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