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