 1034 // If there is an increment, emit it next. 1035 EmitBlock(Continue.getBlock()); 1036 EmitStmt(S.getInc()); 1037 1038 BreakContinueStack.pop_back(); 1039 1040 EmitBranch(CondBlock); 1041 1042 ForScope.ForceCleanup(); 1043 1044 LoopStack.pop(); 1045 1046 // Emit the fall-through block. 1047 EmitBlock(LoopExit.getBlock(), true); 1048 } 1049 1050 void CodeGenFunction::EmitReturnOfRValue(RValue RV, QualType Ty) { 1051 if (RV.isScalar()) { 1052 Builder.CreateStore(RV.getScalarVal(), ReturnValue); 1053 } else if (RV.isAggregate()) { 1054 LValue Dest = MakeAddrLValue(ReturnValue, Ty); 1055 LValue Src = MakeAddrLValue(RV.getAggregateAddress(), Ty); 1056 EmitAggregateCopy(Dest, Src, Ty, getOverlapForReturnValue()); 1057 } else { 1058 EmitStoreOfComplex(RV.getComplexVal(), MakeAddrLValue(ReturnValue, Ty), 1059 /*init*/ true); 1060 } 1061 EmitBranchThroughCleanup(ReturnBlock); 1062 } 1063 1064 /// EmitReturnStmt - Note that due to GCC extensions, this can have an operand 1065 /// if the function returns void, or may be missing one if the function returns 1066 /// non-void. Fun stuff :). 1067 void CodeGenFunction::EmitReturnStmt(const ReturnStmt &S) { 1068 if (requiresReturnValueCheck()) { 1069 llvm::Constant *SLoc = EmitCheckSourceLocation(S.getBeginLoc()); 1070 auto *SLocPtr = 1071 new llvm::GlobalVariable(CGM.getModule(), SLoc->getType(), false, 1072 llvm::GlobalVariable::PrivateLinkage, SLoc); 1073 SLocPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); 1074 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(SLocPtr); 1075 assert(ReturnLocation.isValid() && "No valid return location"); 1076 Builder.CreateStore(Builder.CreateBitCast(SLocPtr, Int8PtrTy), 1077 ReturnLocation); 1078 } 1079 1080 // Returning from an outlined SEH helper is UB, and we already warn on it. 1081 if (IsOutlinedSEHHelper) { 1082 Builder.CreateUnreachable(); 1083 Builder.ClearInsertionPoint(); 1084 } 1085 1086 // Emit the result value, even if unused, to evaluate the side effects. 1087 const Expr *RV = S.getRetValue(); 1088 1089 // Treat block literals in a return expression as if they appeared 1090 // in their own scope. This permits a small, easily-implemented 1091 // exception to our over-conservative rules about not jumping to 1092 // statements following block literals with non-trivial cleanups. 1093 RunCleanupsScope cleanupScope(*this); 1094 if (const FullExpr *fe = dyn_cast_or_null<FullExpr>(RV)) { 1095 enterFullExpression(fe); 1096 RV = fe->getSubExpr(); 1097 } 1098 1099 // FIXME: Clean this up by using an LValue for ReturnTemp, 1100 // EmitStoreThroughLValue, and EmitAnyExpr. 1101 if (getLangOpts().ElideConstructors && 1102 S.getNRVOCandidate() && S.getNRVOCandidate()->isNRVOVariable()) { 1103 // Apply the named return value optimization for this return statement, 1104 // which means doing nothing: the appropriate result has already been 1105 // constructed into the NRVO variable. 1106 1107 // If there is an NRVO flag for this variable, set it to 1 into indicate 1108 // that the cleanup code should not destroy the variable. 1109 if (llvm::Value *NRVOFlag = NRVOFlags[S.getNRVOCandidate()]) 1110 Builder.CreateFlagStore(Builder.getTrue(), NRVOFlag); 1111 } else if (!ReturnValue.isValid() || (RV && RV->getType()->isVoidType())) { 1112 // Make sure not to return anything, but evaluate the expression 1113 // for side effects. 1114 if (RV) 1115 EmitAnyExpr(RV); 1116 } else if (!RV) { 1117 // Do nothing (return value is left uninitialized) 1118 } else if (FnRetTy->isReferenceType()) { 1119 // If this function returns a reference, take the address of the expression 1120 // rather than the value. 1121 RValue Result = EmitReferenceBindingToExpr(RV); 1122 Builder.CreateStore(Result.getScalarVal(), ReturnValue); 1123 } else { 1124 switch (getEvaluationKind(RV->getType())) { 1125 case TEK_Scalar: 1126 Builder.CreateStore(EmitScalarExpr(RV), ReturnValue); 1127 break; 1128 case TEK_Complex: 1129 EmitComplexExprIntoLValue(RV, MakeAddrLValue(ReturnValue, RV->getType()), 1130 /*isInit*/ true); 1131 break; 1132 case TEK_Aggregate: 1133 EmitAggExpr(RV, AggValueSlot::forAddr( 1134 ReturnValue, Qualifiers(), 1135 AggValueSlot::IsDestructed, 1136 AggValueSlot::DoesNotNeedGCBarriers, 1137 AggValueSlot::IsNotAliased, 1138 getOverlapForReturnValue())); 1139 break; 1140 } 1141 } 1142 1143 ++NumReturnExprs; 1144 if (!RV || RV->isEvaluatable(getContext())) 1145 ++NumSimpleReturnExprs; 1146 1147 cleanupScope.ForceCleanup(); 1148 EmitBranchThroughCleanup(ReturnBlock); 1149 } 1150 1151 void CodeGenFunction::EmitDeclStmt(const DeclStmt &S) { 1152 // As long as debug info is modeled with instructions, we have to ensure we 1153 // have a place to insert here and write the stop point here. 1154 if (HaveInsertPoint()) 1155 EmitStopPoint(&S); 1156 1157 for (const auto *I : S.decls()) 1158 EmitDecl(*I); 1159 } 1160 1161 void CodeGenFunction::EmitBreakStmt(const BreakStmt &S) { 1162 assert(!BreakContinueStack.empty() && "break stmt not in a loop or switch!"); 1163 1164 // If this code is reachable then emit a stop point (if generating 1165 // debug info). We have to do this ourselves because we are on the 1166 // "simple" statement path. 1167 if (HaveInsertPoint()) 1168 EmitStopPoint(&S); 1169 1170 EmitBranchThroughCleanup(BreakContinueStack.back().BreakBlock); 1171 } 1172 1173 void CodeGenFunction::EmitContinueStmt(const ContinueStmt &S) { 1174 assert(!BreakContinueStack.empty() && "continue stmt not in a loop!"); 1175 1176 // If this code is reachable then emit a stop point (if generating 1177 // debug info). We have to do this ourselves because we are on the 1178 // "simple" statement path. 1179 if (HaveInsertPoint()) 1180 EmitStopPoint(&S); 1181 1182 EmitBranchThroughCleanup(BreakContinueStack.back().ContinueBlock); 1183 } 1184 1185 /// EmitCaseStmtRange - If case statement range is not too big then 1186 /// add multiple cases to switch instruction, one for each value within 1187 /// the range. If range is too big then emit "if" condition check. 1188 void CodeGenFunction::EmitCaseStmtRange(const CaseStmt &S) { 1189 assert(S.getRHS() && "Expected RHS value in CaseStmt"); 1190 1191 llvm::APSInt LHS = S.getLHS()->EvaluateKnownConstInt(getContext()); 1192 llvm::APSInt RHS = S.getRHS()->EvaluateKnownConstInt(getContext()); 1193 1194 // Emit the code for this case. We do this first to make sure it is 1195 // properly chained from our predecessor before generating the 1196 // switch machinery to enter this block. 1197 llvm::BasicBlock *CaseDest = createBasicBlock("sw.bb"); 1198 EmitBlockWithFallThrough(CaseDest, &S); 1199 EmitStmt(S.getSubStmt()); 1200 1201 // If range is empty, do nothing. 1202 if (LHS.isSigned() ? RHS.slt(LHS) : RHS.ult(LHS)) 1203 return; 1204 1205 llvm::APInt Range = RHS - LHS; 1206 // FIXME: parameters such as this should not be hardcoded. 1207 if (Range.ult(llvm::APInt(Range.getBitWidth(), 64))) { 1208 // Range is small enough to add multiple switch instruction cases. 1209 uint64_t Total = getProfileCount(&S); 1210 unsigned NCases = Range.getZExtValue() + 1; 1211 // We only have one region counter for the entire set of cases here, so we 1212 // need to divide the weights evenly between the generated cases, ensuring 1213 // that the total weight is preserved. E.g., a weight of 5 over three cases 1214 // will be distributed as weights of 2, 2, and 1. 1215 uint64_t Weight = Total / NCases, Rem = Total % NCases; 1216 for (unsigned I = 0; I != NCases; ++I) { 1217 if (SwitchWeights) 1218 SwitchWeights->push_back(Weight + (Rem ? 1 : 0)); 1219 if (Rem) 1220 Rem--; 1221 SwitchInsn->addCase(Builder.getInt(LHS), CaseDest); 1222 ++LHS; 1223 } 1224 return; 1225 } 1226 1227 // The range is too big. Emit "if" condition into a new block, 1228 // making sure to save and restore the current insertion point. 1229 llvm::BasicBlock *RestoreBB = Builder.GetInsertBlock(); 1230 1231 // Push this test onto the chain of range checks (which terminates 1232 // in the default basic block). The switch's default will be changed 1233 // to the top of this chain after switch emission is complete. 1234 llvm::BasicBlock *FalseDest = CaseRangeBlock; 1235 CaseRangeBlock = createBasicBlock("sw.caserange"); 1236 1237 CurFn->getBasicBlockList().push_back(CaseRangeBlock); 1238 Builder.SetInsertPoint(CaseRangeBlock); 1239 1240 // Emit range check. 1241 llvm::Value *Diff = 1242 Builder.CreateSub(SwitchInsn->getCondition(), Builder.getInt(LHS)); 1243 llvm::Value *Cond = 1244 Builder.CreateICmpULE(Diff, Builder.getInt(Range), "inbounds"); 1245 1246 llvm::MDNode *Weights = nullptr; 1247 if (SwitchWeights) { 1248 uint64_t ThisCount = getProfileCount(&S); 1249 uint64_t DefaultCount = (*SwitchWeights)[0]; 1250 Weights = createProfileWeights(ThisCount, DefaultCount); 1251 1252 // Since we're chaining the switch default through each large case range, we 1253 // need to update the weight for the default, ie, the first case, to include 1254 // this case. 1255 (*SwitchWeights)[0] += ThisCount; 1256 } 1257 Builder.CreateCondBr(Cond, CaseDest, FalseDest, Weights); 1258 1259 // Restore the appropriate insertion point. 1260 if (RestoreBB) 1261 Builder.SetInsertPoint(RestoreBB); 1262 else 1263 Builder.ClearInsertionPoint(); 1264 } 1265 1266 void CodeGenFunction::EmitCaseStmt(const CaseStmt &S) { 1267 // If there is no enclosing switch instance that we're aware of, then this 1268 // case statement and its block can be elided. This situation only happens 1269 // when we've constant-folded the switch, are emitting the constant case, 1270 // and part of the constant case includes another case statement. For 1271 // instance: switch (4) { case 4: do { case 5: } while (1); } 1272 if (!SwitchInsn) { 1273 EmitStmt(S.getSubStmt()); 1274 return; 1275 } 1276 1277 // Handle case ranges. 1278 if (S.getRHS()) { 1279 EmitCaseStmtRange(S); 1280 return; 1281 } 1282 1283 llvm::ConstantInt *CaseVal = 1284 Builder.getInt(S.getLHS()->EvaluateKnownConstInt(getContext())); 1285 1286 // If the body of the case is just a 'break', try to not emit an empty block. 1287 // If we're profiling or we're not optimizing, leave the block in for better 1288 // debug and coverage analysis. 1289 if (!CGM.getCodeGenOpts().hasProfileClangInstr() && 1290 CGM.getCodeGenOpts().OptimizationLevel > 0 && 1291 isa<BreakStmt>(S.getSubStmt())) { 1292 JumpDest Block = BreakContinueStack.back().BreakBlock; 1293 1294 // Only do this optimization if there are no cleanups that need emitting. 1295 if (isObviouslyBranchWithoutCleanups(Block)) { 1296 if (SwitchWeights) 1297 SwitchWeights->push_back(getProfileCount(&S)); 1298 SwitchInsn->addCase(CaseVal, Block.getBlock()); 1299 1300 // If there was a fallthrough into this case, make sure to redirect it to 1301 // the end of the switch as well. 1302 if (Builder.GetInsertBlock()) { 1303 Builder.CreateBr(Block.getBlock()); 1304 Builder.ClearInsertionPoint(); 1305 } 1306 return; 1307 } 1308 } 1309 1310 llvm::BasicBlock *CaseDest = createBasicBlock("sw.bb"); 1311 EmitBlockWithFallThrough(CaseDest, &S); 1312 if (SwitchWeights) 1313 SwitchWeights->push_back(getProfileCount(&S)); 1314 SwitchInsn->addCase(CaseVal, CaseDest); 1315 1316 // Recursively emitting the statement is acceptable, but is not wonderful for 1317 // code where we have many case statements nested together, i.e.: 1318 // case 1: 1319 // case 2: 1320 // case 3: etc. 1321 // Handling this recursively will create a new block for each case statement 1322 // that falls through to the next case which is IR intensive. It also causes 1323 // deep recursion which can run into stack depth limitations. Handle 1324 // sequential non-range case statements specially. 1325 const CaseStmt *CurCase = &S; 1326 const CaseStmt *NextCase = dyn_cast<CaseStmt>(S.getSubStmt()); 1327 1328 // Otherwise, iteratively add consecutive cases to this switch stmt. 1329 while (NextCase && NextCase->getRHS() == nullptr) { 1330 CurCase = NextCase; 1331 llvm::ConstantInt *CaseVal = 1332 Builder.getInt(CurCase->getLHS()->EvaluateKnownConstInt(getContext())); 1333 1334 if (SwitchWeights) 1335 SwitchWeights->push_back(getProfileCount(NextCase)); 1336 if (CGM.getCodeGenOpts().hasProfileClangInstr()) { 1337 CaseDest = createBasicBlock("sw.bb"); 1338 EmitBlockWithFallThrough(CaseDest, &S); 1339 } 1340 1341 SwitchInsn->addCase(CaseVal, CaseDest); 1342 NextCase = dyn_cast<CaseStmt>(CurCase->getSubStmt()); 1343 } 1344 1345 // Normal default recursion for non-cases. 1346 EmitStmt(CurCase->getSubStmt()); 1347 } 1348 1349 void CodeGenFunction::EmitDefaultStmt(const DefaultStmt &S) { 1350 // If there is no enclosing switch instance that we're aware of, then this 1351 // default statement can be elided. This situation only happens when we've 1352 // constant-folded the switch. 1353 if (!SwitchInsn) { 1354 EmitStmt(S.getSubStmt()); 1355 return; 1356 } 1357 1358 llvm::BasicBlock *DefaultBlock = SwitchInsn->getDefaultDest(); 1359 assert(DefaultBlock->empty() && 1360 "EmitDefaultStmt: Default block already defined?"); 1361 1362 EmitBlockWithFallThrough(DefaultBlock, &S); 1363 1364 EmitStmt(S.getSubStmt()); 1365 } 1366 1367 /// CollectStatementsForCase - Given the body of a 'switch' statement and a 1368 /// constant value that is being switched on, see if we can dead code eliminate 1369 /// the body of the switch to a simple series of statements to emit. Basically, 1370 /// on a switch (5) we want to find these statements: 1371 /// case 5: 1372 /// printf(...); <-- 1373 /// ++i; <-- 1374 /// break; 1375 /// 1376 /// and add them to the ResultStmts vector. If it is unsafe to do this 1377 /// transformation (for example, one of the elided statements contains a label 1378 /// that might be jumped to), return CSFC_Failure. If we handled it and 'S' 1379 /// should include statements after it (e.g. the printf() line is a substmt of 1380 /// the case) then return CSFC_FallThrough. If we handled it and found a break 1381 /// statement, then return CSFC_Success. 1382 /// 1383 /// If Case is non-null, then we are looking for the specified case, checking 1384 /// that nothing we jump over contains labels. If Case is null, then we found 1385 /// the case and are looking for the break. 1386 /// 1387 /// If the recursive walk actually finds our Case, then we set FoundCase to 1388 /// true. 1389 /// 1390 enum CSFC_Result { CSFC_Failure, CSFC_FallThrough, CSFC_Success }; 1391 static CSFC_Result CollectStatementsForCase(const Stmt *S, 1392 const SwitchCase *Case, 1393 bool &FoundCase, 1394 SmallVectorImpl<const Stmt*> &ResultStmts) { 1395 // If this is a null statement, just succeed. 1396 if (!S) 1397 return Case ? CSFC_Success : CSFC_FallThrough; 1398 1399 // If this is the switchcase (case 4: or default) that we're looking for, then 1400 // we're in business. Just add the substatement. 1401 if (const SwitchCase *SC = dyn_cast<SwitchCase>(S)) { 1402 if (S == Case) { 1403 FoundCase = true; 1404 return CollectStatementsForCase(SC->getSubStmt(), nullptr, FoundCase, 1405 ResultStmts); 1406 } 1407 1408 // Otherwise, this is some other case or default statement, just ignore it. 1409 return CollectStatementsForCase(SC->getSubStmt(), Case, FoundCase, 1410 ResultStmts); 1411 } 1412 1413 // If we are in the live part of the code and we found our break statement, 1414 // return a success! 1415 if (!Case && isa<BreakStmt>(S)) 1416 return CSFC_Success; 1417 1418 // If this is a switch statement, then it might contain the SwitchCase, the 1419 // break, or neither. 1420 if (const CompoundStmt *CS = dyn_cast<CompoundStmt>(S)) { 1421 // Handle this as two cases: we might be looking for the SwitchCase (if so 1422 // the skipped statements must be skippable) or we might already have it. 1423 CompoundStmt::const_body_iterator I = CS->body_begin(), E = CS->body_end(); 1424 bool StartedInLiveCode = FoundCase; 1425 unsigned StartSize = ResultStmts.size(); 1426 1427 // If we've not found the case yet, scan through looking for it. 1428 if (Case) { 1429 // Keep track of whether we see a skipped declaration. The code could be 1430 // using the declaration even if it is skipped, so we can't optimize out 1431 // the decl if the kept statements might refer to it. 1432 bool HadSkippedDecl = false; 1433 1434 // If we're looking for the case, just see if we can skip each of the 1435 // substatements. 1436 for (; Case && I != E; ++I) { 1437 HadSkippedDecl |= CodeGenFunction::mightAddDeclToScope(*I); 1438 1439 switch (CollectStatementsForCase(*I, Case, FoundCase, ResultStmts)) { 1440 case CSFC_Failure: return CSFC_Failure; 1441 case CSFC_Success: 1442 // A successful result means that either 1) that the statement doesn't 1443 // have the case and is skippable, or 2) does contain the case value 1444 // and also contains the break to exit the switch. In the later case, 1445 // we just verify the rest of the statements are elidable. 1446 if (FoundCase) { 1447 // If we found the case and skipped declarations, we can't do the 1448 // optimization. 1449 if (HadSkippedDecl) 1450 return CSFC_Failure; 1451 1452 for (++I; I != E; ++I) 1453 if (CodeGenFunction::ContainsLabel(*I, true)) 1454 return CSFC_Failure; 1455 return CSFC_Success; 1456 } 1457 break; 1458 case CSFC_FallThrough: 1459 // If we have a fallthrough condition, then we must have found the 1460 // case started to include statements. Consider the rest of the 1461 // statements in the compound statement as candidates for inclusion. 1462 assert(FoundCase && "Didn't find case but returned fallthrough?"); 1463 // We recursively found Case, so we're not looking for it anymore. 1464 Case = nullptr; 1465 1466 // If we found the case and skipped declarations, we can't do the 1467 // optimization. 1468 if (HadSkippedDecl) 1469 return CSFC_Failure; 1470 break; 1471 } 1472 } 1473 1474 if (!FoundCase) 1475 return CSFC_Success; 1476 1477 assert(!HadSkippedDecl && "fallthrough after skipping decl"); 1478 } 1479 1480 // If we have statements in our range, then we know that the statements are 1481 // live and need to be added to the set of statements we're tracking. 1482 bool AnyDecls = false; 1483 for (; I != E; ++I) { 1484 AnyDecls |= CodeGenFunction::mightAddDeclToScope(*I); 1485 1486 switch (CollectStatementsForCase(*I, nullptr, FoundCase, ResultStmts)) { 1487 case CSFC_Failure: return CSFC_Failure; 1488 case CSFC_FallThrough: 1489 // A fallthrough result means that the statement was simple and just 1490 // included in ResultStmt, keep adding them afterwards. 1491 break; 1492 case CSFC_Success: 1493 // A successful result means that we found the break statement and 1494 // stopped statement inclusion. We just ensure that any leftover stmts 1495 // are skippable and return success ourselves. 1496 for (++I; I != E; ++I) 1497 if (CodeGenFunction::ContainsLabel(*I, true)) 1498 return CSFC_Failure; 1499 return CSFC_Success; 1500 } 1501 } 1502 1503 // If we're about to fall out of a scope without hitting a 'break;', we 1504 // can't perform the optimization if there were any decls in that scope 1505 // (we'd lose their end-of-lifetime). 1506 if (AnyDecls) { 1507 // If the entire compound statement was live, there's one more thing we 1508 // can try before giving up: emit the whole thing as a single statement. 1509 // We can do that unless the statement contains a 'break;'. 1510 // FIXME: Such a break must be at the end of a construct within this one. 1511 // We could emit this by just ignoring the BreakStmts entirely. 1512 if (StartedInLiveCode && !CodeGenFunction::containsBreak(S)) { 1513 ResultStmts.resize(StartSize); 1514 ResultStmts.push_back(S); 1515 } else { 1516 return CSFC_Failure; 1517 } 1518 } 1519 1520 return CSFC_FallThrough; 1521 } 1522 1523 // Okay, this is some other statement that we don't handle explicitly, like a 1524 // for statement or increment etc. If we are skipping over this statement, 1525 // just verify it doesn't have labels, which would make it invalid to elide. 1526 if (Case) { 1527 if (CodeGenFunction::ContainsLabel(S, true)) 1528 return CSFC_Failure; 1529 return CSFC_Success; 1530 } 1531 1532 // Otherwise, we want to include this statement. Everything is cool with that 1533 // so long as it doesn't contain a break out of the switch we're in. 1534 if (CodeGenFunction::containsBreak(S)) return CSFC_Failure; 1535 1536 // Otherwise, everything is great. Include the statement and tell the caller 1537 // that we fall through and include the next statement as well. 1538 ResultStmts.push_back(S); 1539 return CSFC_FallThrough; 1540 } 1541 1542 /// FindCaseStatementsForValue - Find the case statement being jumped to and 1543 /// then invoke CollectStatementsForCase to find the list of statements to emit 1544 /// for a switch on constant. See the comment above CollectStatementsForCase 1545 /// for more details. 1546 static bool FindCaseStatementsForValue(const SwitchStmt &S, 1547 const llvm::APSInt &ConstantCondValue, 1548 SmallVectorImpl<const Stmt*> &ResultStmts, 1549 ASTContext &C, 1550 const SwitchCase *&ResultCase) { 1551 // First step, find the switch case that is being branched to. We can do this 1552 // efficiently by scanning the SwitchCase list. 1553 const SwitchCase *Case = S.getSwitchCaseList(); 1554 const DefaultStmt *DefaultCase = nullptr; 1555 1556 for (; Case; Case = Case->getNextSwitchCase()) { 1557 // It's either a default or case. Just remember the default statement in 1558 // case we're not jumping to any numbered cases. 1559 if (const DefaultStmt *DS = dyn_cast<DefaultStmt>(Case)) { 1560 DefaultCase = DS; 1561 continue; 1562 } 1563 1564 // Check to see if this case is the one we're looking for. 1565 const CaseStmt *CS = cast<CaseStmt>(Case); 1566 // Don't handle case ranges yet. 1567 if (CS->getRHS()) return false; 1568 1569 // If we found our case, remember it as 'case'. 1570 if (CS->getLHS()->EvaluateKnownConstInt(C) == ConstantCondValue) 1571 break; 1572 } 1573 1574 // If we didn't find a matching case, we use a default if it exists, or we 1575 // elide the whole switch body! 1576 if (!Case) { 1577 // It is safe to elide the body of the switch if it doesn't contain labels 1578 // etc. If it is safe, return successfully with an empty ResultStmts list. 1579 if (!DefaultCase) 1580 return !CodeGenFunction::ContainsLabel(&S); 1581 Case = DefaultCase; 1582 } 1583 1584 // Ok, we know which case is being jumped to, try to collect all the 1585 // statements that follow it. This can fail for a variety of reasons. Also, 1586 // check to see that the recursive walk actually found our case statement. 1587 // Insane cases like this can fail to find it in the recursive walk since we 1588 // don't handle every stmt kind: 1589 // switch (4) { 1590 // while (1) { 1591 // case 4: ... 1592 bool FoundCase = false; 1593 ResultCase = Case; 1594 return CollectStatementsForCase(S.getBody(), Case, FoundCase, 1595 ResultStmts) != CSFC_Failure && 1596 FoundCase; 1597 } 1598 1599 void CodeGenFunction::EmitSwitchStmt(const SwitchStmt &S) { 1600 // Handle nested switch statements. 1601 llvm::SwitchInst *SavedSwitchInsn = SwitchInsn; 1602 SmallVector<uint64_t, 16> *SavedSwitchWeights = SwitchWeights; 1603 llvm::BasicBlock *SavedCRBlock = CaseRangeBlock; 1604 1605 // See if we can constant fold the condition of the switch and therefore only 1606 // emit the live case statement (if any) of the switch. 1607 llvm::APSInt ConstantCondValue; 1608 if (ConstantFoldsToSimpleInteger(S.getCond(), ConstantCondValue)) { 1609 SmallVector<const Stmt*, 4> CaseStmts; 1610 const SwitchCase *Case = nullptr; 1611 if (FindCaseStatementsForValue(S, ConstantCondValue, CaseStmts, 1612 getContext(), Case)) { 1613 if (Case) 1614 incrementProfileCounter(Case); 1615 RunCleanupsScope ExecutedScope(*this); 1616 1617 if (S.getInit()) 1618 EmitStmt(S.getInit()); 1619 1620 // Emit the condition variable if needed inside the entire cleanup scope 1621 // used by this special case for constant folded switches. 1622 if (S.getConditionVariable()) 1623 EmitDecl(*S.getConditionVariable()); 1624 1625 // At this point, we are no longer "within" a switch instance, so 1626 // we can temporarily enforce this to ensure that any embedded case 1627 // statements are not emitted. 1628 SwitchInsn = nullptr; 1629 1630 // Okay, we can dead code eliminate everything except this case. Emit the 1631 // specified series of statements and we're good. 1632 for (unsigned i = 0, e = CaseStmts.size(); i != e; ++i) 1633 EmitStmt(CaseStmts[i]); 1634 incrementProfileCounter(&S); 1635 1636 // Now we want to restore the saved switch instance so that nested 1637 // switches continue to function properly 1638 SwitchInsn = SavedSwitchInsn; 1639 1640 return; 1641 } 1642 } 1643 1644 JumpDest SwitchExit = getJumpDestInCurrentScope("sw.epilog"); 1645 1646 RunCleanupsScope ConditionScope(*this); 1647 1648 if (S.getInit()) 1649 EmitStmt(S.getInit()); 1650 1651 if (S.getConditionVariable()) 1652 EmitDecl(*S.getConditionVariable()); 1653 llvm::Value *CondV = EmitScalarExpr(S.getCond()); 1654 1655 // Create basic block to hold stuff that comes after switch 1656 // statement. We also need to create a default block now so that 1657 // explicit case ranges tests can have a place to jump to on 1658 // failure. 1659 llvm::BasicBlock *DefaultBlock = createBasicBlock("sw.default"); 1660 SwitchInsn = Builder.CreateSwitch(CondV, DefaultBlock); 1661 if (PGO.haveRegionCounts()) { 1662 // Walk the SwitchCase list to find how many there are. 1663 uint64_t DefaultCount = 0; 1664 unsigned NumCases = 0; 1665 for (const SwitchCase *Case = S.getSwitchCaseList(); 1666 Case; 1667 Case = Case->getNextSwitchCase()) { 1668 if (isa<DefaultStmt>(Case)) 1669 DefaultCount = getProfileCount(Case); 1670 NumCases += 1; 1671 } 1672 SwitchWeights = new SmallVector<uint64_t, 16>(); 1673 SwitchWeights->reserve(NumCases); 1674 // The default needs to be first. We store the edge count, so we already 1675 // know the right weight. 1676 SwitchWeights->push_back(DefaultCount); 1677 } 1678 CaseRangeBlock = DefaultBlock; 1679 1680 // Clear the insertion point to indicate we are in unreachable code. 1681 Builder.ClearInsertionPoint(); 1682 1683 // All break statements jump to NextBlock. If BreakContinueStack is non-empty 1684 // then reuse last ContinueBlock. 1685 JumpDest OuterContinue; 1686 if (!BreakContinueStack.empty()) 1687 OuterContinue = BreakContinueStack.back().ContinueBlock; 1688 1689 BreakContinueStack.push_back(BreakContinue(SwitchExit, OuterContinue)); 1690 1691 // Emit switch body. 1692 EmitStmt(S.getBody()); 1693 1694 BreakContinueStack.pop_back(); 1695 1696 // Update the default block in case explicit case range tests have 1697 // been chained on top. 1698 SwitchInsn->setDefaultDest(CaseRangeBlock); 1699 1700 // If a default was never emitted: 1701 if (!DefaultBlock->getParent()) { 1702 // If we have cleanups, emit the default block so that there's a 1703 // place to jump through the cleanups from. 1704 if (ConditionScope.requiresCleanups()) { 1705 EmitBlock(DefaultBlock); 1706 1707 // Otherwise, just forward the default block to the switch end. 1708 } else { 1709 DefaultBlock->replaceAllUsesWith(SwitchExit.getBlock()); 1710 delete DefaultBlock; 1711 } 1712 } 1713 1714 ConditionScope.ForceCleanup(); 1715 1716 // Emit continuation. 1717 EmitBlock(SwitchExit.getBlock(), true); 1718 incrementProfileCounter(&S); 1719 1720 // If the switch has a condition wrapped by __builtin_unpredictable, 1721 // create metadata that specifies that the switch is unpredictable. 1722 // Don't bother if not optimizing because that metadata would not be used. 1723 auto *Call = dyn_cast<CallExpr>(S.getCond()); 1724 if (Call && CGM.getCodeGenOpts().OptimizationLevel != 0) { 1725 auto *FD = dyn_cast_or_null<FunctionDecl>(Call->getCalleeDecl()); 1726 if (FD && FD->getBuiltinID() == Builtin::BI__builtin_unpredictable) { 1727 llvm::MDBuilder MDHelper(getLLVMContext()); 1728 SwitchInsn->setMetadata(llvm::LLVMContext::MD_unpredictable, 1729 MDHelper.createUnpredictable()); 1730 } 1731 } 1732 1733 if (SwitchWeights) { 1734 assert(SwitchWeights->size() == 1 + SwitchInsn->getNumCases() && 1735 "switch weights do not match switch cases"); 1736 // If there's only one jump destination there's no sense weighting it. 1737 if (SwitchWeights->size() > 1) 1738 SwitchInsn->setMetadata(llvm::LLVMContext::MD_prof, 1739 createProfileWeights(*SwitchWeights)); 1740 delete SwitchWeights; 1741 } 1742 SwitchInsn = SavedSwitchInsn; 1743 SwitchWeights = SavedSwitchWeights; 1744 CaseRangeBlock = SavedCRBlock; 1745 } 1746 1747 static std::string 1748 SimplifyConstraint(const char *Constraint, const TargetInfo &Target, 1749 SmallVectorImpl<TargetInfo::ConstraintInfo> *OutCons=nullptr) { 1750 std::string Result; 1751 1752 while (*Constraint) { 1753 switch (*Constraint) { 1754 default: 1755 Result += Target.convertConstraint(Constraint); 1756 break; 1757 // Ignore these 1758 case '*': 1759 case '?': 1760 case '!': 1761 case '=': // Will see this and the following in mult-alt constraints. 1762 case '+': 1763 break; 1764 case '#': // Ignore the rest of the constraint alternative. 1765 while (Constraint[1] && Constraint[1] != ',') 1766 Constraint++; 1767 break; 1768 case '&': 1769 case '%': 1770 Result += *Constraint; 1771 while (Constraint[1] && Constraint[1] == *Constraint) 1772 Constraint++; 1773 break; 1774 case ',': 1775 Result += "|"; 1776 break; 1777 case 'g': 1778 Result += "imr"; 1779 break; 1780 case '[': { 1781 assert(OutCons && 1782 "Must pass output names to constraints with a symbolic name"); 1783 unsigned Index; 1784 bool result = Target.resolveSymbolicName(Constraint, *OutCons, Index); 1785 assert(result && "Could not resolve symbolic name"); (void)result; 1786 Result += llvm::utostr(Index); 1787 break; 1788 } 1789 } 1790 1791 Constraint++; 1792 } 1793 1794 return Result; 1795 } 1796 1797 /// AddVariableConstraints - Look at AsmExpr and if it is a variable declared 1798 /// as using a particular register add that as a constraint that will be used 1799 /// in this asm stmt. 1800 static std::string 1801 AddVariableConstraints(const std::string &Constraint, const Expr &AsmExpr, 1802 const TargetInfo &Target, CodeGenModule &CGM, 1803 const AsmStmt &Stmt, const bool EarlyClobber) { 1804 const DeclRefExpr *AsmDeclRef = dyn_cast<DeclRefExpr>(&AsmExpr); 1805 if (!AsmDeclRef) 1806 return Constraint; 1807 const ValueDecl &Value = *AsmDeclRef->getDecl(); 1808 const VarDecl *Variable = dyn_cast<VarDecl>(&Value); 1809 if (!Variable) 1810 return Constraint; 1811 if (Variable->getStorageClass() != SC_Register) 1812 return Constraint; 1813 AsmLabelAttr *Attr = Variable->getAttr<AsmLabelAttr>(); 1814 if (!Attr) 1815 return Constraint; 1816 StringRef Register = Attr->getLabel(); 1817 assert(Target.isValidGCCRegisterName(Register)); 1818 // We're using validateOutputConstraint here because we only care if 1819 // this is a register constraint. 1820 TargetInfo::ConstraintInfo Info(Constraint, ""); 1821 if (Target.validateOutputConstraint(Info) && 1822 !Info.allowsRegister()) { 1823 CGM.ErrorUnsupported(&Stmt, "__asm__"); 1824 return Constraint; 1825 } 1826 // Canonicalize the register here before returning it. 1827 Register = Target.getNormalizedGCCRegisterName(Register); 1828 return (EarlyClobber ? "&{" : "{") + Register.str() + "}"; 1829 } 1830 1831 llvm::Value* 1832 CodeGenFunction::EmitAsmInputLValue(const TargetInfo::ConstraintInfo &Info, 1833 LValue InputValue, QualType InputType, 1834 std::string &ConstraintStr, 1835 SourceLocation Loc) { 1836 llvm::Value *Arg; 1837 if (Info.allowsRegister() || !Info.allowsMemory()) { 1838 if (CodeGenFunction::hasScalarEvaluationKind(InputType)) { 1839 Arg = EmitLoadOfLValue(InputValue, Loc).getScalarVal(); 1840 } else { 1841 llvm::Type *Ty = ConvertType(InputType); 1842 uint64_t Size = CGM.getDataLayout().getTypeSizeInBits(Ty); 1843 if (Size <= 64 && llvm::isPowerOf2_64(Size)) { 1844 Ty = llvm::IntegerType::get(getLLVMContext(), Size); 1845 Ty = llvm::PointerType::getUnqual(Ty); 1846 1847 Arg = Builder.CreateLoad( 1848 Builder.CreateBitCast(InputValue.getAddress(*this), Ty)); 1849 } else { 1850 Arg = InputValue.getPointer(*this); 1851 ConstraintStr += '*'; 1852 } 1853 } 1854 } else { 1855 Arg = InputValue.getPointer(*this); 1856 ConstraintStr += '*'; 1857 } 1858 1859 return Arg; 1860 } 1861 1862 llvm::Value* CodeGenFunction::EmitAsmInput( 1863 const TargetInfo::ConstraintInfo &Info, 1864 const Expr *InputExpr, 1865 std::string &ConstraintStr) { 1866 // If this can't be a register or memory, i.e., has to be a constant 1867 // (immediate or symbolic), try to emit it as such. 1868 if (!Info.allowsRegister() && !Info.allowsMemory()) { 1869 if (Info.requiresImmediateConstant()) { 1870 Expr::EvalResult EVResult; 1871 InputExpr->EvaluateAsRValue(EVResult, getContext(), true); 1872 1873 llvm::APSInt IntResult; 1874 if (EVResult.Val.toIntegralConstant(IntResult, InputExpr->getType(), 1875 getContext())) 1876 return llvm::ConstantInt::get(getLLVMContext(), IntResult); 1877 } 1878 1879 Expr::EvalResult Result; 1880 if (InputExpr->EvaluateAsInt(Result, getContext())) 1881 return llvm::ConstantInt::get(getLLVMContext(), Result.Val.getInt()); 1882 } 1883 1884 if (Info.allowsRegister() || !Info.allowsMemory()) 1885 if (CodeGenFunction::hasScalarEvaluationKind(InputExpr->getType())) 1886 return EmitScalarExpr(InputExpr); 1887 if (InputExpr->getStmtClass() == Expr::CXXThisExprClass) 1888 return EmitScalarExpr(InputExpr); 1889 InputExpr = InputExpr->IgnoreParenNoopCasts(getContext()); 1890 LValue Dest = EmitLValue(InputExpr); 1891 return EmitAsmInputLValue(Info, Dest, InputExpr->getType(), ConstraintStr, 1892 InputExpr->getExprLoc()); 1893 } 1894 1895 /// getAsmSrcLocInfo - Return the !srcloc metadata node to attach to an inline 1896 /// asm call instruction. The !srcloc MDNode contains a list of constant 1897 /// integers which are the source locations of the start of each line in the 1898 /// asm. 1899 static llvm::MDNode *getAsmSrcLocInfo(const StringLiteral *Str, 1900 CodeGenFunction &CGF) { 1901 SmallVector<llvm::Metadata *, 8> Locs; 1902 // Add the location of the first line to the MDNode. 1903 Locs.push_back(llvm::ConstantAsMetadata::get(llvm::ConstantInt::get( 1904 CGF.Int32Ty, Str->getBeginLoc().getRawEncoding()))); 1905 StringRef StrVal = Str->getString(); 1906 if (!StrVal.empty()) { 1907 const SourceManager &SM = CGF.CGM.getContext().getSourceManager(); 1908 const LangOptions &LangOpts = CGF.CGM.getLangOpts(); 1909 unsigned StartToken = 0; 1910 unsigned ByteOffset = 0; 1911 1912 // Add the location of the start of each subsequent line of the asm to the 1913 // MDNode. 1914 for (unsigned i = 0, e = StrVal.size() - 1; i != e; ++i) { 1915 if (StrVal[i] != '\n') continue; 1916 SourceLocation LineLoc = Str->getLocationOfByte( 1917 i + 1, SM, LangOpts, CGF.getTarget(), &StartToken, &ByteOffset); 1918 Locs.push_back(llvm::ConstantAsMetadata::get( 1919 llvm::ConstantInt::get(CGF.Int32Ty, LineLoc.getRawEncoding()))); 1920 } 1921 } 1922 1923 return llvm::MDNode::get(CGF.getLLVMContext(), Locs); 1924 } 1925 1926 static void UpdateAsmCallInst(llvm::CallBase &Result, bool HasSideEffect, 1927 bool ReadOnly, bool ReadNone, const AsmStmt &S, 1928 const std::vector<llvm::Type *> &ResultRegTypes, 1929 CodeGenFunction &CGF, 1930 std::vector<llvm::Value *> &RegResults) { 1931 Result.addAttribute(llvm::AttributeList::FunctionIndex, 1932 llvm::Attribute::NoUnwind); 1933 // Attach readnone and readonly attributes. 1934 if (!HasSideEffect) { 1935 if (ReadNone) 1936 Result.addAttribute(llvm::AttributeList::FunctionIndex, 1937 llvm::Attribute::ReadNone); 1938 else if (ReadOnly) 1939 Result.addAttribute(llvm::AttributeList::FunctionIndex, 1940 llvm::Attribute::ReadOnly); 1941 } 1942 1943 // Slap the source location of the inline asm into a !srcloc metadata on the 1944 // call. 1945 if (const auto *gccAsmStmt = dyn_cast<GCCAsmStmt>(&S)) 1946 Result.setMetadata("srcloc", 1947 getAsmSrcLocInfo(gccAsmStmt->getAsmString(), CGF)); 1948 else { 1949 // At least put the line number on MS inline asm blobs. 1950 llvm::Constant *Loc = llvm::ConstantInt::get(CGF.Int32Ty, 1951 S.getAsmLoc().getRawEncoding()); 1952 Result.setMetadata("srcloc", 1953 llvm::MDNode::get(CGF.getLLVMContext(), 1954 llvm::ConstantAsMetadata::get(Loc))); 1955 } 1956 1957 if (CGF.getLangOpts().assumeFunctionsAreConvergent()) 1958 // Conservatively, mark all inline asm blocks in CUDA or OpenCL as 1959 // convergent (meaning, they may call an intrinsically convergent op, such 1960 // as bar.sync, and so can't have certain optimizations applied around 1961 // them). 1962 Result.addAttribute(llvm::AttributeList::FunctionIndex, 1963 llvm::Attribute::Convergent); 1964 // Extract all of the register value results from the asm. 1965 if (ResultRegTypes.size() == 1) { 1966 RegResults.push_back(&Result); 1967 } else { 1968 for (unsigned i = 0, e = ResultRegTypes.size(); i != e; ++i) { 1969 llvm::Value *Tmp = CGF.Builder.CreateExtractValue(&Result, i, "asmresult"); 1970 RegResults.push_back(Tmp); 1971 } 1972 } 1973 } 1974 1975 void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) { 1976 // Assemble the final asm string. 1977 std::string AsmString = S.generateAsmString(getContext()); 1978 1979 // Get all the output and input constraints together. 1980 SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 1981 SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; 1982 1983 for (unsigned i = 0, e = S.getNumOutputs(); i != e; i++) { 1984 StringRef Name; 1985 if (const GCCAsmStmt *GAS = dyn_cast<GCCAsmStmt>(&S)) 1986 Name = GAS->getOutputName(i); 1987 TargetInfo::ConstraintInfo Info(S.getOutputConstraint(i), Name); 1988 bool IsValid = getTarget().validateOutputConstraint(Info); (void)IsValid; 1989 assert(IsValid && "Failed to parse output constraint"); 1990 OutputConstraintInfos.push_back(Info); 1991 } 1992 1993 for (unsigned i = 0, e = S.getNumInputs(); i != e; i++) { 1994 StringRef Name; 1995 if (const GCCAsmStmt *GAS = dyn_cast<GCCAsmStmt>(&S)) 1996 Name = GAS->getInputName(i); 1997 TargetInfo::ConstraintInfo Info(S.getInputConstraint(i), Name); 1998 bool IsValid = 1999 getTarget().validateInputConstraint(OutputConstraintInfos, Info); 2000 assert(IsValid && "Failed to parse input constraint"); (void)IsValid; 2001 InputConstraintInfos.push_back(Info); 2002 } 2003 2004 std::string Constraints; 2005 2006 std::vector<LValue> ResultRegDests; 2007 std::vector<QualType> ResultRegQualTys; 2008 std::vector<llvm::Type *> ResultRegTypes; 2009 std::vector<llvm::Type *> ResultTruncRegTypes; 2010 std::vector<llvm::Type *> ArgTypes; 2011 std::vector<llvm::Value*> Args; 2012 llvm::BitVector ResultTypeRequiresCast; 2013 2014 // Keep track of inout constraints. 2015 std::string InOutConstraints; 2016 std::vector<llvm::Value*> InOutArgs; 2017 std::vector<llvm::Type*> InOutArgTypes; 2018 2019 // Keep track of out constraints for tied input operand. 2020 std::vector<std::string> OutputConstraints; 2021 2022 // An inline asm can be marked readonly if it meets the following conditions: 2023 // - it doesn't have any sideeffects 2024 // - it doesn't clobber memory 2025 // - it doesn't return a value by-reference 2026 // It can be marked readnone if it doesn't have any input memory constraints 2027 // in addition to meeting the conditions listed above. 2028 bool ReadOnly = true, ReadNone = true; 2029 2030 for (unsigned i = 0, e = S.getNumOutputs(); i != e; i++) { 2031 TargetInfo::ConstraintInfo &Info = OutputConstraintInfos[i]; 2032 2033 // Simplify the output constraint. 2034 std::string OutputConstraint(S.getOutputConstraint(i)); 2035 OutputConstraint = SimplifyConstraint(OutputConstraint.c_str() + 1, 2036 getTarget(), &OutputConstraintInfos); 2037 2038 const Expr *OutExpr = S.getOutputExpr(i); 2039 OutExpr = OutExpr->IgnoreParenNoopCasts(getContext()); 2040 2041 OutputConstraint = AddVariableConstraints(OutputConstraint, *OutExpr, 2042 getTarget(), CGM, S, 2043 Info.earlyClobber()); 2044 OutputConstraints.push_back(OutputConstraint); 2045 LValue Dest = EmitLValue(OutExpr); 2046 if (!Constraints.empty()) 2047 Constraints += ','; 2048 2049 // If this is a register output, then make the inline asm return it 2050 // by-value. If this is a memory result, return the value by-reference. 2051 bool isScalarizableAggregate = 2052 hasAggregateEvaluationKind(OutExpr->getType()); 2053 if (!Info.allowsMemory() && (hasScalarEvaluationKind(OutExpr->getType()) || 2054 isScalarizableAggregate)) { 2055 Constraints += "=" + OutputConstraint; 2056 ResultRegQualTys.push_back(OutExpr->getType()); 2057 ResultRegDests.push_back(Dest); 2058 ResultTruncRegTypes.push_back(ConvertTypeForMem(OutExpr->getType())); 2059 if (Info.allowsRegister() && isScalarizableAggregate) { 2060 ResultTypeRequiresCast.push_back(true); 2061 unsigned Size = getContext().getTypeSize(OutExpr->getType()); 2062 llvm::Type *ConvTy = llvm::IntegerType::get(getLLVMContext(), Size); 2063 ResultRegTypes.push_back(ConvTy); 2064 } else { 2065 ResultTypeRequiresCast.push_back(false); 2066 ResultRegTypes.push_back(ResultTruncRegTypes.back()); 2067 } 2068 // If this output is tied to an input, and if the input is larger, then 2069 // we need to set the actual result type of the inline asm node to be the 2070 // same as the input type. 2071 if (Info.hasMatchingInput()) { 2072 unsigned InputNo; 2073 for (InputNo = 0; InputNo != S.getNumInputs(); ++InputNo) { 2074 TargetInfo::ConstraintInfo &Input = InputConstraintInfos[InputNo]; 2075 if (Input.hasTiedOperand() && Input.getTiedOperand() == i) 2076 break; 2077 } 2078 assert(InputNo != S.getNumInputs() && "Didn't find matching input!"); 2079 2080 QualType InputTy = S.getInputExpr(InputNo)->getType(); 2081 QualType OutputType = OutExpr->getType(); 2082 2083 uint64_t InputSize = getContext().getTypeSize(InputTy); 2084 if (getContext().getTypeSize(OutputType) < InputSize) { 2085 // Form the asm to return the value as a larger integer or fp type. 2086 ResultRegTypes.back() = ConvertType(InputTy); 2087 } 2088 } 2089 if (llvm::Type* AdjTy = 2090 getTargetHooks().adjustInlineAsmType(*this, OutputConstraint, 2091 ResultRegTypes.back())) 2092 ResultRegTypes.back() = AdjTy; 2093 else { 2094 CGM.getDiags().Report(S.getAsmLoc(), 2095 diag::err_asm_invalid_type_in_input) 2096 << OutExpr->getType() << OutputConstraint; 2097 } 2098 2099 // Update largest vector width for any vector types. 2100 if (auto *VT = dyn_cast<llvm::VectorType>(ResultRegTypes.back())) 2101 LargestVectorWidth = 2102 std::max((uint64_t)LargestVectorWidth, 2103 VT->getPrimitiveSizeInBits().getKnownMinSize()); 2104 } else { 2105 ArgTypes.push_back(Dest.getAddress(*this).getType()); 2106 Args.push_back(Dest.getPointer(*this)); 2107 Constraints += "=*"; 2108 Constraints += OutputConstraint; 2109 ReadOnly = ReadNone = false; 2110 } 2111 2112 if (Info.isReadWrite()) { 2113 InOutConstraints += ','; 2114 2115 const Expr *InputExpr = S.getOutputExpr(i); 2116 llvm::Value *Arg = EmitAsmInputLValue(Info, Dest, InputExpr->getType(), 2117 InOutConstraints, 2118 InputExpr->getExprLoc()); 2119 2120 if (llvm::Type* AdjTy = 2121 getTargetHooks().adjustInlineAsmType(*this, OutputConstraint, 2122 Arg->getType())) 2123 Arg = Builder.CreateBitCast(Arg, AdjTy); 2124 2125 // Update largest vector width for any vector types. 2126 if (auto *VT = dyn_cast<llvm::VectorType>(Arg->getType())) 2127 LargestVectorWidth = 2128 std::max((uint64_t)LargestVectorWidth, 2129 VT->getPrimitiveSizeInBits().getKnownMinSize()); 2130 if (Info.allowsRegister()) 2131 InOutConstraints += llvm::utostr(i); 2132 else 2133 InOutConstraints += OutputConstraint; 2134 2135 InOutArgTypes.push_back(Arg->getType()); 2136 InOutArgs.push_back(Arg); 2137 } 2138 } 2139 2140 // If this is a Microsoft-style asm blob, store the return registers (EAX:EDX) 2141 // to the return value slot. Only do this when returning in registers. 2142 if (isa<MSAsmStmt>(&S)) { 2143 const ABIArgInfo &RetAI = CurFnInfo->getReturnInfo(); 2144 if (RetAI.isDirect() || RetAI.isExtend()) { 2145 // Make a fake lvalue for the return value slot. 2146 LValue ReturnSlot = MakeAddrLValue(ReturnValue, FnRetTy); 2147 CGM.getTargetCodeGenInfo().addReturnRegisterOutputs( 2148 *this, ReturnSlot, Constraints, ResultRegTypes, ResultTruncRegTypes, 2149 ResultRegDests, AsmString, S.getNumOutputs()); 2150 SawAsmBlock = true; 2151 } 2152 } 2153 2154 for (unsigned i = 0, e = S.getNumInputs(); i != e; i++) { 2155 const Expr *InputExpr = S.getInputExpr(i); 2156 2157 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; 2158 2159 if (Info.allowsMemory()) 2160 ReadNone = false; 2161 2162 if (!Constraints.empty()) 2163 Constraints += ','; 2164 2165 // Simplify the input constraint. 2166 std::string InputConstraint(S.getInputConstraint(i)); 2167 InputConstraint = SimplifyConstraint(InputConstraint.c_str(), getTarget(), 2168 &OutputConstraintInfos); 2169 2170 InputConstraint = AddVariableConstraints( 2171 InputConstraint, *InputExpr->IgnoreParenNoopCasts(getContext()), 2172 getTarget(), CGM, S, false /* No EarlyClobber */); 2173 2174 std::string ReplaceConstraint (InputConstraint); 2175 llvm::Value *Arg = EmitAsmInput(Info, InputExpr, Constraints); 2176 2177 // If this input argument is tied to a larger output result, extend the 2178 // input to be the same size as the output. The LLVM backend wants to see 2179 // the input and output of a matching constraint be the same size. Note 2180 // that GCC does not define what the top bits are here. We use zext because 2181 // that is usually cheaper, but LLVM IR should really get an anyext someday. 2182 if (Info.hasTiedOperand()) { 2183 unsigned Output = Info.getTiedOperand(); 2184 QualType OutputType = S.getOutputExpr(Output)->getType(); 2185 QualType InputTy = InputExpr->getType(); 2186 2187 if (getContext().getTypeSize(OutputType) > 2188 getContext().getTypeSize(InputTy)) { 2189 // Use ptrtoint as appropriate so that we can do our extension. 2190 if (isa<llvm::PointerType>(Arg->getType())) 2191 Arg = Builder.CreatePtrToInt(Arg, IntPtrTy); 2192 llvm::Type *OutputTy = ConvertType(OutputType); 2193 if (isa<llvm::IntegerType>(OutputTy)) 2194 Arg = Builder.CreateZExt(Arg, OutputTy); 2195 else if (isa<llvm::PointerType>(OutputTy)) 2196 Arg = Builder.CreateZExt(Arg, IntPtrTy); 2197 else { 2198 assert(OutputTy->isFloatingPointTy() && "Unexpected output type"); 2199 Arg = Builder.CreateFPExt(Arg, OutputTy); 2200 } 2201 } 2202 // Deal with the tied operands' constraint code in adjustInlineAsmType. 2203 ReplaceConstraint = OutputConstraints[Output]; 2204 } 2205 if (llvm::Type* AdjTy = 2206 getTargetHooks().adjustInlineAsmType(*this, ReplaceConstraint, 2207 Arg->getType())) 2208 Arg = Builder.CreateBitCast(Arg, AdjTy); 2209 else 2210 CGM.getDiags().Report(S.getAsmLoc(), diag::err_asm_invalid_type_in_input) 2211 << InputExpr->getType() << InputConstraint; 2212 2213 // Update largest vector width for any vector types. 2214 if (auto *VT = dyn_cast<llvm::VectorType>(Arg->getType())) 2215 LargestVectorWidth = 2216 std::max((uint64_t)LargestVectorWidth, 2217 VT->getPrimitiveSizeInBits().getKnownMinSize()); 2218 2219 ArgTypes.push_back(Arg->getType()); 2220 Args.push_back(Arg); 2221 Constraints += InputConstraint; 2222 } 2223 2224 // Labels 2225 SmallVector<llvm::BasicBlock *, 16> Transfer; 2226 llvm::BasicBlock *Fallthrough = nullptr; 2227 bool IsGCCAsmGoto = false; 2228 if (const auto *GS = dyn_cast<GCCAsmStmt>(&S)) { 2229 IsGCCAsmGoto = GS->isAsmGoto(); 2230 if (IsGCCAsmGoto) { 2231 for (const auto *E : GS->labels()) { 2232 JumpDest Dest = getJumpDestForLabel(E->getLabel()); 2233 Transfer.push_back(Dest.getBlock()); 2234 llvm::BlockAddress *BA = 2235 llvm::BlockAddress::get(CurFn, Dest.getBlock()); 2236 Args.push_back(BA); 2237 ArgTypes.push_back(BA->getType()); 2238 if (!Constraints.empty()) 2239 Constraints += ','; 2240 Constraints += 'X'; 2241 } 2242 Fallthrough = createBasicBlock("asm.fallthrough"); 2243 } 2244 } 2245 2246 // Append the "input" part of inout constraints last. 2247 for (unsigned i = 0, e = InOutArgs.size(); i != e; i++) { 2248 ArgTypes.push_back(InOutArgTypes[i]); 2249 Args.push_back(InOutArgs[i]); 2250 } 2251 Constraints += InOutConstraints; 2252 2253 // Clobbers 2254 for (unsigned i = 0, e = S.getNumClobbers(); i != e; i++) { 2255 StringRef Clobber = S.getClobber(i); 2256 2257 if (Clobber == "memory") 2258 ReadOnly = ReadNone = false; 2259 else if (Clobber != "cc") { 2260 Clobber = getTarget().getNormalizedGCCRegisterName(Clobber); 2261 if (CGM.getCodeGenOpts().StackClashProtector && 2262 getTarget().isSPRegName(Clobber)) { 2263 CGM.getDiags().Report(S.getAsmLoc(), 2264 diag::warn_stack_clash_protection_inline_asm); 2265 } 2266 } 2267 2268 if (!Constraints.empty()) 2269 Constraints += ','; 2270 2271 Constraints += "~{"; 2272 Constraints += Clobber; 2273 Constraints += '}'; 2274 } 2275 2276 // Add machine specific clobbers 2277 std::string MachineClobbers = getTarget().getClobbers(); 2278 if (!MachineClobbers.empty()) { 2279 if (!Constraints.empty()) 2280 Constraints += ','; 2281 Constraints += MachineClobbers; 2282 } 2283 2284 llvm::Type *ResultType; 2285 if (ResultRegTypes.empty()) 2286 ResultType = VoidTy; 2287 else if (ResultRegTypes.size() == 1) 2288 ResultType = ResultRegTypes[0]; 2289 else 2290 ResultType = llvm::StructType::get(getLLVMContext(), ResultRegTypes); 2291 2292 llvm::FunctionType *FTy = 2293 llvm::FunctionType::get(ResultType, ArgTypes, false); 2294 2295 bool HasSideEffect = S.isVolatile() || S.getNumOutputs() == 0; 2296 llvm::InlineAsm::AsmDialect AsmDialect = isa<MSAsmStmt>(&S) ? 2297 llvm::InlineAsm::AD_Intel : llvm::InlineAsm::AD_ATT; 2298 llvm::InlineAsm *IA = 2299 llvm::InlineAsm::get(FTy, AsmString, Constraints, HasSideEffect, 2300 /* IsAlignStack */ false, AsmDialect); 2301 std::vector<llvm::Value*> RegResults; 2302 if (IsGCCAsmGoto) { 2303 llvm::CallBrInst *Result = 2304 Builder.CreateCallBr(IA, Fallthrough, Transfer, Args); 2305 EmitBlock(Fallthrough); 2306 UpdateAsmCallInst(cast<llvm::CallBase>(*Result), HasSideEffect, ReadOnly, 2307 ReadNone, S, ResultRegTypes, *this, RegResults); 2308 } else { 2309 llvm::CallInst *Result = 2310 Builder.CreateCall(IA, Args, getBundlesForFunclet(IA)); 2311 UpdateAsmCallInst(cast<llvm::CallBase>(*Result), HasSideEffect, ReadOnly, 2312 ReadNone, S, ResultRegTypes, *this, RegResults); 2313 } 2314 2315 assert(RegResults.size() == ResultRegTypes.size()); 2316 assert(RegResults.size() == ResultTruncRegTypes.size()); 2317 assert(RegResults.size() == ResultRegDests.size()); 2318 // ResultRegDests can be also populated by addReturnRegisterOutputs() above, 2319 // in which case its size may grow. 2320 assert(ResultTypeRequiresCast.size() <= ResultRegDests.size()); 2321 for (unsigned i = 0, e = RegResults.size(); i != e; ++i) { 2322 llvm::Value *Tmp = RegResults[i]; 2323 2324 // If the result type of the LLVM IR asm doesn't match the result type of 2325 // the expression, do the conversion. 2326 if (ResultRegTypes[i] != ResultTruncRegTypes[i]) { 2327 llvm::Type *TruncTy = ResultTruncRegTypes[i]; 2328 2329 // Truncate the integer result to the right size, note that TruncTy can be 2330 // a pointer. 2331 if (TruncTy->isFloatingPointTy()) 2332 Tmp = Builder.CreateFPTrunc(Tmp, TruncTy); 2333 else if (TruncTy->isPointerTy() && Tmp->getType()->isIntegerTy()) { 2334 uint64_t ResSize = CGM.getDataLayout().getTypeSizeInBits(TruncTy); 2335 Tmp = Builder.CreateTrunc(Tmp, 2336 llvm::IntegerType::get(getLLVMContext(), (unsigned)ResSize)); 2337 Tmp = Builder.CreateIntToPtr(Tmp, TruncTy); 2338 } else if (Tmp->getType()->isPointerTy() && TruncTy->isIntegerTy()) { 2339 uint64_t TmpSize =CGM.getDataLayout().getTypeSizeInBits(Tmp->getType()); 2340 Tmp = Builder.CreatePtrToInt(Tmp, 2341 llvm::IntegerType::get(getLLVMContext(), (unsigned)TmpSize)); 2342 Tmp = Builder.CreateTrunc(Tmp, TruncTy); 2343 } else if (TruncTy->isIntegerTy()) { 2344 Tmp = Builder.CreateZExtOrTrunc(Tmp, TruncTy); 2345 } else if (TruncTy->isVectorTy()) { 2346 Tmp = Builder.CreateBitCast(Tmp, TruncTy); 2347 } 2348 } 2349 2350 LValue Dest = ResultRegDests[i]; 2351 // ResultTypeRequiresCast elements correspond to the first 2352 // ResultTypeRequiresCast.size() elements of RegResults. 2353 if ((i < ResultTypeRequiresCast.size()) && ResultTypeRequiresCast[i]) { 2354 unsigned Size = getContext().getTypeSize(ResultRegQualTys[i]); 2355 Address A = Builder.CreateBitCast(Dest.getAddress(*this), 2356 ResultRegTypes[i]->getPointerTo()); 2357 QualType Ty = getContext().getIntTypeForBitwidth(Size, /*Signed*/ false); 2358 if (Ty.isNull()) { 2359 const Expr *OutExpr = S.getOutputExpr(i); 2360 CGM.Error( 2361 OutExpr->getExprLoc(), 2362 "impossible constraint in asm: can't store value into a register"); 2363 return; 2364 } 2365 Dest = MakeAddrLValue(A, Ty); 2366 } 2367 EmitStoreThroughLValue(RValue::get(Tmp), Dest); 2368 } 2369 } 2370 2371 LValue CodeGenFunction::InitCapturedStruct(const CapturedStmt &S) { 2372 const RecordDecl *RD = S.getCapturedRecordDecl(); 2373 QualType RecordTy = getContext().getRecordType(RD); 2374 2375 // Initialize the captured struct. 2376 LValue SlotLV = 2377 MakeAddrLValue(CreateMemTemp(RecordTy, "agg.captured"), RecordTy); 2378 2379 RecordDecl::field_iterator CurField = RD->field_begin(); 2380 for (CapturedStmt::const_capture_init_iterator I = S.capture_init_begin(), 2381 E = S.capture_init_end(); 2382 I != E; ++I, ++CurField) { 2383 LValue LV = EmitLValueForFieldInitialization(SlotLV, *CurField); 2384 if (CurField->hasCapturedVLAType()) { 2385 auto VAT = CurField->getCapturedVLAType(); 2386 EmitStoreThroughLValue(RValue::get(VLASizeMap[VAT->getSizeExpr()]), LV); 2387 } else { 2388 EmitInitializerForField(*CurField, LV, *I); 2389 } 2390 } 2391 2392 return SlotLV; 2393 } 2394 2395 /// Generate an outlined function for the body of a CapturedStmt, store any 2396 /// captured variables into the captured struct, and call the outlined function. 2397 llvm::Function * 2398 CodeGenFunction::EmitCapturedStmt(const CapturedStmt &S, CapturedRegionKind K) { 2399 LValue CapStruct = InitCapturedStruct(S); 2400 2401 // Emit the CapturedDecl 2402 CodeGenFunction CGF(CGM, true); 2403 CGCapturedStmtRAII CapInfoRAII(CGF, new CGCapturedStmtInfo(S, K)); 2404 llvm::Function *F = CGF.GenerateCapturedStmtFunction(S); 2405 delete CGF.CapturedStmtInfo; 2406 2407 // Emit call to the helper function. 2408 EmitCallOrInvoke(F, CapStruct.getPointer(*this)); 2409 2410 return F; 2411 } 2412 2413 Address CodeGenFunction::GenerateCapturedStmtArgument(const CapturedStmt &S) { 2414 LValue CapStruct = InitCapturedStruct(S); 2415 return CapStruct.getAddress(*this); 2416 } 2417 2418 /// Creates the outlined function for a CapturedStmt. 2419 llvm::Function * 2420 CodeGenFunction::GenerateCapturedStmtFunction(const CapturedStmt &S) { 2421 assert(CapturedStmtInfo && 2422 "CapturedStmtInfo should be set when generating the captured function"); 2423 const CapturedDecl *CD = S.getCapturedDecl(); 2424 const RecordDecl *RD = S.getCapturedRecordDecl(); 2425 SourceLocation Loc = S.getBeginLoc(); 2426 assert(CD->hasBody() && "missing CapturedDecl body"); 2427 2428 // Build the argument list. 2429 ASTContext &Ctx = CGM.getContext(); 2430 FunctionArgList Args; 2431 Args.append(CD->param_begin(), CD->param_end()); 2432 2433 // Create the function declaration. 2434 const CGFunctionInfo &FuncInfo = 2435 CGM.getTypes().arrangeBuiltinFunctionDeclaration(Ctx.VoidTy, Args); 2436 llvm::FunctionType *FuncLLVMTy = CGM.getTypes().GetFunctionType(FuncInfo); 2437 2438 llvm::Function *F = 2439 llvm::Function::Create(FuncLLVMTy, llvm::GlobalValue::InternalLinkage, 2440 CapturedStmtInfo->getHelperName(), &CGM.getModule()); 2441 CGM.SetInternalFunctionAttributes(CD, F, FuncInfo); 2442 if (CD->isNothrow()) 2443 F->addFnAttr(llvm::Attribute::NoUnwind); 2444 2445 // Generate the function. 2446 StartFunction(CD, Ctx.VoidTy, F, FuncInfo, Args, CD->getLocation(), 2447 CD->getBody()->getBeginLoc()); 2448 // Set the context parameter in CapturedStmtInfo. 2449 Address DeclPtr = GetAddrOfLocalVar(CD->getContextParam()); 2450 CapturedStmtInfo->setContextValue(Builder.CreateLoad(DeclPtr)); 2451 2452 // Initialize variable-length arrays. 2453 LValue Base = MakeNaturalAlignAddrLValue(CapturedStmtInfo->getContextValue(), 2454 Ctx.getTagDeclType(RD)); 2455 for (auto *FD : RD->fields()) { 2456 if (FD->hasCapturedVLAType()) { 2457 auto *ExprArg = 2458 EmitLoadOfLValue(EmitLValueForField(Base, FD), S.getBeginLoc()) 2459 .getScalarVal(); 2460 auto VAT = FD->getCapturedVLAType(); 2461 VLASizeMap[VAT->getSizeExpr()] = ExprArg; 2462 } 2463 } 2464 2465 // If 'this' is captured, load it into CXXThisValue. 2466 if (CapturedStmtInfo->isCXXThisExprCaptured()) { 2467 FieldDecl *FD = CapturedStmtInfo->getThisFieldDecl(); 2468 LValue ThisLValue = EmitLValueForField(Base, FD); 2469 CXXThisValue = EmitLoadOfLValue(ThisLValue, Loc).getScalarVal(); 2470 } 2471 2472 PGO.assignRegionCounters(GlobalDecl(CD), F); 2473 CapturedStmtInfo->EmitBody(*this, CD->getBody()); 2474 FinishFunction(CD->getBodyRBrace()); 2475 2476 return F; 2477 } 2478