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 "CGOpenMPRuntime.h" 15 #include "CodeGenFunction.h" 16 #include "CodeGenModule.h" 17 #include "TargetInfo.h" 18 #include "clang/AST/Attr.h" 19 #include "clang/AST/Expr.h" 20 #include "clang/AST/Stmt.h" 21 #include "clang/AST/StmtVisitor.h" 22 #include "clang/Basic/Builtins.h" 23 #include "clang/Basic/DiagnosticSema.h" 24 #include "clang/Basic/PrettyStackTrace.h" 25 #include "clang/Basic/SourceManager.h" 26 #include "clang/Basic/TargetInfo.h" 27 #include "llvm/ADT/ArrayRef.h" 28 #include "llvm/ADT/DenseMap.h" 29 #include "llvm/ADT/SmallSet.h" 30 #include "llvm/ADT/StringExtras.h" 31 #include "llvm/IR/Assumptions.h" 32 #include "llvm/IR/DataLayout.h" 33 #include "llvm/IR/InlineAsm.h" 34 #include "llvm/IR/Intrinsics.h" 35 #include "llvm/IR/MDBuilder.h" 36 #include "llvm/Support/SaveAndRestore.h" 37 #include <optional> 38 39 using namespace clang; 40 using namespace CodeGen; 41 42 //===----------------------------------------------------------------------===// 43 // Statement Emission 44 //===----------------------------------------------------------------------===// 45 46 void CodeGenFunction::EmitStopPoint(const Stmt *S) { 47 if (CGDebugInfo *DI = getDebugInfo()) { 48 SourceLocation Loc; 49 Loc = S->getBeginLoc(); 50 DI->EmitLocation(Builder, Loc); 51 52 LastStopPoint = Loc; 53 } 54 } 55 56 void CodeGenFunction::EmitStmt(const Stmt *S, ArrayRef<const Attr *> Attrs) { 57 assert(S && "Null statement?"); 58 PGO.setCurrentStmt(S); 59 60 // These statements have their own debug info handling. 61 if (EmitSimpleStmt(S, Attrs)) 62 return; 63 64 // Check if we are generating unreachable code. 65 if (!HaveInsertPoint()) { 66 // If so, and the statement doesn't contain a label, then we do not need to 67 // generate actual code. This is safe because (1) the current point is 68 // unreachable, so we don't need to execute the code, and (2) we've already 69 // handled the statements which update internal data structures (like the 70 // local variable map) which could be used by subsequent statements. 71 if (!ContainsLabel(S)) { 72 // Verify that any decl statements were handled as simple, they may be in 73 // scope of subsequent reachable statements. 74 assert(!isa<DeclStmt>(*S) && "Unexpected DeclStmt!"); 75 return; 76 } 77 78 // Otherwise, make a new block to hold the code. 79 EnsureInsertPoint(); 80 } 81 82 // Generate a stoppoint if we are emitting debug info. 83 EmitStopPoint(S); 84 85 // Ignore all OpenMP directives except for simd if OpenMP with Simd is 86 // enabled. 87 if (getLangOpts().OpenMP && getLangOpts().OpenMPSimd) { 88 if (const auto *D = dyn_cast<OMPExecutableDirective>(S)) { 89 EmitSimpleOMPExecutableDirective(*D); 90 return; 91 } 92 } 93 94 switch (S->getStmtClass()) { 95 case Stmt::NoStmtClass: 96 case Stmt::CXXCatchStmtClass: 97 case Stmt::SEHExceptStmtClass: 98 case Stmt::SEHFinallyStmtClass: 99 case Stmt::MSDependentExistsStmtClass: 100 llvm_unreachable("invalid statement class to emit generically"); 101 case Stmt::NullStmtClass: 102 case Stmt::CompoundStmtClass: 103 case Stmt::DeclStmtClass: 104 case Stmt::LabelStmtClass: 105 case Stmt::AttributedStmtClass: 106 case Stmt::GotoStmtClass: 107 case Stmt::BreakStmtClass: 108 case Stmt::ContinueStmtClass: 109 case Stmt::DefaultStmtClass: 110 case Stmt::CaseStmtClass: 111 case Stmt::SEHLeaveStmtClass: 112 llvm_unreachable("should have emitted these statements as simple"); 113 114 #define STMT(Type, Base) 115 #define ABSTRACT_STMT(Op) 116 #define EXPR(Type, Base) \ 117 case Stmt::Type##Class: 118 #include "clang/AST/StmtNodes.inc" 119 { 120 // Remember the block we came in on. 121 llvm::BasicBlock *incoming = Builder.GetInsertBlock(); 122 assert(incoming && "expression emission must have an insertion point"); 123 124 EmitIgnoredExpr(cast<Expr>(S)); 125 126 llvm::BasicBlock *outgoing = Builder.GetInsertBlock(); 127 assert(outgoing && "expression emission cleared block!"); 128 129 // The expression emitters assume (reasonably!) that the insertion 130 // point is always set. To maintain that, the call-emission code 131 // for noreturn functions has to enter a new block with no 132 // predecessors. We want to kill that block and mark the current 133 // insertion point unreachable in the common case of a call like 134 // "exit();". Since expression emission doesn't otherwise create 135 // blocks with no predecessors, we can just test for that. 136 // However, we must be careful not to do this to our incoming 137 // block, because *statement* emission does sometimes create 138 // reachable blocks which will have no predecessors until later in 139 // the function. This occurs with, e.g., labels that are not 140 // reachable by fallthrough. 141 if (incoming != outgoing && outgoing->use_empty()) { 142 outgoing->eraseFromParent(); 143 Builder.ClearInsertionPoint(); 144 } 145 break; 146 } 147 148 case Stmt::IndirectGotoStmtClass: 149 EmitIndirectGotoStmt(cast<IndirectGotoStmt>(*S)); break; 150 151 case Stmt::IfStmtClass: EmitIfStmt(cast<IfStmt>(*S)); break; 152 case Stmt::WhileStmtClass: EmitWhileStmt(cast<WhileStmt>(*S), Attrs); break; 153 case Stmt::DoStmtClass: EmitDoStmt(cast<DoStmt>(*S), Attrs); break; 154 case Stmt::ForStmtClass: EmitForStmt(cast<ForStmt>(*S), Attrs); break; 155 156 case Stmt::ReturnStmtClass: EmitReturnStmt(cast<ReturnStmt>(*S)); break; 157 158 case Stmt::SwitchStmtClass: EmitSwitchStmt(cast<SwitchStmt>(*S)); break; 159 case Stmt::GCCAsmStmtClass: // Intentional fall-through. 160 case Stmt::MSAsmStmtClass: EmitAsmStmt(cast<AsmStmt>(*S)); break; 161 case Stmt::CoroutineBodyStmtClass: 162 EmitCoroutineBody(cast<CoroutineBodyStmt>(*S)); 163 break; 164 case Stmt::CoreturnStmtClass: 165 EmitCoreturnStmt(cast<CoreturnStmt>(*S)); 166 break; 167 case Stmt::CapturedStmtClass: { 168 const CapturedStmt *CS = cast<CapturedStmt>(S); 169 EmitCapturedStmt(*CS, CS->getCapturedRegionKind()); 170 } 171 break; 172 case Stmt::ObjCAtTryStmtClass: 173 EmitObjCAtTryStmt(cast<ObjCAtTryStmt>(*S)); 174 break; 175 case Stmt::ObjCAtCatchStmtClass: 176 llvm_unreachable( 177 "@catch statements should be handled by EmitObjCAtTryStmt"); 178 case Stmt::ObjCAtFinallyStmtClass: 179 llvm_unreachable( 180 "@finally statements should be handled by EmitObjCAtTryStmt"); 181 case Stmt::ObjCAtThrowStmtClass: 182 EmitObjCAtThrowStmt(cast<ObjCAtThrowStmt>(*S)); 183 break; 184 case Stmt::ObjCAtSynchronizedStmtClass: 185 EmitObjCAtSynchronizedStmt(cast<ObjCAtSynchronizedStmt>(*S)); 186 break; 187 case Stmt::ObjCForCollectionStmtClass: 188 EmitObjCForCollectionStmt(cast<ObjCForCollectionStmt>(*S)); 189 break; 190 case Stmt::ObjCAutoreleasePoolStmtClass: 191 EmitObjCAutoreleasePoolStmt(cast<ObjCAutoreleasePoolStmt>(*S)); 192 break; 193 194 case Stmt::CXXTryStmtClass: 195 EmitCXXTryStmt(cast<CXXTryStmt>(*S)); 196 break; 197 case Stmt::CXXForRangeStmtClass: 198 EmitCXXForRangeStmt(cast<CXXForRangeStmt>(*S), Attrs); 199 break; 200 case Stmt::SEHTryStmtClass: 201 EmitSEHTryStmt(cast<SEHTryStmt>(*S)); 202 break; 203 case Stmt::OMPMetaDirectiveClass: 204 EmitOMPMetaDirective(cast<OMPMetaDirective>(*S)); 205 break; 206 case Stmt::OMPCanonicalLoopClass: 207 EmitOMPCanonicalLoop(cast<OMPCanonicalLoop>(S)); 208 break; 209 case Stmt::OMPParallelDirectiveClass: 210 EmitOMPParallelDirective(cast<OMPParallelDirective>(*S)); 211 break; 212 case Stmt::OMPSimdDirectiveClass: 213 EmitOMPSimdDirective(cast<OMPSimdDirective>(*S)); 214 break; 215 case Stmt::OMPTileDirectiveClass: 216 EmitOMPTileDirective(cast<OMPTileDirective>(*S)); 217 break; 218 case Stmt::OMPUnrollDirectiveClass: 219 EmitOMPUnrollDirective(cast<OMPUnrollDirective>(*S)); 220 break; 221 case Stmt::OMPForDirectiveClass: 222 EmitOMPForDirective(cast<OMPForDirective>(*S)); 223 break; 224 case Stmt::OMPForSimdDirectiveClass: 225 EmitOMPForSimdDirective(cast<OMPForSimdDirective>(*S)); 226 break; 227 case Stmt::OMPSectionsDirectiveClass: 228 EmitOMPSectionsDirective(cast<OMPSectionsDirective>(*S)); 229 break; 230 case Stmt::OMPSectionDirectiveClass: 231 EmitOMPSectionDirective(cast<OMPSectionDirective>(*S)); 232 break; 233 case Stmt::OMPSingleDirectiveClass: 234 EmitOMPSingleDirective(cast<OMPSingleDirective>(*S)); 235 break; 236 case Stmt::OMPMasterDirectiveClass: 237 EmitOMPMasterDirective(cast<OMPMasterDirective>(*S)); 238 break; 239 case Stmt::OMPCriticalDirectiveClass: 240 EmitOMPCriticalDirective(cast<OMPCriticalDirective>(*S)); 241 break; 242 case Stmt::OMPParallelForDirectiveClass: 243 EmitOMPParallelForDirective(cast<OMPParallelForDirective>(*S)); 244 break; 245 case Stmt::OMPParallelForSimdDirectiveClass: 246 EmitOMPParallelForSimdDirective(cast<OMPParallelForSimdDirective>(*S)); 247 break; 248 case Stmt::OMPParallelMasterDirectiveClass: 249 EmitOMPParallelMasterDirective(cast<OMPParallelMasterDirective>(*S)); 250 break; 251 case Stmt::OMPParallelSectionsDirectiveClass: 252 EmitOMPParallelSectionsDirective(cast<OMPParallelSectionsDirective>(*S)); 253 break; 254 case Stmt::OMPTaskDirectiveClass: 255 EmitOMPTaskDirective(cast<OMPTaskDirective>(*S)); 256 break; 257 case Stmt::OMPTaskyieldDirectiveClass: 258 EmitOMPTaskyieldDirective(cast<OMPTaskyieldDirective>(*S)); 259 break; 260 case Stmt::OMPErrorDirectiveClass: 261 EmitOMPErrorDirective(cast<OMPErrorDirective>(*S)); 262 break; 263 case Stmt::OMPBarrierDirectiveClass: 264 EmitOMPBarrierDirective(cast<OMPBarrierDirective>(*S)); 265 break; 266 case Stmt::OMPTaskwaitDirectiveClass: 267 EmitOMPTaskwaitDirective(cast<OMPTaskwaitDirective>(*S)); 268 break; 269 case Stmt::OMPTaskgroupDirectiveClass: 270 EmitOMPTaskgroupDirective(cast<OMPTaskgroupDirective>(*S)); 271 break; 272 case Stmt::OMPFlushDirectiveClass: 273 EmitOMPFlushDirective(cast<OMPFlushDirective>(*S)); 274 break; 275 case Stmt::OMPDepobjDirectiveClass: 276 EmitOMPDepobjDirective(cast<OMPDepobjDirective>(*S)); 277 break; 278 case Stmt::OMPScanDirectiveClass: 279 EmitOMPScanDirective(cast<OMPScanDirective>(*S)); 280 break; 281 case Stmt::OMPOrderedDirectiveClass: 282 EmitOMPOrderedDirective(cast<OMPOrderedDirective>(*S)); 283 break; 284 case Stmt::OMPAtomicDirectiveClass: 285 EmitOMPAtomicDirective(cast<OMPAtomicDirective>(*S)); 286 break; 287 case Stmt::OMPTargetDirectiveClass: 288 EmitOMPTargetDirective(cast<OMPTargetDirective>(*S)); 289 break; 290 case Stmt::OMPTeamsDirectiveClass: 291 EmitOMPTeamsDirective(cast<OMPTeamsDirective>(*S)); 292 break; 293 case Stmt::OMPCancellationPointDirectiveClass: 294 EmitOMPCancellationPointDirective(cast<OMPCancellationPointDirective>(*S)); 295 break; 296 case Stmt::OMPCancelDirectiveClass: 297 EmitOMPCancelDirective(cast<OMPCancelDirective>(*S)); 298 break; 299 case Stmt::OMPTargetDataDirectiveClass: 300 EmitOMPTargetDataDirective(cast<OMPTargetDataDirective>(*S)); 301 break; 302 case Stmt::OMPTargetEnterDataDirectiveClass: 303 EmitOMPTargetEnterDataDirective(cast<OMPTargetEnterDataDirective>(*S)); 304 break; 305 case Stmt::OMPTargetExitDataDirectiveClass: 306 EmitOMPTargetExitDataDirective(cast<OMPTargetExitDataDirective>(*S)); 307 break; 308 case Stmt::OMPTargetParallelDirectiveClass: 309 EmitOMPTargetParallelDirective(cast<OMPTargetParallelDirective>(*S)); 310 break; 311 case Stmt::OMPTargetParallelForDirectiveClass: 312 EmitOMPTargetParallelForDirective(cast<OMPTargetParallelForDirective>(*S)); 313 break; 314 case Stmt::OMPTaskLoopDirectiveClass: 315 EmitOMPTaskLoopDirective(cast<OMPTaskLoopDirective>(*S)); 316 break; 317 case Stmt::OMPTaskLoopSimdDirectiveClass: 318 EmitOMPTaskLoopSimdDirective(cast<OMPTaskLoopSimdDirective>(*S)); 319 break; 320 case Stmt::OMPMasterTaskLoopDirectiveClass: 321 EmitOMPMasterTaskLoopDirective(cast<OMPMasterTaskLoopDirective>(*S)); 322 break; 323 case Stmt::OMPMaskedTaskLoopDirectiveClass: 324 llvm_unreachable("masked taskloop directive not supported yet."); 325 break; 326 case Stmt::OMPMasterTaskLoopSimdDirectiveClass: 327 EmitOMPMasterTaskLoopSimdDirective( 328 cast<OMPMasterTaskLoopSimdDirective>(*S)); 329 break; 330 case Stmt::OMPMaskedTaskLoopSimdDirectiveClass: 331 llvm_unreachable("masked taskloop simd directive not supported yet."); 332 break; 333 case Stmt::OMPParallelMasterTaskLoopDirectiveClass: 334 EmitOMPParallelMasterTaskLoopDirective( 335 cast<OMPParallelMasterTaskLoopDirective>(*S)); 336 break; 337 case Stmt::OMPParallelMaskedTaskLoopDirectiveClass: 338 llvm_unreachable("parallel masked taskloop directive not supported yet."); 339 break; 340 case Stmt::OMPParallelMasterTaskLoopSimdDirectiveClass: 341 EmitOMPParallelMasterTaskLoopSimdDirective( 342 cast<OMPParallelMasterTaskLoopSimdDirective>(*S)); 343 break; 344 case Stmt::OMPParallelMaskedTaskLoopSimdDirectiveClass: 345 llvm_unreachable( 346 "parallel masked taskloop simd directive not supported yet."); 347 break; 348 case Stmt::OMPDistributeDirectiveClass: 349 EmitOMPDistributeDirective(cast<OMPDistributeDirective>(*S)); 350 break; 351 case Stmt::OMPTargetUpdateDirectiveClass: 352 EmitOMPTargetUpdateDirective(cast<OMPTargetUpdateDirective>(*S)); 353 break; 354 case Stmt::OMPDistributeParallelForDirectiveClass: 355 EmitOMPDistributeParallelForDirective( 356 cast<OMPDistributeParallelForDirective>(*S)); 357 break; 358 case Stmt::OMPDistributeParallelForSimdDirectiveClass: 359 EmitOMPDistributeParallelForSimdDirective( 360 cast<OMPDistributeParallelForSimdDirective>(*S)); 361 break; 362 case Stmt::OMPDistributeSimdDirectiveClass: 363 EmitOMPDistributeSimdDirective(cast<OMPDistributeSimdDirective>(*S)); 364 break; 365 case Stmt::OMPTargetParallelForSimdDirectiveClass: 366 EmitOMPTargetParallelForSimdDirective( 367 cast<OMPTargetParallelForSimdDirective>(*S)); 368 break; 369 case Stmt::OMPTargetSimdDirectiveClass: 370 EmitOMPTargetSimdDirective(cast<OMPTargetSimdDirective>(*S)); 371 break; 372 case Stmt::OMPTeamsDistributeDirectiveClass: 373 EmitOMPTeamsDistributeDirective(cast<OMPTeamsDistributeDirective>(*S)); 374 break; 375 case Stmt::OMPTeamsDistributeSimdDirectiveClass: 376 EmitOMPTeamsDistributeSimdDirective( 377 cast<OMPTeamsDistributeSimdDirective>(*S)); 378 break; 379 case Stmt::OMPTeamsDistributeParallelForSimdDirectiveClass: 380 EmitOMPTeamsDistributeParallelForSimdDirective( 381 cast<OMPTeamsDistributeParallelForSimdDirective>(*S)); 382 break; 383 case Stmt::OMPTeamsDistributeParallelForDirectiveClass: 384 EmitOMPTeamsDistributeParallelForDirective( 385 cast<OMPTeamsDistributeParallelForDirective>(*S)); 386 break; 387 case Stmt::OMPTargetTeamsDirectiveClass: 388 EmitOMPTargetTeamsDirective(cast<OMPTargetTeamsDirective>(*S)); 389 break; 390 case Stmt::OMPTargetTeamsDistributeDirectiveClass: 391 EmitOMPTargetTeamsDistributeDirective( 392 cast<OMPTargetTeamsDistributeDirective>(*S)); 393 break; 394 case Stmt::OMPTargetTeamsDistributeParallelForDirectiveClass: 395 EmitOMPTargetTeamsDistributeParallelForDirective( 396 cast<OMPTargetTeamsDistributeParallelForDirective>(*S)); 397 break; 398 case Stmt::OMPTargetTeamsDistributeParallelForSimdDirectiveClass: 399 EmitOMPTargetTeamsDistributeParallelForSimdDirective( 400 cast<OMPTargetTeamsDistributeParallelForSimdDirective>(*S)); 401 break; 402 case Stmt::OMPTargetTeamsDistributeSimdDirectiveClass: 403 EmitOMPTargetTeamsDistributeSimdDirective( 404 cast<OMPTargetTeamsDistributeSimdDirective>(*S)); 405 break; 406 case Stmt::OMPInteropDirectiveClass: 407 EmitOMPInteropDirective(cast<OMPInteropDirective>(*S)); 408 break; 409 case Stmt::OMPDispatchDirectiveClass: 410 llvm_unreachable("Dispatch directive not supported yet."); 411 break; 412 case Stmt::OMPMaskedDirectiveClass: 413 EmitOMPMaskedDirective(cast<OMPMaskedDirective>(*S)); 414 break; 415 case Stmt::OMPGenericLoopDirectiveClass: 416 EmitOMPGenericLoopDirective(cast<OMPGenericLoopDirective>(*S)); 417 break; 418 case Stmt::OMPTeamsGenericLoopDirectiveClass: 419 EmitOMPTeamsGenericLoopDirective(cast<OMPTeamsGenericLoopDirective>(*S)); 420 break; 421 case Stmt::OMPTargetTeamsGenericLoopDirectiveClass: 422 EmitOMPTargetTeamsGenericLoopDirective( 423 cast<OMPTargetTeamsGenericLoopDirective>(*S)); 424 break; 425 case Stmt::OMPParallelGenericLoopDirectiveClass: 426 EmitOMPParallelGenericLoopDirective( 427 cast<OMPParallelGenericLoopDirective>(*S)); 428 break; 429 case Stmt::OMPTargetParallelGenericLoopDirectiveClass: 430 EmitOMPTargetParallelGenericLoopDirective( 431 cast<OMPTargetParallelGenericLoopDirective>(*S)); 432 break; 433 case Stmt::OMPParallelMaskedDirectiveClass: 434 EmitOMPParallelMaskedDirective(cast<OMPParallelMaskedDirective>(*S)); 435 break; 436 } 437 } 438 439 bool CodeGenFunction::EmitSimpleStmt(const Stmt *S, 440 ArrayRef<const Attr *> Attrs) { 441 switch (S->getStmtClass()) { 442 default: 443 return false; 444 case Stmt::NullStmtClass: 445 break; 446 case Stmt::CompoundStmtClass: 447 EmitCompoundStmt(cast<CompoundStmt>(*S)); 448 break; 449 case Stmt::DeclStmtClass: 450 EmitDeclStmt(cast<DeclStmt>(*S)); 451 break; 452 case Stmt::LabelStmtClass: 453 EmitLabelStmt(cast<LabelStmt>(*S)); 454 break; 455 case Stmt::AttributedStmtClass: 456 EmitAttributedStmt(cast<AttributedStmt>(*S)); 457 break; 458 case Stmt::GotoStmtClass: 459 EmitGotoStmt(cast<GotoStmt>(*S)); 460 break; 461 case Stmt::BreakStmtClass: 462 EmitBreakStmt(cast<BreakStmt>(*S)); 463 break; 464 case Stmt::ContinueStmtClass: 465 EmitContinueStmt(cast<ContinueStmt>(*S)); 466 break; 467 case Stmt::DefaultStmtClass: 468 EmitDefaultStmt(cast<DefaultStmt>(*S), Attrs); 469 break; 470 case Stmt::CaseStmtClass: 471 EmitCaseStmt(cast<CaseStmt>(*S), Attrs); 472 break; 473 case Stmt::SEHLeaveStmtClass: 474 EmitSEHLeaveStmt(cast<SEHLeaveStmt>(*S)); 475 break; 476 } 477 return true; 478 } 479 480 /// EmitCompoundStmt - Emit a compound statement {..} node. If GetLast is true, 481 /// this captures the expression result of the last sub-statement and returns it 482 /// (for use by the statement expression extension). 483 Address CodeGenFunction::EmitCompoundStmt(const CompoundStmt &S, bool GetLast, 484 AggValueSlot AggSlot) { 485 PrettyStackTraceLoc CrashInfo(getContext().getSourceManager(),S.getLBracLoc(), 486 "LLVM IR generation of compound statement ('{}')"); 487 488 // Keep track of the current cleanup stack depth, including debug scopes. 489 LexicalScope Scope(*this, S.getSourceRange()); 490 491 return EmitCompoundStmtWithoutScope(S, GetLast, AggSlot); 492 } 493 494 Address 495 CodeGenFunction::EmitCompoundStmtWithoutScope(const CompoundStmt &S, 496 bool GetLast, 497 AggValueSlot AggSlot) { 498 499 const Stmt *ExprResult = S.getStmtExprResult(); 500 assert((!GetLast || (GetLast && ExprResult)) && 501 "If GetLast is true then the CompoundStmt must have a StmtExprResult"); 502 503 Address RetAlloca = Address::invalid(); 504 505 for (auto *CurStmt : S.body()) { 506 if (GetLast && ExprResult == CurStmt) { 507 // We have to special case labels here. They are statements, but when put 508 // at the end of a statement expression, they yield the value of their 509 // subexpression. Handle this by walking through all labels we encounter, 510 // emitting them before we evaluate the subexpr. 511 // Similar issues arise for attributed statements. 512 while (!isa<Expr>(ExprResult)) { 513 if (const auto *LS = dyn_cast<LabelStmt>(ExprResult)) { 514 EmitLabel(LS->getDecl()); 515 ExprResult = LS->getSubStmt(); 516 } else if (const auto *AS = dyn_cast<AttributedStmt>(ExprResult)) { 517 // FIXME: Update this if we ever have attributes that affect the 518 // semantics of an expression. 519 ExprResult = AS->getSubStmt(); 520 } else { 521 llvm_unreachable("unknown value statement"); 522 } 523 } 524 525 EnsureInsertPoint(); 526 527 const Expr *E = cast<Expr>(ExprResult); 528 QualType ExprTy = E->getType(); 529 if (hasAggregateEvaluationKind(ExprTy)) { 530 EmitAggExpr(E, AggSlot); 531 } else { 532 // We can't return an RValue here because there might be cleanups at 533 // the end of the StmtExpr. Because of that, we have to emit the result 534 // here into a temporary alloca. 535 RetAlloca = CreateMemTemp(ExprTy); 536 EmitAnyExprToMem(E, RetAlloca, Qualifiers(), 537 /*IsInit*/ false); 538 } 539 } else { 540 EmitStmt(CurStmt); 541 } 542 } 543 544 return RetAlloca; 545 } 546 547 void CodeGenFunction::SimplifyForwardingBlocks(llvm::BasicBlock *BB) { 548 llvm::BranchInst *BI = dyn_cast<llvm::BranchInst>(BB->getTerminator()); 549 550 // If there is a cleanup stack, then we it isn't worth trying to 551 // simplify this block (we would need to remove it from the scope map 552 // and cleanup entry). 553 if (!EHStack.empty()) 554 return; 555 556 // Can only simplify direct branches. 557 if (!BI || !BI->isUnconditional()) 558 return; 559 560 // Can only simplify empty blocks. 561 if (BI->getIterator() != BB->begin()) 562 return; 563 564 BB->replaceAllUsesWith(BI->getSuccessor(0)); 565 BI->eraseFromParent(); 566 BB->eraseFromParent(); 567 } 568 569 void CodeGenFunction::EmitBlock(llvm::BasicBlock *BB, bool IsFinished) { 570 llvm::BasicBlock *CurBB = Builder.GetInsertBlock(); 571 572 // Fall out of the current block (if necessary). 573 EmitBranch(BB); 574 575 if (IsFinished && BB->use_empty()) { 576 delete BB; 577 return; 578 } 579 580 // Place the block after the current block, if possible, or else at 581 // the end of the function. 582 if (CurBB && CurBB->getParent()) 583 CurFn->insert(std::next(CurBB->getIterator()), BB); 584 else 585 CurFn->insert(CurFn->end(), BB); 586 Builder.SetInsertPoint(BB); 587 } 588 589 void CodeGenFunction::EmitBranch(llvm::BasicBlock *Target) { 590 // Emit a branch from the current block to the target one if this 591 // was a real block. If this was just a fall-through block after a 592 // terminator, don't emit it. 593 llvm::BasicBlock *CurBB = Builder.GetInsertBlock(); 594 595 if (!CurBB || CurBB->getTerminator()) { 596 // If there is no insert point or the previous block is already 597 // terminated, don't touch it. 598 } else { 599 // Otherwise, create a fall-through branch. 600 Builder.CreateBr(Target); 601 } 602 603 Builder.ClearInsertionPoint(); 604 } 605 606 void CodeGenFunction::EmitBlockAfterUses(llvm::BasicBlock *block) { 607 bool inserted = false; 608 for (llvm::User *u : block->users()) { 609 if (llvm::Instruction *insn = dyn_cast<llvm::Instruction>(u)) { 610 CurFn->insert(std::next(insn->getParent()->getIterator()), block); 611 inserted = true; 612 break; 613 } 614 } 615 616 if (!inserted) 617 CurFn->insert(CurFn->end(), block); 618 619 Builder.SetInsertPoint(block); 620 } 621 622 CodeGenFunction::JumpDest 623 CodeGenFunction::getJumpDestForLabel(const LabelDecl *D) { 624 JumpDest &Dest = LabelMap[D]; 625 if (Dest.isValid()) return Dest; 626 627 // Create, but don't insert, the new block. 628 Dest = JumpDest(createBasicBlock(D->getName()), 629 EHScopeStack::stable_iterator::invalid(), 630 NextCleanupDestIndex++); 631 return Dest; 632 } 633 634 void CodeGenFunction::EmitLabel(const LabelDecl *D) { 635 // Add this label to the current lexical scope if we're within any 636 // normal cleanups. Jumps "in" to this label --- when permitted by 637 // the language --- may need to be routed around such cleanups. 638 if (EHStack.hasNormalCleanups() && CurLexicalScope) 639 CurLexicalScope->addLabel(D); 640 641 JumpDest &Dest = LabelMap[D]; 642 643 // If we didn't need a forward reference to this label, just go 644 // ahead and create a destination at the current scope. 645 if (!Dest.isValid()) { 646 Dest = getJumpDestInCurrentScope(D->getName()); 647 648 // Otherwise, we need to give this label a target depth and remove 649 // it from the branch-fixups list. 650 } else { 651 assert(!Dest.getScopeDepth().isValid() && "already emitted label!"); 652 Dest.setScopeDepth(EHStack.stable_begin()); 653 ResolveBranchFixups(Dest.getBlock()); 654 } 655 656 EmitBlock(Dest.getBlock()); 657 658 // Emit debug info for labels. 659 if (CGDebugInfo *DI = getDebugInfo()) { 660 if (CGM.getCodeGenOpts().hasReducedDebugInfo()) { 661 DI->setLocation(D->getLocation()); 662 DI->EmitLabel(D, Builder); 663 } 664 } 665 666 incrementProfileCounter(D->getStmt()); 667 } 668 669 /// Change the cleanup scope of the labels in this lexical scope to 670 /// match the scope of the enclosing context. 671 void CodeGenFunction::LexicalScope::rescopeLabels() { 672 assert(!Labels.empty()); 673 EHScopeStack::stable_iterator innermostScope 674 = CGF.EHStack.getInnermostNormalCleanup(); 675 676 // Change the scope depth of all the labels. 677 for (SmallVectorImpl<const LabelDecl*>::const_iterator 678 i = Labels.begin(), e = Labels.end(); i != e; ++i) { 679 assert(CGF.LabelMap.count(*i)); 680 JumpDest &dest = CGF.LabelMap.find(*i)->second; 681 assert(dest.getScopeDepth().isValid()); 682 assert(innermostScope.encloses(dest.getScopeDepth())); 683 dest.setScopeDepth(innermostScope); 684 } 685 686 // Reparent the labels if the new scope also has cleanups. 687 if (innermostScope != EHScopeStack::stable_end() && ParentScope) { 688 ParentScope->Labels.append(Labels.begin(), Labels.end()); 689 } 690 } 691 692 693 void CodeGenFunction::EmitLabelStmt(const LabelStmt &S) { 694 EmitLabel(S.getDecl()); 695 696 // IsEHa - emit eha.scope.begin if it's a side entry of a scope 697 if (getLangOpts().EHAsynch && S.isSideEntry()) 698 EmitSehCppScopeBegin(); 699 700 EmitStmt(S.getSubStmt()); 701 } 702 703 void CodeGenFunction::EmitAttributedStmt(const AttributedStmt &S) { 704 bool nomerge = false; 705 bool noinline = false; 706 bool alwaysinline = false; 707 const CallExpr *musttail = nullptr; 708 709 for (const auto *A : S.getAttrs()) { 710 switch (A->getKind()) { 711 default: 712 break; 713 case attr::NoMerge: 714 nomerge = true; 715 break; 716 case attr::NoInline: 717 noinline = true; 718 break; 719 case attr::AlwaysInline: 720 alwaysinline = true; 721 break; 722 case attr::MustTail: 723 const Stmt *Sub = S.getSubStmt(); 724 const ReturnStmt *R = cast<ReturnStmt>(Sub); 725 musttail = cast<CallExpr>(R->getRetValue()->IgnoreParens()); 726 break; 727 } 728 } 729 SaveAndRestore save_nomerge(InNoMergeAttributedStmt, nomerge); 730 SaveAndRestore save_noinline(InNoInlineAttributedStmt, noinline); 731 SaveAndRestore save_alwaysinline(InAlwaysInlineAttributedStmt, alwaysinline); 732 SaveAndRestore save_musttail(MustTailCall, musttail); 733 EmitStmt(S.getSubStmt(), S.getAttrs()); 734 } 735 736 void CodeGenFunction::EmitGotoStmt(const GotoStmt &S) { 737 // If this code is reachable then emit a stop point (if generating 738 // debug info). We have to do this ourselves because we are on the 739 // "simple" statement path. 740 if (HaveInsertPoint()) 741 EmitStopPoint(&S); 742 743 EmitBranchThroughCleanup(getJumpDestForLabel(S.getLabel())); 744 } 745 746 747 void CodeGenFunction::EmitIndirectGotoStmt(const IndirectGotoStmt &S) { 748 if (const LabelDecl *Target = S.getConstantTarget()) { 749 EmitBranchThroughCleanup(getJumpDestForLabel(Target)); 750 return; 751 } 752 753 // Ensure that we have an i8* for our PHI node. 754 llvm::Value *V = Builder.CreateBitCast(EmitScalarExpr(S.getTarget()), 755 Int8PtrTy, "addr"); 756 llvm::BasicBlock *CurBB = Builder.GetInsertBlock(); 757 758 // Get the basic block for the indirect goto. 759 llvm::BasicBlock *IndGotoBB = GetIndirectGotoBlock(); 760 761 // The first instruction in the block has to be the PHI for the switch dest, 762 // add an entry for this branch. 763 cast<llvm::PHINode>(IndGotoBB->begin())->addIncoming(V, CurBB); 764 765 EmitBranch(IndGotoBB); 766 } 767 768 void CodeGenFunction::EmitIfStmt(const IfStmt &S) { 769 // The else branch of a consteval if statement is always the only branch that 770 // can be runtime evaluated. 771 if (S.isConsteval()) { 772 const Stmt *Executed = S.isNegatedConsteval() ? S.getThen() : S.getElse(); 773 if (Executed) { 774 RunCleanupsScope ExecutedScope(*this); 775 EmitStmt(Executed); 776 } 777 return; 778 } 779 780 // C99 6.8.4.1: The first substatement is executed if the expression compares 781 // unequal to 0. The condition must be a scalar type. 782 LexicalScope ConditionScope(*this, S.getCond()->getSourceRange()); 783 784 if (S.getInit()) 785 EmitStmt(S.getInit()); 786 787 if (S.getConditionVariable()) 788 EmitDecl(*S.getConditionVariable()); 789 790 // If the condition constant folds and can be elided, try to avoid emitting 791 // the condition and the dead arm of the if/else. 792 bool CondConstant; 793 if (ConstantFoldsToSimpleInteger(S.getCond(), CondConstant, 794 S.isConstexpr())) { 795 // Figure out which block (then or else) is executed. 796 const Stmt *Executed = S.getThen(); 797 const Stmt *Skipped = S.getElse(); 798 if (!CondConstant) // Condition false? 799 std::swap(Executed, Skipped); 800 801 // If the skipped block has no labels in it, just emit the executed block. 802 // This avoids emitting dead code and simplifies the CFG substantially. 803 if (S.isConstexpr() || !ContainsLabel(Skipped)) { 804 if (CondConstant) 805 incrementProfileCounter(&S); 806 if (Executed) { 807 RunCleanupsScope ExecutedScope(*this); 808 EmitStmt(Executed); 809 } 810 return; 811 } 812 } 813 814 // Otherwise, the condition did not fold, or we couldn't elide it. Just emit 815 // the conditional branch. 816 llvm::BasicBlock *ThenBlock = createBasicBlock("if.then"); 817 llvm::BasicBlock *ContBlock = createBasicBlock("if.end"); 818 llvm::BasicBlock *ElseBlock = ContBlock; 819 if (S.getElse()) 820 ElseBlock = createBasicBlock("if.else"); 821 822 // Prefer the PGO based weights over the likelihood attribute. 823 // When the build isn't optimized the metadata isn't used, so don't generate 824 // it. 825 // Also, differentiate between disabled PGO and a never executed branch with 826 // PGO. Assuming PGO is in use: 827 // - we want to ignore the [[likely]] attribute if the branch is never 828 // executed, 829 // - assuming the profile is poor, preserving the attribute may still be 830 // beneficial. 831 // As an approximation, preserve the attribute only if both the branch and the 832 // parent context were not executed. 833 Stmt::Likelihood LH = Stmt::LH_None; 834 uint64_t ThenCount = getProfileCount(S.getThen()); 835 if (!ThenCount && !getCurrentProfileCount() && 836 CGM.getCodeGenOpts().OptimizationLevel) 837 LH = Stmt::getLikelihood(S.getThen(), S.getElse()); 838 EmitBranchOnBoolExpr(S.getCond(), ThenBlock, ElseBlock, ThenCount, LH); 839 840 // Emit the 'then' code. 841 EmitBlock(ThenBlock); 842 incrementProfileCounter(&S); 843 { 844 RunCleanupsScope ThenScope(*this); 845 EmitStmt(S.getThen()); 846 } 847 EmitBranch(ContBlock); 848 849 // Emit the 'else' code if present. 850 if (const Stmt *Else = S.getElse()) { 851 { 852 // There is no need to emit line number for an unconditional branch. 853 auto NL = ApplyDebugLocation::CreateEmpty(*this); 854 EmitBlock(ElseBlock); 855 } 856 { 857 RunCleanupsScope ElseScope(*this); 858 EmitStmt(Else); 859 } 860 { 861 // There is no need to emit line number for an unconditional branch. 862 auto NL = ApplyDebugLocation::CreateEmpty(*this); 863 EmitBranch(ContBlock); 864 } 865 } 866 867 // Emit the continuation block for code after the if. 868 EmitBlock(ContBlock, true); 869 } 870 871 void CodeGenFunction::EmitWhileStmt(const WhileStmt &S, 872 ArrayRef<const Attr *> WhileAttrs) { 873 // Emit the header for the loop, which will also become 874 // the continue target. 875 JumpDest LoopHeader = getJumpDestInCurrentScope("while.cond"); 876 EmitBlock(LoopHeader.getBlock()); 877 878 // Create an exit block for when the condition fails, which will 879 // also become the break target. 880 JumpDest LoopExit = getJumpDestInCurrentScope("while.end"); 881 882 // Store the blocks to use for break and continue. 883 BreakContinueStack.push_back(BreakContinue(LoopExit, LoopHeader)); 884 885 // C++ [stmt.while]p2: 886 // When the condition of a while statement is a declaration, the 887 // scope of the variable that is declared extends from its point 888 // of declaration (3.3.2) to the end of the while statement. 889 // [...] 890 // The object created in a condition is destroyed and created 891 // with each iteration of the loop. 892 RunCleanupsScope ConditionScope(*this); 893 894 if (S.getConditionVariable()) 895 EmitDecl(*S.getConditionVariable()); 896 897 // Evaluate the conditional in the while header. C99 6.8.5.1: The 898 // evaluation of the controlling expression takes place before each 899 // execution of the loop body. 900 llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond()); 901 902 // while(1) is common, avoid extra exit blocks. Be sure 903 // to correctly handle break/continue though. 904 llvm::ConstantInt *C = dyn_cast<llvm::ConstantInt>(BoolCondVal); 905 bool CondIsConstInt = C != nullptr; 906 bool EmitBoolCondBranch = !CondIsConstInt || !C->isOne(); 907 const SourceRange &R = S.getSourceRange(); 908 LoopStack.push(LoopHeader.getBlock(), CGM.getContext(), CGM.getCodeGenOpts(), 909 WhileAttrs, SourceLocToDebugLoc(R.getBegin()), 910 SourceLocToDebugLoc(R.getEnd()), 911 checkIfLoopMustProgress(CondIsConstInt)); 912 913 // As long as the condition is true, go to the loop body. 914 llvm::BasicBlock *LoopBody = createBasicBlock("while.body"); 915 if (EmitBoolCondBranch) { 916 llvm::BasicBlock *ExitBlock = LoopExit.getBlock(); 917 if (ConditionScope.requiresCleanups()) 918 ExitBlock = createBasicBlock("while.exit"); 919 llvm::MDNode *Weights = 920 createProfileWeightsForLoop(S.getCond(), getProfileCount(S.getBody())); 921 if (!Weights && CGM.getCodeGenOpts().OptimizationLevel) 922 BoolCondVal = emitCondLikelihoodViaExpectIntrinsic( 923 BoolCondVal, Stmt::getLikelihood(S.getBody())); 924 Builder.CreateCondBr(BoolCondVal, LoopBody, ExitBlock, Weights); 925 926 if (ExitBlock != LoopExit.getBlock()) { 927 EmitBlock(ExitBlock); 928 EmitBranchThroughCleanup(LoopExit); 929 } 930 } else if (const Attr *A = Stmt::getLikelihoodAttr(S.getBody())) { 931 CGM.getDiags().Report(A->getLocation(), 932 diag::warn_attribute_has_no_effect_on_infinite_loop) 933 << A << A->getRange(); 934 CGM.getDiags().Report( 935 S.getWhileLoc(), 936 diag::note_attribute_has_no_effect_on_infinite_loop_here) 937 << SourceRange(S.getWhileLoc(), S.getRParenLoc()); 938 } 939 940 // Emit the loop body. We have to emit this in a cleanup scope 941 // because it might be a singleton DeclStmt. 942 { 943 RunCleanupsScope BodyScope(*this); 944 EmitBlock(LoopBody); 945 incrementProfileCounter(&S); 946 EmitStmt(S.getBody()); 947 } 948 949 BreakContinueStack.pop_back(); 950 951 // Immediately force cleanup. 952 ConditionScope.ForceCleanup(); 953 954 EmitStopPoint(&S); 955 // Branch to the loop header again. 956 EmitBranch(LoopHeader.getBlock()); 957 958 LoopStack.pop(); 959 960 // Emit the exit block. 961 EmitBlock(LoopExit.getBlock(), true); 962 963 // The LoopHeader typically is just a branch if we skipped emitting 964 // a branch, try to erase it. 965 if (!EmitBoolCondBranch) 966 SimplifyForwardingBlocks(LoopHeader.getBlock()); 967 } 968 969 void CodeGenFunction::EmitDoStmt(const DoStmt &S, 970 ArrayRef<const Attr *> DoAttrs) { 971 JumpDest LoopExit = getJumpDestInCurrentScope("do.end"); 972 JumpDest LoopCond = getJumpDestInCurrentScope("do.cond"); 973 974 uint64_t ParentCount = getCurrentProfileCount(); 975 976 // Store the blocks to use for break and continue. 977 BreakContinueStack.push_back(BreakContinue(LoopExit, LoopCond)); 978 979 // Emit the body of the loop. 980 llvm::BasicBlock *LoopBody = createBasicBlock("do.body"); 981 982 EmitBlockWithFallThrough(LoopBody, &S); 983 { 984 RunCleanupsScope BodyScope(*this); 985 EmitStmt(S.getBody()); 986 } 987 988 EmitBlock(LoopCond.getBlock()); 989 990 // C99 6.8.5.2: "The evaluation of the controlling expression takes place 991 // after each execution of the loop body." 992 993 // Evaluate the conditional in the while header. 994 // C99 6.8.5p2/p4: The first substatement is executed if the expression 995 // compares unequal to 0. The condition must be a scalar type. 996 llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond()); 997 998 BreakContinueStack.pop_back(); 999 1000 // "do {} while (0)" is common in macros, avoid extra blocks. Be sure 1001 // to correctly handle break/continue though. 1002 llvm::ConstantInt *C = dyn_cast<llvm::ConstantInt>(BoolCondVal); 1003 bool CondIsConstInt = C; 1004 bool EmitBoolCondBranch = !C || !C->isZero(); 1005 1006 const SourceRange &R = S.getSourceRange(); 1007 LoopStack.push(LoopBody, CGM.getContext(), CGM.getCodeGenOpts(), DoAttrs, 1008 SourceLocToDebugLoc(R.getBegin()), 1009 SourceLocToDebugLoc(R.getEnd()), 1010 checkIfLoopMustProgress(CondIsConstInt)); 1011 1012 // As long as the condition is true, iterate the loop. 1013 if (EmitBoolCondBranch) { 1014 uint64_t BackedgeCount = getProfileCount(S.getBody()) - ParentCount; 1015 Builder.CreateCondBr( 1016 BoolCondVal, LoopBody, LoopExit.getBlock(), 1017 createProfileWeightsForLoop(S.getCond(), BackedgeCount)); 1018 } 1019 1020 LoopStack.pop(); 1021 1022 // Emit the exit block. 1023 EmitBlock(LoopExit.getBlock()); 1024 1025 // The DoCond block typically is just a branch if we skipped 1026 // emitting a branch, try to erase it. 1027 if (!EmitBoolCondBranch) 1028 SimplifyForwardingBlocks(LoopCond.getBlock()); 1029 } 1030 1031 void CodeGenFunction::EmitForStmt(const ForStmt &S, 1032 ArrayRef<const Attr *> ForAttrs) { 1033 JumpDest LoopExit = getJumpDestInCurrentScope("for.end"); 1034 1035 LexicalScope ForScope(*this, S.getSourceRange()); 1036 1037 // Evaluate the first part before the loop. 1038 if (S.getInit()) 1039 EmitStmt(S.getInit()); 1040 1041 // Start the loop with a block that tests the condition. 1042 // If there's an increment, the continue scope will be overwritten 1043 // later. 1044 JumpDest CondDest = getJumpDestInCurrentScope("for.cond"); 1045 llvm::BasicBlock *CondBlock = CondDest.getBlock(); 1046 EmitBlock(CondBlock); 1047 1048 Expr::EvalResult Result; 1049 bool CondIsConstInt = 1050 !S.getCond() || S.getCond()->EvaluateAsInt(Result, getContext()); 1051 1052 const SourceRange &R = S.getSourceRange(); 1053 LoopStack.push(CondBlock, CGM.getContext(), CGM.getCodeGenOpts(), ForAttrs, 1054 SourceLocToDebugLoc(R.getBegin()), 1055 SourceLocToDebugLoc(R.getEnd()), 1056 checkIfLoopMustProgress(CondIsConstInt)); 1057 1058 // Create a cleanup scope for the condition variable cleanups. 1059 LexicalScope ConditionScope(*this, S.getSourceRange()); 1060 1061 // If the for loop doesn't have an increment we can just use the condition as 1062 // the continue block. Otherwise, if there is no condition variable, we can 1063 // form the continue block now. If there is a condition variable, we can't 1064 // form the continue block until after we've emitted the condition, because 1065 // the condition is in scope in the increment, but Sema's jump diagnostics 1066 // ensure that there are no continues from the condition variable that jump 1067 // to the loop increment. 1068 JumpDest Continue; 1069 if (!S.getInc()) 1070 Continue = CondDest; 1071 else if (!S.getConditionVariable()) 1072 Continue = getJumpDestInCurrentScope("for.inc"); 1073 BreakContinueStack.push_back(BreakContinue(LoopExit, Continue)); 1074 1075 if (S.getCond()) { 1076 // If the for statement has a condition scope, emit the local variable 1077 // declaration. 1078 if (S.getConditionVariable()) { 1079 EmitDecl(*S.getConditionVariable()); 1080 1081 // We have entered the condition variable's scope, so we're now able to 1082 // jump to the continue block. 1083 Continue = S.getInc() ? getJumpDestInCurrentScope("for.inc") : CondDest; 1084 BreakContinueStack.back().ContinueBlock = Continue; 1085 } 1086 1087 llvm::BasicBlock *ExitBlock = LoopExit.getBlock(); 1088 // If there are any cleanups between here and the loop-exit scope, 1089 // create a block to stage a loop exit along. 1090 if (ForScope.requiresCleanups()) 1091 ExitBlock = createBasicBlock("for.cond.cleanup"); 1092 1093 // As long as the condition is true, iterate the loop. 1094 llvm::BasicBlock *ForBody = createBasicBlock("for.body"); 1095 1096 // C99 6.8.5p2/p4: The first substatement is executed if the expression 1097 // compares unequal to 0. The condition must be a scalar type. 1098 llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond()); 1099 llvm::MDNode *Weights = 1100 createProfileWeightsForLoop(S.getCond(), getProfileCount(S.getBody())); 1101 if (!Weights && CGM.getCodeGenOpts().OptimizationLevel) 1102 BoolCondVal = emitCondLikelihoodViaExpectIntrinsic( 1103 BoolCondVal, Stmt::getLikelihood(S.getBody())); 1104 1105 Builder.CreateCondBr(BoolCondVal, ForBody, ExitBlock, Weights); 1106 1107 if (ExitBlock != LoopExit.getBlock()) { 1108 EmitBlock(ExitBlock); 1109 EmitBranchThroughCleanup(LoopExit); 1110 } 1111 1112 EmitBlock(ForBody); 1113 } else { 1114 // Treat it as a non-zero constant. Don't even create a new block for the 1115 // body, just fall into it. 1116 } 1117 incrementProfileCounter(&S); 1118 1119 { 1120 // Create a separate cleanup scope for the body, in case it is not 1121 // a compound statement. 1122 RunCleanupsScope BodyScope(*this); 1123 EmitStmt(S.getBody()); 1124 } 1125 1126 // If there is an increment, emit it next. 1127 if (S.getInc()) { 1128 EmitBlock(Continue.getBlock()); 1129 EmitStmt(S.getInc()); 1130 } 1131 1132 BreakContinueStack.pop_back(); 1133 1134 ConditionScope.ForceCleanup(); 1135 1136 EmitStopPoint(&S); 1137 EmitBranch(CondBlock); 1138 1139 ForScope.ForceCleanup(); 1140 1141 LoopStack.pop(); 1142 1143 // Emit the fall-through block. 1144 EmitBlock(LoopExit.getBlock(), true); 1145 } 1146 1147 void 1148 CodeGenFunction::EmitCXXForRangeStmt(const CXXForRangeStmt &S, 1149 ArrayRef<const Attr *> ForAttrs) { 1150 JumpDest LoopExit = getJumpDestInCurrentScope("for.end"); 1151 1152 LexicalScope ForScope(*this, S.getSourceRange()); 1153 1154 // Evaluate the first pieces before the loop. 1155 if (S.getInit()) 1156 EmitStmt(S.getInit()); 1157 EmitStmt(S.getRangeStmt()); 1158 EmitStmt(S.getBeginStmt()); 1159 EmitStmt(S.getEndStmt()); 1160 1161 // Start the loop with a block that tests the condition. 1162 // If there's an increment, the continue scope will be overwritten 1163 // later. 1164 llvm::BasicBlock *CondBlock = createBasicBlock("for.cond"); 1165 EmitBlock(CondBlock); 1166 1167 const SourceRange &R = S.getSourceRange(); 1168 LoopStack.push(CondBlock, CGM.getContext(), CGM.getCodeGenOpts(), ForAttrs, 1169 SourceLocToDebugLoc(R.getBegin()), 1170 SourceLocToDebugLoc(R.getEnd())); 1171 1172 // If there are any cleanups between here and the loop-exit scope, 1173 // create a block to stage a loop exit along. 1174 llvm::BasicBlock *ExitBlock = LoopExit.getBlock(); 1175 if (ForScope.requiresCleanups()) 1176 ExitBlock = createBasicBlock("for.cond.cleanup"); 1177 1178 // The loop body, consisting of the specified body and the loop variable. 1179 llvm::BasicBlock *ForBody = createBasicBlock("for.body"); 1180 1181 // The body is executed if the expression, contextually converted 1182 // to bool, is true. 1183 llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond()); 1184 llvm::MDNode *Weights = 1185 createProfileWeightsForLoop(S.getCond(), getProfileCount(S.getBody())); 1186 if (!Weights && CGM.getCodeGenOpts().OptimizationLevel) 1187 BoolCondVal = emitCondLikelihoodViaExpectIntrinsic( 1188 BoolCondVal, Stmt::getLikelihood(S.getBody())); 1189 Builder.CreateCondBr(BoolCondVal, ForBody, ExitBlock, Weights); 1190 1191 if (ExitBlock != LoopExit.getBlock()) { 1192 EmitBlock(ExitBlock); 1193 EmitBranchThroughCleanup(LoopExit); 1194 } 1195 1196 EmitBlock(ForBody); 1197 incrementProfileCounter(&S); 1198 1199 // Create a block for the increment. In case of a 'continue', we jump there. 1200 JumpDest Continue = getJumpDestInCurrentScope("for.inc"); 1201 1202 // Store the blocks to use for break and continue. 1203 BreakContinueStack.push_back(BreakContinue(LoopExit, Continue)); 1204 1205 { 1206 // Create a separate cleanup scope for the loop variable and body. 1207 LexicalScope BodyScope(*this, S.getSourceRange()); 1208 EmitStmt(S.getLoopVarStmt()); 1209 EmitStmt(S.getBody()); 1210 } 1211 1212 EmitStopPoint(&S); 1213 // If there is an increment, emit it next. 1214 EmitBlock(Continue.getBlock()); 1215 EmitStmt(S.getInc()); 1216 1217 BreakContinueStack.pop_back(); 1218 1219 EmitBranch(CondBlock); 1220 1221 ForScope.ForceCleanup(); 1222 1223 LoopStack.pop(); 1224 1225 // Emit the fall-through block. 1226 EmitBlock(LoopExit.getBlock(), true); 1227 } 1228 1229 void CodeGenFunction::EmitReturnOfRValue(RValue RV, QualType Ty) { 1230 if (RV.isScalar()) { 1231 Builder.CreateStore(RV.getScalarVal(), ReturnValue); 1232 } else if (RV.isAggregate()) { 1233 LValue Dest = MakeAddrLValue(ReturnValue, Ty); 1234 LValue Src = MakeAddrLValue(RV.getAggregateAddress(), Ty); 1235 EmitAggregateCopy(Dest, Src, Ty, getOverlapForReturnValue()); 1236 } else { 1237 EmitStoreOfComplex(RV.getComplexVal(), MakeAddrLValue(ReturnValue, Ty), 1238 /*init*/ true); 1239 } 1240 EmitBranchThroughCleanup(ReturnBlock); 1241 } 1242 1243 namespace { 1244 // RAII struct used to save and restore a return statment's result expression. 1245 struct SaveRetExprRAII { 1246 SaveRetExprRAII(const Expr *RetExpr, CodeGenFunction &CGF) 1247 : OldRetExpr(CGF.RetExpr), CGF(CGF) { 1248 CGF.RetExpr = RetExpr; 1249 } 1250 ~SaveRetExprRAII() { CGF.RetExpr = OldRetExpr; } 1251 const Expr *OldRetExpr; 1252 CodeGenFunction &CGF; 1253 }; 1254 } // namespace 1255 1256 /// If we have 'return f(...);', where both caller and callee are SwiftAsync, 1257 /// codegen it as 'tail call ...; ret void;'. 1258 static void makeTailCallIfSwiftAsync(const CallExpr *CE, CGBuilderTy &Builder, 1259 const CGFunctionInfo *CurFnInfo) { 1260 auto calleeQualType = CE->getCallee()->getType(); 1261 const FunctionType *calleeType = nullptr; 1262 if (calleeQualType->isFunctionPointerType() || 1263 calleeQualType->isFunctionReferenceType() || 1264 calleeQualType->isBlockPointerType() || 1265 calleeQualType->isMemberFunctionPointerType()) { 1266 calleeType = calleeQualType->getPointeeType()->castAs<FunctionType>(); 1267 } else if (auto *ty = dyn_cast<FunctionType>(calleeQualType)) { 1268 calleeType = ty; 1269 } else if (auto CMCE = dyn_cast<CXXMemberCallExpr>(CE)) { 1270 if (auto methodDecl = CMCE->getMethodDecl()) { 1271 // getMethodDecl() doesn't handle member pointers at the moment. 1272 calleeType = methodDecl->getType()->castAs<FunctionType>(); 1273 } else { 1274 return; 1275 } 1276 } else { 1277 return; 1278 } 1279 if (calleeType->getCallConv() == CallingConv::CC_SwiftAsync && 1280 (CurFnInfo->getASTCallingConvention() == CallingConv::CC_SwiftAsync)) { 1281 auto CI = cast<llvm::CallInst>(&Builder.GetInsertBlock()->back()); 1282 CI->setTailCallKind(llvm::CallInst::TCK_MustTail); 1283 Builder.CreateRetVoid(); 1284 Builder.ClearInsertionPoint(); 1285 } 1286 } 1287 1288 /// EmitReturnStmt - Note that due to GCC extensions, this can have an operand 1289 /// if the function returns void, or may be missing one if the function returns 1290 /// non-void. Fun stuff :). 1291 void CodeGenFunction::EmitReturnStmt(const ReturnStmt &S) { 1292 if (requiresReturnValueCheck()) { 1293 llvm::Constant *SLoc = EmitCheckSourceLocation(S.getBeginLoc()); 1294 auto *SLocPtr = 1295 new llvm::GlobalVariable(CGM.getModule(), SLoc->getType(), false, 1296 llvm::GlobalVariable::PrivateLinkage, SLoc); 1297 SLocPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); 1298 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(SLocPtr); 1299 assert(ReturnLocation.isValid() && "No valid return location"); 1300 Builder.CreateStore(Builder.CreateBitCast(SLocPtr, Int8PtrTy), 1301 ReturnLocation); 1302 } 1303 1304 // Returning from an outlined SEH helper is UB, and we already warn on it. 1305 if (IsOutlinedSEHHelper) { 1306 Builder.CreateUnreachable(); 1307 Builder.ClearInsertionPoint(); 1308 } 1309 1310 // Emit the result value, even if unused, to evaluate the side effects. 1311 const Expr *RV = S.getRetValue(); 1312 1313 // Record the result expression of the return statement. The recorded 1314 // expression is used to determine whether a block capture's lifetime should 1315 // end at the end of the full expression as opposed to the end of the scope 1316 // enclosing the block expression. 1317 // 1318 // This permits a small, easily-implemented exception to our over-conservative 1319 // rules about not jumping to statements following block literals with 1320 // non-trivial cleanups. 1321 SaveRetExprRAII SaveRetExpr(RV, *this); 1322 1323 RunCleanupsScope cleanupScope(*this); 1324 if (const auto *EWC = dyn_cast_or_null<ExprWithCleanups>(RV)) 1325 RV = EWC->getSubExpr(); 1326 // FIXME: Clean this up by using an LValue for ReturnTemp, 1327 // EmitStoreThroughLValue, and EmitAnyExpr. 1328 // Check if the NRVO candidate was not globalized in OpenMP mode. 1329 if (getLangOpts().ElideConstructors && S.getNRVOCandidate() && 1330 S.getNRVOCandidate()->isNRVOVariable() && 1331 (!getLangOpts().OpenMP || 1332 !CGM.getOpenMPRuntime() 1333 .getAddressOfLocalVariable(*this, S.getNRVOCandidate()) 1334 .isValid())) { 1335 // Apply the named return value optimization for this return statement, 1336 // which means doing nothing: the appropriate result has already been 1337 // constructed into the NRVO variable. 1338 1339 // If there is an NRVO flag for this variable, set it to 1 into indicate 1340 // that the cleanup code should not destroy the variable. 1341 if (llvm::Value *NRVOFlag = NRVOFlags[S.getNRVOCandidate()]) 1342 Builder.CreateFlagStore(Builder.getTrue(), NRVOFlag); 1343 } else if (!ReturnValue.isValid() || (RV && RV->getType()->isVoidType())) { 1344 // Make sure not to return anything, but evaluate the expression 1345 // for side effects. 1346 if (RV) { 1347 EmitAnyExpr(RV); 1348 if (auto *CE = dyn_cast<CallExpr>(RV)) 1349 makeTailCallIfSwiftAsync(CE, Builder, CurFnInfo); 1350 } 1351 } else if (!RV) { 1352 // Do nothing (return value is left uninitialized) 1353 } else if (FnRetTy->isReferenceType()) { 1354 // If this function returns a reference, take the address of the expression 1355 // rather than the value. 1356 RValue Result = EmitReferenceBindingToExpr(RV); 1357 Builder.CreateStore(Result.getScalarVal(), ReturnValue); 1358 } else { 1359 switch (getEvaluationKind(RV->getType())) { 1360 case TEK_Scalar: 1361 Builder.CreateStore(EmitScalarExpr(RV), ReturnValue); 1362 break; 1363 case TEK_Complex: 1364 EmitComplexExprIntoLValue(RV, MakeAddrLValue(ReturnValue, RV->getType()), 1365 /*isInit*/ true); 1366 break; 1367 case TEK_Aggregate: 1368 EmitAggExpr(RV, AggValueSlot::forAddr( 1369 ReturnValue, Qualifiers(), 1370 AggValueSlot::IsDestructed, 1371 AggValueSlot::DoesNotNeedGCBarriers, 1372 AggValueSlot::IsNotAliased, 1373 getOverlapForReturnValue())); 1374 break; 1375 } 1376 } 1377 1378 ++NumReturnExprs; 1379 if (!RV || RV->isEvaluatable(getContext())) 1380 ++NumSimpleReturnExprs; 1381 1382 cleanupScope.ForceCleanup(); 1383 EmitBranchThroughCleanup(ReturnBlock); 1384 } 1385 1386 void CodeGenFunction::EmitDeclStmt(const DeclStmt &S) { 1387 // As long as debug info is modeled with instructions, we have to ensure we 1388 // have a place to insert here and write the stop point here. 1389 if (HaveInsertPoint()) 1390 EmitStopPoint(&S); 1391 1392 for (const auto *I : S.decls()) 1393 EmitDecl(*I); 1394 } 1395 1396 void CodeGenFunction::EmitBreakStmt(const BreakStmt &S) { 1397 assert(!BreakContinueStack.empty() && "break stmt not in a loop or switch!"); 1398 1399 // If this code is reachable then emit a stop point (if generating 1400 // debug info). We have to do this ourselves because we are on the 1401 // "simple" statement path. 1402 if (HaveInsertPoint()) 1403 EmitStopPoint(&S); 1404 1405 EmitBranchThroughCleanup(BreakContinueStack.back().BreakBlock); 1406 } 1407 1408 void CodeGenFunction::EmitContinueStmt(const ContinueStmt &S) { 1409 assert(!BreakContinueStack.empty() && "continue stmt not in a loop!"); 1410 1411 // If this code is reachable then emit a stop point (if generating 1412 // debug info). We have to do this ourselves because we are on the 1413 // "simple" statement path. 1414 if (HaveInsertPoint()) 1415 EmitStopPoint(&S); 1416 1417 EmitBranchThroughCleanup(BreakContinueStack.back().ContinueBlock); 1418 } 1419 1420 /// EmitCaseStmtRange - If case statement range is not too big then 1421 /// add multiple cases to switch instruction, one for each value within 1422 /// the range. If range is too big then emit "if" condition check. 1423 void CodeGenFunction::EmitCaseStmtRange(const CaseStmt &S, 1424 ArrayRef<const Attr *> Attrs) { 1425 assert(S.getRHS() && "Expected RHS value in CaseStmt"); 1426 1427 llvm::APSInt LHS = S.getLHS()->EvaluateKnownConstInt(getContext()); 1428 llvm::APSInt RHS = S.getRHS()->EvaluateKnownConstInt(getContext()); 1429 1430 // Emit the code for this case. We do this first to make sure it is 1431 // properly chained from our predecessor before generating the 1432 // switch machinery to enter this block. 1433 llvm::BasicBlock *CaseDest = createBasicBlock("sw.bb"); 1434 EmitBlockWithFallThrough(CaseDest, &S); 1435 EmitStmt(S.getSubStmt()); 1436 1437 // If range is empty, do nothing. 1438 if (LHS.isSigned() ? RHS.slt(LHS) : RHS.ult(LHS)) 1439 return; 1440 1441 Stmt::Likelihood LH = Stmt::getLikelihood(Attrs); 1442 llvm::APInt Range = RHS - LHS; 1443 // FIXME: parameters such as this should not be hardcoded. 1444 if (Range.ult(llvm::APInt(Range.getBitWidth(), 64))) { 1445 // Range is small enough to add multiple switch instruction cases. 1446 uint64_t Total = getProfileCount(&S); 1447 unsigned NCases = Range.getZExtValue() + 1; 1448 // We only have one region counter for the entire set of cases here, so we 1449 // need to divide the weights evenly between the generated cases, ensuring 1450 // that the total weight is preserved. E.g., a weight of 5 over three cases 1451 // will be distributed as weights of 2, 2, and 1. 1452 uint64_t Weight = Total / NCases, Rem = Total % NCases; 1453 for (unsigned I = 0; I != NCases; ++I) { 1454 if (SwitchWeights) 1455 SwitchWeights->push_back(Weight + (Rem ? 1 : 0)); 1456 else if (SwitchLikelihood) 1457 SwitchLikelihood->push_back(LH); 1458 1459 if (Rem) 1460 Rem--; 1461 SwitchInsn->addCase(Builder.getInt(LHS), CaseDest); 1462 ++LHS; 1463 } 1464 return; 1465 } 1466 1467 // The range is too big. Emit "if" condition into a new block, 1468 // making sure to save and restore the current insertion point. 1469 llvm::BasicBlock *RestoreBB = Builder.GetInsertBlock(); 1470 1471 // Push this test onto the chain of range checks (which terminates 1472 // in the default basic block). The switch's default will be changed 1473 // to the top of this chain after switch emission is complete. 1474 llvm::BasicBlock *FalseDest = CaseRangeBlock; 1475 CaseRangeBlock = createBasicBlock("sw.caserange"); 1476 1477 CurFn->insert(CurFn->end(), CaseRangeBlock); 1478 Builder.SetInsertPoint(CaseRangeBlock); 1479 1480 // Emit range check. 1481 llvm::Value *Diff = 1482 Builder.CreateSub(SwitchInsn->getCondition(), Builder.getInt(LHS)); 1483 llvm::Value *Cond = 1484 Builder.CreateICmpULE(Diff, Builder.getInt(Range), "inbounds"); 1485 1486 llvm::MDNode *Weights = nullptr; 1487 if (SwitchWeights) { 1488 uint64_t ThisCount = getProfileCount(&S); 1489 uint64_t DefaultCount = (*SwitchWeights)[0]; 1490 Weights = createProfileWeights(ThisCount, DefaultCount); 1491 1492 // Since we're chaining the switch default through each large case range, we 1493 // need to update the weight for the default, ie, the first case, to include 1494 // this case. 1495 (*SwitchWeights)[0] += ThisCount; 1496 } else if (SwitchLikelihood) 1497 Cond = emitCondLikelihoodViaExpectIntrinsic(Cond, LH); 1498 1499 Builder.CreateCondBr(Cond, CaseDest, FalseDest, Weights); 1500 1501 // Restore the appropriate insertion point. 1502 if (RestoreBB) 1503 Builder.SetInsertPoint(RestoreBB); 1504 else 1505 Builder.ClearInsertionPoint(); 1506 } 1507 1508 void CodeGenFunction::EmitCaseStmt(const CaseStmt &S, 1509 ArrayRef<const Attr *> Attrs) { 1510 // If there is no enclosing switch instance that we're aware of, then this 1511 // case statement and its block can be elided. This situation only happens 1512 // when we've constant-folded the switch, are emitting the constant case, 1513 // and part of the constant case includes another case statement. For 1514 // instance: switch (4) { case 4: do { case 5: } while (1); } 1515 if (!SwitchInsn) { 1516 EmitStmt(S.getSubStmt()); 1517 return; 1518 } 1519 1520 // Handle case ranges. 1521 if (S.getRHS()) { 1522 EmitCaseStmtRange(S, Attrs); 1523 return; 1524 } 1525 1526 llvm::ConstantInt *CaseVal = 1527 Builder.getInt(S.getLHS()->EvaluateKnownConstInt(getContext())); 1528 1529 // Emit debuginfo for the case value if it is an enum value. 1530 const ConstantExpr *CE; 1531 if (auto ICE = dyn_cast<ImplicitCastExpr>(S.getLHS())) 1532 CE = dyn_cast<ConstantExpr>(ICE->getSubExpr()); 1533 else 1534 CE = dyn_cast<ConstantExpr>(S.getLHS()); 1535 if (CE) { 1536 if (auto DE = dyn_cast<DeclRefExpr>(CE->getSubExpr())) 1537 if (CGDebugInfo *Dbg = getDebugInfo()) 1538 if (CGM.getCodeGenOpts().hasReducedDebugInfo()) 1539 Dbg->EmitGlobalVariable(DE->getDecl(), 1540 APValue(llvm::APSInt(CaseVal->getValue()))); 1541 } 1542 1543 if (SwitchLikelihood) 1544 SwitchLikelihood->push_back(Stmt::getLikelihood(Attrs)); 1545 1546 // If the body of the case is just a 'break', try to not emit an empty block. 1547 // If we're profiling or we're not optimizing, leave the block in for better 1548 // debug and coverage analysis. 1549 if (!CGM.getCodeGenOpts().hasProfileClangInstr() && 1550 CGM.getCodeGenOpts().OptimizationLevel > 0 && 1551 isa<BreakStmt>(S.getSubStmt())) { 1552 JumpDest Block = BreakContinueStack.back().BreakBlock; 1553 1554 // Only do this optimization if there are no cleanups that need emitting. 1555 if (isObviouslyBranchWithoutCleanups(Block)) { 1556 if (SwitchWeights) 1557 SwitchWeights->push_back(getProfileCount(&S)); 1558 SwitchInsn->addCase(CaseVal, Block.getBlock()); 1559 1560 // If there was a fallthrough into this case, make sure to redirect it to 1561 // the end of the switch as well. 1562 if (Builder.GetInsertBlock()) { 1563 Builder.CreateBr(Block.getBlock()); 1564 Builder.ClearInsertionPoint(); 1565 } 1566 return; 1567 } 1568 } 1569 1570 llvm::BasicBlock *CaseDest = createBasicBlock("sw.bb"); 1571 EmitBlockWithFallThrough(CaseDest, &S); 1572 if (SwitchWeights) 1573 SwitchWeights->push_back(getProfileCount(&S)); 1574 SwitchInsn->addCase(CaseVal, CaseDest); 1575 1576 // Recursively emitting the statement is acceptable, but is not wonderful for 1577 // code where we have many case statements nested together, i.e.: 1578 // case 1: 1579 // case 2: 1580 // case 3: etc. 1581 // Handling this recursively will create a new block for each case statement 1582 // that falls through to the next case which is IR intensive. It also causes 1583 // deep recursion which can run into stack depth limitations. Handle 1584 // sequential non-range case statements specially. 1585 // 1586 // TODO When the next case has a likelihood attribute the code returns to the 1587 // recursive algorithm. Maybe improve this case if it becomes common practice 1588 // to use a lot of attributes. 1589 const CaseStmt *CurCase = &S; 1590 const CaseStmt *NextCase = dyn_cast<CaseStmt>(S.getSubStmt()); 1591 1592 // Otherwise, iteratively add consecutive cases to this switch stmt. 1593 while (NextCase && NextCase->getRHS() == nullptr) { 1594 CurCase = NextCase; 1595 llvm::ConstantInt *CaseVal = 1596 Builder.getInt(CurCase->getLHS()->EvaluateKnownConstInt(getContext())); 1597 1598 if (SwitchWeights) 1599 SwitchWeights->push_back(getProfileCount(NextCase)); 1600 if (CGM.getCodeGenOpts().hasProfileClangInstr()) { 1601 CaseDest = createBasicBlock("sw.bb"); 1602 EmitBlockWithFallThrough(CaseDest, CurCase); 1603 } 1604 // Since this loop is only executed when the CaseStmt has no attributes 1605 // use a hard-coded value. 1606 if (SwitchLikelihood) 1607 SwitchLikelihood->push_back(Stmt::LH_None); 1608 1609 SwitchInsn->addCase(CaseVal, CaseDest); 1610 NextCase = dyn_cast<CaseStmt>(CurCase->getSubStmt()); 1611 } 1612 1613 // Generate a stop point for debug info if the case statement is 1614 // followed by a default statement. A fallthrough case before a 1615 // default case gets its own branch target. 1616 if (CurCase->getSubStmt()->getStmtClass() == Stmt::DefaultStmtClass) 1617 EmitStopPoint(CurCase); 1618 1619 // Normal default recursion for non-cases. 1620 EmitStmt(CurCase->getSubStmt()); 1621 } 1622 1623 void CodeGenFunction::EmitDefaultStmt(const DefaultStmt &S, 1624 ArrayRef<const Attr *> Attrs) { 1625 // If there is no enclosing switch instance that we're aware of, then this 1626 // default statement can be elided. This situation only happens when we've 1627 // constant-folded the switch. 1628 if (!SwitchInsn) { 1629 EmitStmt(S.getSubStmt()); 1630 return; 1631 } 1632 1633 llvm::BasicBlock *DefaultBlock = SwitchInsn->getDefaultDest(); 1634 assert(DefaultBlock->empty() && 1635 "EmitDefaultStmt: Default block already defined?"); 1636 1637 if (SwitchLikelihood) 1638 SwitchLikelihood->front() = Stmt::getLikelihood(Attrs); 1639 1640 EmitBlockWithFallThrough(DefaultBlock, &S); 1641 1642 EmitStmt(S.getSubStmt()); 1643 } 1644 1645 /// CollectStatementsForCase - Given the body of a 'switch' statement and a 1646 /// constant value that is being switched on, see if we can dead code eliminate 1647 /// the body of the switch to a simple series of statements to emit. Basically, 1648 /// on a switch (5) we want to find these statements: 1649 /// case 5: 1650 /// printf(...); <-- 1651 /// ++i; <-- 1652 /// break; 1653 /// 1654 /// and add them to the ResultStmts vector. If it is unsafe to do this 1655 /// transformation (for example, one of the elided statements contains a label 1656 /// that might be jumped to), return CSFC_Failure. If we handled it and 'S' 1657 /// should include statements after it (e.g. the printf() line is a substmt of 1658 /// the case) then return CSFC_FallThrough. If we handled it and found a break 1659 /// statement, then return CSFC_Success. 1660 /// 1661 /// If Case is non-null, then we are looking for the specified case, checking 1662 /// that nothing we jump over contains labels. If Case is null, then we found 1663 /// the case and are looking for the break. 1664 /// 1665 /// If the recursive walk actually finds our Case, then we set FoundCase to 1666 /// true. 1667 /// 1668 enum CSFC_Result { CSFC_Failure, CSFC_FallThrough, CSFC_Success }; 1669 static CSFC_Result CollectStatementsForCase(const Stmt *S, 1670 const SwitchCase *Case, 1671 bool &FoundCase, 1672 SmallVectorImpl<const Stmt*> &ResultStmts) { 1673 // If this is a null statement, just succeed. 1674 if (!S) 1675 return Case ? CSFC_Success : CSFC_FallThrough; 1676 1677 // If this is the switchcase (case 4: or default) that we're looking for, then 1678 // we're in business. Just add the substatement. 1679 if (const SwitchCase *SC = dyn_cast<SwitchCase>(S)) { 1680 if (S == Case) { 1681 FoundCase = true; 1682 return CollectStatementsForCase(SC->getSubStmt(), nullptr, FoundCase, 1683 ResultStmts); 1684 } 1685 1686 // Otherwise, this is some other case or default statement, just ignore it. 1687 return CollectStatementsForCase(SC->getSubStmt(), Case, FoundCase, 1688 ResultStmts); 1689 } 1690 1691 // If we are in the live part of the code and we found our break statement, 1692 // return a success! 1693 if (!Case && isa<BreakStmt>(S)) 1694 return CSFC_Success; 1695 1696 // If this is a switch statement, then it might contain the SwitchCase, the 1697 // break, or neither. 1698 if (const CompoundStmt *CS = dyn_cast<CompoundStmt>(S)) { 1699 // Handle this as two cases: we might be looking for the SwitchCase (if so 1700 // the skipped statements must be skippable) or we might already have it. 1701 CompoundStmt::const_body_iterator I = CS->body_begin(), E = CS->body_end(); 1702 bool StartedInLiveCode = FoundCase; 1703 unsigned StartSize = ResultStmts.size(); 1704 1705 // If we've not found the case yet, scan through looking for it. 1706 if (Case) { 1707 // Keep track of whether we see a skipped declaration. The code could be 1708 // using the declaration even if it is skipped, so we can't optimize out 1709 // the decl if the kept statements might refer to it. 1710 bool HadSkippedDecl = false; 1711 1712 // If we're looking for the case, just see if we can skip each of the 1713 // substatements. 1714 for (; Case && I != E; ++I) { 1715 HadSkippedDecl |= CodeGenFunction::mightAddDeclToScope(*I); 1716 1717 switch (CollectStatementsForCase(*I, Case, FoundCase, ResultStmts)) { 1718 case CSFC_Failure: return CSFC_Failure; 1719 case CSFC_Success: 1720 // A successful result means that either 1) that the statement doesn't 1721 // have the case and is skippable, or 2) does contain the case value 1722 // and also contains the break to exit the switch. In the later case, 1723 // we just verify the rest of the statements are elidable. 1724 if (FoundCase) { 1725 // If we found the case and skipped declarations, we can't do the 1726 // optimization. 1727 if (HadSkippedDecl) 1728 return CSFC_Failure; 1729 1730 for (++I; I != E; ++I) 1731 if (CodeGenFunction::ContainsLabel(*I, true)) 1732 return CSFC_Failure; 1733 return CSFC_Success; 1734 } 1735 break; 1736 case CSFC_FallThrough: 1737 // If we have a fallthrough condition, then we must have found the 1738 // case started to include statements. Consider the rest of the 1739 // statements in the compound statement as candidates for inclusion. 1740 assert(FoundCase && "Didn't find case but returned fallthrough?"); 1741 // We recursively found Case, so we're not looking for it anymore. 1742 Case = nullptr; 1743 1744 // If we found the case and skipped declarations, we can't do the 1745 // optimization. 1746 if (HadSkippedDecl) 1747 return CSFC_Failure; 1748 break; 1749 } 1750 } 1751 1752 if (!FoundCase) 1753 return CSFC_Success; 1754 1755 assert(!HadSkippedDecl && "fallthrough after skipping decl"); 1756 } 1757 1758 // If we have statements in our range, then we know that the statements are 1759 // live and need to be added to the set of statements we're tracking. 1760 bool AnyDecls = false; 1761 for (; I != E; ++I) { 1762 AnyDecls |= CodeGenFunction::mightAddDeclToScope(*I); 1763 1764 switch (CollectStatementsForCase(*I, nullptr, FoundCase, ResultStmts)) { 1765 case CSFC_Failure: return CSFC_Failure; 1766 case CSFC_FallThrough: 1767 // A fallthrough result means that the statement was simple and just 1768 // included in ResultStmt, keep adding them afterwards. 1769 break; 1770 case CSFC_Success: 1771 // A successful result means that we found the break statement and 1772 // stopped statement inclusion. We just ensure that any leftover stmts 1773 // are skippable and return success ourselves. 1774 for (++I; I != E; ++I) 1775 if (CodeGenFunction::ContainsLabel(*I, true)) 1776 return CSFC_Failure; 1777 return CSFC_Success; 1778 } 1779 } 1780 1781 // If we're about to fall out of a scope without hitting a 'break;', we 1782 // can't perform the optimization if there were any decls in that scope 1783 // (we'd lose their end-of-lifetime). 1784 if (AnyDecls) { 1785 // If the entire compound statement was live, there's one more thing we 1786 // can try before giving up: emit the whole thing as a single statement. 1787 // We can do that unless the statement contains a 'break;'. 1788 // FIXME: Such a break must be at the end of a construct within this one. 1789 // We could emit this by just ignoring the BreakStmts entirely. 1790 if (StartedInLiveCode && !CodeGenFunction::containsBreak(S)) { 1791 ResultStmts.resize(StartSize); 1792 ResultStmts.push_back(S); 1793 } else { 1794 return CSFC_Failure; 1795 } 1796 } 1797 1798 return CSFC_FallThrough; 1799 } 1800 1801 // Okay, this is some other statement that we don't handle explicitly, like a 1802 // for statement or increment etc. If we are skipping over this statement, 1803 // just verify it doesn't have labels, which would make it invalid to elide. 1804 if (Case) { 1805 if (CodeGenFunction::ContainsLabel(S, true)) 1806 return CSFC_Failure; 1807 return CSFC_Success; 1808 } 1809 1810 // Otherwise, we want to include this statement. Everything is cool with that 1811 // so long as it doesn't contain a break out of the switch we're in. 1812 if (CodeGenFunction::containsBreak(S)) return CSFC_Failure; 1813 1814 // Otherwise, everything is great. Include the statement and tell the caller 1815 // that we fall through and include the next statement as well. 1816 ResultStmts.push_back(S); 1817 return CSFC_FallThrough; 1818 } 1819 1820 /// FindCaseStatementsForValue - Find the case statement being jumped to and 1821 /// then invoke CollectStatementsForCase to find the list of statements to emit 1822 /// for a switch on constant. See the comment above CollectStatementsForCase 1823 /// for more details. 1824 static bool FindCaseStatementsForValue(const SwitchStmt &S, 1825 const llvm::APSInt &ConstantCondValue, 1826 SmallVectorImpl<const Stmt*> &ResultStmts, 1827 ASTContext &C, 1828 const SwitchCase *&ResultCase) { 1829 // First step, find the switch case that is being branched to. We can do this 1830 // efficiently by scanning the SwitchCase list. 1831 const SwitchCase *Case = S.getSwitchCaseList(); 1832 const DefaultStmt *DefaultCase = nullptr; 1833 1834 for (; Case; Case = Case->getNextSwitchCase()) { 1835 // It's either a default or case. Just remember the default statement in 1836 // case we're not jumping to any numbered cases. 1837 if (const DefaultStmt *DS = dyn_cast<DefaultStmt>(Case)) { 1838 DefaultCase = DS; 1839 continue; 1840 } 1841 1842 // Check to see if this case is the one we're looking for. 1843 const CaseStmt *CS = cast<CaseStmt>(Case); 1844 // Don't handle case ranges yet. 1845 if (CS->getRHS()) return false; 1846 1847 // If we found our case, remember it as 'case'. 1848 if (CS->getLHS()->EvaluateKnownConstInt(C) == ConstantCondValue) 1849 break; 1850 } 1851 1852 // If we didn't find a matching case, we use a default if it exists, or we 1853 // elide the whole switch body! 1854 if (!Case) { 1855 // It is safe to elide the body of the switch if it doesn't contain labels 1856 // etc. If it is safe, return successfully with an empty ResultStmts list. 1857 if (!DefaultCase) 1858 return !CodeGenFunction::ContainsLabel(&S); 1859 Case = DefaultCase; 1860 } 1861 1862 // Ok, we know which case is being jumped to, try to collect all the 1863 // statements that follow it. This can fail for a variety of reasons. Also, 1864 // check to see that the recursive walk actually found our case statement. 1865 // Insane cases like this can fail to find it in the recursive walk since we 1866 // don't handle every stmt kind: 1867 // switch (4) { 1868 // while (1) { 1869 // case 4: ... 1870 bool FoundCase = false; 1871 ResultCase = Case; 1872 return CollectStatementsForCase(S.getBody(), Case, FoundCase, 1873 ResultStmts) != CSFC_Failure && 1874 FoundCase; 1875 } 1876 1877 static std::optional<SmallVector<uint64_t, 16>> 1878 getLikelihoodWeights(ArrayRef<Stmt::Likelihood> Likelihoods) { 1879 // Are there enough branches to weight them? 1880 if (Likelihoods.size() <= 1) 1881 return std::nullopt; 1882 1883 uint64_t NumUnlikely = 0; 1884 uint64_t NumNone = 0; 1885 uint64_t NumLikely = 0; 1886 for (const auto LH : Likelihoods) { 1887 switch (LH) { 1888 case Stmt::LH_Unlikely: 1889 ++NumUnlikely; 1890 break; 1891 case Stmt::LH_None: 1892 ++NumNone; 1893 break; 1894 case Stmt::LH_Likely: 1895 ++NumLikely; 1896 break; 1897 } 1898 } 1899 1900 // Is there a likelihood attribute used? 1901 if (NumUnlikely == 0 && NumLikely == 0) 1902 return std::nullopt; 1903 1904 // When multiple cases share the same code they can be combined during 1905 // optimization. In that case the weights of the branch will be the sum of 1906 // the individual weights. Make sure the combined sum of all neutral cases 1907 // doesn't exceed the value of a single likely attribute. 1908 // The additions both avoid divisions by 0 and make sure the weights of None 1909 // don't exceed the weight of Likely. 1910 const uint64_t Likely = INT32_MAX / (NumLikely + 2); 1911 const uint64_t None = Likely / (NumNone + 1); 1912 const uint64_t Unlikely = 0; 1913 1914 SmallVector<uint64_t, 16> Result; 1915 Result.reserve(Likelihoods.size()); 1916 for (const auto LH : Likelihoods) { 1917 switch (LH) { 1918 case Stmt::LH_Unlikely: 1919 Result.push_back(Unlikely); 1920 break; 1921 case Stmt::LH_None: 1922 Result.push_back(None); 1923 break; 1924 case Stmt::LH_Likely: 1925 Result.push_back(Likely); 1926 break; 1927 } 1928 } 1929 1930 return Result; 1931 } 1932 1933 void CodeGenFunction::EmitSwitchStmt(const SwitchStmt &S) { 1934 // Handle nested switch statements. 1935 llvm::SwitchInst *SavedSwitchInsn = SwitchInsn; 1936 SmallVector<uint64_t, 16> *SavedSwitchWeights = SwitchWeights; 1937 SmallVector<Stmt::Likelihood, 16> *SavedSwitchLikelihood = SwitchLikelihood; 1938 llvm::BasicBlock *SavedCRBlock = CaseRangeBlock; 1939 1940 // See if we can constant fold the condition of the switch and therefore only 1941 // emit the live case statement (if any) of the switch. 1942 llvm::APSInt ConstantCondValue; 1943 if (ConstantFoldsToSimpleInteger(S.getCond(), ConstantCondValue)) { 1944 SmallVector<const Stmt*, 4> CaseStmts; 1945 const SwitchCase *Case = nullptr; 1946 if (FindCaseStatementsForValue(S, ConstantCondValue, CaseStmts, 1947 getContext(), Case)) { 1948 if (Case) 1949 incrementProfileCounter(Case); 1950 RunCleanupsScope ExecutedScope(*this); 1951 1952 if (S.getInit()) 1953 EmitStmt(S.getInit()); 1954 1955 // Emit the condition variable if needed inside the entire cleanup scope 1956 // used by this special case for constant folded switches. 1957 if (S.getConditionVariable()) 1958 EmitDecl(*S.getConditionVariable()); 1959 1960 // At this point, we are no longer "within" a switch instance, so 1961 // we can temporarily enforce this to ensure that any embedded case 1962 // statements are not emitted. 1963 SwitchInsn = nullptr; 1964 1965 // Okay, we can dead code eliminate everything except this case. Emit the 1966 // specified series of statements and we're good. 1967 for (unsigned i = 0, e = CaseStmts.size(); i != e; ++i) 1968 EmitStmt(CaseStmts[i]); 1969 incrementProfileCounter(&S); 1970 1971 // Now we want to restore the saved switch instance so that nested 1972 // switches continue to function properly 1973 SwitchInsn = SavedSwitchInsn; 1974 1975 return; 1976 } 1977 } 1978 1979 JumpDest SwitchExit = getJumpDestInCurrentScope("sw.epilog"); 1980 1981 RunCleanupsScope ConditionScope(*this); 1982 1983 if (S.getInit()) 1984 EmitStmt(S.getInit()); 1985 1986 if (S.getConditionVariable()) 1987 EmitDecl(*S.getConditionVariable()); 1988 llvm::Value *CondV = EmitScalarExpr(S.getCond()); 1989 1990 // Create basic block to hold stuff that comes after switch 1991 // statement. We also need to create a default block now so that 1992 // explicit case ranges tests can have a place to jump to on 1993 // failure. 1994 llvm::BasicBlock *DefaultBlock = createBasicBlock("sw.default"); 1995 SwitchInsn = Builder.CreateSwitch(CondV, DefaultBlock); 1996 if (PGO.haveRegionCounts()) { 1997 // Walk the SwitchCase list to find how many there are. 1998 uint64_t DefaultCount = 0; 1999 unsigned NumCases = 0; 2000 for (const SwitchCase *Case = S.getSwitchCaseList(); 2001 Case; 2002 Case = Case->getNextSwitchCase()) { 2003 if (isa<DefaultStmt>(Case)) 2004 DefaultCount = getProfileCount(Case); 2005 NumCases += 1; 2006 } 2007 SwitchWeights = new SmallVector<uint64_t, 16>(); 2008 SwitchWeights->reserve(NumCases); 2009 // The default needs to be first. We store the edge count, so we already 2010 // know the right weight. 2011 SwitchWeights->push_back(DefaultCount); 2012 } else if (CGM.getCodeGenOpts().OptimizationLevel) { 2013 SwitchLikelihood = new SmallVector<Stmt::Likelihood, 16>(); 2014 // Initialize the default case. 2015 SwitchLikelihood->push_back(Stmt::LH_None); 2016 } 2017 2018 CaseRangeBlock = DefaultBlock; 2019 2020 // Clear the insertion point to indicate we are in unreachable code. 2021 Builder.ClearInsertionPoint(); 2022 2023 // All break statements jump to NextBlock. If BreakContinueStack is non-empty 2024 // then reuse last ContinueBlock. 2025 JumpDest OuterContinue; 2026 if (!BreakContinueStack.empty()) 2027 OuterContinue = BreakContinueStack.back().ContinueBlock; 2028 2029 BreakContinueStack.push_back(BreakContinue(SwitchExit, OuterContinue)); 2030 2031 // Emit switch body. 2032 EmitStmt(S.getBody()); 2033 2034 BreakContinueStack.pop_back(); 2035 2036 // Update the default block in case explicit case range tests have 2037 // been chained on top. 2038 SwitchInsn->setDefaultDest(CaseRangeBlock); 2039 2040 // If a default was never emitted: 2041 if (!DefaultBlock->getParent()) { 2042 // If we have cleanups, emit the default block so that there's a 2043 // place to jump through the cleanups from. 2044 if (ConditionScope.requiresCleanups()) { 2045 EmitBlock(DefaultBlock); 2046 2047 // Otherwise, just forward the default block to the switch end. 2048 } else { 2049 DefaultBlock->replaceAllUsesWith(SwitchExit.getBlock()); 2050 delete DefaultBlock; 2051 } 2052 } 2053 2054 ConditionScope.ForceCleanup(); 2055 2056 // Emit continuation. 2057 EmitBlock(SwitchExit.getBlock(), true); 2058 incrementProfileCounter(&S); 2059 2060 // If the switch has a condition wrapped by __builtin_unpredictable, 2061 // create metadata that specifies that the switch is unpredictable. 2062 // Don't bother if not optimizing because that metadata would not be used. 2063 auto *Call = dyn_cast<CallExpr>(S.getCond()); 2064 if (Call && CGM.getCodeGenOpts().OptimizationLevel != 0) { 2065 auto *FD = dyn_cast_or_null<FunctionDecl>(Call->getCalleeDecl()); 2066 if (FD && FD->getBuiltinID() == Builtin::BI__builtin_unpredictable) { 2067 llvm::MDBuilder MDHelper(getLLVMContext()); 2068 SwitchInsn->setMetadata(llvm::LLVMContext::MD_unpredictable, 2069 MDHelper.createUnpredictable()); 2070 } 2071 } 2072 2073 if (SwitchWeights) { 2074 assert(SwitchWeights->size() == 1 + SwitchInsn->getNumCases() && 2075 "switch weights do not match switch cases"); 2076 // If there's only one jump destination there's no sense weighting it. 2077 if (SwitchWeights->size() > 1) 2078 SwitchInsn->setMetadata(llvm::LLVMContext::MD_prof, 2079 createProfileWeights(*SwitchWeights)); 2080 delete SwitchWeights; 2081 } else if (SwitchLikelihood) { 2082 assert(SwitchLikelihood->size() == 1 + SwitchInsn->getNumCases() && 2083 "switch likelihoods do not match switch cases"); 2084 std::optional<SmallVector<uint64_t, 16>> LHW = 2085 getLikelihoodWeights(*SwitchLikelihood); 2086 if (LHW) { 2087 llvm::MDBuilder MDHelper(CGM.getLLVMContext()); 2088 SwitchInsn->setMetadata(llvm::LLVMContext::MD_prof, 2089 createProfileWeights(*LHW)); 2090 } 2091 delete SwitchLikelihood; 2092 } 2093 SwitchInsn = SavedSwitchInsn; 2094 SwitchWeights = SavedSwitchWeights; 2095 SwitchLikelihood = SavedSwitchLikelihood; 2096 CaseRangeBlock = SavedCRBlock; 2097 } 2098 2099 static std::string 2100 SimplifyConstraint(const char *Constraint, const TargetInfo &Target, 2101 SmallVectorImpl<TargetInfo::ConstraintInfo> *OutCons=nullptr) { 2102 std::string Result; 2103 2104 while (*Constraint) { 2105 switch (*Constraint) { 2106 default: 2107 Result += Target.convertConstraint(Constraint); 2108 break; 2109 // Ignore these 2110 case '*': 2111 case '?': 2112 case '!': 2113 case '=': // Will see this and the following in mult-alt constraints. 2114 case '+': 2115 break; 2116 case '#': // Ignore the rest of the constraint alternative. 2117 while (Constraint[1] && Constraint[1] != ',') 2118 Constraint++; 2119 break; 2120 case '&': 2121 case '%': 2122 Result += *Constraint; 2123 while (Constraint[1] && Constraint[1] == *Constraint) 2124 Constraint++; 2125 break; 2126 case ',': 2127 Result += "|"; 2128 break; 2129 case 'g': 2130 Result += "imr"; 2131 break; 2132 case '[': { 2133 assert(OutCons && 2134 "Must pass output names to constraints with a symbolic name"); 2135 unsigned Index; 2136 bool result = Target.resolveSymbolicName(Constraint, *OutCons, Index); 2137 assert(result && "Could not resolve symbolic name"); (void)result; 2138 Result += llvm::utostr(Index); 2139 break; 2140 } 2141 } 2142 2143 Constraint++; 2144 } 2145 2146 return Result; 2147 } 2148 2149 /// AddVariableConstraints - Look at AsmExpr and if it is a variable declared 2150 /// as using a particular register add that as a constraint that will be used 2151 /// in this asm stmt. 2152 static std::string 2153 AddVariableConstraints(const std::string &Constraint, const Expr &AsmExpr, 2154 const TargetInfo &Target, CodeGenModule &CGM, 2155 const AsmStmt &Stmt, const bool EarlyClobber, 2156 std::string *GCCReg = nullptr) { 2157 const DeclRefExpr *AsmDeclRef = dyn_cast<DeclRefExpr>(&AsmExpr); 2158 if (!AsmDeclRef) 2159 return Constraint; 2160 const ValueDecl &Value = *AsmDeclRef->getDecl(); 2161 const VarDecl *Variable = dyn_cast<VarDecl>(&Value); 2162 if (!Variable) 2163 return Constraint; 2164 if (Variable->getStorageClass() != SC_Register) 2165 return Constraint; 2166 AsmLabelAttr *Attr = Variable->getAttr<AsmLabelAttr>(); 2167 if (!Attr) 2168 return Constraint; 2169 StringRef Register = Attr->getLabel(); 2170 assert(Target.isValidGCCRegisterName(Register)); 2171 // We're using validateOutputConstraint here because we only care if 2172 // this is a register constraint. 2173 TargetInfo::ConstraintInfo Info(Constraint, ""); 2174 if (Target.validateOutputConstraint(Info) && 2175 !Info.allowsRegister()) { 2176 CGM.ErrorUnsupported(&Stmt, "__asm__"); 2177 return Constraint; 2178 } 2179 // Canonicalize the register here before returning it. 2180 Register = Target.getNormalizedGCCRegisterName(Register); 2181 if (GCCReg != nullptr) 2182 *GCCReg = Register.str(); 2183 return (EarlyClobber ? "&{" : "{") + Register.str() + "}"; 2184 } 2185 2186 std::pair<llvm::Value*, llvm::Type *> CodeGenFunction::EmitAsmInputLValue( 2187 const TargetInfo::ConstraintInfo &Info, LValue InputValue, 2188 QualType InputType, std::string &ConstraintStr, SourceLocation Loc) { 2189 if (Info.allowsRegister() || !Info.allowsMemory()) { 2190 if (CodeGenFunction::hasScalarEvaluationKind(InputType)) 2191 return {EmitLoadOfLValue(InputValue, Loc).getScalarVal(), nullptr}; 2192 2193 llvm::Type *Ty = ConvertType(InputType); 2194 uint64_t Size = CGM.getDataLayout().getTypeSizeInBits(Ty); 2195 if ((Size <= 64 && llvm::isPowerOf2_64(Size)) || 2196 getTargetHooks().isScalarizableAsmOperand(*this, Ty)) { 2197 Ty = llvm::IntegerType::get(getLLVMContext(), Size); 2198 2199 return { 2200 Builder.CreateLoad(InputValue.getAddress(*this).withElementType(Ty)), 2201 nullptr}; 2202 } 2203 } 2204 2205 Address Addr = InputValue.getAddress(*this); 2206 ConstraintStr += '*'; 2207 return {Addr.getPointer(), Addr.getElementType()}; 2208 } 2209 2210 std::pair<llvm::Value *, llvm::Type *> 2211 CodeGenFunction::EmitAsmInput(const TargetInfo::ConstraintInfo &Info, 2212 const Expr *InputExpr, 2213 std::string &ConstraintStr) { 2214 // If this can't be a register or memory, i.e., has to be a constant 2215 // (immediate or symbolic), try to emit it as such. 2216 if (!Info.allowsRegister() && !Info.allowsMemory()) { 2217 if (Info.requiresImmediateConstant()) { 2218 Expr::EvalResult EVResult; 2219 InputExpr->EvaluateAsRValue(EVResult, getContext(), true); 2220 2221 llvm::APSInt IntResult; 2222 if (EVResult.Val.toIntegralConstant(IntResult, InputExpr->getType(), 2223 getContext())) 2224 return {llvm::ConstantInt::get(getLLVMContext(), IntResult), nullptr}; 2225 } 2226 2227 Expr::EvalResult Result; 2228 if (InputExpr->EvaluateAsInt(Result, getContext())) 2229 return {llvm::ConstantInt::get(getLLVMContext(), Result.Val.getInt()), 2230 nullptr}; 2231 } 2232 2233 if (Info.allowsRegister() || !Info.allowsMemory()) 2234 if (CodeGenFunction::hasScalarEvaluationKind(InputExpr->getType())) 2235 return {EmitScalarExpr(InputExpr), nullptr}; 2236 if (InputExpr->getStmtClass() == Expr::CXXThisExprClass) 2237 return {EmitScalarExpr(InputExpr), nullptr}; 2238 InputExpr = InputExpr->IgnoreParenNoopCasts(getContext()); 2239 LValue Dest = EmitLValue(InputExpr); 2240 return EmitAsmInputLValue(Info, Dest, InputExpr->getType(), ConstraintStr, 2241 InputExpr->getExprLoc()); 2242 } 2243 2244 /// getAsmSrcLocInfo - Return the !srcloc metadata node to attach to an inline 2245 /// asm call instruction. The !srcloc MDNode contains a list of constant 2246 /// integers which are the source locations of the start of each line in the 2247 /// asm. 2248 static llvm::MDNode *getAsmSrcLocInfo(const StringLiteral *Str, 2249 CodeGenFunction &CGF) { 2250 SmallVector<llvm::Metadata *, 8> Locs; 2251 // Add the location of the first line to the MDNode. 2252 Locs.push_back(llvm::ConstantAsMetadata::get(llvm::ConstantInt::get( 2253 CGF.Int64Ty, Str->getBeginLoc().getRawEncoding()))); 2254 StringRef StrVal = Str->getString(); 2255 if (!StrVal.empty()) { 2256 const SourceManager &SM = CGF.CGM.getContext().getSourceManager(); 2257 const LangOptions &LangOpts = CGF.CGM.getLangOpts(); 2258 unsigned StartToken = 0; 2259 unsigned ByteOffset = 0; 2260 2261 // Add the location of the start of each subsequent line of the asm to the 2262 // MDNode. 2263 for (unsigned i = 0, e = StrVal.size() - 1; i != e; ++i) { 2264 if (StrVal[i] != '\n') continue; 2265 SourceLocation LineLoc = Str->getLocationOfByte( 2266 i + 1, SM, LangOpts, CGF.getTarget(), &StartToken, &ByteOffset); 2267 Locs.push_back(llvm::ConstantAsMetadata::get( 2268 llvm::ConstantInt::get(CGF.Int64Ty, LineLoc.getRawEncoding()))); 2269 } 2270 } 2271 2272 return llvm::MDNode::get(CGF.getLLVMContext(), Locs); 2273 } 2274 2275 static void UpdateAsmCallInst(llvm::CallBase &Result, bool HasSideEffect, 2276 bool HasUnwindClobber, bool ReadOnly, 2277 bool ReadNone, bool NoMerge, const AsmStmt &S, 2278 const std::vector<llvm::Type *> &ResultRegTypes, 2279 const std::vector<llvm::Type *> &ArgElemTypes, 2280 CodeGenFunction &CGF, 2281 std::vector<llvm::Value *> &RegResults) { 2282 if (!HasUnwindClobber) 2283 Result.addFnAttr(llvm::Attribute::NoUnwind); 2284 2285 if (NoMerge) 2286 Result.addFnAttr(llvm::Attribute::NoMerge); 2287 // Attach readnone and readonly attributes. 2288 if (!HasSideEffect) { 2289 if (ReadNone) 2290 Result.setDoesNotAccessMemory(); 2291 else if (ReadOnly) 2292 Result.setOnlyReadsMemory(); 2293 } 2294 2295 // Add elementtype attribute for indirect constraints. 2296 for (auto Pair : llvm::enumerate(ArgElemTypes)) { 2297 if (Pair.value()) { 2298 auto Attr = llvm::Attribute::get( 2299 CGF.getLLVMContext(), llvm::Attribute::ElementType, Pair.value()); 2300 Result.addParamAttr(Pair.index(), Attr); 2301 } 2302 } 2303 2304 // Slap the source location of the inline asm into a !srcloc metadata on the 2305 // call. 2306 if (const auto *gccAsmStmt = dyn_cast<GCCAsmStmt>(&S)) 2307 Result.setMetadata("srcloc", 2308 getAsmSrcLocInfo(gccAsmStmt->getAsmString(), CGF)); 2309 else { 2310 // At least put the line number on MS inline asm blobs. 2311 llvm::Constant *Loc = 2312 llvm::ConstantInt::get(CGF.Int64Ty, S.getAsmLoc().getRawEncoding()); 2313 Result.setMetadata("srcloc", 2314 llvm::MDNode::get(CGF.getLLVMContext(), 2315 llvm::ConstantAsMetadata::get(Loc))); 2316 } 2317 2318 if (CGF.getLangOpts().assumeFunctionsAreConvergent()) 2319 // Conservatively, mark all inline asm blocks in CUDA or OpenCL as 2320 // convergent (meaning, they may call an intrinsically convergent op, such 2321 // as bar.sync, and so can't have certain optimizations applied around 2322 // them). 2323 Result.addFnAttr(llvm::Attribute::Convergent); 2324 // Extract all of the register value results from the asm. 2325 if (ResultRegTypes.size() == 1) { 2326 RegResults.push_back(&Result); 2327 } else { 2328 for (unsigned i = 0, e = ResultRegTypes.size(); i != e; ++i) { 2329 llvm::Value *Tmp = CGF.Builder.CreateExtractValue(&Result, i, "asmresult"); 2330 RegResults.push_back(Tmp); 2331 } 2332 } 2333 } 2334 2335 static void 2336 EmitAsmStores(CodeGenFunction &CGF, const AsmStmt &S, 2337 const llvm::ArrayRef<llvm::Value *> RegResults, 2338 const llvm::ArrayRef<llvm::Type *> ResultRegTypes, 2339 const llvm::ArrayRef<llvm::Type *> ResultTruncRegTypes, 2340 const llvm::ArrayRef<LValue> ResultRegDests, 2341 const llvm::ArrayRef<QualType> ResultRegQualTys, 2342 const llvm::BitVector &ResultTypeRequiresCast, 2343 const llvm::BitVector &ResultRegIsFlagReg) { 2344 CGBuilderTy &Builder = CGF.Builder; 2345 CodeGenModule &CGM = CGF.CGM; 2346 llvm::LLVMContext &CTX = CGF.getLLVMContext(); 2347 2348 assert(RegResults.size() == ResultRegTypes.size()); 2349 assert(RegResults.size() == ResultTruncRegTypes.size()); 2350 assert(RegResults.size() == ResultRegDests.size()); 2351 // ResultRegDests can be also populated by addReturnRegisterOutputs() above, 2352 // in which case its size may grow. 2353 assert(ResultTypeRequiresCast.size() <= ResultRegDests.size()); 2354 assert(ResultRegIsFlagReg.size() <= ResultRegDests.size()); 2355 2356 for (unsigned i = 0, e = RegResults.size(); i != e; ++i) { 2357 llvm::Value *Tmp = RegResults[i]; 2358 llvm::Type *TruncTy = ResultTruncRegTypes[i]; 2359 2360 if ((i < ResultRegIsFlagReg.size()) && ResultRegIsFlagReg[i]) { 2361 // Target must guarantee the Value `Tmp` here is lowered to a boolean 2362 // value. 2363 llvm::Constant *Two = llvm::ConstantInt::get(Tmp->getType(), 2); 2364 llvm::Value *IsBooleanValue = 2365 Builder.CreateCmp(llvm::CmpInst::ICMP_ULT, Tmp, Two); 2366 llvm::Function *FnAssume = CGM.getIntrinsic(llvm::Intrinsic::assume); 2367 Builder.CreateCall(FnAssume, IsBooleanValue); 2368 } 2369 2370 // If the result type of the LLVM IR asm doesn't match the result type of 2371 // the expression, do the conversion. 2372 if (ResultRegTypes[i] != TruncTy) { 2373 2374 // Truncate the integer result to the right size, note that TruncTy can be 2375 // a pointer. 2376 if (TruncTy->isFloatingPointTy()) 2377 Tmp = Builder.CreateFPTrunc(Tmp, TruncTy); 2378 else if (TruncTy->isPointerTy() && Tmp->getType()->isIntegerTy()) { 2379 uint64_t ResSize = CGM.getDataLayout().getTypeSizeInBits(TruncTy); 2380 Tmp = Builder.CreateTrunc( 2381 Tmp, llvm::IntegerType::get(CTX, (unsigned)ResSize)); 2382 Tmp = Builder.CreateIntToPtr(Tmp, TruncTy); 2383 } else if (Tmp->getType()->isPointerTy() && TruncTy->isIntegerTy()) { 2384 uint64_t TmpSize = 2385 CGM.getDataLayout().getTypeSizeInBits(Tmp->getType()); 2386 Tmp = Builder.CreatePtrToInt( 2387 Tmp, llvm::IntegerType::get(CTX, (unsigned)TmpSize)); 2388 Tmp = Builder.CreateTrunc(Tmp, TruncTy); 2389 } else if (TruncTy->isIntegerTy()) { 2390 Tmp = Builder.CreateZExtOrTrunc(Tmp, TruncTy); 2391 } else if (TruncTy->isVectorTy()) { 2392 Tmp = Builder.CreateBitCast(Tmp, TruncTy); 2393 } 2394 } 2395 2396 LValue Dest = ResultRegDests[i]; 2397 // ResultTypeRequiresCast elements correspond to the first 2398 // ResultTypeRequiresCast.size() elements of RegResults. 2399 if ((i < ResultTypeRequiresCast.size()) && ResultTypeRequiresCast[i]) { 2400 unsigned Size = CGF.getContext().getTypeSize(ResultRegQualTys[i]); 2401 Address A = Dest.getAddress(CGF).withElementType(ResultRegTypes[i]); 2402 if (CGF.getTargetHooks().isScalarizableAsmOperand(CGF, TruncTy)) { 2403 Builder.CreateStore(Tmp, A); 2404 continue; 2405 } 2406 2407 QualType Ty = 2408 CGF.getContext().getIntTypeForBitwidth(Size, /*Signed=*/false); 2409 if (Ty.isNull()) { 2410 const Expr *OutExpr = S.getOutputExpr(i); 2411 CGM.getDiags().Report(OutExpr->getExprLoc(), 2412 diag::err_store_value_to_reg); 2413 return; 2414 } 2415 Dest = CGF.MakeAddrLValue(A, Ty); 2416 } 2417 CGF.EmitStoreThroughLValue(RValue::get(Tmp), Dest); 2418 } 2419 } 2420 2421 void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) { 2422 // Pop all cleanup blocks at the end of the asm statement. 2423 CodeGenFunction::RunCleanupsScope Cleanups(*this); 2424 2425 // Assemble the final asm string. 2426 std::string AsmString = S.generateAsmString(getContext()); 2427 2428 // Get all the output and input constraints together. 2429 SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 2430 SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; 2431 2432 for (unsigned i = 0, e = S.getNumOutputs(); i != e; i++) { 2433 StringRef Name; 2434 if (const GCCAsmStmt *GAS = dyn_cast<GCCAsmStmt>(&S)) 2435 Name = GAS->getOutputName(i); 2436 TargetInfo::ConstraintInfo Info(S.getOutputConstraint(i), Name); 2437 bool IsValid = getTarget().validateOutputConstraint(Info); (void)IsValid; 2438 assert(IsValid && "Failed to parse output constraint"); 2439 OutputConstraintInfos.push_back(Info); 2440 } 2441 2442 for (unsigned i = 0, e = S.getNumInputs(); i != e; i++) { 2443 StringRef Name; 2444 if (const GCCAsmStmt *GAS = dyn_cast<GCCAsmStmt>(&S)) 2445 Name = GAS->getInputName(i); 2446 TargetInfo::ConstraintInfo Info(S.getInputConstraint(i), Name); 2447 bool IsValid = 2448 getTarget().validateInputConstraint(OutputConstraintInfos, Info); 2449 assert(IsValid && "Failed to parse input constraint"); (void)IsValid; 2450 InputConstraintInfos.push_back(Info); 2451 } 2452 2453 std::string Constraints; 2454 2455 std::vector<LValue> ResultRegDests; 2456 std::vector<QualType> ResultRegQualTys; 2457 std::vector<llvm::Type *> ResultRegTypes; 2458 std::vector<llvm::Type *> ResultTruncRegTypes; 2459 std::vector<llvm::Type *> ArgTypes; 2460 std::vector<llvm::Type *> ArgElemTypes; 2461 std::vector<llvm::Value*> Args; 2462 llvm::BitVector ResultTypeRequiresCast; 2463 llvm::BitVector ResultRegIsFlagReg; 2464 2465 // Keep track of inout constraints. 2466 std::string InOutConstraints; 2467 std::vector<llvm::Value*> InOutArgs; 2468 std::vector<llvm::Type*> InOutArgTypes; 2469 std::vector<llvm::Type*> InOutArgElemTypes; 2470 2471 // Keep track of out constraints for tied input operand. 2472 std::vector<std::string> OutputConstraints; 2473 2474 // Keep track of defined physregs. 2475 llvm::SmallSet<std::string, 8> PhysRegOutputs; 2476 2477 // An inline asm can be marked readonly if it meets the following conditions: 2478 // - it doesn't have any sideeffects 2479 // - it doesn't clobber memory 2480 // - it doesn't return a value by-reference 2481 // It can be marked readnone if it doesn't have any input memory constraints 2482 // in addition to meeting the conditions listed above. 2483 bool ReadOnly = true, ReadNone = true; 2484 2485 for (unsigned i = 0, e = S.getNumOutputs(); i != e; i++) { 2486 TargetInfo::ConstraintInfo &Info = OutputConstraintInfos[i]; 2487 2488 // Simplify the output constraint. 2489 std::string OutputConstraint(S.getOutputConstraint(i)); 2490 OutputConstraint = SimplifyConstraint(OutputConstraint.c_str() + 1, 2491 getTarget(), &OutputConstraintInfos); 2492 2493 const Expr *OutExpr = S.getOutputExpr(i); 2494 OutExpr = OutExpr->IgnoreParenNoopCasts(getContext()); 2495 2496 std::string GCCReg; 2497 OutputConstraint = AddVariableConstraints(OutputConstraint, *OutExpr, 2498 getTarget(), CGM, S, 2499 Info.earlyClobber(), 2500 &GCCReg); 2501 // Give an error on multiple outputs to same physreg. 2502 if (!GCCReg.empty() && !PhysRegOutputs.insert(GCCReg).second) 2503 CGM.Error(S.getAsmLoc(), "multiple outputs to hard register: " + GCCReg); 2504 2505 OutputConstraints.push_back(OutputConstraint); 2506 LValue Dest = EmitLValue(OutExpr); 2507 if (!Constraints.empty()) 2508 Constraints += ','; 2509 2510 // If this is a register output, then make the inline asm return it 2511 // by-value. If this is a memory result, return the value by-reference. 2512 QualType QTy = OutExpr->getType(); 2513 const bool IsScalarOrAggregate = hasScalarEvaluationKind(QTy) || 2514 hasAggregateEvaluationKind(QTy); 2515 if (!Info.allowsMemory() && IsScalarOrAggregate) { 2516 2517 Constraints += "=" + OutputConstraint; 2518 ResultRegQualTys.push_back(QTy); 2519 ResultRegDests.push_back(Dest); 2520 2521 bool IsFlagReg = llvm::StringRef(OutputConstraint).startswith("{@cc"); 2522 ResultRegIsFlagReg.push_back(IsFlagReg); 2523 2524 llvm::Type *Ty = ConvertTypeForMem(QTy); 2525 const bool RequiresCast = Info.allowsRegister() && 2526 (getTargetHooks().isScalarizableAsmOperand(*this, Ty) || 2527 Ty->isAggregateType()); 2528 2529 ResultTruncRegTypes.push_back(Ty); 2530 ResultTypeRequiresCast.push_back(RequiresCast); 2531 2532 if (RequiresCast) { 2533 unsigned Size = getContext().getTypeSize(QTy); 2534 Ty = llvm::IntegerType::get(getLLVMContext(), Size); 2535 } 2536 ResultRegTypes.push_back(Ty); 2537 // If this output is tied to an input, and if the input is larger, then 2538 // we need to set the actual result type of the inline asm node to be the 2539 // same as the input type. 2540 if (Info.hasMatchingInput()) { 2541 unsigned InputNo; 2542 for (InputNo = 0; InputNo != S.getNumInputs(); ++InputNo) { 2543 TargetInfo::ConstraintInfo &Input = InputConstraintInfos[InputNo]; 2544 if (Input.hasTiedOperand() && Input.getTiedOperand() == i) 2545 break; 2546 } 2547 assert(InputNo != S.getNumInputs() && "Didn't find matching input!"); 2548 2549 QualType InputTy = S.getInputExpr(InputNo)->getType(); 2550 QualType OutputType = OutExpr->getType(); 2551 2552 uint64_t InputSize = getContext().getTypeSize(InputTy); 2553 if (getContext().getTypeSize(OutputType) < InputSize) { 2554 // Form the asm to return the value as a larger integer or fp type. 2555 ResultRegTypes.back() = ConvertType(InputTy); 2556 } 2557 } 2558 if (llvm::Type* AdjTy = 2559 getTargetHooks().adjustInlineAsmType(*this, OutputConstraint, 2560 ResultRegTypes.back())) 2561 ResultRegTypes.back() = AdjTy; 2562 else { 2563 CGM.getDiags().Report(S.getAsmLoc(), 2564 diag::err_asm_invalid_type_in_input) 2565 << OutExpr->getType() << OutputConstraint; 2566 } 2567 2568 // Update largest vector width for any vector types. 2569 if (auto *VT = dyn_cast<llvm::VectorType>(ResultRegTypes.back())) 2570 LargestVectorWidth = 2571 std::max((uint64_t)LargestVectorWidth, 2572 VT->getPrimitiveSizeInBits().getKnownMinValue()); 2573 } else { 2574 Address DestAddr = Dest.getAddress(*this); 2575 // Matrix types in memory are represented by arrays, but accessed through 2576 // vector pointers, with the alignment specified on the access operation. 2577 // For inline assembly, update pointer arguments to use vector pointers. 2578 // Otherwise there will be a mis-match if the matrix is also an 2579 // input-argument which is represented as vector. 2580 if (isa<MatrixType>(OutExpr->getType().getCanonicalType())) 2581 DestAddr = DestAddr.withElementType(ConvertType(OutExpr->getType())); 2582 2583 ArgTypes.push_back(DestAddr.getType()); 2584 ArgElemTypes.push_back(DestAddr.getElementType()); 2585 Args.push_back(DestAddr.getPointer()); 2586 Constraints += "=*"; 2587 Constraints += OutputConstraint; 2588 ReadOnly = ReadNone = false; 2589 } 2590 2591 if (Info.isReadWrite()) { 2592 InOutConstraints += ','; 2593 2594 const Expr *InputExpr = S.getOutputExpr(i); 2595 llvm::Value *Arg; 2596 llvm::Type *ArgElemType; 2597 std::tie(Arg, ArgElemType) = EmitAsmInputLValue( 2598 Info, Dest, InputExpr->getType(), InOutConstraints, 2599 InputExpr->getExprLoc()); 2600 2601 if (llvm::Type* AdjTy = 2602 getTargetHooks().adjustInlineAsmType(*this, OutputConstraint, 2603 Arg->getType())) 2604 Arg = Builder.CreateBitCast(Arg, AdjTy); 2605 2606 // Update largest vector width for any vector types. 2607 if (auto *VT = dyn_cast<llvm::VectorType>(Arg->getType())) 2608 LargestVectorWidth = 2609 std::max((uint64_t)LargestVectorWidth, 2610 VT->getPrimitiveSizeInBits().getKnownMinValue()); 2611 // Only tie earlyclobber physregs. 2612 if (Info.allowsRegister() && (GCCReg.empty() || Info.earlyClobber())) 2613 InOutConstraints += llvm::utostr(i); 2614 else 2615 InOutConstraints += OutputConstraint; 2616 2617 InOutArgTypes.push_back(Arg->getType()); 2618 InOutArgElemTypes.push_back(ArgElemType); 2619 InOutArgs.push_back(Arg); 2620 } 2621 } 2622 2623 // If this is a Microsoft-style asm blob, store the return registers (EAX:EDX) 2624 // to the return value slot. Only do this when returning in registers. 2625 if (isa<MSAsmStmt>(&S)) { 2626 const ABIArgInfo &RetAI = CurFnInfo->getReturnInfo(); 2627 if (RetAI.isDirect() || RetAI.isExtend()) { 2628 // Make a fake lvalue for the return value slot. 2629 LValue ReturnSlot = MakeAddrLValueWithoutTBAA(ReturnValue, FnRetTy); 2630 CGM.getTargetCodeGenInfo().addReturnRegisterOutputs( 2631 *this, ReturnSlot, Constraints, ResultRegTypes, ResultTruncRegTypes, 2632 ResultRegDests, AsmString, S.getNumOutputs()); 2633 SawAsmBlock = true; 2634 } 2635 } 2636 2637 for (unsigned i = 0, e = S.getNumInputs(); i != e; i++) { 2638 const Expr *InputExpr = S.getInputExpr(i); 2639 2640 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; 2641 2642 if (Info.allowsMemory()) 2643 ReadNone = false; 2644 2645 if (!Constraints.empty()) 2646 Constraints += ','; 2647 2648 // Simplify the input constraint. 2649 std::string InputConstraint(S.getInputConstraint(i)); 2650 InputConstraint = SimplifyConstraint(InputConstraint.c_str(), getTarget(), 2651 &OutputConstraintInfos); 2652 2653 InputConstraint = AddVariableConstraints( 2654 InputConstraint, *InputExpr->IgnoreParenNoopCasts(getContext()), 2655 getTarget(), CGM, S, false /* No EarlyClobber */); 2656 2657 std::string ReplaceConstraint (InputConstraint); 2658 llvm::Value *Arg; 2659 llvm::Type *ArgElemType; 2660 std::tie(Arg, ArgElemType) = EmitAsmInput(Info, InputExpr, Constraints); 2661 2662 // If this input argument is tied to a larger output result, extend the 2663 // input to be the same size as the output. The LLVM backend wants to see 2664 // the input and output of a matching constraint be the same size. Note 2665 // that GCC does not define what the top bits are here. We use zext because 2666 // that is usually cheaper, but LLVM IR should really get an anyext someday. 2667 if (Info.hasTiedOperand()) { 2668 unsigned Output = Info.getTiedOperand(); 2669 QualType OutputType = S.getOutputExpr(Output)->getType(); 2670 QualType InputTy = InputExpr->getType(); 2671 2672 if (getContext().getTypeSize(OutputType) > 2673 getContext().getTypeSize(InputTy)) { 2674 // Use ptrtoint as appropriate so that we can do our extension. 2675 if (isa<llvm::PointerType>(Arg->getType())) 2676 Arg = Builder.CreatePtrToInt(Arg, IntPtrTy); 2677 llvm::Type *OutputTy = ConvertType(OutputType); 2678 if (isa<llvm::IntegerType>(OutputTy)) 2679 Arg = Builder.CreateZExt(Arg, OutputTy); 2680 else if (isa<llvm::PointerType>(OutputTy)) 2681 Arg = Builder.CreateZExt(Arg, IntPtrTy); 2682 else if (OutputTy->isFloatingPointTy()) 2683 Arg = Builder.CreateFPExt(Arg, OutputTy); 2684 } 2685 // Deal with the tied operands' constraint code in adjustInlineAsmType. 2686 ReplaceConstraint = OutputConstraints[Output]; 2687 } 2688 if (llvm::Type* AdjTy = 2689 getTargetHooks().adjustInlineAsmType(*this, ReplaceConstraint, 2690 Arg->getType())) 2691 Arg = Builder.CreateBitCast(Arg, AdjTy); 2692 else 2693 CGM.getDiags().Report(S.getAsmLoc(), diag::err_asm_invalid_type_in_input) 2694 << InputExpr->getType() << InputConstraint; 2695 2696 // Update largest vector width for any vector types. 2697 if (auto *VT = dyn_cast<llvm::VectorType>(Arg->getType())) 2698 LargestVectorWidth = 2699 std::max((uint64_t)LargestVectorWidth, 2700 VT->getPrimitiveSizeInBits().getKnownMinValue()); 2701 2702 ArgTypes.push_back(Arg->getType()); 2703 ArgElemTypes.push_back(ArgElemType); 2704 Args.push_back(Arg); 2705 Constraints += InputConstraint; 2706 } 2707 2708 // Append the "input" part of inout constraints. 2709 for (unsigned i = 0, e = InOutArgs.size(); i != e; i++) { 2710 ArgTypes.push_back(InOutArgTypes[i]); 2711 ArgElemTypes.push_back(InOutArgElemTypes[i]); 2712 Args.push_back(InOutArgs[i]); 2713 } 2714 Constraints += InOutConstraints; 2715 2716 // Labels 2717 SmallVector<llvm::BasicBlock *, 16> Transfer; 2718 llvm::BasicBlock *Fallthrough = nullptr; 2719 bool IsGCCAsmGoto = false; 2720 if (const auto *GS = dyn_cast<GCCAsmStmt>(&S)) { 2721 IsGCCAsmGoto = GS->isAsmGoto(); 2722 if (IsGCCAsmGoto) { 2723 for (const auto *E : GS->labels()) { 2724 JumpDest Dest = getJumpDestForLabel(E->getLabel()); 2725 Transfer.push_back(Dest.getBlock()); 2726 if (!Constraints.empty()) 2727 Constraints += ','; 2728 Constraints += "!i"; 2729 } 2730 Fallthrough = createBasicBlock("asm.fallthrough"); 2731 } 2732 } 2733 2734 bool HasUnwindClobber = false; 2735 2736 // Clobbers 2737 for (unsigned i = 0, e = S.getNumClobbers(); i != e; i++) { 2738 StringRef Clobber = S.getClobber(i); 2739 2740 if (Clobber == "memory") 2741 ReadOnly = ReadNone = false; 2742 else if (Clobber == "unwind") { 2743 HasUnwindClobber = true; 2744 continue; 2745 } else if (Clobber != "cc") { 2746 Clobber = getTarget().getNormalizedGCCRegisterName(Clobber); 2747 if (CGM.getCodeGenOpts().StackClashProtector && 2748 getTarget().isSPRegName(Clobber)) { 2749 CGM.getDiags().Report(S.getAsmLoc(), 2750 diag::warn_stack_clash_protection_inline_asm); 2751 } 2752 } 2753 2754 if (isa<MSAsmStmt>(&S)) { 2755 if (Clobber == "eax" || Clobber == "edx") { 2756 if (Constraints.find("=&A") != std::string::npos) 2757 continue; 2758 std::string::size_type position1 = 2759 Constraints.find("={" + Clobber.str() + "}"); 2760 if (position1 != std::string::npos) { 2761 Constraints.insert(position1 + 1, "&"); 2762 continue; 2763 } 2764 std::string::size_type position2 = Constraints.find("=A"); 2765 if (position2 != std::string::npos) { 2766 Constraints.insert(position2 + 1, "&"); 2767 continue; 2768 } 2769 } 2770 } 2771 if (!Constraints.empty()) 2772 Constraints += ','; 2773 2774 Constraints += "~{"; 2775 Constraints += Clobber; 2776 Constraints += '}'; 2777 } 2778 2779 assert(!(HasUnwindClobber && IsGCCAsmGoto) && 2780 "unwind clobber can't be used with asm goto"); 2781 2782 // Add machine specific clobbers 2783 std::string_view MachineClobbers = getTarget().getClobbers(); 2784 if (!MachineClobbers.empty()) { 2785 if (!Constraints.empty()) 2786 Constraints += ','; 2787 Constraints += MachineClobbers; 2788 } 2789 2790 llvm::Type *ResultType; 2791 if (ResultRegTypes.empty()) 2792 ResultType = VoidTy; 2793 else if (ResultRegTypes.size() == 1) 2794 ResultType = ResultRegTypes[0]; 2795 else 2796 ResultType = llvm::StructType::get(getLLVMContext(), ResultRegTypes); 2797 2798 llvm::FunctionType *FTy = 2799 llvm::FunctionType::get(ResultType, ArgTypes, false); 2800 2801 bool HasSideEffect = S.isVolatile() || S.getNumOutputs() == 0; 2802 2803 llvm::InlineAsm::AsmDialect GnuAsmDialect = 2804 CGM.getCodeGenOpts().getInlineAsmDialect() == CodeGenOptions::IAD_ATT 2805 ? llvm::InlineAsm::AD_ATT 2806 : llvm::InlineAsm::AD_Intel; 2807 llvm::InlineAsm::AsmDialect AsmDialect = isa<MSAsmStmt>(&S) ? 2808 llvm::InlineAsm::AD_Intel : GnuAsmDialect; 2809 2810 llvm::InlineAsm *IA = llvm::InlineAsm::get( 2811 FTy, AsmString, Constraints, HasSideEffect, 2812 /* IsAlignStack */ false, AsmDialect, HasUnwindClobber); 2813 std::vector<llvm::Value*> RegResults; 2814 llvm::CallBrInst *CBR; 2815 llvm::DenseMap<llvm::BasicBlock *, SmallVector<llvm::Value *, 4>> 2816 CBRRegResults; 2817 if (IsGCCAsmGoto) { 2818 CBR = Builder.CreateCallBr(IA, Fallthrough, Transfer, Args); 2819 EmitBlock(Fallthrough); 2820 UpdateAsmCallInst(*CBR, HasSideEffect, false, ReadOnly, ReadNone, 2821 InNoMergeAttributedStmt, S, ResultRegTypes, ArgElemTypes, 2822 *this, RegResults); 2823 // Because we are emitting code top to bottom, we don't have enough 2824 // information at this point to know precisely whether we have a critical 2825 // edge. If we have outputs, split all indirect destinations. 2826 if (!RegResults.empty()) { 2827 unsigned i = 0; 2828 for (llvm::BasicBlock *Dest : CBR->getIndirectDests()) { 2829 llvm::Twine SynthName = Dest->getName() + ".split"; 2830 llvm::BasicBlock *SynthBB = createBasicBlock(SynthName); 2831 llvm::IRBuilderBase::InsertPointGuard IPG(Builder); 2832 Builder.SetInsertPoint(SynthBB); 2833 2834 if (ResultRegTypes.size() == 1) { 2835 CBRRegResults[SynthBB].push_back(CBR); 2836 } else { 2837 for (unsigned j = 0, e = ResultRegTypes.size(); j != e; ++j) { 2838 llvm::Value *Tmp = Builder.CreateExtractValue(CBR, j, "asmresult"); 2839 CBRRegResults[SynthBB].push_back(Tmp); 2840 } 2841 } 2842 2843 EmitBranch(Dest); 2844 EmitBlock(SynthBB); 2845 CBR->setIndirectDest(i++, SynthBB); 2846 } 2847 } 2848 } else if (HasUnwindClobber) { 2849 llvm::CallBase *Result = EmitCallOrInvoke(IA, Args, ""); 2850 UpdateAsmCallInst(*Result, HasSideEffect, true, ReadOnly, ReadNone, 2851 InNoMergeAttributedStmt, S, ResultRegTypes, ArgElemTypes, 2852 *this, RegResults); 2853 } else { 2854 llvm::CallInst *Result = 2855 Builder.CreateCall(IA, Args, getBundlesForFunclet(IA)); 2856 UpdateAsmCallInst(*Result, HasSideEffect, false, ReadOnly, ReadNone, 2857 InNoMergeAttributedStmt, S, ResultRegTypes, ArgElemTypes, 2858 *this, RegResults); 2859 } 2860 2861 EmitAsmStores(*this, S, RegResults, ResultRegTypes, ResultTruncRegTypes, 2862 ResultRegDests, ResultRegQualTys, ResultTypeRequiresCast, 2863 ResultRegIsFlagReg); 2864 2865 // If this is an asm goto with outputs, repeat EmitAsmStores, but with a 2866 // different insertion point; one for each indirect destination and with 2867 // CBRRegResults rather than RegResults. 2868 if (IsGCCAsmGoto && !CBRRegResults.empty()) { 2869 for (llvm::BasicBlock *Succ : CBR->getIndirectDests()) { 2870 llvm::IRBuilderBase::InsertPointGuard IPG(Builder); 2871 Builder.SetInsertPoint(Succ, --(Succ->end())); 2872 EmitAsmStores(*this, S, CBRRegResults[Succ], ResultRegTypes, 2873 ResultTruncRegTypes, ResultRegDests, ResultRegQualTys, 2874 ResultTypeRequiresCast, ResultRegIsFlagReg); 2875 } 2876 } 2877 } 2878 2879 LValue CodeGenFunction::InitCapturedStruct(const CapturedStmt &S) { 2880 const RecordDecl *RD = S.getCapturedRecordDecl(); 2881 QualType RecordTy = getContext().getRecordType(RD); 2882 2883 // Initialize the captured struct. 2884 LValue SlotLV = 2885 MakeAddrLValue(CreateMemTemp(RecordTy, "agg.captured"), RecordTy); 2886 2887 RecordDecl::field_iterator CurField = RD->field_begin(); 2888 for (CapturedStmt::const_capture_init_iterator I = S.capture_init_begin(), 2889 E = S.capture_init_end(); 2890 I != E; ++I, ++CurField) { 2891 LValue LV = EmitLValueForFieldInitialization(SlotLV, *CurField); 2892 if (CurField->hasCapturedVLAType()) { 2893 EmitLambdaVLACapture(CurField->getCapturedVLAType(), LV); 2894 } else { 2895 EmitInitializerForField(*CurField, LV, *I); 2896 } 2897 } 2898 2899 return SlotLV; 2900 } 2901 2902 /// Generate an outlined function for the body of a CapturedStmt, store any 2903 /// captured variables into the captured struct, and call the outlined function. 2904 llvm::Function * 2905 CodeGenFunction::EmitCapturedStmt(const CapturedStmt &S, CapturedRegionKind K) { 2906 LValue CapStruct = InitCapturedStruct(S); 2907 2908 // Emit the CapturedDecl 2909 CodeGenFunction CGF(CGM, true); 2910 CGCapturedStmtRAII CapInfoRAII(CGF, new CGCapturedStmtInfo(S, K)); 2911 llvm::Function *F = CGF.GenerateCapturedStmtFunction(S); 2912 delete CGF.CapturedStmtInfo; 2913 2914 // Emit call to the helper function. 2915 EmitCallOrInvoke(F, CapStruct.getPointer(*this)); 2916 2917 return F; 2918 } 2919 2920 Address CodeGenFunction::GenerateCapturedStmtArgument(const CapturedStmt &S) { 2921 LValue CapStruct = InitCapturedStruct(S); 2922 return CapStruct.getAddress(*this); 2923 } 2924 2925 /// Creates the outlined function for a CapturedStmt. 2926 llvm::Function * 2927 CodeGenFunction::GenerateCapturedStmtFunction(const CapturedStmt &S) { 2928 assert(CapturedStmtInfo && 2929 "CapturedStmtInfo should be set when generating the captured function"); 2930 const CapturedDecl *CD = S.getCapturedDecl(); 2931 const RecordDecl *RD = S.getCapturedRecordDecl(); 2932 SourceLocation Loc = S.getBeginLoc(); 2933 assert(CD->hasBody() && "missing CapturedDecl body"); 2934 2935 // Build the argument list. 2936 ASTContext &Ctx = CGM.getContext(); 2937 FunctionArgList Args; 2938 Args.append(CD->param_begin(), CD->param_end()); 2939 2940 // Create the function declaration. 2941 const CGFunctionInfo &FuncInfo = 2942 CGM.getTypes().arrangeBuiltinFunctionDeclaration(Ctx.VoidTy, Args); 2943 llvm::FunctionType *FuncLLVMTy = CGM.getTypes().GetFunctionType(FuncInfo); 2944 2945 llvm::Function *F = 2946 llvm::Function::Create(FuncLLVMTy, llvm::GlobalValue::InternalLinkage, 2947 CapturedStmtInfo->getHelperName(), &CGM.getModule()); 2948 CGM.SetInternalFunctionAttributes(CD, F, FuncInfo); 2949 if (CD->isNothrow()) 2950 F->addFnAttr(llvm::Attribute::NoUnwind); 2951 2952 // Generate the function. 2953 StartFunction(CD, Ctx.VoidTy, F, FuncInfo, Args, CD->getLocation(), 2954 CD->getBody()->getBeginLoc()); 2955 // Set the context parameter in CapturedStmtInfo. 2956 Address DeclPtr = GetAddrOfLocalVar(CD->getContextParam()); 2957 CapturedStmtInfo->setContextValue(Builder.CreateLoad(DeclPtr)); 2958 2959 // Initialize variable-length arrays. 2960 LValue Base = MakeNaturalAlignAddrLValue(CapturedStmtInfo->getContextValue(), 2961 Ctx.getTagDeclType(RD)); 2962 for (auto *FD : RD->fields()) { 2963 if (FD->hasCapturedVLAType()) { 2964 auto *ExprArg = 2965 EmitLoadOfLValue(EmitLValueForField(Base, FD), S.getBeginLoc()) 2966 .getScalarVal(); 2967 auto VAT = FD->getCapturedVLAType(); 2968 VLASizeMap[VAT->getSizeExpr()] = ExprArg; 2969 } 2970 } 2971 2972 // If 'this' is captured, load it into CXXThisValue. 2973 if (CapturedStmtInfo->isCXXThisExprCaptured()) { 2974 FieldDecl *FD = CapturedStmtInfo->getThisFieldDecl(); 2975 LValue ThisLValue = EmitLValueForField(Base, FD); 2976 CXXThisValue = EmitLoadOfLValue(ThisLValue, Loc).getScalarVal(); 2977 } 2978 2979 PGO.assignRegionCounters(GlobalDecl(CD), F); 2980 CapturedStmtInfo->EmitBody(*this, CD->getBody()); 2981 FinishFunction(CD->getBodyRBrace()); 2982 2983 return F; 2984 } 2985