contrib/llvm-project/clang/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp

   1 //===---- CGOpenMPRuntimeNVPTX.cpp - Interface to OpenMP NVPTX Runtimes ---===//
   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 provides a class for OpenMP runtime code generation specialized to NVPTX
  10 // targets.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "CGOpenMPRuntimeNVPTX.h"
  15 #include "CodeGenFunction.h"
  16 #include "clang/AST/Attr.h"
  17 #include "clang/AST/DeclOpenMP.h"
  18 #include "clang/AST/StmtOpenMP.h"
  19 #include "clang/AST/StmtVisitor.h"
  20 #include "clang/Basic/Cuda.h"
  21 #include "llvm/ADT/SmallPtrSet.h"
  22 #include "llvm/IR/IntrinsicsNVPTX.h"
  23
  24 using namespace clang;
  25 using namespace CodeGen;
  26 using namespace llvm::omp;
  27
  28 namespace {
  29 enum OpenMPRTLFunctionNVPTX {
  30   /// Call to void __kmpc_kernel_init(kmp_int32 thread_limit,
  31   /// int16_t RequiresOMPRuntime);
  32   OMPRTL_NVPTX__kmpc_kernel_init,
  33   /// Call to void __kmpc_kernel_deinit(int16_t IsOMPRuntimeInitialized);
  34   OMPRTL_NVPTX__kmpc_kernel_deinit,
  35   /// Call to void __kmpc_spmd_kernel_init(kmp_int32 thread_limit,
  36   /// int16_t RequiresOMPRuntime, int16_t RequiresDataSharing);
  37   OMPRTL_NVPTX__kmpc_spmd_kernel_init,
  38   /// Call to void __kmpc_spmd_kernel_deinit_v2(int16_t RequiresOMPRuntime);
  39   OMPRTL_NVPTX__kmpc_spmd_kernel_deinit_v2,
  40   /// Call to void __kmpc_kernel_prepare_parallel(void
  41   /// *outlined_function);
  42   OMPRTL_NVPTX__kmpc_kernel_prepare_parallel,
  43   /// Call to bool __kmpc_kernel_parallel(void **outlined_function);
  44   OMPRTL_NVPTX__kmpc_kernel_parallel,
  45   /// Call to void __kmpc_kernel_end_parallel();
  46   OMPRTL_NVPTX__kmpc_kernel_end_parallel,
  47   /// Call to void __kmpc_serialized_parallel(ident_t *loc, kmp_int32
  48   /// global_tid);
  49   OMPRTL_NVPTX__kmpc_serialized_parallel,
  50   /// Call to void __kmpc_end_serialized_parallel(ident_t *loc, kmp_int32
  51   /// global_tid);
  52   OMPRTL_NVPTX__kmpc_end_serialized_parallel,
  53   /// Call to int32_t __kmpc_shuffle_int32(int32_t element,
  54   /// int16_t lane_offset, int16_t warp_size);
  55   OMPRTL_NVPTX__kmpc_shuffle_int32,
  56   /// Call to int64_t __kmpc_shuffle_int64(int64_t element,
  57   /// int16_t lane_offset, int16_t warp_size);
  58   OMPRTL_NVPTX__kmpc_shuffle_int64,
  59   /// Call to __kmpc_nvptx_parallel_reduce_nowait_v2(ident_t *loc, kmp_int32
  60   /// global_tid, kmp_int32 num_vars, size_t reduce_size, void* reduce_data,
  61   /// void (*kmp_ShuffleReductFctPtr)(void *rhsData, int16_t lane_id, int16_t
  62   /// lane_offset, int16_t shortCircuit),
  63   /// void (*kmp_InterWarpCopyFctPtr)(void* src, int32_t warp_num));
  64   OMPRTL_NVPTX__kmpc_nvptx_parallel_reduce_nowait_v2,
  65   /// Call to __kmpc_nvptx_teams_reduce_nowait_v2(ident_t *loc, kmp_int32
  66   /// global_tid, void *global_buffer, int32_t num_of_records, void*
  67   /// reduce_data,
  68   /// void (*kmp_ShuffleReductFctPtr)(void *rhsData, int16_t lane_id, int16_t
  69   /// lane_offset, int16_t shortCircuit),
  70   /// void (*kmp_InterWarpCopyFctPtr)(void* src, int32_t warp_num), void
  71   /// (*kmp_ListToGlobalCpyFctPtr)(void *buffer, int idx, void *reduce_data),
  72   /// void (*kmp_GlobalToListCpyFctPtr)(void *buffer, int idx,
  73   /// void *reduce_data), void (*kmp_GlobalToListCpyPtrsFctPtr)(void *buffer,
  74   /// int idx, void *reduce_data), void (*kmp_GlobalToListRedFctPtr)(void
  75   /// *buffer, int idx, void *reduce_data));
  76   OMPRTL_NVPTX__kmpc_nvptx_teams_reduce_nowait_v2,
  77   /// Call to __kmpc_nvptx_end_reduce_nowait(int32_t global_tid);
  78   OMPRTL_NVPTX__kmpc_end_reduce_nowait,
  79   /// Call to void __kmpc_data_sharing_init_stack();
  80   OMPRTL_NVPTX__kmpc_data_sharing_init_stack,
  81   /// Call to void __kmpc_data_sharing_init_stack_spmd();
  82   OMPRTL_NVPTX__kmpc_data_sharing_init_stack_spmd,
  83   /// Call to void* __kmpc_data_sharing_coalesced_push_stack(size_t size,
  84   /// int16_t UseSharedMemory);
  85   OMPRTL_NVPTX__kmpc_data_sharing_coalesced_push_stack,
  86   /// Call to void* __kmpc_data_sharing_push_stack(size_t size, int16_t
  87   /// UseSharedMemory);
  88   OMPRTL_NVPTX__kmpc_data_sharing_push_stack,
  89   /// Call to void __kmpc_data_sharing_pop_stack(void *a);
  90   OMPRTL_NVPTX__kmpc_data_sharing_pop_stack,
  91   /// Call to void __kmpc_begin_sharing_variables(void ***args,
  92   /// size_t n_args);
  93   OMPRTL_NVPTX__kmpc_begin_sharing_variables,
  94   /// Call to void __kmpc_end_sharing_variables();
  95   OMPRTL_NVPTX__kmpc_end_sharing_variables,
  96   /// Call to void __kmpc_get_shared_variables(void ***GlobalArgs)
  97   OMPRTL_NVPTX__kmpc_get_shared_variables,
  98   /// Call to uint16_t __kmpc_parallel_level(ident_t *loc, kmp_int32
  99   /// global_tid);
 100   OMPRTL_NVPTX__kmpc_parallel_level,
 101   /// Call to int8_t __kmpc_is_spmd_exec_mode();
 102   OMPRTL_NVPTX__kmpc_is_spmd_exec_mode,
 103   /// Call to void __kmpc_get_team_static_memory(int16_t isSPMDExecutionMode,
 104   /// const void *buf, size_t size, int16_t is_shared, const void **res);
 105   OMPRTL_NVPTX__kmpc_get_team_static_memory,
 106   /// Call to void __kmpc_restore_team_static_memory(int16_t
 107   /// isSPMDExecutionMode, int16_t is_shared);
 108   OMPRTL_NVPTX__kmpc_restore_team_static_memory,
 109   /// Call to void __kmpc_barrier(ident_t *loc, kmp_int32 global_tid);
 110   OMPRTL__kmpc_barrier,
 111   /// Call to void __kmpc_barrier_simple_spmd(ident_t *loc, kmp_int32
 112   /// global_tid);
 113   OMPRTL__kmpc_barrier_simple_spmd,
 114   /// Call to int32_t __kmpc_warp_active_thread_mask(void);
 115   OMPRTL_NVPTX__kmpc_warp_active_thread_mask,
 116   /// Call to void __kmpc_syncwarp(int32_t Mask);
 117   OMPRTL_NVPTX__kmpc_syncwarp,
 118 };
 119
 120 /// Pre(post)-action for different OpenMP constructs specialized for NVPTX.
 121 class NVPTXActionTy final : public PrePostActionTy {
 122   llvm::FunctionCallee EnterCallee = nullptr;
 123   ArrayRef<llvm::Value *> EnterArgs;
 124   llvm::FunctionCallee ExitCallee = nullptr;
 125   ArrayRef<llvm::Value *> ExitArgs;
 126   bool Conditional = false;
 127   llvm::BasicBlock *ContBlock = nullptr;
 128
 129 public:
 130   NVPTXActionTy(llvm::FunctionCallee EnterCallee,
 131                 ArrayRef<llvm::Value *> EnterArgs,
 132                 llvm::FunctionCallee ExitCallee,
 133                 ArrayRef<llvm::Value *> ExitArgs, bool Conditional = false)
 134       : EnterCallee(EnterCallee), EnterArgs(EnterArgs), ExitCallee(ExitCallee),
 135         ExitArgs(ExitArgs), Conditional(Conditional) {}
 136   void Enter(CodeGenFunction &CGF) override {
 137     llvm::Value *EnterRes = CGF.EmitRuntimeCall(EnterCallee, EnterArgs);
 138     if (Conditional) {
 139       llvm::Value *CallBool = CGF.Builder.CreateIsNotNull(EnterRes);
 140       auto *ThenBlock = CGF.createBasicBlock("omp_if.then");
 141       ContBlock = CGF.createBasicBlock("omp_if.end");
 142       // Generate the branch (If-stmt)
 143       CGF.Builder.CreateCondBr(CallBool, ThenBlock, ContBlock);
 144       CGF.EmitBlock(ThenBlock);
 145     }
 146   }
 147   void Done(CodeGenFunction &CGF) {
 148     // Emit the rest of blocks/branches
 149     CGF.EmitBranch(ContBlock);
 150     CGF.EmitBlock(ContBlock, true);
 151   }
 152   void Exit(CodeGenFunction &CGF) override {
 153     CGF.EmitRuntimeCall(ExitCallee, ExitArgs);
 154   }
 155 };
 156
 157 /// A class to track the execution mode when codegening directives within
 158 /// a target region. The appropriate mode (SPMD|NON-SPMD) is set on entry
 159 /// to the target region and used by containing directives such as 'parallel'
 160 /// to emit optimized code.
 161 class ExecutionRuntimeModesRAII {
 162 private:
 163   CGOpenMPRuntimeNVPTX::ExecutionMode SavedExecMode =
 164       CGOpenMPRuntimeNVPTX::EM_Unknown;
 165   CGOpenMPRuntimeNVPTX::ExecutionMode &ExecMode;
 166   bool SavedRuntimeMode = false;
 167   bool *RuntimeMode = nullptr;
 168
 169 public:
 170   /// Constructor for Non-SPMD mode.
 171   ExecutionRuntimeModesRAII(CGOpenMPRuntimeNVPTX::ExecutionMode &ExecMode)
 172       : ExecMode(ExecMode) {
 173     SavedExecMode = ExecMode;
 174     ExecMode = CGOpenMPRuntimeNVPTX::EM_NonSPMD;
 175   }
 176   /// Constructor for SPMD mode.
 177   ExecutionRuntimeModesRAII(CGOpenMPRuntimeNVPTX::ExecutionMode &ExecMode,
 178                             bool &RuntimeMode, bool FullRuntimeMode)
 179       : ExecMode(ExecMode), RuntimeMode(&RuntimeMode) {
 180     SavedExecMode = ExecMode;
 181     SavedRuntimeMode = RuntimeMode;
 182     ExecMode = CGOpenMPRuntimeNVPTX::EM_SPMD;
 183     RuntimeMode = FullRuntimeMode;
 184   }
 185   ~ExecutionRuntimeModesRAII() {
 186     ExecMode = SavedExecMode;
 187     if (RuntimeMode)
 188       *RuntimeMode = SavedRuntimeMode;
 189   }
 190 };
 191
 192 /// GPU Configuration:  This information can be derived from cuda registers,
 193 /// however, providing compile time constants helps generate more efficient
 194 /// code.  For all practical purposes this is fine because the configuration
 195 /// is the same for all known NVPTX architectures.
 196 enum MachineConfiguration : unsigned {
 197   WarpSize = 32,
 198   /// Number of bits required to represent a lane identifier, which is
 199   /// computed as log_2(WarpSize).
 200   LaneIDBits = 5,
 201   LaneIDMask = WarpSize - 1,
 202
 203   /// Global memory alignment for performance.
 204   GlobalMemoryAlignment = 128,
 205
 206   /// Maximal size of the shared memory buffer.
 207   SharedMemorySize = 128,
 208 };
 209
 210 static const ValueDecl *getPrivateItem(const Expr *RefExpr) {
 211   RefExpr = RefExpr->IgnoreParens();
 212   if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(RefExpr)) {
 213     const Expr *Base = ASE->getBase()->IgnoreParenImpCasts();
 214     while (const auto *TempASE = dyn_cast<ArraySubscriptExpr>(Base))
 215       Base = TempASE->getBase()->IgnoreParenImpCasts();
 216     RefExpr = Base;
 217   } else if (auto *OASE = dyn_cast<OMPArraySectionExpr>(RefExpr)) {
 218     const Expr *Base = OASE->getBase()->IgnoreParenImpCasts();
 219     while (const auto *TempOASE = dyn_cast<OMPArraySectionExpr>(Base))
 220       Base = TempOASE->getBase()->IgnoreParenImpCasts();
 221     while (const auto *TempASE = dyn_cast<ArraySubscriptExpr>(Base))
 222       Base = TempASE->getBase()->IgnoreParenImpCasts();
 223     RefExpr = Base;
 224   }
 225   RefExpr = RefExpr->IgnoreParenImpCasts();
 226   if (const auto *DE = dyn_cast<DeclRefExpr>(RefExpr))
 227     return cast<ValueDecl>(DE->getDecl()->getCanonicalDecl());
 228   const auto *ME = cast<MemberExpr>(RefExpr);
 229   return cast<ValueDecl>(ME->getMemberDecl()->getCanonicalDecl());
 230 }
 231
 232
 233 static RecordDecl *buildRecordForGlobalizedVars(
 234     ASTContext &C, ArrayRef<const ValueDecl *> EscapedDecls,
 235     ArrayRef<const ValueDecl *> EscapedDeclsForTeams,
 236     llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *>
 237         &MappedDeclsFields, int BufSize) {
 238   using VarsDataTy = std::pair<CharUnits /*Align*/, const ValueDecl *>;
 239   if (EscapedDecls.empty() && EscapedDeclsForTeams.empty())
 240     return nullptr;
 241   SmallVector<VarsDataTy, 4> GlobalizedVars;
 242   for (const ValueDecl *D : EscapedDecls)
 243     GlobalizedVars.emplace_back(
 244         CharUnits::fromQuantity(std::max(
 245             C.getDeclAlign(D).getQuantity(),
 246             static_cast<CharUnits::QuantityType>(GlobalMemoryAlignment))),
 247         D);
 248   for (const ValueDecl *D : EscapedDeclsForTeams)
 249     GlobalizedVars.emplace_back(C.getDeclAlign(D), D);
 250   llvm::stable_sort(GlobalizedVars, [](VarsDataTy L, VarsDataTy R) {
 251     return L.first > R.first;
 252   });
 253
 254   // Build struct _globalized_locals_ty {
 255   //         /*  globalized vars  */[WarSize] align (max(decl_align,
 256   //         GlobalMemoryAlignment))
 257   //         /*  globalized vars  */ for EscapedDeclsForTeams
 258   //       };
 259   RecordDecl *GlobalizedRD = C.buildImplicitRecord("_globalized_locals_ty");
 260   GlobalizedRD->startDefinition();
 261   llvm::SmallPtrSet<const ValueDecl *, 16> SingleEscaped(
 262       EscapedDeclsForTeams.begin(), EscapedDeclsForTeams.end());
 263   for (const auto &Pair : GlobalizedVars) {
 264     const ValueDecl *VD = Pair.second;
 265     QualType Type = VD->getType();
 266     if (Type->isLValueReferenceType())
 267       Type = C.getPointerType(Type.getNonReferenceType());
 268     else
 269       Type = Type.getNonReferenceType();
 270     SourceLocation Loc = VD->getLocation();
 271     FieldDecl *Field;
 272     if (SingleEscaped.count(VD)) {
 273       Field = FieldDecl::Create(
 274           C, GlobalizedRD, Loc, Loc, VD->getIdentifier(), Type,
 275           C.getTrivialTypeSourceInfo(Type, SourceLocation()),
 276           /*BW=*/nullptr, /*Mutable=*/false,
 277           /*InitStyle=*/ICIS_NoInit);
 278       Field->setAccess(AS_public);
 279       if (VD->hasAttrs()) {
 280         for (specific_attr_iterator<AlignedAttr> I(VD->getAttrs().begin()),
 281              E(VD->getAttrs().end());
 282              I != E; ++I)
 283           Field->addAttr(*I);
 284       }
 285     } else {
 286       llvm::APInt ArraySize(32, BufSize);
 287       Type = C.getConstantArrayType(Type, ArraySize, nullptr, ArrayType::Normal,
 288                                     0);
 289       Field = FieldDecl::Create(
 290           C, GlobalizedRD, Loc, Loc, VD->getIdentifier(), Type,
 291           C.getTrivialTypeSourceInfo(Type, SourceLocation()),
 292           /*BW=*/nullptr, /*Mutable=*/false,
 293           /*InitStyle=*/ICIS_NoInit);
 294       Field->setAccess(AS_public);
 295       llvm::APInt Align(32, std::max(C.getDeclAlign(VD).getQuantity(),
 296                                      static_cast<CharUnits::QuantityType>(
 297                                          GlobalMemoryAlignment)));
 298       Field->addAttr(AlignedAttr::CreateImplicit(
 299           C, /*IsAlignmentExpr=*/true,
 300           IntegerLiteral::Create(C, Align,
 301                                  C.getIntTypeForBitwidth(32, /*Signed=*/0),
 302                                  SourceLocation()),
 303           {}, AttributeCommonInfo::AS_GNU, AlignedAttr::GNU_aligned));
 304     }
 305     GlobalizedRD->addDecl(Field);
 306     MappedDeclsFields.try_emplace(VD, Field);
 307   }
 308   GlobalizedRD->completeDefinition();
 309   return GlobalizedRD;
 310 }
 311
 312 /// Get the list of variables that can escape their declaration context.
 313 class CheckVarsEscapingDeclContext final
 314     : public ConstStmtVisitor<CheckVarsEscapingDeclContext> {
 315   CodeGenFunction &CGF;
 316   llvm::SetVector<const ValueDecl *> EscapedDecls;
 317   llvm::SetVector<const ValueDecl *> EscapedVariableLengthDecls;
 318   llvm::SmallPtrSet<const Decl *, 4> EscapedParameters;
 319   RecordDecl *GlobalizedRD = nullptr;
 320   llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *> MappedDeclsFields;
 321   bool AllEscaped = false;
 322   bool IsForCombinedParallelRegion = false;
 323
 324   void markAsEscaped(const ValueDecl *VD) {
 325     // Do not globalize declare target variables.
 326     if (!isa<VarDecl>(VD) ||
 327         OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD))
 328       return;
 329     VD = cast<ValueDecl>(VD->getCanonicalDecl());
 330     // Use user-specified allocation.
 331     if (VD->hasAttrs() && VD->hasAttr<OMPAllocateDeclAttr>())
 332       return;
 333     // Variables captured by value must be globalized.
 334     if (auto *CSI = CGF.CapturedStmtInfo) {
 335       if (const FieldDecl *FD = CSI->lookup(cast<VarDecl>(VD))) {
 336         // Check if need to capture the variable that was already captured by
 337         // value in the outer region.
 338         if (!IsForCombinedParallelRegion) {
 339           if (!FD->hasAttrs())
 340             return;
 341           const auto *Attr = FD->getAttr<OMPCaptureKindAttr>();
 342           if (!Attr)
 343             return;
 344           if (((Attr->getCaptureKind() != OMPC_map) &&
 345                !isOpenMPPrivate(Attr->getCaptureKind())) ||
 346               ((Attr->getCaptureKind() == OMPC_map) &&
 347                !FD->getType()->isAnyPointerType()))
 348             return;
 349         }
 350         if (!FD->getType()->isReferenceType()) {
 351           assert(!VD->getType()->isVariablyModifiedType() &&
 352                  "Parameter captured by value with variably modified type");
 353           EscapedParameters.insert(VD);
 354         } else if (!IsForCombinedParallelRegion) {
 355           return;
 356         }
 357       }
 358     }
 359     if ((!CGF.CapturedStmtInfo ||
 360          (IsForCombinedParallelRegion && CGF.CapturedStmtInfo)) &&
 361         VD->getType()->isReferenceType())
 362       // Do not globalize variables with reference type.
 363       return;
 364     if (VD->getType()->isVariablyModifiedType())
 365       EscapedVariableLengthDecls.insert(VD);
 366     else
 367       EscapedDecls.insert(VD);
 368   }
 369
 370   void VisitValueDecl(const ValueDecl *VD) {
 371     if (VD->getType()->isLValueReferenceType())
 372       markAsEscaped(VD);
 373     if (const auto *VarD = dyn_cast<VarDecl>(VD)) {
 374       if (!isa<ParmVarDecl>(VarD) && VarD->hasInit()) {
 375         const bool SavedAllEscaped = AllEscaped;
 376         AllEscaped = VD->getType()->isLValueReferenceType();
 377         Visit(VarD->getInit());
 378         AllEscaped = SavedAllEscaped;
 379       }
 380     }
 381   }
 382   void VisitOpenMPCapturedStmt(const CapturedStmt *S,
 383                                ArrayRef<OMPClause *> Clauses,
 384                                bool IsCombinedParallelRegion) {
 385     if (!S)
 386       return;
 387     for (const CapturedStmt::Capture &C : S->captures()) {
 388       if (C.capturesVariable() && !C.capturesVariableByCopy()) {
 389         const ValueDecl *VD = C.getCapturedVar();
 390         bool SavedIsForCombinedParallelRegion = IsForCombinedParallelRegion;
 391         if (IsCombinedParallelRegion) {
 392           // Check if the variable is privatized in the combined construct and
 393           // those private copies must be shared in the inner parallel
 394           // directive.
 395           IsForCombinedParallelRegion = false;
 396           for (const OMPClause *C : Clauses) {
 397             if (!isOpenMPPrivate(C->getClauseKind()) ||
 398                 C->getClauseKind() == OMPC_reduction ||
 399                 C->getClauseKind() == OMPC_linear ||
 400                 C->getClauseKind() == OMPC_private)
 401               continue;
 402             ArrayRef<const Expr *> Vars;
 403             if (const auto *PC = dyn_cast<OMPFirstprivateClause>(C))
 404               Vars = PC->getVarRefs();
 405             else if (const auto *PC = dyn_cast<OMPLastprivateClause>(C))
 406               Vars = PC->getVarRefs();
 407             else
 408               llvm_unreachable("Unexpected clause.");
 409             for (const auto *E : Vars) {
 410               const Decl *D =
 411                   cast<DeclRefExpr>(E)->getDecl()->getCanonicalDecl();
 412               if (D == VD->getCanonicalDecl()) {
 413                 IsForCombinedParallelRegion = true;
 414                 break;
 415               }
 416             }
 417             if (IsForCombinedParallelRegion)
 418               break;
 419           }
 420         }
 421         markAsEscaped(VD);
 422         if (isa<OMPCapturedExprDecl>(VD))
 423           VisitValueDecl(VD);
 424         IsForCombinedParallelRegion = SavedIsForCombinedParallelRegion;
 425       }
 426     }
 427   }
 428
 429   void buildRecordForGlobalizedVars(bool IsInTTDRegion) {
 430     assert(!GlobalizedRD &&
 431            "Record for globalized variables is built already.");
 432     ArrayRef<const ValueDecl *> EscapedDeclsForParallel, EscapedDeclsForTeams;
 433     if (IsInTTDRegion)
 434       EscapedDeclsForTeams = EscapedDecls.getArrayRef();
 435     else
 436       EscapedDeclsForParallel = EscapedDecls.getArrayRef();
 437     GlobalizedRD = ::buildRecordForGlobalizedVars(
 438         CGF.getContext(), EscapedDeclsForParallel, EscapedDeclsForTeams,
 439         MappedDeclsFields, WarpSize);
 440   }
 441
 442 public:
 443   CheckVarsEscapingDeclContext(CodeGenFunction &CGF,
 444                                ArrayRef<const ValueDecl *> TeamsReductions)
 445       : CGF(CGF), EscapedDecls(TeamsReductions.begin(), TeamsReductions.end()) {
 446   }
 447   virtual ~CheckVarsEscapingDeclContext() = default;
 448   void VisitDeclStmt(const DeclStmt *S) {
 449     if (!S)
 450       return;
 451     for (const Decl *D : S->decls())
 452       if (const auto *VD = dyn_cast_or_null<ValueDecl>(D))
 453         VisitValueDecl(VD);
 454   }
 455   void VisitOMPExecutableDirective(const OMPExecutableDirective *D) {
 456     if (!D)
 457       return;
 458     if (!D->hasAssociatedStmt())
 459       return;
 460     if (const auto *S =
 461             dyn_cast_or_null<CapturedStmt>(D->getAssociatedStmt())) {
 462       // Do not analyze directives that do not actually require capturing,
 463       // like `omp for` or `omp simd` directives.
 464       llvm::SmallVector<OpenMPDirectiveKind, 4> CaptureRegions;
 465       getOpenMPCaptureRegions(CaptureRegions, D->getDirectiveKind());
 466       if (CaptureRegions.size() == 1 && CaptureRegions.back() == OMPD_unknown) {
 467         VisitStmt(S->getCapturedStmt());
 468         return;
 469       }
 470       VisitOpenMPCapturedStmt(
 471           S, D->clauses(),
 472           CaptureRegions.back() == OMPD_parallel &&
 473               isOpenMPDistributeDirective(D->getDirectiveKind()));
 474     }
 475   }
 476   void VisitCapturedStmt(const CapturedStmt *S) {
 477     if (!S)
 478       return;
 479     for (const CapturedStmt::Capture &C : S->captures()) {
 480       if (C.capturesVariable() && !C.capturesVariableByCopy()) {
 481         const ValueDecl *VD = C.getCapturedVar();
 482         markAsEscaped(VD);
 483         if (isa<OMPCapturedExprDecl>(VD))
 484           VisitValueDecl(VD);
 485       }
 486     }
 487   }
 488   void VisitLambdaExpr(const LambdaExpr *E) {
 489     if (!E)
 490       return;
 491     for (const LambdaCapture &C : E->captures()) {
 492       if (C.capturesVariable()) {
 493         if (C.getCaptureKind() == LCK_ByRef) {
 494           const ValueDecl *VD = C.getCapturedVar();
 495           markAsEscaped(VD);
 496           if (E->isInitCapture(&C) || isa<OMPCapturedExprDecl>(VD))
 497             VisitValueDecl(VD);
 498         }
 499       }
 500     }
 501   }
 502   void VisitBlockExpr(const BlockExpr *E) {
 503     if (!E)
 504       return;
 505     for (const BlockDecl::Capture &C : E->getBlockDecl()->captures()) {
 506       if (C.isByRef()) {
 507         const VarDecl *VD = C.getVariable();
 508         markAsEscaped(VD);
 509         if (isa<OMPCapturedExprDecl>(VD) || VD->isInitCapture())
 510           VisitValueDecl(VD);
 511       }
 512     }
 513   }
 514   void VisitCallExpr(const CallExpr *E) {
 515     if (!E)
 516       return;
 517     for (const Expr *Arg : E->arguments()) {
 518       if (!Arg)
 519         continue;
 520       if (Arg->isLValue()) {
 521         const bool SavedAllEscaped = AllEscaped;
 522         AllEscaped = true;
 523         Visit(Arg);
 524         AllEscaped = SavedAllEscaped;
 525       } else {
 526         Visit(Arg);
 527       }
 528     }
 529     Visit(E->getCallee());
 530   }
 531   void VisitDeclRefExpr(const DeclRefExpr *E) {
 532     if (!E)
 533       return;
 534     const ValueDecl *VD = E->getDecl();
 535     if (AllEscaped)
 536       markAsEscaped(VD);
 537     if (isa<OMPCapturedExprDecl>(VD))
 538       VisitValueDecl(VD);
 539     else if (const auto *VarD = dyn_cast<VarDecl>(VD))
 540       if (VarD->isInitCapture())
 541         VisitValueDecl(VD);
 542   }
 543   void VisitUnaryOperator(const UnaryOperator *E) {
 544     if (!E)
 545       return;
 546     if (E->getOpcode() == UO_AddrOf) {
 547       const bool SavedAllEscaped = AllEscaped;
 548       AllEscaped = true;
 549       Visit(E->getSubExpr());
 550       AllEscaped = SavedAllEscaped;
 551     } else {
 552       Visit(E->getSubExpr());
 553     }
 554   }
 555   void VisitImplicitCastExpr(const ImplicitCastExpr *E) {
 556     if (!E)
 557       return;
 558     if (E->getCastKind() == CK_ArrayToPointerDecay) {
 559       const bool SavedAllEscaped = AllEscaped;
 560       AllEscaped = true;
 561       Visit(E->getSubExpr());
 562       AllEscaped = SavedAllEscaped;
 563     } else {
 564       Visit(E->getSubExpr());
 565     }
 566   }
 567   void VisitExpr(const Expr *E) {
 568     if (!E)
 569       return;
 570     bool SavedAllEscaped = AllEscaped;
 571     if (!E->isLValue())
 572       AllEscaped = false;
 573     for (const Stmt *Child : E->children())
 574       if (Child)
 575         Visit(Child);
 576     AllEscaped = SavedAllEscaped;
 577   }
 578   void VisitStmt(const Stmt *S) {
 579     if (!S)
 580       return;
 581     for (const Stmt *Child : S->children())
 582       if (Child)
 583         Visit(Child);
 584   }
 585
 586   /// Returns the record that handles all the escaped local variables and used
 587   /// instead of their original storage.
 588   const RecordDecl *getGlobalizedRecord(bool IsInTTDRegion) {
 589     if (!GlobalizedRD)
 590       buildRecordForGlobalizedVars(IsInTTDRegion);
 591     return GlobalizedRD;
 592   }
 593
 594   /// Returns the field in the globalized record for the escaped variable.
 595   const FieldDecl *getFieldForGlobalizedVar(const ValueDecl *VD) const {
 596     assert(GlobalizedRD &&
 597            "Record for globalized variables must be generated already.");
 598     auto I = MappedDeclsFields.find(VD);
 599     if (I == MappedDeclsFields.end())
 600       return nullptr;
 601     return I->getSecond();
 602   }
 603
 604   /// Returns the list of the escaped local variables/parameters.
 605   ArrayRef<const ValueDecl *> getEscapedDecls() const {
 606     return EscapedDecls.getArrayRef();
 607   }
 608
 609   /// Checks if the escaped local variable is actually a parameter passed by
 610   /// value.
 611   const llvm::SmallPtrSetImpl<const Decl *> &getEscapedParameters() const {
 612     return EscapedParameters;
 613   }
 614
 615   /// Returns the list of the escaped variables with the variably modified
 616   /// types.
 617   ArrayRef<const ValueDecl *> getEscapedVariableLengthDecls() const {
 618     return EscapedVariableLengthDecls.getArrayRef();
 619   }
 620 };
 621 } // anonymous namespace
 622
 623 /// Get the GPU warp size.
 624 static llvm::Value *getNVPTXWarpSize(CodeGenFunction &CGF) {
 625   return CGF.EmitRuntimeCall(
 626       llvm::Intrinsic::getDeclaration(
 627           &CGF.CGM.getModule(), llvm::Intrinsic::nvvm_read_ptx_sreg_warpsize),
 628       "nvptx_warp_size");
 629 }
 630
 631 /// Get the id of the current thread on the GPU.
 632 static llvm::Value *getNVPTXThreadID(CodeGenFunction &CGF) {
 633   return CGF.EmitRuntimeCall(
 634       llvm::Intrinsic::getDeclaration(
 635           &CGF.CGM.getModule(), llvm::Intrinsic::nvvm_read_ptx_sreg_tid_x),
 636       "nvptx_tid");
 637 }
 638
 639 /// Get the id of the warp in the block.
 640 /// We assume that the warp size is 32, which is always the case
 641 /// on the NVPTX device, to generate more efficient code.
 642 static llvm::Value *getNVPTXWarpID(CodeGenFunction &CGF) {
 643   CGBuilderTy &Bld = CGF.Builder;
 644   return Bld.CreateAShr(getNVPTXThreadID(CGF), LaneIDBits, "nvptx_warp_id");
 645 }
 646
 647 /// Get the id of the current lane in the Warp.
 648 /// We assume that the warp size is 32, which is always the case
 649 /// on the NVPTX device, to generate more efficient code.
 650 static llvm::Value *getNVPTXLaneID(CodeGenFunction &CGF) {
 651   CGBuilderTy &Bld = CGF.Builder;
 652   return Bld.CreateAnd(getNVPTXThreadID(CGF), Bld.getInt32(LaneIDMask),
 653                        "nvptx_lane_id");
 654 }
 655
 656 /// Get the maximum number of threads in a block of the GPU.
 657 static llvm::Value *getNVPTXNumThreads(CodeGenFunction &CGF) {
 658   return CGF.EmitRuntimeCall(
 659       llvm::Intrinsic::getDeclaration(
 660           &CGF.CGM.getModule(), llvm::Intrinsic::nvvm_read_ptx_sreg_ntid_x),
 661       "nvptx_num_threads");
 662 }
 663
 664 /// Get the value of the thread_limit clause in the teams directive.
 665 /// For the 'generic' execution mode, the runtime encodes thread_limit in
 666 /// the launch parameters, always starting thread_limit+warpSize threads per
 667 /// CTA. The threads in the last warp are reserved for master execution.
 668 /// For the 'spmd' execution mode, all threads in a CTA are part of the team.
 669 static llvm::Value *getThreadLimit(CodeGenFunction &CGF,
 670                                    bool IsInSPMDExecutionMode = false) {
 671   CGBuilderTy &Bld = CGF.Builder;
 672   return IsInSPMDExecutionMode
 673              ? getNVPTXNumThreads(CGF)
 674              : Bld.CreateNUWSub(getNVPTXNumThreads(CGF), getNVPTXWarpSize(CGF),
 675                                 "thread_limit");
 676 }
 677
 678 /// Get the thread id of the OMP master thread.
 679 /// The master thread id is the first thread (lane) of the last warp in the
 680 /// GPU block.  Warp size is assumed to be some power of 2.
 681 /// Thread id is 0 indexed.
 682 /// E.g: If NumThreads is 33, master id is 32.
 683 ///      If NumThreads is 64, master id is 32.
 684 ///      If NumThreads is 1024, master id is 992.
 685 static llvm::Value *getMasterThreadID(CodeGenFunction &CGF) {
 686   CGBuilderTy &Bld = CGF.Builder;
 687   llvm::Value *NumThreads = getNVPTXNumThreads(CGF);
 688
 689   // We assume that the warp size is a power of 2.
 690   llvm::Value *Mask = Bld.CreateNUWSub(getNVPTXWarpSize(CGF), Bld.getInt32(1));
 691
 692   return Bld.CreateAnd(Bld.CreateNUWSub(NumThreads, Bld.getInt32(1)),
 693                        Bld.CreateNot(Mask), "master_tid");
 694 }
 695
 696 CGOpenMPRuntimeNVPTX::WorkerFunctionState::WorkerFunctionState(
 697     CodeGenModule &CGM, SourceLocation Loc)
 698     : WorkerFn(nullptr), CGFI(CGM.getTypes().arrangeNullaryFunction()),
 699       Loc(Loc) {
 700   createWorkerFunction(CGM);
 701 }
 702
 703 void CGOpenMPRuntimeNVPTX::WorkerFunctionState::createWorkerFunction(
 704     CodeGenModule &CGM) {
 705   // Create an worker function with no arguments.
 706
 707   WorkerFn = llvm::Function::Create(
 708       CGM.getTypes().GetFunctionType(CGFI), llvm::GlobalValue::InternalLinkage,
 709       /*placeholder=*/"_worker", &CGM.getModule());
 710   CGM.SetInternalFunctionAttributes(GlobalDecl(), WorkerFn, CGFI);
 711   WorkerFn->setDoesNotRecurse();
 712 }
 713
 714 CGOpenMPRuntimeNVPTX::ExecutionMode
 715 CGOpenMPRuntimeNVPTX::getExecutionMode() const {
 716   return CurrentExecutionMode;
 717 }
 718
 719 static CGOpenMPRuntimeNVPTX::DataSharingMode
 720 getDataSharingMode(CodeGenModule &CGM) {
 721   return CGM.getLangOpts().OpenMPCUDAMode ? CGOpenMPRuntimeNVPTX::CUDA
 722                                           : CGOpenMPRuntimeNVPTX::Generic;
 723 }
 724
 725 /// Check for inner (nested) SPMD construct, if any
 726 static bool hasNestedSPMDDirective(ASTContext &Ctx,
 727                                    const OMPExecutableDirective &D) {
 728   const auto *CS = D.getInnermostCapturedStmt();
 729   const auto *Body =
 730       CS->getCapturedStmt()->IgnoreContainers(/*IgnoreCaptured=*/true);
 731   const Stmt *ChildStmt = CGOpenMPRuntime::getSingleCompoundChild(Ctx, Body);
 732
 733   if (const auto *NestedDir =
 734           dyn_cast_or_null<OMPExecutableDirective>(ChildStmt)) {
 735     OpenMPDirectiveKind DKind = NestedDir->getDirectiveKind();
 736     switch (D.getDirectiveKind()) {
 737     case OMPD_target:
 738       if (isOpenMPParallelDirective(DKind))
 739         return true;
 740       if (DKind == OMPD_teams) {
 741         Body = NestedDir->getInnermostCapturedStmt()->IgnoreContainers(
 742             /*IgnoreCaptured=*/true);
 743         if (!Body)
 744           return false;
 745         ChildStmt = CGOpenMPRuntime::getSingleCompoundChild(Ctx, Body);
 746         if (const auto *NND =
 747                 dyn_cast_or_null<OMPExecutableDirective>(ChildStmt)) {
 748           DKind = NND->getDirectiveKind();
 749           if (isOpenMPParallelDirective(DKind))
 750             return true;
 751         }
 752       }
 753       return false;
 754     case OMPD_target_teams:
 755       return isOpenMPParallelDirective(DKind);
 756     case OMPD_target_simd:
 757     case OMPD_target_parallel:
 758     case OMPD_target_parallel_for:
 759     case OMPD_target_parallel_for_simd:
 760     case OMPD_target_teams_distribute:
 761     case OMPD_target_teams_distribute_simd:
 762     case OMPD_target_teams_distribute_parallel_for:
 763     case OMPD_target_teams_distribute_parallel_for_simd:
 764     case OMPD_parallel:
 765     case OMPD_for:
 766     case OMPD_parallel_for:
 767     case OMPD_parallel_master:
 768     case OMPD_parallel_sections:
 769     case OMPD_for_simd:
 770     case OMPD_parallel_for_simd:
 771     case OMPD_cancel:
 772     case OMPD_cancellation_point:
 773     case OMPD_ordered:
 774     case OMPD_threadprivate:
 775     case OMPD_allocate:
 776     case OMPD_task:
 777     case OMPD_simd:
 778     case OMPD_sections:
 779     case OMPD_section:
 780     case OMPD_single:
 781     case OMPD_master:
 782     case OMPD_critical:
 783     case OMPD_taskyield:
 784     case OMPD_barrier:
 785     case OMPD_taskwait:
 786     case OMPD_taskgroup:
 787     case OMPD_atomic:
 788     case OMPD_flush:
 789     case OMPD_depobj:
 790     case OMPD_scan:
 791     case OMPD_teams:
 792     case OMPD_target_data:
 793     case OMPD_target_exit_data:
 794     case OMPD_target_enter_data:
 795     case OMPD_distribute:
 796     case OMPD_distribute_simd:
 797     case OMPD_distribute_parallel_for:
 798     case OMPD_distribute_parallel_for_simd:
 799     case OMPD_teams_distribute:
 800     case OMPD_teams_distribute_simd:
 801     case OMPD_teams_distribute_parallel_for:
 802     case OMPD_teams_distribute_parallel_for_simd:
 803     case OMPD_target_update:
 804     case OMPD_declare_simd:
 805     case OMPD_declare_variant:
 806     case OMPD_begin_declare_variant:
 807     case OMPD_end_declare_variant:
 808     case OMPD_declare_target:
 809     case OMPD_end_declare_target:
 810     case OMPD_declare_reduction:
 811     case OMPD_declare_mapper:
 812     case OMPD_taskloop:
 813     case OMPD_taskloop_simd:
 814     case OMPD_master_taskloop:
 815     case OMPD_master_taskloop_simd:
 816     case OMPD_parallel_master_taskloop:
 817     case OMPD_parallel_master_taskloop_simd:
 818     case OMPD_requires:
 819     case OMPD_unknown:
 820     default:
 821       llvm_unreachable("Unexpected directive.");
 822     }
 823   }
 824
 825   return false;
 826 }
 827
 828 static bool supportsSPMDExecutionMode(ASTContext &Ctx,
 829                                       const OMPExecutableDirective &D) {
 830   OpenMPDirectiveKind DirectiveKind = D.getDirectiveKind();
 831   switch (DirectiveKind) {
 832   case OMPD_target:
 833   case OMPD_target_teams:
 834     return hasNestedSPMDDirective(Ctx, D);
 835   case OMPD_target_parallel:
 836   case OMPD_target_parallel_for:
 837   case OMPD_target_parallel_for_simd:
 838   case OMPD_target_teams_distribute_parallel_for:
 839   case OMPD_target_teams_distribute_parallel_for_simd:
 840   case OMPD_target_simd:
 841   case OMPD_target_teams_distribute_simd:
 842     return true;
 843   case OMPD_target_teams_distribute:
 844     return false;
 845   case OMPD_parallel:
 846   case OMPD_for:
 847   case OMPD_parallel_for:
 848   case OMPD_parallel_master:
 849   case OMPD_parallel_sections:
 850   case OMPD_for_simd:
 851   case OMPD_parallel_for_simd:
 852   case OMPD_cancel:
 853   case OMPD_cancellation_point:
 854   case OMPD_ordered:
 855   case OMPD_threadprivate:
 856   case OMPD_allocate:
 857   case OMPD_task:
 858   case OMPD_simd:
 859   case OMPD_sections:
 860   case OMPD_section:
 861   case OMPD_single:
 862   case OMPD_master:
 863   case OMPD_critical:
 864   case OMPD_taskyield:
 865   case OMPD_barrier:
 866   case OMPD_taskwait:
 867   case OMPD_taskgroup:
 868   case OMPD_atomic:
 869   case OMPD_flush:
 870   case OMPD_depobj:
 871   case OMPD_scan:
 872   case OMPD_teams:
 873   case OMPD_target_data:
 874   case OMPD_target_exit_data:
 875   case OMPD_target_enter_data:
 876   case OMPD_distribute:
 877   case OMPD_distribute_simd:
 878   case OMPD_distribute_parallel_for:
 879   case OMPD_distribute_parallel_for_simd:
 880   case OMPD_teams_distribute:
 881   case OMPD_teams_distribute_simd:
 882   case OMPD_teams_distribute_parallel_for:
 883   case OMPD_teams_distribute_parallel_for_simd:
 884   case OMPD_target_update:
 885   case OMPD_declare_simd:
 886   case OMPD_declare_variant:
 887   case OMPD_begin_declare_variant:
 888   case OMPD_end_declare_variant:
 889   case OMPD_declare_target:
 890   case OMPD_end_declare_target:
 891   case OMPD_declare_reduction:
 892   case OMPD_declare_mapper:
 893   case OMPD_taskloop:
 894   case OMPD_taskloop_simd:
 895   case OMPD_master_taskloop:
 896   case OMPD_master_taskloop_simd:
 897   case OMPD_parallel_master_taskloop:
 898   case OMPD_parallel_master_taskloop_simd:
 899   case OMPD_requires:
 900   case OMPD_unknown:
 901   default:
 902     break;
 903   }
 904   llvm_unreachable(
 905       "Unknown programming model for OpenMP directive on NVPTX target.");
 906 }
 907
 908 /// Check if the directive is loops based and has schedule clause at all or has
 909 /// static scheduling.
 910 static bool hasStaticScheduling(const OMPExecutableDirective &D) {
 911   assert(isOpenMPWorksharingDirective(D.getDirectiveKind()) &&
 912          isOpenMPLoopDirective(D.getDirectiveKind()) &&
 913          "Expected loop-based directive.");
 914   return !D.hasClausesOfKind<OMPOrderedClause>() &&
 915          (!D.hasClausesOfKind<OMPScheduleClause>() ||
 916           llvm::any_of(D.getClausesOfKind<OMPScheduleClause>(),
 917                        [](const OMPScheduleClause *C) {
 918                          return C->getScheduleKind() == OMPC_SCHEDULE_static;
 919                        }));
 920 }
 921
 922 /// Check for inner (nested) lightweight runtime construct, if any
 923 static bool hasNestedLightweightDirective(ASTContext &Ctx,
 924                                           const OMPExecutableDirective &D) {
 925   assert(supportsSPMDExecutionMode(Ctx, D) && "Expected SPMD mode directive.");
 926   const auto *CS = D.getInnermostCapturedStmt();
 927   const auto *Body =
 928       CS->getCapturedStmt()->IgnoreContainers(/*IgnoreCaptured=*/true);
 929   const Stmt *ChildStmt = CGOpenMPRuntime::getSingleCompoundChild(Ctx, Body);
 930
 931   if (const auto *NestedDir =
 932           dyn_cast_or_null<OMPExecutableDirective>(ChildStmt)) {
 933     OpenMPDirectiveKind DKind = NestedDir->getDirectiveKind();
 934     switch (D.getDirectiveKind()) {
 935     case OMPD_target:
 936       if (isOpenMPParallelDirective(DKind) &&
 937           isOpenMPWorksharingDirective(DKind) && isOpenMPLoopDirective(DKind) &&
 938           hasStaticScheduling(*NestedDir))
 939         return true;
 940       if (DKind == OMPD_teams_distribute_simd || DKind == OMPD_simd)
 941         return true;
 942       if (DKind == OMPD_parallel) {
 943         Body = NestedDir->getInnermostCapturedStmt()->IgnoreContainers(
 944             /*IgnoreCaptured=*/true);
 945         if (!Body)
 946           return false;
 947         ChildStmt = CGOpenMPRuntime::getSingleCompoundChild(Ctx, Body);
 948         if (const auto *NND =
 949                 dyn_cast_or_null<OMPExecutableDirective>(ChildStmt)) {
 950           DKind = NND->getDirectiveKind();
 951           if (isOpenMPWorksharingDirective(DKind) &&
 952               isOpenMPLoopDirective(DKind) && hasStaticScheduling(*NND))
 953             return true;
 954         }
 955       } else if (DKind == OMPD_teams) {
 956         Body = NestedDir->getInnermostCapturedStmt()->IgnoreContainers(
 957             /*IgnoreCaptured=*/true);
 958         if (!Body)
 959           return false;
 960         ChildStmt = CGOpenMPRuntime::getSingleCompoundChild(Ctx, Body);
 961         if (const auto *NND =
 962                 dyn_cast_or_null<OMPExecutableDirective>(ChildStmt)) {
 963           DKind = NND->getDirectiveKind();
 964           if (isOpenMPParallelDirective(DKind) &&
 965               isOpenMPWorksharingDirective(DKind) &&
 966               isOpenMPLoopDirective(DKind) && hasStaticScheduling(*NND))
 967             return true;
 968           if (DKind == OMPD_parallel) {
 969             Body = NND->getInnermostCapturedStmt()->IgnoreContainers(
 970                 /*IgnoreCaptured=*/true);
 971             if (!Body)
 972               return false;
 973             ChildStmt = CGOpenMPRuntime::getSingleCompoundChild(Ctx, Body);
 974             if (const auto *NND =
 975                     dyn_cast_or_null<OMPExecutableDirective>(ChildStmt)) {
 976               DKind = NND->getDirectiveKind();
 977               if (isOpenMPWorksharingDirective(DKind) &&
 978                   isOpenMPLoopDirective(DKind) && hasStaticScheduling(*NND))
 979                 return true;
 980             }
 981           }
 982         }
 983       }
 984       return false;
 985     case OMPD_target_teams:
 986       if (isOpenMPParallelDirective(DKind) &&
 987           isOpenMPWorksharingDirective(DKind) && isOpenMPLoopDirective(DKind) &&
 988           hasStaticScheduling(*NestedDir))
 989         return true;
 990       if (DKind == OMPD_distribute_simd || DKind == OMPD_simd)
 991         return true;
 992       if (DKind == OMPD_parallel) {
 993         Body = NestedDir->getInnermostCapturedStmt()->IgnoreContainers(
 994             /*IgnoreCaptured=*/true);
 995         if (!Body)
 996           return false;
 997         ChildStmt = CGOpenMPRuntime::getSingleCompoundChild(Ctx, Body);
 998         if (const auto *NND =
 999                 dyn_cast_or_null<OMPExecutableDirective>(ChildStmt)) {
1000           DKind = NND->getDirectiveKind();
1001           if (isOpenMPWorksharingDirective(DKind) &&
1002               isOpenMPLoopDirective(DKind) && hasStaticScheduling(*NND))
1003             return true;
1004         }
1005       }
1006       return false;
1007     case OMPD_target_parallel:
1008       if (DKind == OMPD_simd)
1009         return true;
1010       return isOpenMPWorksharingDirective(DKind) &&
1011              isOpenMPLoopDirective(DKind) && hasStaticScheduling(*NestedDir);
1012     case OMPD_target_teams_distribute:
1013     case OMPD_target_simd:
1014     case OMPD_target_parallel_for:
1015     case OMPD_target_parallel_for_simd:
1016     case OMPD_target_teams_distribute_simd:
1017     case OMPD_target_teams_distribute_parallel_for:
1018     case OMPD_target_teams_distribute_parallel_for_simd:
1019     case OMPD_parallel:
1020     case OMPD_for:
1021     case OMPD_parallel_for:
1022     case OMPD_parallel_master:
1023     case OMPD_parallel_sections:
1024     case OMPD_for_simd:
1025     case OMPD_parallel_for_simd:
1026     case OMPD_cancel:
1027     case OMPD_cancellation_point:
1028     case OMPD_ordered:
1029     case OMPD_threadprivate:
1030     case OMPD_allocate:
1031     case OMPD_task:
1032     case OMPD_simd:
1033     case OMPD_sections:
1034     case OMPD_section:
1035     case OMPD_single:
1036     case OMPD_master:
1037     case OMPD_critical:
1038     case OMPD_taskyield:
1039     case OMPD_barrier:
1040     case OMPD_taskwait:
1041     case OMPD_taskgroup:
1042     case OMPD_atomic:
1043     case OMPD_flush:
1044     case OMPD_depobj:
1045     case OMPD_scan:
1046     case OMPD_teams:
1047     case OMPD_target_data:
1048     case OMPD_target_exit_data:
1049     case OMPD_target_enter_data:
1050     case OMPD_distribute:
1051     case OMPD_distribute_simd:
1052     case OMPD_distribute_parallel_for:
1053     case OMPD_distribute_parallel_for_simd:
1054     case OMPD_teams_distribute:
1055     case OMPD_teams_distribute_simd:
1056     case OMPD_teams_distribute_parallel_for:
1057     case OMPD_teams_distribute_parallel_for_simd:
1058     case OMPD_target_update:
1059     case OMPD_declare_simd:
1060     case OMPD_declare_variant:
1061     case OMPD_begin_declare_variant:
1062     case OMPD_end_declare_variant:
1063     case OMPD_declare_target:
1064     case OMPD_end_declare_target:
1065     case OMPD_declare_reduction:
1066     case OMPD_declare_mapper:
1067     case OMPD_taskloop:
1068     case OMPD_taskloop_simd:
1069     case OMPD_master_taskloop:
1070     case OMPD_master_taskloop_simd:
1071     case OMPD_parallel_master_taskloop:
1072     case OMPD_parallel_master_taskloop_simd:
1073     case OMPD_requires:
1074     case OMPD_unknown:
1075     default:
1076       llvm_unreachable("Unexpected directive.");
1077     }
1078   }
1079
1080   return false;
1081 }
1082
1083 /// Checks if the construct supports lightweight runtime. It must be SPMD
1084 /// construct + inner loop-based construct with static scheduling.
1085 static bool supportsLightweightRuntime(ASTContext &Ctx,
1086                                        const OMPExecutableDirective &D) {
1087   if (!supportsSPMDExecutionMode(Ctx, D))
1088     return false;
1089   OpenMPDirectiveKind DirectiveKind = D.getDirectiveKind();
1090   switch (DirectiveKind) {
1091   case OMPD_target:
1092   case OMPD_target_teams:
1093   case OMPD_target_parallel:
1094     return hasNestedLightweightDirective(Ctx, D);
1095   case OMPD_target_parallel_for:
1096   case OMPD_target_parallel_for_simd:
1097   case OMPD_target_teams_distribute_parallel_for:
1098   case OMPD_target_teams_distribute_parallel_for_simd:
1099     // (Last|First)-privates must be shared in parallel region.
1100     return hasStaticScheduling(D);
1101   case OMPD_target_simd:
1102   case OMPD_target_teams_distribute_simd:
1103     return true;
1104   case OMPD_target_teams_distribute:
1105     return false;
1106   case OMPD_parallel:
1107   case OMPD_for:
1108   case OMPD_parallel_for:
1109   case OMPD_parallel_master:
1110   case OMPD_parallel_sections:
1111   case OMPD_for_simd:
1112   case OMPD_parallel_for_simd:
1113   case OMPD_cancel:
1114   case OMPD_cancellation_point:
1115   case OMPD_ordered:
1116   case OMPD_threadprivate:
1117   case OMPD_allocate:
1118   case OMPD_task:
1119   case OMPD_simd:
1120   case OMPD_sections:
1121   case OMPD_section:
1122   case OMPD_single:
1123   case OMPD_master:
1124   case OMPD_critical:
1125   case OMPD_taskyield:
1126   case OMPD_barrier:
1127   case OMPD_taskwait:
1128   case OMPD_taskgroup:
1129   case OMPD_atomic:
1130   case OMPD_flush:
1131   case OMPD_depobj:
1132   case OMPD_scan:
1133   case OMPD_teams:
1134   case OMPD_target_data:
1135   case OMPD_target_exit_data:
1136   case OMPD_target_enter_data:
1137   case OMPD_distribute:
1138   case OMPD_distribute_simd:
1139   case OMPD_distribute_parallel_for:
1140   case OMPD_distribute_parallel_for_simd:
1141   case OMPD_teams_distribute:
1142   case OMPD_teams_distribute_simd:
1143   case OMPD_teams_distribute_parallel_for:
1144   case OMPD_teams_distribute_parallel_for_simd:
1145   case OMPD_target_update:
1146   case OMPD_declare_simd:
1147   case OMPD_declare_variant:
1148   case OMPD_begin_declare_variant:
1149   case OMPD_end_declare_variant:
1150   case OMPD_declare_target:
1151   case OMPD_end_declare_target:
1152   case OMPD_declare_reduction:
1153   case OMPD_declare_mapper:
1154   case OMPD_taskloop:
1155   case OMPD_taskloop_simd:
1156   case OMPD_master_taskloop:
1157   case OMPD_master_taskloop_simd:
1158   case OMPD_parallel_master_taskloop:
1159   case OMPD_parallel_master_taskloop_simd:
1160   case OMPD_requires:
1161   case OMPD_unknown:
1162   default:
1163     break;
1164   }
1165   llvm_unreachable(
1166       "Unknown programming model for OpenMP directive on NVPTX target.");
1167 }
1168
1169 void CGOpenMPRuntimeNVPTX::emitNonSPMDKernel(const OMPExecutableDirective &D,
1170                                              StringRef ParentName,
1171                                              llvm::Function *&OutlinedFn,
1172                                              llvm::Constant *&OutlinedFnID,
1173                                              bool IsOffloadEntry,
1174                                              const RegionCodeGenTy &CodeGen) {
1175   ExecutionRuntimeModesRAII ModeRAII(CurrentExecutionMode);
1176   EntryFunctionState EST;
1177   WorkerFunctionState WST(CGM, D.getBeginLoc());
1178   Work.clear();
1179   WrapperFunctionsMap.clear();
1180
1181   // Emit target region as a standalone region.
1182   class NVPTXPrePostActionTy : public PrePostActionTy {
1183     CGOpenMPRuntimeNVPTX::EntryFunctionState &EST;
1184     CGOpenMPRuntimeNVPTX::WorkerFunctionState &WST;
1185
1186   public:
1187     NVPTXPrePostActionTy(CGOpenMPRuntimeNVPTX::EntryFunctionState &EST,
1188                          CGOpenMPRuntimeNVPTX::WorkerFunctionState &WST)
1189         : EST(EST), WST(WST) {}
1190     void Enter(CodeGenFunction &CGF) override {
1191       auto &RT =
1192           static_cast<CGOpenMPRuntimeNVPTX &>(CGF.CGM.getOpenMPRuntime());
1193       RT.emitNonSPMDEntryHeader(CGF, EST, WST);
1194       // Skip target region initialization.
1195       RT.setLocThreadIdInsertPt(CGF, /*AtCurrentPoint=*/true);
1196     }
1197     void Exit(CodeGenFunction &CGF) override {
1198       auto &RT =
1199           static_cast<CGOpenMPRuntimeNVPTX &>(CGF.CGM.getOpenMPRuntime());
1200       RT.clearLocThreadIdInsertPt(CGF);
1201       RT.emitNonSPMDEntryFooter(CGF, EST);
1202     }
1203   } Action(EST, WST);
1204   CodeGen.setAction(Action);
1205   IsInTTDRegion = true;
1206   // Reserve place for the globalized memory.
1207   GlobalizedRecords.emplace_back();
1208   if (!KernelStaticGlobalized) {
1209     KernelStaticGlobalized = new llvm::GlobalVariable(
1210         CGM.getModule(), CGM.VoidPtrTy, /*isConstant=*/false,
1211         llvm::GlobalValue::InternalLinkage,
1212         llvm::ConstantPointerNull::get(CGM.VoidPtrTy),
1213         "_openmp_kernel_static_glob_rd$ptr", /*InsertBefore=*/nullptr,
1214         llvm::GlobalValue::NotThreadLocal,
1215         CGM.getContext().getTargetAddressSpace(LangAS::cuda_shared));
1216   }
1217   emitTargetOutlinedFunctionHelper(D, ParentName, OutlinedFn, OutlinedFnID,
1218                                    IsOffloadEntry, CodeGen);
1219   IsInTTDRegion = false;
1220
1221   // Now change the name of the worker function to correspond to this target
1222   // region's entry function.
1223   WST.WorkerFn->setName(Twine(OutlinedFn->getName(), "_worker"));
1224
1225   // Create the worker function
1226   emitWorkerFunction(WST);
1227 }
1228
1229 // Setup NVPTX threads for master-worker OpenMP scheme.
1230 void CGOpenMPRuntimeNVPTX::emitNonSPMDEntryHeader(CodeGenFunction &CGF,
1231                                                   EntryFunctionState &EST,
1232                                                   WorkerFunctionState &WST) {
1233   CGBuilderTy &Bld = CGF.Builder;
1234
1235   llvm::BasicBlock *WorkerBB = CGF.createBasicBlock(".worker");
1236   llvm::BasicBlock *MasterCheckBB = CGF.createBasicBlock(".mastercheck");
1237   llvm::BasicBlock *MasterBB = CGF.createBasicBlock(".master");
1238   EST.ExitBB = CGF.createBasicBlock(".exit");
1239
1240   llvm::Value *IsWorker =
1241       Bld.CreateICmpULT(getNVPTXThreadID(CGF), getThreadLimit(CGF));
1242   Bld.CreateCondBr(IsWorker, WorkerBB, MasterCheckBB);
1243
1244   CGF.EmitBlock(WorkerBB);
1245   emitCall(CGF, WST.Loc, WST.WorkerFn);
1246   CGF.EmitBranch(EST.ExitBB);
1247
1248   CGF.EmitBlock(MasterCheckBB);
1249   llvm::Value *IsMaster =
1250       Bld.CreateICmpEQ(getNVPTXThreadID(CGF), getMasterThreadID(CGF));
1251   Bld.CreateCondBr(IsMaster, MasterBB, EST.ExitBB);
1252
1253   CGF.EmitBlock(MasterBB);
1254   IsInTargetMasterThreadRegion = true;
1255   // SEQUENTIAL (MASTER) REGION START
1256   // First action in sequential region:
1257   // Initialize the state of the OpenMP runtime library on the GPU.
1258   // TODO: Optimize runtime initialization and pass in correct value.
1259   llvm::Value *Args[] = {getThreadLimit(CGF),
1260                          Bld.getInt16(/*RequiresOMPRuntime=*/1)};
1261   CGF.EmitRuntimeCall(
1262       createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_kernel_init), Args);
1263
1264   // For data sharing, we need to initialize the stack.
1265   CGF.EmitRuntimeCall(
1266       createNVPTXRuntimeFunction(
1267           OMPRTL_NVPTX__kmpc_data_sharing_init_stack));
1268
1269   emitGenericVarsProlog(CGF, WST.Loc);
1270 }
1271
1272 void CGOpenMPRuntimeNVPTX::emitNonSPMDEntryFooter(CodeGenFunction &CGF,
1273                                                   EntryFunctionState &EST) {
1274   IsInTargetMasterThreadRegion = false;
1275   if (!CGF.HaveInsertPoint())
1276     return;
1277
1278   emitGenericVarsEpilog(CGF);
1279
1280   if (!EST.ExitBB)
1281     EST.ExitBB = CGF.createBasicBlock(".exit");
1282
1283   llvm::BasicBlock *TerminateBB = CGF.createBasicBlock(".termination.notifier");
1284   CGF.EmitBranch(TerminateBB);
1285
1286   CGF.EmitBlock(TerminateBB);
1287   // Signal termination condition.
1288   // TODO: Optimize runtime initialization and pass in correct value.
1289   llvm::Value *Args[] = {CGF.Builder.getInt16(/*IsOMPRuntimeInitialized=*/1)};
1290   CGF.EmitRuntimeCall(
1291       createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_kernel_deinit), Args);
1292   // Barrier to terminate worker threads.
1293   syncCTAThreads(CGF);
1294   // Master thread jumps to exit point.
1295   CGF.EmitBranch(EST.ExitBB);
1296
1297   CGF.EmitBlock(EST.ExitBB);
1298   EST.ExitBB = nullptr;
1299 }
1300
1301 void CGOpenMPRuntimeNVPTX::emitSPMDKernel(const OMPExecutableDirective &D,
1302                                           StringRef ParentName,
1303                                           llvm::Function *&OutlinedFn,
1304                                           llvm::Constant *&OutlinedFnID,
1305                                           bool IsOffloadEntry,
1306                                           const RegionCodeGenTy &CodeGen) {
1307   ExecutionRuntimeModesRAII ModeRAII(
1308       CurrentExecutionMode, RequiresFullRuntime,
1309       CGM.getLangOpts().OpenMPCUDAForceFullRuntime ||
1310           !supportsLightweightRuntime(CGM.getContext(), D));
1311   EntryFunctionState EST;
1312
1313   // Emit target region as a standalone region.
1314   class NVPTXPrePostActionTy : public PrePostActionTy {
1315     CGOpenMPRuntimeNVPTX &RT;
1316     CGOpenMPRuntimeNVPTX::EntryFunctionState &EST;
1317     const OMPExecutableDirective &D;
1318
1319   public:
1320     NVPTXPrePostActionTy(CGOpenMPRuntimeNVPTX &RT,
1321                          CGOpenMPRuntimeNVPTX::EntryFunctionState &EST,
1322                          const OMPExecutableDirective &D)
1323         : RT(RT), EST(EST), D(D) {}
1324     void Enter(CodeGenFunction &CGF) override {
1325       RT.emitSPMDEntryHeader(CGF, EST, D);
1326       // Skip target region initialization.
1327       RT.setLocThreadIdInsertPt(CGF, /*AtCurrentPoint=*/true);
1328     }
1329     void Exit(CodeGenFunction &CGF) override {
1330       RT.clearLocThreadIdInsertPt(CGF);
1331       RT.emitSPMDEntryFooter(CGF, EST);
1332     }
1333   } Action(*this, EST, D);
1334   CodeGen.setAction(Action);
1335   IsInTTDRegion = true;
1336   // Reserve place for the globalized memory.
1337   GlobalizedRecords.emplace_back();
1338   if (!KernelStaticGlobalized) {
1339     KernelStaticGlobalized = new llvm::GlobalVariable(
1340         CGM.getModule(), CGM.VoidPtrTy, /*isConstant=*/false,
1341         llvm::GlobalValue::InternalLinkage,
1342         llvm::ConstantPointerNull::get(CGM.VoidPtrTy),
1343         "_openmp_kernel_static_glob_rd$ptr", /*InsertBefore=*/nullptr,
1344         llvm::GlobalValue::NotThreadLocal,
1345         CGM.getContext().getTargetAddressSpace(LangAS::cuda_shared));
1346   }
1347   emitTargetOutlinedFunctionHelper(D, ParentName, OutlinedFn, OutlinedFnID,
1348                                    IsOffloadEntry, CodeGen);
1349   IsInTTDRegion = false;
1350 }
1351
1352 void CGOpenMPRuntimeNVPTX::emitSPMDEntryHeader(
1353     CodeGenFunction &CGF, EntryFunctionState &EST,
1354     const OMPExecutableDirective &D) {
1355   CGBuilderTy &Bld = CGF.Builder;
1356
1357   // Setup BBs in entry function.
1358   llvm::BasicBlock *ExecuteBB = CGF.createBasicBlock(".execute");
1359   EST.ExitBB = CGF.createBasicBlock(".exit");
1360
1361   llvm::Value *Args[] = {getThreadLimit(CGF, /*IsInSPMDExecutionMode=*/true),
1362                          /*RequiresOMPRuntime=*/
1363                          Bld.getInt16(RequiresFullRuntime ? 1 : 0),
1364                          /*RequiresDataSharing=*/Bld.getInt16(0)};
1365   CGF.EmitRuntimeCall(
1366       createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_spmd_kernel_init), Args);
1367
1368   if (RequiresFullRuntime) {
1369     // For data sharing, we need to initialize the stack.
1370     CGF.EmitRuntimeCall(createNVPTXRuntimeFunction(
1371         OMPRTL_NVPTX__kmpc_data_sharing_init_stack_spmd));
1372   }
1373
1374   CGF.EmitBranch(ExecuteBB);
1375
1376   CGF.EmitBlock(ExecuteBB);
1377
1378   IsInTargetMasterThreadRegion = true;
1379 }
1380
1381 void CGOpenMPRuntimeNVPTX::emitSPMDEntryFooter(CodeGenFunction &CGF,
1382                                                EntryFunctionState &EST) {
1383   IsInTargetMasterThreadRegion = false;
1384   if (!CGF.HaveInsertPoint())
1385     return;
1386
1387   if (!EST.ExitBB)
1388     EST.ExitBB = CGF.createBasicBlock(".exit");
1389
1390   llvm::BasicBlock *OMPDeInitBB = CGF.createBasicBlock(".omp.deinit");
1391   CGF.EmitBranch(OMPDeInitBB);
1392
1393   CGF.EmitBlock(OMPDeInitBB);
1394   // DeInitialize the OMP state in the runtime; called by all active threads.
1395   llvm::Value *Args[] = {/*RequiresOMPRuntime=*/
1396                          CGF.Builder.getInt16(RequiresFullRuntime ? 1 : 0)};
1397   CGF.EmitRuntimeCall(
1398       createNVPTXRuntimeFunction(
1399           OMPRTL_NVPTX__kmpc_spmd_kernel_deinit_v2), Args);
1400   CGF.EmitBranch(EST.ExitBB);
1401
1402   CGF.EmitBlock(EST.ExitBB);
1403   EST.ExitBB = nullptr;
1404 }
1405
1406 // Create a unique global variable to indicate the execution mode of this target
1407 // region. The execution mode is either 'generic', or 'spmd' depending on the
1408 // target directive. This variable is picked up by the offload library to setup
1409 // the device appropriately before kernel launch. If the execution mode is
1410 // 'generic', the runtime reserves one warp for the master, otherwise, all
1411 // warps participate in parallel work.
1412 static void setPropertyExecutionMode(CodeGenModule &CGM, StringRef Name,
1413                                      bool Mode) {
1414   auto *GVMode =
1415       new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty, /*isConstant=*/true,
1416                                llvm::GlobalValue::WeakAnyLinkage,
1417                                llvm::ConstantInt::get(CGM.Int8Ty, Mode ? 0 : 1),
1418                                Twine(Name, "_exec_mode"));
1419   CGM.addCompilerUsedGlobal(GVMode);
1420 }
1421
1422 void CGOpenMPRuntimeNVPTX::emitWorkerFunction(WorkerFunctionState &WST) {
1423   ASTContext &Ctx = CGM.getContext();
1424
1425   CodeGenFunction CGF(CGM, /*suppressNewContext=*/true);
1426   CGF.StartFunction(GlobalDecl(), Ctx.VoidTy, WST.WorkerFn, WST.CGFI, {},
1427                     WST.Loc, WST.Loc);
1428   emitWorkerLoop(CGF, WST);
1429   CGF.FinishFunction();
1430 }
1431
1432 void CGOpenMPRuntimeNVPTX::emitWorkerLoop(CodeGenFunction &CGF,
1433                                           WorkerFunctionState &WST) {
1434   //
1435   // The workers enter this loop and wait for parallel work from the master.
1436   // When the master encounters a parallel region it sets up the work + variable
1437   // arguments, and wakes up the workers.  The workers first check to see if
1438   // they are required for the parallel region, i.e., within the # of requested
1439   // parallel threads.  The activated workers load the variable arguments and
1440   // execute the parallel work.
1441   //
1442
1443   CGBuilderTy &Bld = CGF.Builder;
1444
1445   llvm::BasicBlock *AwaitBB = CGF.createBasicBlock(".await.work");
1446   llvm::BasicBlock *SelectWorkersBB = CGF.createBasicBlock(".select.workers");
1447   llvm::BasicBlock *ExecuteBB = CGF.createBasicBlock(".execute.parallel");
1448   llvm::BasicBlock *TerminateBB = CGF.createBasicBlock(".terminate.parallel");
1449   llvm::BasicBlock *BarrierBB = CGF.createBasicBlock(".barrier.parallel");
1450   llvm::BasicBlock *ExitBB = CGF.createBasicBlock(".exit");
1451
1452   CGF.EmitBranch(AwaitBB);
1453
1454   // Workers wait for work from master.
1455   CGF.EmitBlock(AwaitBB);
1456   // Wait for parallel work
1457   syncCTAThreads(CGF);
1458
1459   Address WorkFn =
1460       CGF.CreateDefaultAlignTempAlloca(CGF.Int8PtrTy, /*Name=*/"work_fn");
1461   Address ExecStatus =
1462       CGF.CreateDefaultAlignTempAlloca(CGF.Int8Ty, /*Name=*/"exec_status");
1463   CGF.InitTempAlloca(ExecStatus, Bld.getInt8(/*C=*/0));
1464   CGF.InitTempAlloca(WorkFn, llvm::Constant::getNullValue(CGF.Int8PtrTy));
1465
1466   // TODO: Optimize runtime initialization and pass in correct value.
1467   llvm::Value *Args[] = {WorkFn.getPointer()};
1468   llvm::Value *Ret = CGF.EmitRuntimeCall(
1469       createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_kernel_parallel), Args);
1470   Bld.CreateStore(Bld.CreateZExt(Ret, CGF.Int8Ty), ExecStatus);
1471
1472   // On termination condition (workid == 0), exit loop.
1473   llvm::Value *WorkID = Bld.CreateLoad(WorkFn);
1474   llvm::Value *ShouldTerminate = Bld.CreateIsNull(WorkID, "should_terminate");
1475   Bld.CreateCondBr(ShouldTerminate, ExitBB, SelectWorkersBB);
1476
1477   // Activate requested workers.
1478   CGF.EmitBlock(SelectWorkersBB);
1479   llvm::Value *IsActive =
1480       Bld.CreateIsNotNull(Bld.CreateLoad(ExecStatus), "is_active");
1481   Bld.CreateCondBr(IsActive, ExecuteBB, BarrierBB);
1482
1483   // Signal start of parallel region.
1484   CGF.EmitBlock(ExecuteBB);
1485   // Skip initialization.
1486   setLocThreadIdInsertPt(CGF, /*AtCurrentPoint=*/true);
1487
1488   // Process work items: outlined parallel functions.
1489   for (llvm::Function *W : Work) {
1490     // Try to match this outlined function.
1491     llvm::Value *ID = Bld.CreatePointerBitCastOrAddrSpaceCast(W, CGM.Int8PtrTy);
1492
1493     llvm::Value *WorkFnMatch =
1494         Bld.CreateICmpEQ(Bld.CreateLoad(WorkFn), ID, "work_match");
1495
1496     llvm::BasicBlock *ExecuteFNBB = CGF.createBasicBlock(".execute.fn");
1497     llvm::BasicBlock *CheckNextBB = CGF.createBasicBlock(".check.next");
1498     Bld.CreateCondBr(WorkFnMatch, ExecuteFNBB, CheckNextBB);
1499
1500     // Execute this outlined function.
1501     CGF.EmitBlock(ExecuteFNBB);
1502
1503     // Insert call to work function via shared wrapper. The shared
1504     // wrapper takes two arguments:
1505     //   - the parallelism level;
1506     //   - the thread ID;
1507     emitCall(CGF, WST.Loc, W,
1508              {Bld.getInt16(/*ParallelLevel=*/0), getThreadID(CGF, WST.Loc)});
1509
1510     // Go to end of parallel region.
1511     CGF.EmitBranch(TerminateBB);
1512
1513     CGF.EmitBlock(CheckNextBB);
1514   }
1515   // Default case: call to outlined function through pointer if the target
1516   // region makes a declare target call that may contain an orphaned parallel
1517   // directive.
1518   auto *ParallelFnTy =
1519       llvm::FunctionType::get(CGM.VoidTy, {CGM.Int16Ty, CGM.Int32Ty},
1520                               /*isVarArg=*/false);
1521   llvm::Value *WorkFnCast =
1522       Bld.CreateBitCast(WorkID, ParallelFnTy->getPointerTo());
1523   // Insert call to work function via shared wrapper. The shared
1524   // wrapper takes two arguments:
1525   //   - the parallelism level;
1526   //   - the thread ID;
1527   emitCall(CGF, WST.Loc, {ParallelFnTy, WorkFnCast},
1528            {Bld.getInt16(/*ParallelLevel=*/0), getThreadID(CGF, WST.Loc)});
1529   // Go to end of parallel region.
1530   CGF.EmitBranch(TerminateBB);
1531
1532   // Signal end of parallel region.
1533   CGF.EmitBlock(TerminateBB);
1534   CGF.EmitRuntimeCall(
1535       createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_kernel_end_parallel),
1536       llvm::None);
1537   CGF.EmitBranch(BarrierBB);
1538
1539   // All active and inactive workers wait at a barrier after parallel region.
1540   CGF.EmitBlock(BarrierBB);
1541   // Barrier after parallel region.
1542   syncCTAThreads(CGF);
1543   CGF.EmitBranch(AwaitBB);
1544
1545   // Exit target region.
1546   CGF.EmitBlock(ExitBB);
1547   // Skip initialization.
1548   clearLocThreadIdInsertPt(CGF);
1549 }
1550
1551 /// Returns specified OpenMP runtime function for the current OpenMP
1552 /// implementation.  Specialized for the NVPTX device.
1553 /// \param Function OpenMP runtime function.
1554 /// \return Specified function.
1555 llvm::FunctionCallee
1556 CGOpenMPRuntimeNVPTX::createNVPTXRuntimeFunction(unsigned Function) {
1557   llvm::FunctionCallee RTLFn = nullptr;
1558   switch (static_cast<OpenMPRTLFunctionNVPTX>(Function)) {
1559   case OMPRTL_NVPTX__kmpc_kernel_init: {
1560     // Build void __kmpc_kernel_init(kmp_int32 thread_limit, int16_t
1561     // RequiresOMPRuntime);
1562     llvm::Type *TypeParams[] = {CGM.Int32Ty, CGM.Int16Ty};
1563     auto *FnTy =
1564         llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
1565     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_kernel_init");
1566     break;
1567   }
1568   case OMPRTL_NVPTX__kmpc_kernel_deinit: {
1569     // Build void __kmpc_kernel_deinit(int16_t IsOMPRuntimeInitialized);
1570     llvm::Type *TypeParams[] = {CGM.Int16Ty};
1571     auto *FnTy =
1572         llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
1573     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_kernel_deinit");
1574     break;
1575   }
1576   case OMPRTL_NVPTX__kmpc_spmd_kernel_init: {
1577     // Build void __kmpc_spmd_kernel_init(kmp_int32 thread_limit,
1578     // int16_t RequiresOMPRuntime, int16_t RequiresDataSharing);
1579     llvm::Type *TypeParams[] = {CGM.Int32Ty, CGM.Int16Ty, CGM.Int16Ty};
1580     auto *FnTy =
1581         llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
1582     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_spmd_kernel_init");
1583     break;
1584   }
1585   case OMPRTL_NVPTX__kmpc_spmd_kernel_deinit_v2: {
1586     // Build void __kmpc_spmd_kernel_deinit_v2(int16_t RequiresOMPRuntime);
1587     llvm::Type *TypeParams[] = {CGM.Int16Ty};
1588     auto *FnTy =
1589         llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
1590     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_spmd_kernel_deinit_v2");
1591     break;
1592   }
1593   case OMPRTL_NVPTX__kmpc_kernel_prepare_parallel: {
1594     /// Build void __kmpc_kernel_prepare_parallel(
1595     /// void *outlined_function);
1596     llvm::Type *TypeParams[] = {CGM.Int8PtrTy};
1597     auto *FnTy =
1598         llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
1599     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_kernel_prepare_parallel");
1600     break;
1601   }
1602   case OMPRTL_NVPTX__kmpc_kernel_parallel: {
1603     /// Build bool __kmpc_kernel_parallel(void **outlined_function);
1604     llvm::Type *TypeParams[] = {CGM.Int8PtrPtrTy};
1605     llvm::Type *RetTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy);
1606     auto *FnTy =
1607         llvm::FunctionType::get(RetTy, TypeParams, /*isVarArg*/ false);
1608     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_kernel_parallel");
1609     break;
1610   }
1611   case OMPRTL_NVPTX__kmpc_kernel_end_parallel: {
1612     /// Build void __kmpc_kernel_end_parallel();
1613     auto *FnTy =
1614         llvm::FunctionType::get(CGM.VoidTy, llvm::None, /*isVarArg*/ false);
1615     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_kernel_end_parallel");
1616     break;
1617   }
1618   case OMPRTL_NVPTX__kmpc_serialized_parallel: {
1619     // Build void __kmpc_serialized_parallel(ident_t *loc, kmp_int32
1620     // global_tid);
1621     llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty};
1622     auto *FnTy =
1623         llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
1624     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_serialized_parallel");
1625     break;
1626   }
1627   case OMPRTL_NVPTX__kmpc_end_serialized_parallel: {
1628     // Build void __kmpc_end_serialized_parallel(ident_t *loc, kmp_int32
1629     // global_tid);
1630     llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty};
1631     auto *FnTy =
1632         llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
1633     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_end_serialized_parallel");
1634     break;
1635   }
1636   case OMPRTL_NVPTX__kmpc_shuffle_int32: {
1637     // Build int32_t __kmpc_shuffle_int32(int32_t element,
1638     // int16_t lane_offset, int16_t warp_size);
1639     llvm::Type *TypeParams[] = {CGM.Int32Ty, CGM.Int16Ty, CGM.Int16Ty};
1640     auto *FnTy =
1641         llvm::FunctionType::get(CGM.Int32Ty, TypeParams, /*isVarArg*/ false);
1642     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_shuffle_int32");
1643     break;
1644   }
1645   case OMPRTL_NVPTX__kmpc_shuffle_int64: {
1646     // Build int64_t __kmpc_shuffle_int64(int64_t element,
1647     // int16_t lane_offset, int16_t warp_size);
1648     llvm::Type *TypeParams[] = {CGM.Int64Ty, CGM.Int16Ty, CGM.Int16Ty};
1649     auto *FnTy =
1650         llvm::FunctionType::get(CGM.Int64Ty, TypeParams, /*isVarArg*/ false);
1651     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_shuffle_int64");
1652     break;
1653   }
1654   case OMPRTL_NVPTX__kmpc_nvptx_parallel_reduce_nowait_v2: {
1655     // Build int32_t kmpc_nvptx_parallel_reduce_nowait_v2(ident_t *loc,
1656     // kmp_int32 global_tid, kmp_int32 num_vars, size_t reduce_size, void*
1657     // reduce_data, void (*kmp_ShuffleReductFctPtr)(void *rhsData, int16_t
1658     // lane_id, int16_t lane_offset, int16_t Algorithm Version), void
1659     // (*kmp_InterWarpCopyFctPtr)(void* src, int warp_num));
1660     llvm::Type *ShuffleReduceTypeParams[] = {CGM.VoidPtrTy, CGM.Int16Ty,
1661                                              CGM.Int16Ty, CGM.Int16Ty};
1662     auto *ShuffleReduceFnTy =
1663         llvm::FunctionType::get(CGM.VoidTy, ShuffleReduceTypeParams,
1664                                 /*isVarArg=*/false);
1665     llvm::Type *InterWarpCopyTypeParams[] = {CGM.VoidPtrTy, CGM.Int32Ty};
1666     auto *InterWarpCopyFnTy =
1667         llvm::FunctionType::get(CGM.VoidTy, InterWarpCopyTypeParams,
1668                                 /*isVarArg=*/false);
1669     llvm::Type *TypeParams[] = {getIdentTyPointerTy(),
1670                                 CGM.Int32Ty,
1671                                 CGM.Int32Ty,
1672                                 CGM.SizeTy,
1673                                 CGM.VoidPtrTy,
1674                                 ShuffleReduceFnTy->getPointerTo(),
1675                                 InterWarpCopyFnTy->getPointerTo()};
1676     auto *FnTy =
1677         llvm::FunctionType::get(CGM.Int32Ty, TypeParams, /*isVarArg=*/false);
1678     RTLFn = CGM.CreateRuntimeFunction(
1679         FnTy, /*Name=*/"__kmpc_nvptx_parallel_reduce_nowait_v2");
1680     break;
1681   }
1682   case OMPRTL_NVPTX__kmpc_end_reduce_nowait: {
1683     // Build __kmpc_end_reduce_nowait(kmp_int32 global_tid);
1684     llvm::Type *TypeParams[] = {CGM.Int32Ty};
1685     auto *FnTy =
1686         llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg=*/false);
1687     RTLFn = CGM.CreateRuntimeFunction(
1688         FnTy, /*Name=*/"__kmpc_nvptx_end_reduce_nowait");
1689     break;
1690   }
1691   case OMPRTL_NVPTX__kmpc_nvptx_teams_reduce_nowait_v2: {
1692     // Build int32_t __kmpc_nvptx_teams_reduce_nowait_v2(ident_t *loc, kmp_int32
1693     // global_tid, void *global_buffer, int32_t num_of_records, void*
1694     // reduce_data,
1695     // void (*kmp_ShuffleReductFctPtr)(void *rhsData, int16_t lane_id, int16_t
1696     // lane_offset, int16_t shortCircuit),
1697     // void (*kmp_InterWarpCopyFctPtr)(void* src, int32_t warp_num), void
1698     // (*kmp_ListToGlobalCpyFctPtr)(void *buffer, int idx, void *reduce_data),
1699     // void (*kmp_GlobalToListCpyFctPtr)(void *buffer, int idx,
1700     // void *reduce_data), void (*kmp_GlobalToListCpyPtrsFctPtr)(void *buffer,
1701     // int idx, void *reduce_data), void (*kmp_GlobalToListRedFctPtr)(void
1702     // *buffer, int idx, void *reduce_data));
1703     llvm::Type *ShuffleReduceTypeParams[] = {CGM.VoidPtrTy, CGM.Int16Ty,
1704                                              CGM.Int16Ty, CGM.Int16Ty};
1705     auto *ShuffleReduceFnTy =
1706         llvm::FunctionType::get(CGM.VoidTy, ShuffleReduceTypeParams,
1707                                 /*isVarArg=*/false);
1708     llvm::Type *InterWarpCopyTypeParams[] = {CGM.VoidPtrTy, CGM.Int32Ty};
1709     auto *InterWarpCopyFnTy =
1710         llvm::FunctionType::get(CGM.VoidTy, InterWarpCopyTypeParams,
1711                                 /*isVarArg=*/false);
1712     llvm::Type *GlobalListTypeParams[] = {CGM.VoidPtrTy, CGM.IntTy,
1713                                           CGM.VoidPtrTy};
1714     auto *GlobalListFnTy =
1715         llvm::FunctionType::get(CGM.VoidTy, GlobalListTypeParams,
1716                                 /*isVarArg=*/false);
1717     llvm::Type *TypeParams[] = {getIdentTyPointerTy(),
1718                                 CGM.Int32Ty,
1719                                 CGM.VoidPtrTy,
1720                                 CGM.Int32Ty,
1721                                 CGM.VoidPtrTy,
1722                                 ShuffleReduceFnTy->getPointerTo(),
1723                                 InterWarpCopyFnTy->getPointerTo(),
1724                                 GlobalListFnTy->getPointerTo(),
1725                                 GlobalListFnTy->getPointerTo(),
1726                                 GlobalListFnTy->getPointerTo(),
1727                                 GlobalListFnTy->getPointerTo()};
1728     auto *FnTy =
1729         llvm::FunctionType::get(CGM.Int32Ty, TypeParams, /*isVarArg=*/false);
1730     RTLFn = CGM.CreateRuntimeFunction(
1731         FnTy, /*Name=*/"__kmpc_nvptx_teams_reduce_nowait_v2");
1732     break;
1733   }
1734   case OMPRTL_NVPTX__kmpc_data_sharing_init_stack: {
1735     /// Build void __kmpc_data_sharing_init_stack();
1736     auto *FnTy =
1737         llvm::FunctionType::get(CGM.VoidTy, llvm::None, /*isVarArg*/ false);
1738     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_data_sharing_init_stack");
1739     break;
1740   }
1741   case OMPRTL_NVPTX__kmpc_data_sharing_init_stack_spmd: {
1742     /// Build void __kmpc_data_sharing_init_stack_spmd();
1743     auto *FnTy =
1744         llvm::FunctionType::get(CGM.VoidTy, llvm::None, /*isVarArg*/ false);
1745     RTLFn =
1746         CGM.CreateRuntimeFunction(FnTy, "__kmpc_data_sharing_init_stack_spmd");
1747     break;
1748   }
1749   case OMPRTL_NVPTX__kmpc_data_sharing_coalesced_push_stack: {
1750     // Build void *__kmpc_data_sharing_coalesced_push_stack(size_t size,
1751     // int16_t UseSharedMemory);
1752     llvm::Type *TypeParams[] = {CGM.SizeTy, CGM.Int16Ty};
1753     auto *FnTy =
1754         llvm::FunctionType::get(CGM.VoidPtrTy, TypeParams, /*isVarArg=*/false);
1755     RTLFn = CGM.CreateRuntimeFunction(
1756         FnTy, /*Name=*/"__kmpc_data_sharing_coalesced_push_stack");
1757     break;
1758   }
1759   case OMPRTL_NVPTX__kmpc_data_sharing_push_stack: {
1760     // Build void *__kmpc_data_sharing_push_stack(size_t size, int16_t
1761     // UseSharedMemory);
1762     llvm::Type *TypeParams[] = {CGM.SizeTy, CGM.Int16Ty};
1763     auto *FnTy =
1764         llvm::FunctionType::get(CGM.VoidPtrTy, TypeParams, /*isVarArg=*/false);
1765     RTLFn = CGM.CreateRuntimeFunction(
1766         FnTy, /*Name=*/"__kmpc_data_sharing_push_stack");
1767     break;
1768   }
1769   case OMPRTL_NVPTX__kmpc_data_sharing_pop_stack: {
1770     // Build void __kmpc_data_sharing_pop_stack(void *a);
1771     llvm::Type *TypeParams[] = {CGM.VoidPtrTy};
1772     auto *FnTy =
1773         llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg=*/false);
1774     RTLFn = CGM.CreateRuntimeFunction(FnTy,
1775                                       /*Name=*/"__kmpc_data_sharing_pop_stack");
1776     break;
1777   }
1778   case OMPRTL_NVPTX__kmpc_begin_sharing_variables: {
1779     /// Build void __kmpc_begin_sharing_variables(void ***args,
1780     /// size_t n_args);
1781     llvm::Type *TypeParams[] = {CGM.Int8PtrPtrTy->getPointerTo(), CGM.SizeTy};
1782     auto *FnTy =
1783         llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
1784     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_begin_sharing_variables");
1785     break;
1786   }
1787   case OMPRTL_NVPTX__kmpc_end_sharing_variables: {
1788     /// Build void __kmpc_end_sharing_variables();
1789     auto *FnTy =
1790         llvm::FunctionType::get(CGM.VoidTy, llvm::None, /*isVarArg*/ false);
1791     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_end_sharing_variables");
1792     break;
1793   }
1794   case OMPRTL_NVPTX__kmpc_get_shared_variables: {
1795     /// Build void __kmpc_get_shared_variables(void ***GlobalArgs);
1796     llvm::Type *TypeParams[] = {CGM.Int8PtrPtrTy->getPointerTo()};
1797     auto *FnTy =
1798         llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
1799     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_get_shared_variables");
1800     break;
1801   }
1802   case OMPRTL_NVPTX__kmpc_parallel_level: {
1803     // Build uint16_t __kmpc_parallel_level(ident_t *loc, kmp_int32 global_tid);
1804     llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty};
1805     auto *FnTy =
1806         llvm::FunctionType::get(CGM.Int16Ty, TypeParams, /*isVarArg*/ false);
1807     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_parallel_level");
1808     break;
1809   }
1810   case OMPRTL_NVPTX__kmpc_is_spmd_exec_mode: {
1811     // Build int8_t __kmpc_is_spmd_exec_mode();
1812     auto *FnTy = llvm::FunctionType::get(CGM.Int8Ty, /*isVarArg=*/false);
1813     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_is_spmd_exec_mode");
1814     break;
1815   }
1816   case OMPRTL_NVPTX__kmpc_get_team_static_memory: {
1817     // Build void __kmpc_get_team_static_memory(int16_t isSPMDExecutionMode,
1818     // const void *buf, size_t size, int16_t is_shared, const void **res);
1819     llvm::Type *TypeParams[] = {CGM.Int16Ty, CGM.VoidPtrTy, CGM.SizeTy,
1820                                 CGM.Int16Ty, CGM.VoidPtrPtrTy};
1821     auto *FnTy =
1822         llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
1823     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_get_team_static_memory");
1824     break;
1825   }
1826   case OMPRTL_NVPTX__kmpc_restore_team_static_memory: {
1827     // Build void __kmpc_restore_team_static_memory(int16_t isSPMDExecutionMode,
1828     // int16_t is_shared);
1829     llvm::Type *TypeParams[] = {CGM.Int16Ty, CGM.Int16Ty};
1830     auto *FnTy =
1831         llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg=*/false);
1832     RTLFn =
1833         CGM.CreateRuntimeFunction(FnTy, "__kmpc_restore_team_static_memory");
1834     break;
1835   }
1836   case OMPRTL__kmpc_barrier: {
1837     // Build void __kmpc_barrier(ident_t *loc, kmp_int32 global_tid);
1838     llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty};
1839     auto *FnTy =
1840         llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
1841     RTLFn =
1842         CGM.CreateConvergentRuntimeFunction(FnTy, /*Name*/ "__kmpc_barrier");
1843     break;
1844   }
1845   case OMPRTL__kmpc_barrier_simple_spmd: {
1846     // Build void __kmpc_barrier_simple_spmd(ident_t *loc, kmp_int32
1847     // global_tid);
1848     llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty};
1849     auto *FnTy =
1850         llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
1851     RTLFn = CGM.CreateConvergentRuntimeFunction(
1852         FnTy, /*Name*/ "__kmpc_barrier_simple_spmd");
1853     break;
1854   }
1855   case OMPRTL_NVPTX__kmpc_warp_active_thread_mask: {
1856     // Build int32_t __kmpc_warp_active_thread_mask(void);
1857     auto *FnTy =
1858         llvm::FunctionType::get(CGM.Int32Ty, llvm::None, /*isVarArg=*/false);
1859     RTLFn = CGM.CreateConvergentRuntimeFunction(FnTy, "__kmpc_warp_active_thread_mask");
1860     break;
1861   }
1862   case OMPRTL_NVPTX__kmpc_syncwarp: {
1863     // Build void __kmpc_syncwarp(kmp_int32 Mask);
1864     auto *FnTy =
1865         llvm::FunctionType::get(CGM.VoidTy, CGM.Int32Ty, /*isVarArg=*/false);
1866     RTLFn = CGM.CreateConvergentRuntimeFunction(FnTy, "__kmpc_syncwarp");
1867     break;
1868   }
1869   }
1870   return RTLFn;
1871 }
1872
1873 void CGOpenMPRuntimeNVPTX::createOffloadEntry(llvm::Constant *ID,
1874                                               llvm::Constant *Addr,
1875                                               uint64_t Size, int32_t,
1876                                               llvm::GlobalValue::LinkageTypes) {
1877   // TODO: Add support for global variables on the device after declare target
1878   // support.
1879   if (!isa<llvm::Function>(Addr))
1880     return;
1881   llvm::Module &M = CGM.getModule();
1882   llvm::LLVMContext &Ctx = CGM.getLLVMContext();
1883
1884   // Get "nvvm.annotations" metadata node
1885   llvm::NamedMDNode *MD = M.getOrInsertNamedMetadata("nvvm.annotations");
1886
1887   llvm::Metadata *MDVals[] = {
1888       llvm::ConstantAsMetadata::get(Addr), llvm::MDString::get(Ctx, "kernel"),
1889       llvm::ConstantAsMetadata::get(
1890           llvm::ConstantInt::get(llvm::Type::getInt32Ty(Ctx), 1))};
1891   // Append metadata to nvvm.annotations
1892   MD->addOperand(llvm::MDNode::get(Ctx, MDVals));
1893 }
1894
1895 void CGOpenMPRuntimeNVPTX::emitTargetOutlinedFunction(
1896     const OMPExecutableDirective &D, StringRef ParentName,
1897     llvm::Function *&OutlinedFn, llvm::Constant *&OutlinedFnID,
1898     bool IsOffloadEntry, const RegionCodeGenTy &CodeGen) {
1899   if (!IsOffloadEntry) // Nothing to do.
1900     return;
1901
1902   assert(!ParentName.empty() && "Invalid target region parent name!");
1903
1904   bool Mode = supportsSPMDExecutionMode(CGM.getContext(), D);
1905   if (Mode)
1906     emitSPMDKernel(D, ParentName, OutlinedFn, OutlinedFnID, IsOffloadEntry,
1907                    CodeGen);
1908   else
1909     emitNonSPMDKernel(D, ParentName, OutlinedFn, OutlinedFnID, IsOffloadEntry,
1910                       CodeGen);
1911
1912   setPropertyExecutionMode(CGM, OutlinedFn->getName(), Mode);
1913 }
1914
1915 namespace {
1916 LLVM_ENABLE_BITMASK_ENUMS_IN_NAMESPACE();
1917 /// Enum for accesseing the reserved_2 field of the ident_t struct.
1918 enum ModeFlagsTy : unsigned {
1919   /// Bit set to 1 when in SPMD mode.
1920   KMP_IDENT_SPMD_MODE = 0x01,
1921   /// Bit set to 1 when a simplified runtime is used.
1922   KMP_IDENT_SIMPLE_RT_MODE = 0x02,
1923   LLVM_MARK_AS_BITMASK_ENUM(/*LargestValue=*/KMP_IDENT_SIMPLE_RT_MODE)
1924 };
1925
1926 /// Special mode Undefined. Is the combination of Non-SPMD mode + SimpleRuntime.
1927 static const ModeFlagsTy UndefinedMode =
1928     (~KMP_IDENT_SPMD_MODE) & KMP_IDENT_SIMPLE_RT_MODE;
1929 } // anonymous namespace
1930
1931 unsigned CGOpenMPRuntimeNVPTX::getDefaultLocationReserved2Flags() const {
1932   switch (getExecutionMode()) {
1933   case EM_SPMD:
1934     if (requiresFullRuntime())
1935       return KMP_IDENT_SPMD_MODE & (~KMP_IDENT_SIMPLE_RT_MODE);
1936     return KMP_IDENT_SPMD_MODE | KMP_IDENT_SIMPLE_RT_MODE;
1937   case EM_NonSPMD:
1938     assert(requiresFullRuntime() && "Expected full runtime.");
1939     return (~KMP_IDENT_SPMD_MODE) & (~KMP_IDENT_SIMPLE_RT_MODE);
1940   case EM_Unknown:
1941     return UndefinedMode;
1942   }
1943   llvm_unreachable("Unknown flags are requested.");
1944 }
1945
1946 CGOpenMPRuntimeNVPTX::CGOpenMPRuntimeNVPTX(CodeGenModule &CGM)
1947     : CGOpenMPRuntime(CGM, "_", "$") {
1948   if (!CGM.getLangOpts().OpenMPIsDevice)
1949     llvm_unreachable("OpenMP NVPTX can only handle device code.");
1950 }
1951
1952 void CGOpenMPRuntimeNVPTX::emitProcBindClause(CodeGenFunction &CGF,
1953                                               ProcBindKind ProcBind,
1954                                               SourceLocation Loc) {
1955   // Do nothing in case of SPMD mode and L0 parallel.
1956   if (getExecutionMode() == CGOpenMPRuntimeNVPTX::EM_SPMD)
1957     return;
1958
1959   CGOpenMPRuntime::emitProcBindClause(CGF, ProcBind, Loc);
1960 }
1961
1962 void CGOpenMPRuntimeNVPTX::emitNumThreadsClause(CodeGenFunction &CGF,
1963                                                 llvm::Value *NumThreads,
1964                                                 SourceLocation Loc) {
1965   // Do nothing in case of SPMD mode and L0 parallel.
1966   if (getExecutionMode() == CGOpenMPRuntimeNVPTX::EM_SPMD)
1967     return;
1968
1969   CGOpenMPRuntime::emitNumThreadsClause(CGF, NumThreads, Loc);
1970 }
1971
1972 void CGOpenMPRuntimeNVPTX::emitNumTeamsClause(CodeGenFunction &CGF,
1973                                               const Expr *NumTeams,
1974                                               const Expr *ThreadLimit,
1975                                               SourceLocation Loc) {}
1976
1977 llvm::Function *CGOpenMPRuntimeNVPTX::emitParallelOutlinedFunction(
1978     const OMPExecutableDirective &D, const VarDecl *ThreadIDVar,
1979     OpenMPDirectiveKind InnermostKind, const RegionCodeGenTy &CodeGen) {
1980   // Emit target region as a standalone region.
1981   class NVPTXPrePostActionTy : public PrePostActionTy {
1982     bool &IsInParallelRegion;
1983     bool PrevIsInParallelRegion;
1984
1985   public:
1986     NVPTXPrePostActionTy(bool &IsInParallelRegion)
1987         : IsInParallelRegion(IsInParallelRegion) {}
1988     void Enter(CodeGenFunction &CGF) override {
1989       PrevIsInParallelRegion = IsInParallelRegion;
1990       IsInParallelRegion = true;
1991     }
1992     void Exit(CodeGenFunction &CGF) override {
1993       IsInParallelRegion = PrevIsInParallelRegion;
1994     }
1995   } Action(IsInParallelRegion);
1996   CodeGen.setAction(Action);
1997   bool PrevIsInTTDRegion = IsInTTDRegion;
1998   IsInTTDRegion = false;
1999   bool PrevIsInTargetMasterThreadRegion = IsInTargetMasterThreadRegion;
2000   IsInTargetMasterThreadRegion = false;
2001   auto *OutlinedFun =
2002       cast<llvm::Function>(CGOpenMPRuntime::emitParallelOutlinedFunction(
2003           D, ThreadIDVar, InnermostKind, CodeGen));
2004   if (CGM.getLangOpts().Optimize) {
2005     OutlinedFun->removeFnAttr(llvm::Attribute::NoInline);
2006     OutlinedFun->removeFnAttr(llvm::Attribute::OptimizeNone);
2007     OutlinedFun->addFnAttr(llvm::Attribute::AlwaysInline);
2008   }
2009   IsInTargetMasterThreadRegion = PrevIsInTargetMasterThreadRegion;
2010   IsInTTDRegion = PrevIsInTTDRegion;
2011   if (getExecutionMode() != CGOpenMPRuntimeNVPTX::EM_SPMD &&
2012       !IsInParallelRegion) {
2013     llvm::Function *WrapperFun =
2014         createParallelDataSharingWrapper(OutlinedFun, D);
2015     WrapperFunctionsMap[OutlinedFun] = WrapperFun;
2016   }
2017
2018   return OutlinedFun;
2019 }
2020
2021 /// Get list of lastprivate variables from the teams distribute ... or
2022 /// teams {distribute ...} directives.
2023 static void
2024 getDistributeLastprivateVars(ASTContext &Ctx, const OMPExecutableDirective &D,
2025                              llvm::SmallVectorImpl<const ValueDecl *> &Vars) {
2026   assert(isOpenMPTeamsDirective(D.getDirectiveKind()) &&
2027          "expected teams directive.");
2028   const OMPExecutableDirective *Dir = &D;
2029   if (!isOpenMPDistributeDirective(D.getDirectiveKind())) {
2030     if (const Stmt *S = CGOpenMPRuntime::getSingleCompoundChild(
2031             Ctx,
2032             D.getInnermostCapturedStmt()->getCapturedStmt()->IgnoreContainers(
2033                 /*IgnoreCaptured=*/true))) {
2034       Dir = dyn_cast_or_null<OMPExecutableDirective>(S);
2035       if (Dir && !isOpenMPDistributeDirective(Dir->getDirectiveKind()))
2036         Dir = nullptr;
2037     }
2038   }
2039   if (!Dir)
2040     return;
2041   for (const auto *C : Dir->getClausesOfKind<OMPLastprivateClause>()) {
2042     for (const Expr *E : C->getVarRefs())
2043       Vars.push_back(getPrivateItem(E));
2044   }
2045 }
2046
2047 /// Get list of reduction variables from the teams ... directives.
2048 static void
2049 getTeamsReductionVars(ASTContext &Ctx, const OMPExecutableDirective &D,
2050                       llvm::SmallVectorImpl<const ValueDecl *> &Vars) {
2051   assert(isOpenMPTeamsDirective(D.getDirectiveKind()) &&
2052          "expected teams directive.");
2053   for (const auto *C : D.getClausesOfKind<OMPReductionClause>()) {
2054     for (const Expr *E : C->privates())
2055       Vars.push_back(getPrivateItem(E));
2056   }
2057 }
2058
2059 llvm::Function *CGOpenMPRuntimeNVPTX::emitTeamsOutlinedFunction(
2060     const OMPExecutableDirective &D, const VarDecl *ThreadIDVar,
2061     OpenMPDirectiveKind InnermostKind, const RegionCodeGenTy &CodeGen) {
2062   SourceLocation Loc = D.getBeginLoc();
2063
2064   const RecordDecl *GlobalizedRD = nullptr;
2065   llvm::SmallVector<const ValueDecl *, 4> LastPrivatesReductions;
2066   llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *> MappedDeclsFields;
2067   // Globalize team reductions variable unconditionally in all modes.
2068   if (getExecutionMode() != CGOpenMPRuntimeNVPTX::EM_SPMD)
2069     getTeamsReductionVars(CGM.getContext(), D, LastPrivatesReductions);
2070   if (getExecutionMode() == CGOpenMPRuntimeNVPTX::EM_SPMD) {
2071     getDistributeLastprivateVars(CGM.getContext(), D, LastPrivatesReductions);
2072     if (!LastPrivatesReductions.empty()) {
2073       GlobalizedRD = ::buildRecordForGlobalizedVars(
2074           CGM.getContext(), llvm::None, LastPrivatesReductions,
2075           MappedDeclsFields, WarpSize);
2076     }
2077   } else if (!LastPrivatesReductions.empty()) {
2078     assert(!TeamAndReductions.first &&
2079            "Previous team declaration is not expected.");
2080     TeamAndReductions.first = D.getCapturedStmt(OMPD_teams)->getCapturedDecl();
2081     std::swap(TeamAndReductions.second, LastPrivatesReductions);
2082   }
2083
2084   // Emit target region as a standalone region.
2085   class NVPTXPrePostActionTy : public PrePostActionTy {
2086     SourceLocation &Loc;
2087     const RecordDecl *GlobalizedRD;
2088     llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *>
2089         &MappedDeclsFields;
2090
2091   public:
2092     NVPTXPrePostActionTy(
2093         SourceLocation &Loc, const RecordDecl *GlobalizedRD,
2094         llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *>
2095             &MappedDeclsFields)
2096         : Loc(Loc), GlobalizedRD(GlobalizedRD),
2097           MappedDeclsFields(MappedDeclsFields) {}
2098     void Enter(CodeGenFunction &CGF) override {
2099       auto &Rt =
2100           static_cast<CGOpenMPRuntimeNVPTX &>(CGF.CGM.getOpenMPRuntime());
2101       if (GlobalizedRD) {
2102         auto I = Rt.FunctionGlobalizedDecls.try_emplace(CGF.CurFn).first;
2103         I->getSecond().GlobalRecord = GlobalizedRD;
2104         I->getSecond().MappedParams =
2105             std::make_unique<CodeGenFunction::OMPMapVars>();
2106         DeclToAddrMapTy &Data = I->getSecond().LocalVarData;
2107         for (const auto &Pair : MappedDeclsFields) {
2108           assert(Pair.getFirst()->isCanonicalDecl() &&
2109                  "Expected canonical declaration");
2110           Data.insert(std::make_pair(Pair.getFirst(),
2111                                      MappedVarData(Pair.getSecond(),
2112                                                    /*IsOnePerTeam=*/true)));
2113         }
2114       }
2115       Rt.emitGenericVarsProlog(CGF, Loc);
2116     }
2117     void Exit(CodeGenFunction &CGF) override {
2118       static_cast<CGOpenMPRuntimeNVPTX &>(CGF.CGM.getOpenMPRuntime())
2119           .emitGenericVarsEpilog(CGF);
2120     }
2121   } Action(Loc, GlobalizedRD, MappedDeclsFields);
2122   CodeGen.setAction(Action);
2123   llvm::Function *OutlinedFun = CGOpenMPRuntime::emitTeamsOutlinedFunction(
2124       D, ThreadIDVar, InnermostKind, CodeGen);
2125   if (CGM.getLangOpts().Optimize) {
2126     OutlinedFun->removeFnAttr(llvm::Attribute::NoInline);
2127     OutlinedFun->removeFnAttr(llvm::Attribute::OptimizeNone);
2128     OutlinedFun->addFnAttr(llvm::Attribute::AlwaysInline);
2129   }
2130
2131   return OutlinedFun;
2132 }
2133
2134 void CGOpenMPRuntimeNVPTX::emitGenericVarsProlog(CodeGenFunction &CGF,
2135                                                  SourceLocation Loc,
2136                                                  bool WithSPMDCheck) {
2137   if (getDataSharingMode(CGM) != CGOpenMPRuntimeNVPTX::Generic &&
2138       getExecutionMode() != CGOpenMPRuntimeNVPTX::EM_SPMD)
2139     return;
2140
2141   CGBuilderTy &Bld = CGF.Builder;
2142
2143   const auto I = FunctionGlobalizedDecls.find(CGF.CurFn);
2144   if (I == FunctionGlobalizedDecls.end())
2145     return;
2146   if (const RecordDecl *GlobalizedVarsRecord = I->getSecond().GlobalRecord) {
2147     QualType GlobalRecTy = CGM.getContext().getRecordType(GlobalizedVarsRecord);
2148     QualType SecGlobalRecTy;
2149
2150     // Recover pointer to this function's global record. The runtime will
2151     // handle the specifics of the allocation of the memory.
2152     // Use actual memory size of the record including the padding
2153     // for alignment purposes.
2154     unsigned Alignment =
2155         CGM.getContext().getTypeAlignInChars(GlobalRecTy).getQuantity();
2156     unsigned GlobalRecordSize =
2157         CGM.getContext().getTypeSizeInChars(GlobalRecTy).getQuantity();
2158     GlobalRecordSize = llvm::alignTo(GlobalRecordSize, Alignment);
2159
2160     llvm::PointerType *GlobalRecPtrTy =
2161         CGF.ConvertTypeForMem(GlobalRecTy)->getPointerTo();
2162     llvm::Value *GlobalRecCastAddr;
2163     llvm::Value *IsTTD = nullptr;
2164     if (!IsInTTDRegion &&
2165         (WithSPMDCheck ||
2166          getExecutionMode() == CGOpenMPRuntimeNVPTX::EM_Unknown)) {
2167       llvm::BasicBlock *ExitBB = CGF.createBasicBlock(".exit");
2168       llvm::BasicBlock *SPMDBB = CGF.createBasicBlock(".spmd");
2169       llvm::BasicBlock *NonSPMDBB = CGF.createBasicBlock(".non-spmd");
2170       if (I->getSecond().SecondaryGlobalRecord.hasValue()) {
2171         llvm::Value *RTLoc = emitUpdateLocation(CGF, Loc);
2172         llvm::Value *ThreadID = getThreadID(CGF, Loc);
2173         llvm::Value *PL = CGF.EmitRuntimeCall(
2174             createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_parallel_level),
2175             {RTLoc, ThreadID});
2176         IsTTD = Bld.CreateIsNull(PL);
2177       }
2178       llvm::Value *IsSPMD = Bld.CreateIsNotNull(CGF.EmitNounwindRuntimeCall(
2179           createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_is_spmd_exec_mode)));
2180       Bld.CreateCondBr(IsSPMD, SPMDBB, NonSPMDBB);
2181       // There is no need to emit line number for unconditional branch.
2182       (void)ApplyDebugLocation::CreateEmpty(CGF);
2183       CGF.EmitBlock(SPMDBB);
2184       Address RecPtr = Address(llvm::ConstantPointerNull::get(GlobalRecPtrTy),
2185                                CharUnits::fromQuantity(Alignment));
2186       CGF.EmitBranch(ExitBB);
2187       // There is no need to emit line number for unconditional branch.
2188       (void)ApplyDebugLocation::CreateEmpty(CGF);
2189       CGF.EmitBlock(NonSPMDBB);
2190       llvm::Value *Size = llvm::ConstantInt::get(CGM.SizeTy, GlobalRecordSize);
2191       if (const RecordDecl *SecGlobalizedVarsRecord =
2192               I->getSecond().SecondaryGlobalRecord.getValueOr(nullptr)) {
2193         SecGlobalRecTy =
2194             CGM.getContext().getRecordType(SecGlobalizedVarsRecord);
2195
2196         // Recover pointer to this function's global record. The runtime will
2197         // handle the specifics of the allocation of the memory.
2198         // Use actual memory size of the record including the padding
2199         // for alignment purposes.
2200         unsigned Alignment =
2201             CGM.getContext().getTypeAlignInChars(SecGlobalRecTy).getQuantity();
2202         unsigned GlobalRecordSize =
2203             CGM.getContext().getTypeSizeInChars(SecGlobalRecTy).getQuantity();
2204         GlobalRecordSize = llvm::alignTo(GlobalRecordSize, Alignment);
2205         Size = Bld.CreateSelect(
2206             IsTTD, llvm::ConstantInt::get(CGM.SizeTy, GlobalRecordSize), Size);
2207       }
2208       // TODO: allow the usage of shared memory to be controlled by
2209       // the user, for now, default to global.
2210       llvm::Value *GlobalRecordSizeArg[] = {
2211           Size, CGF.Builder.getInt16(/*UseSharedMemory=*/0)};
2212       llvm::Value *GlobalRecValue = CGF.EmitRuntimeCall(
2213           createNVPTXRuntimeFunction(
2214               OMPRTL_NVPTX__kmpc_data_sharing_coalesced_push_stack),
2215           GlobalRecordSizeArg);
2216       GlobalRecCastAddr = Bld.CreatePointerBitCastOrAddrSpaceCast(
2217           GlobalRecValue, GlobalRecPtrTy);
2218       CGF.EmitBlock(ExitBB);
2219       auto *Phi = Bld.CreatePHI(GlobalRecPtrTy,
2220                                 /*NumReservedValues=*/2, "_select_stack");
2221       Phi->addIncoming(RecPtr.getPointer(), SPMDBB);
2222       Phi->addIncoming(GlobalRecCastAddr, NonSPMDBB);
2223       GlobalRecCastAddr = Phi;
2224       I->getSecond().GlobalRecordAddr = Phi;
2225       I->getSecond().IsInSPMDModeFlag = IsSPMD;
2226     } else if (!CGM.getLangOpts().OpenMPCUDATargetParallel && IsInTTDRegion) {
2227       assert(GlobalizedRecords.back().Records.size() < 2 &&
2228              "Expected less than 2 globalized records: one for target and one "
2229              "for teams.");
2230       unsigned Offset = 0;
2231       for (const RecordDecl *RD : GlobalizedRecords.back().Records) {
2232         QualType RDTy = CGM.getContext().getRecordType(RD);
2233         unsigned Alignment =
2234             CGM.getContext().getTypeAlignInChars(RDTy).getQuantity();
2235         unsigned Size = CGM.getContext().getTypeSizeInChars(RDTy).getQuantity();
2236         Offset =
2237             llvm::alignTo(llvm::alignTo(Offset, Alignment) + Size, Alignment);
2238       }
2239       unsigned Alignment =
2240           CGM.getContext().getTypeAlignInChars(GlobalRecTy).getQuantity();
2241       Offset = llvm::alignTo(Offset, Alignment);
2242       GlobalizedRecords.back().Records.push_back(GlobalizedVarsRecord);
2243       ++GlobalizedRecords.back().RegionCounter;
2244       if (GlobalizedRecords.back().Records.size() == 1) {
2245         assert(KernelStaticGlobalized &&
2246                "Kernel static pointer must be initialized already.");
2247         auto *UseSharedMemory = new llvm::GlobalVariable(
2248             CGM.getModule(), CGM.Int16Ty, /*isConstant=*/true,
2249             llvm::GlobalValue::InternalLinkage, nullptr,
2250             "_openmp_static_kernel$is_shared");
2251         UseSharedMemory->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2252         QualType Int16Ty = CGM.getContext().getIntTypeForBitwidth(
2253             /*DestWidth=*/16, /*Signed=*/0);
2254         llvm::Value *IsInSharedMemory = CGF.EmitLoadOfScalar(
2255             Address(UseSharedMemory,
2256                     CGM.getContext().getTypeAlignInChars(Int16Ty)),
2257             /*Volatile=*/false, Int16Ty, Loc);
2258         auto *StaticGlobalized = new llvm::GlobalVariable(
2259             CGM.getModule(), CGM.Int8Ty, /*isConstant=*/false,
2260             llvm::GlobalValue::CommonLinkage, nullptr);
2261         auto *RecSize = new llvm::GlobalVariable(
2262             CGM.getModule(), CGM.SizeTy, /*isConstant=*/true,
2263             llvm::GlobalValue::InternalLinkage, nullptr,
2264             "_openmp_static_kernel$size");
2265         RecSize->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2266         llvm::Value *Ld = CGF.EmitLoadOfScalar(
2267             Address(RecSize, CGM.getSizeAlign()), /*Volatile=*/false,
2268             CGM.getContext().getSizeType(), Loc);
2269         llvm::Value *ResAddr = Bld.CreatePointerBitCastOrAddrSpaceCast(
2270             KernelStaticGlobalized, CGM.VoidPtrPtrTy);
2271         llvm::Value *GlobalRecordSizeArg[] = {
2272             llvm::ConstantInt::get(
2273                 CGM.Int16Ty,
2274                 getExecutionMode() == CGOpenMPRuntimeNVPTX::EM_SPMD ? 1 : 0),
2275             StaticGlobalized, Ld, IsInSharedMemory, ResAddr};
2276         CGF.EmitRuntimeCall(createNVPTXRuntimeFunction(
2277                                 OMPRTL_NVPTX__kmpc_get_team_static_memory),
2278                             GlobalRecordSizeArg);
2279         GlobalizedRecords.back().Buffer = StaticGlobalized;
2280         GlobalizedRecords.back().RecSize = RecSize;
2281         GlobalizedRecords.back().UseSharedMemory = UseSharedMemory;
2282         GlobalizedRecords.back().Loc = Loc;
2283       }
2284       assert(KernelStaticGlobalized && "Global address must be set already.");
2285       Address FrameAddr = CGF.EmitLoadOfPointer(
2286           Address(KernelStaticGlobalized, CGM.getPointerAlign()),
2287           CGM.getContext()
2288               .getPointerType(CGM.getContext().VoidPtrTy)
2289               .castAs<PointerType>());
2290       llvm::Value *GlobalRecValue =
2291           Bld.CreateConstInBoundsGEP(FrameAddr, Offset).getPointer();
2292       I->getSecond().GlobalRecordAddr = GlobalRecValue;
2293       I->getSecond().IsInSPMDModeFlag = nullptr;
2294       GlobalRecCastAddr = Bld.CreatePointerBitCastOrAddrSpaceCast(
2295           GlobalRecValue, CGF.ConvertTypeForMem(GlobalRecTy)->getPointerTo());
2296     } else {
2297       // TODO: allow the usage of shared memory to be controlled by
2298       // the user, for now, default to global.
2299       bool UseSharedMemory =
2300           IsInTTDRegion && GlobalRecordSize <= SharedMemorySize;
2301       llvm::Value *GlobalRecordSizeArg[] = {
2302           llvm::ConstantInt::get(CGM.SizeTy, GlobalRecordSize),
2303           CGF.Builder.getInt16(UseSharedMemory ? 1 : 0)};
2304       llvm::Value *GlobalRecValue = CGF.EmitRuntimeCall(
2305           createNVPTXRuntimeFunction(
2306               IsInTTDRegion
2307                   ? OMPRTL_NVPTX__kmpc_data_sharing_push_stack
2308                   : OMPRTL_NVPTX__kmpc_data_sharing_coalesced_push_stack),
2309           GlobalRecordSizeArg);
2310       GlobalRecCastAddr = Bld.CreatePointerBitCastOrAddrSpaceCast(
2311           GlobalRecValue, GlobalRecPtrTy);
2312       I->getSecond().GlobalRecordAddr = GlobalRecValue;
2313       I->getSecond().IsInSPMDModeFlag = nullptr;
2314     }
2315     LValue Base =
2316         CGF.MakeNaturalAlignPointeeAddrLValue(GlobalRecCastAddr, GlobalRecTy);
2317
2318     // Emit the "global alloca" which is a GEP from the global declaration
2319     // record using the pointer returned by the runtime.
2320     LValue SecBase;
2321     decltype(I->getSecond().LocalVarData)::const_iterator SecIt;
2322     if (IsTTD) {
2323       SecIt = I->getSecond().SecondaryLocalVarData->begin();
2324       llvm::PointerType *SecGlobalRecPtrTy =
2325           CGF.ConvertTypeForMem(SecGlobalRecTy)->getPointerTo();
2326       SecBase = CGF.MakeNaturalAlignPointeeAddrLValue(
2327           Bld.CreatePointerBitCastOrAddrSpaceCast(
2328               I->getSecond().GlobalRecordAddr, SecGlobalRecPtrTy),
2329           SecGlobalRecTy);
2330     }
2331     for (auto &Rec : I->getSecond().LocalVarData) {
2332       bool EscapedParam = I->getSecond().EscapedParameters.count(Rec.first);
2333       llvm::Value *ParValue;
2334       if (EscapedParam) {
2335         const auto *VD = cast<VarDecl>(Rec.first);
2336         LValue ParLVal =
2337             CGF.MakeAddrLValue(CGF.GetAddrOfLocalVar(VD), VD->getType());
2338         ParValue = CGF.EmitLoadOfScalar(ParLVal, Loc);
2339       }
2340       LValue VarAddr = CGF.EmitLValueForField(Base, Rec.second.FD);
2341       // Emit VarAddr basing on lane-id if required.
2342       QualType VarTy;
2343       if (Rec.second.IsOnePerTeam) {
2344         VarTy = Rec.second.FD->getType();
2345       } else {
2346         llvm::Value *Ptr = CGF.Builder.CreateInBoundsGEP(
2347             VarAddr.getAddress(CGF).getPointer(),
2348             {Bld.getInt32(0), getNVPTXLaneID(CGF)});
2349         VarTy =
2350             Rec.second.FD->getType()->castAsArrayTypeUnsafe()->getElementType();
2351         VarAddr = CGF.MakeAddrLValue(
2352             Address(Ptr, CGM.getContext().getDeclAlign(Rec.first)), VarTy,
2353             AlignmentSource::Decl);
2354       }
2355       Rec.second.PrivateAddr = VarAddr.getAddress(CGF);
2356       if (!IsInTTDRegion &&
2357           (WithSPMDCheck ||
2358            getExecutionMode() == CGOpenMPRuntimeNVPTX::EM_Unknown)) {
2359         assert(I->getSecond().IsInSPMDModeFlag &&
2360                "Expected unknown execution mode or required SPMD check.");
2361         if (IsTTD) {
2362           assert(SecIt->second.IsOnePerTeam &&
2363                  "Secondary glob data must be one per team.");
2364           LValue SecVarAddr = CGF.EmitLValueForField(SecBase, SecIt->second.FD);
2365           VarAddr.setAddress(
2366               Address(Bld.CreateSelect(IsTTD, SecVarAddr.getPointer(CGF),
2367                                        VarAddr.getPointer(CGF)),
2368                       VarAddr.getAlignment()));
2369           Rec.second.PrivateAddr = VarAddr.getAddress(CGF);
2370         }
2371         Address GlobalPtr = Rec.second.PrivateAddr;
2372         Address LocalAddr = CGF.CreateMemTemp(VarTy, Rec.second.FD->getName());
2373         Rec.second.PrivateAddr = Address(
2374             Bld.CreateSelect(I->getSecond().IsInSPMDModeFlag,
2375                              LocalAddr.getPointer(), GlobalPtr.getPointer()),
2376             LocalAddr.getAlignment());
2377       }
2378       if (EscapedParam) {
2379         const auto *VD = cast<VarDecl>(Rec.first);
2380         CGF.EmitStoreOfScalar(ParValue, VarAddr);
2381         I->getSecond().MappedParams->setVarAddr(CGF, VD,
2382                                                 VarAddr.getAddress(CGF));
2383       }
2384       if (IsTTD)
2385         ++SecIt;
2386     }
2387   }
2388   for (const ValueDecl *VD : I->getSecond().EscapedVariableLengthDecls) {
2389     // Recover pointer to this function's global record. The runtime will
2390     // handle the specifics of the allocation of the memory.
2391     // Use actual memory size of the record including the padding
2392     // for alignment purposes.
2393     CGBuilderTy &Bld = CGF.Builder;
2394     llvm::Value *Size = CGF.getTypeSize(VD->getType());
2395     CharUnits Align = CGM.getContext().getDeclAlign(VD);
2396     Size = Bld.CreateNUWAdd(
2397         Size, llvm::ConstantInt::get(CGF.SizeTy, Align.getQuantity() - 1));
2398     llvm::Value *AlignVal =
2399         llvm::ConstantInt::get(CGF.SizeTy, Align.getQuantity());
2400     Size = Bld.CreateUDiv(Size, AlignVal);
2401     Size = Bld.CreateNUWMul(Size, AlignVal);
2402     // TODO: allow the usage of shared memory to be controlled by
2403     // the user, for now, default to global.
2404     llvm::Value *GlobalRecordSizeArg[] = {
2405         Size, CGF.Builder.getInt16(/*UseSharedMemory=*/0)};
2406     llvm::Value *GlobalRecValue = CGF.EmitRuntimeCall(
2407         createNVPTXRuntimeFunction(
2408             OMPRTL_NVPTX__kmpc_data_sharing_coalesced_push_stack),
2409         GlobalRecordSizeArg);
2410     llvm::Value *GlobalRecCastAddr = Bld.CreatePointerBitCastOrAddrSpaceCast(
2411         GlobalRecValue, CGF.ConvertTypeForMem(VD->getType())->getPointerTo());
2412     LValue Base = CGF.MakeAddrLValue(GlobalRecCastAddr, VD->getType(),
2413                                      CGM.getContext().getDeclAlign(VD),
2414                                      AlignmentSource::Decl);
2415     I->getSecond().MappedParams->setVarAddr(CGF, cast<VarDecl>(VD),
2416                                             Base.getAddress(CGF));
2417     I->getSecond().EscapedVariableLengthDeclsAddrs.emplace_back(GlobalRecValue);
2418   }
2419   I->getSecond().MappedParams->apply(CGF);
2420 }
2421
2422 void CGOpenMPRuntimeNVPTX::emitGenericVarsEpilog(CodeGenFunction &CGF,
2423                                                  bool WithSPMDCheck) {
2424   if (getDataSharingMode(CGM) != CGOpenMPRuntimeNVPTX::Generic &&
2425       getExecutionMode() != CGOpenMPRuntimeNVPTX::EM_SPMD)
2426     return;
2427
2428   const auto I = FunctionGlobalizedDecls.find(CGF.CurFn);
2429   if (I != FunctionGlobalizedDecls.end()) {
2430     I->getSecond().MappedParams->restore(CGF);
2431     if (!CGF.HaveInsertPoint())
2432       return;
2433     for (llvm::Value *Addr :
2434          llvm::reverse(I->getSecond().EscapedVariableLengthDeclsAddrs)) {
2435       CGF.EmitRuntimeCall(
2436           createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_data_sharing_pop_stack),
2437           Addr);
2438     }
2439     if (I->getSecond().GlobalRecordAddr) {
2440       if (!IsInTTDRegion &&
2441           (WithSPMDCheck ||
2442            getExecutionMode() == CGOpenMPRuntimeNVPTX::EM_Unknown)) {
2443         CGBuilderTy &Bld = CGF.Builder;
2444         llvm::BasicBlock *ExitBB = CGF.createBasicBlock(".exit");
2445         llvm::BasicBlock *NonSPMDBB = CGF.createBasicBlock(".non-spmd");
2446         Bld.CreateCondBr(I->getSecond().IsInSPMDModeFlag, ExitBB, NonSPMDBB);
2447         // There is no need to emit line number for unconditional branch.
2448         (void)ApplyDebugLocation::CreateEmpty(CGF);
2449         CGF.EmitBlock(NonSPMDBB);
2450         CGF.EmitRuntimeCall(
2451             createNVPTXRuntimeFunction(
2452                 OMPRTL_NVPTX__kmpc_data_sharing_pop_stack),
2453             CGF.EmitCastToVoidPtr(I->getSecond().GlobalRecordAddr));
2454         CGF.EmitBlock(ExitBB);
2455       } else if (!CGM.getLangOpts().OpenMPCUDATargetParallel && IsInTTDRegion) {
2456         assert(GlobalizedRecords.back().RegionCounter > 0 &&
2457                "region counter must be > 0.");
2458         --GlobalizedRecords.back().RegionCounter;
2459         // Emit the restore function only in the target region.
2460         if (GlobalizedRecords.back().RegionCounter == 0) {
2461           QualType Int16Ty = CGM.getContext().getIntTypeForBitwidth(
2462               /*DestWidth=*/16, /*Signed=*/0);
2463           llvm::Value *IsInSharedMemory = CGF.EmitLoadOfScalar(
2464               Address(GlobalizedRecords.back().UseSharedMemory,
2465                       CGM.getContext().getTypeAlignInChars(Int16Ty)),
2466               /*Volatile=*/false, Int16Ty, GlobalizedRecords.back().Loc);
2467           llvm::Value *Args[] = {
2468               llvm::ConstantInt::get(
2469                   CGM.Int16Ty,
2470                   getExecutionMode() == CGOpenMPRuntimeNVPTX::EM_SPMD ? 1 : 0),
2471               IsInSharedMemory};
2472           CGF.EmitRuntimeCall(
2473               createNVPTXRuntimeFunction(
2474                   OMPRTL_NVPTX__kmpc_restore_team_static_memory),
2475               Args);
2476         }
2477       } else {
2478         CGF.EmitRuntimeCall(createNVPTXRuntimeFunction(
2479                                 OMPRTL_NVPTX__kmpc_data_sharing_pop_stack),
2480                             I->getSecond().GlobalRecordAddr);
2481       }
2482     }
2483   }
2484 }
2485
2486 void CGOpenMPRuntimeNVPTX::emitTeamsCall(CodeGenFunction &CGF,
2487                                          const OMPExecutableDirective &D,
2488                                          SourceLocation Loc,
2489                                          llvm::Function *OutlinedFn,
2490                                          ArrayRef<llvm::Value *> CapturedVars) {
2491   if (!CGF.HaveInsertPoint())
2492     return;
2493
2494   Address ZeroAddr = CGF.CreateDefaultAlignTempAlloca(CGF.Int32Ty,
2495                                                       /*Name=*/".zero.addr");
2496   CGF.InitTempAlloca(ZeroAddr, CGF.Builder.getInt32(/*C*/ 0));
2497   llvm::SmallVector<llvm::Value *, 16> OutlinedFnArgs;
2498   OutlinedFnArgs.push_back(emitThreadIDAddress(CGF, Loc).getPointer());
2499   OutlinedFnArgs.push_back(ZeroAddr.getPointer());
2500   OutlinedFnArgs.append(CapturedVars.begin(), CapturedVars.end());
2501   emitOutlinedFunctionCall(CGF, Loc, OutlinedFn, OutlinedFnArgs);
2502 }
2503
2504 void CGOpenMPRuntimeNVPTX::emitParallelCall(
2505     CodeGenFunction &CGF, SourceLocation Loc, llvm::Function *OutlinedFn,
2506     ArrayRef<llvm::Value *> CapturedVars, const Expr *IfCond) {
2507   if (!CGF.HaveInsertPoint())
2508     return;
2509
2510   if (getExecutionMode() == CGOpenMPRuntimeNVPTX::EM_SPMD)
2511     emitSPMDParallelCall(CGF, Loc, OutlinedFn, CapturedVars, IfCond);
2512   else
2513     emitNonSPMDParallelCall(CGF, Loc, OutlinedFn, CapturedVars, IfCond);
2514 }
2515
2516 void CGOpenMPRuntimeNVPTX::emitNonSPMDParallelCall(
2517     CodeGenFunction &CGF, SourceLocation Loc, llvm::Value *OutlinedFn,
2518     ArrayRef<llvm::Value *> CapturedVars, const Expr *IfCond) {
2519   llvm::Function *Fn = cast<llvm::Function>(OutlinedFn);
2520
2521   // Force inline this outlined function at its call site.
2522   Fn->setLinkage(llvm::GlobalValue::InternalLinkage);
2523
2524   Address ZeroAddr = CGF.CreateDefaultAlignTempAlloca(CGF.Int32Ty,
2525                                                       /*Name=*/".zero.addr");
2526   CGF.InitTempAlloca(ZeroAddr, CGF.Builder.getInt32(/*C*/ 0));
2527   // ThreadId for serialized parallels is 0.
2528   Address ThreadIDAddr = ZeroAddr;
2529   auto &&CodeGen = [this, Fn, CapturedVars, Loc, &ThreadIDAddr](
2530                        CodeGenFunction &CGF, PrePostActionTy &Action) {
2531     Action.Enter(CGF);
2532
2533     Address ZeroAddr =
2534         CGF.CreateDefaultAlignTempAlloca(CGF.Int32Ty,
2535                                          /*Name=*/".bound.zero.addr");
2536     CGF.InitTempAlloca(ZeroAddr, CGF.Builder.getInt32(/*C*/ 0));
2537     llvm::SmallVector<llvm::Value *, 16> OutlinedFnArgs;
2538     OutlinedFnArgs.push_back(ThreadIDAddr.getPointer());
2539     OutlinedFnArgs.push_back(ZeroAddr.getPointer());
2540     OutlinedFnArgs.append(CapturedVars.begin(), CapturedVars.end());
2541     emitOutlinedFunctionCall(CGF, Loc, Fn, OutlinedFnArgs);
2542   };
2543   auto &&SeqGen = [this, &CodeGen, Loc](CodeGenFunction &CGF,
2544                                         PrePostActionTy &) {
2545
2546     RegionCodeGenTy RCG(CodeGen);
2547     llvm::Value *RTLoc = emitUpdateLocation(CGF, Loc);
2548     llvm::Value *ThreadID = getThreadID(CGF, Loc);
2549     llvm::Value *Args[] = {RTLoc, ThreadID};
2550
2551     NVPTXActionTy Action(
2552         createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_serialized_parallel),
2553         Args,
2554         createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_end_serialized_parallel),
2555         Args);
2556     RCG.setAction(Action);
2557     RCG(CGF);
2558   };
2559
2560   auto &&L0ParallelGen = [this, CapturedVars, Fn](CodeGenFunction &CGF,
2561                                                   PrePostActionTy &Action) {
2562     CGBuilderTy &Bld = CGF.Builder;
2563     llvm::Function *WFn = WrapperFunctionsMap[Fn];
2564     assert(WFn && "Wrapper function does not exist!");
2565     llvm::Value *ID = Bld.CreateBitOrPointerCast(WFn, CGM.Int8PtrTy);
2566
2567     // Prepare for parallel region. Indicate the outlined function.
2568     llvm::Value *Args[] = {ID};
2569     CGF.EmitRuntimeCall(
2570         createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_kernel_prepare_parallel),
2571         Args);
2572
2573     // Create a private scope that will globalize the arguments
2574     // passed from the outside of the target region.
2575     CodeGenFunction::OMPPrivateScope PrivateArgScope(CGF);
2576
2577     // There's something to share.
2578     if (!CapturedVars.empty()) {
2579       // Prepare for parallel region. Indicate the outlined function.
2580       Address SharedArgs =
2581           CGF.CreateDefaultAlignTempAlloca(CGF.VoidPtrPtrTy, "shared_arg_refs");
2582       llvm::Value *SharedArgsPtr = SharedArgs.getPointer();
2583
2584       llvm::Value *DataSharingArgs[] = {
2585           SharedArgsPtr,
2586           llvm::ConstantInt::get(CGM.SizeTy, CapturedVars.size())};
2587       CGF.EmitRuntimeCall(createNVPTXRuntimeFunction(
2588                               OMPRTL_NVPTX__kmpc_begin_sharing_variables),
2589                           DataSharingArgs);
2590
2591       // Store variable address in a list of references to pass to workers.
2592       unsigned Idx = 0;
2593       ASTContext &Ctx = CGF.getContext();
2594       Address SharedArgListAddress = CGF.EmitLoadOfPointer(
2595           SharedArgs, Ctx.getPointerType(Ctx.getPointerType(Ctx.VoidPtrTy))
2596                           .castAs<PointerType>());
2597       for (llvm::Value *V : CapturedVars) {
2598         Address Dst = Bld.CreateConstInBoundsGEP(SharedArgListAddress, Idx);
2599         llvm::Value *PtrV;
2600         if (V->getType()->isIntegerTy())
2601           PtrV = Bld.CreateIntToPtr(V, CGF.VoidPtrTy);
2602         else
2603           PtrV = Bld.CreatePointerBitCastOrAddrSpaceCast(V, CGF.VoidPtrTy);
2604         CGF.EmitStoreOfScalar(PtrV, Dst, /*Volatile=*/false,
2605                               Ctx.getPointerType(Ctx.VoidPtrTy));
2606         ++Idx;
2607       }
2608     }
2609
2610     // Activate workers. This barrier is used by the master to signal
2611     // work for the workers.
2612     syncCTAThreads(CGF);
2613
2614     // OpenMP [2.5, Parallel Construct, p.49]
2615     // There is an implied barrier at the end of a parallel region. After the
2616     // end of a parallel region, only the master thread of the team resumes
2617     // execution of the enclosing task region.
2618     //
2619     // The master waits at this barrier until all workers are done.
2620     syncCTAThreads(CGF);
2621
2622     if (!CapturedVars.empty())
2623       CGF.EmitRuntimeCall(
2624           createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_end_sharing_variables));
2625
2626     // Remember for post-processing in worker loop.
2627     Work.emplace_back(WFn);
2628   };
2629
2630   auto &&LNParallelGen = [this, Loc, &SeqGen, &L0ParallelGen](
2631                              CodeGenFunction &CGF, PrePostActionTy &Action) {
2632     if (IsInParallelRegion) {
2633       SeqGen(CGF, Action);
2634     } else if (IsInTargetMasterThreadRegion) {
2635       L0ParallelGen(CGF, Action);
2636     } else {
2637       // Check for master and then parallelism:
2638       // if (__kmpc_is_spmd_exec_mode() || __kmpc_parallel_level(loc, gtid)) {
2639       //   Serialized execution.
2640       // } else {
2641       //   Worker call.
2642       // }
2643       CGBuilderTy &Bld = CGF.Builder;
2644       llvm::BasicBlock *ExitBB = CGF.createBasicBlock(".exit");
2645       llvm::BasicBlock *SeqBB = CGF.createBasicBlock(".sequential");
2646       llvm::BasicBlock *ParallelCheckBB = CGF.createBasicBlock(".parcheck");
2647       llvm::BasicBlock *MasterBB = CGF.createBasicBlock(".master");
2648       llvm::Value *IsSPMD = Bld.CreateIsNotNull(CGF.EmitNounwindRuntimeCall(
2649           createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_is_spmd_exec_mode)));
2650       Bld.CreateCondBr(IsSPMD, SeqBB, ParallelCheckBB);
2651       // There is no need to emit line number for unconditional branch.
2652       (void)ApplyDebugLocation::CreateEmpty(CGF);
2653       CGF.EmitBlock(ParallelCheckBB);
2654       llvm::Value *RTLoc = emitUpdateLocation(CGF, Loc);
2655       llvm::Value *ThreadID = getThreadID(CGF, Loc);
2656       llvm::Value *PL = CGF.EmitRuntimeCall(
2657           createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_parallel_level),
2658           {RTLoc, ThreadID});
2659       llvm::Value *Res = Bld.CreateIsNotNull(PL);
2660       Bld.CreateCondBr(Res, SeqBB, MasterBB);
2661       CGF.EmitBlock(SeqBB);
2662       SeqGen(CGF, Action);
2663       CGF.EmitBranch(ExitBB);
2664       // There is no need to emit line number for unconditional branch.
2665       (void)ApplyDebugLocation::CreateEmpty(CGF);
2666       CGF.EmitBlock(MasterBB);
2667       L0ParallelGen(CGF, Action);
2668       CGF.EmitBranch(ExitBB);
2669       // There is no need to emit line number for unconditional branch.
2670       (void)ApplyDebugLocation::CreateEmpty(CGF);
2671       // Emit the continuation block for code after the if.
2672       CGF.EmitBlock(ExitBB, /*IsFinished=*/true);
2673     }
2674   };
2675
2676   if (IfCond) {
2677     emitIfClause(CGF, IfCond, LNParallelGen, SeqGen);
2678   } else {
2679     CodeGenFunction::RunCleanupsScope Scope(CGF);
2680     RegionCodeGenTy ThenRCG(LNParallelGen);
2681     ThenRCG(CGF);
2682   }
2683 }
2684
2685 void CGOpenMPRuntimeNVPTX::emitSPMDParallelCall(
2686     CodeGenFunction &CGF, SourceLocation Loc, llvm::Function *OutlinedFn,
2687     ArrayRef<llvm::Value *> CapturedVars, const Expr *IfCond) {
2688   // Just call the outlined function to execute the parallel region.
2689   // OutlinedFn(&GTid, &zero, CapturedStruct);
2690   //
2691   llvm::SmallVector<llvm::Value *, 16> OutlinedFnArgs;
2692
2693   Address ZeroAddr = CGF.CreateDefaultAlignTempAlloca(CGF.Int32Ty,
2694                                                       /*Name=*/".zero.addr");
2695   CGF.InitTempAlloca(ZeroAddr, CGF.Builder.getInt32(/*C*/ 0));
2696   // ThreadId for serialized parallels is 0.
2697   Address ThreadIDAddr = ZeroAddr;
2698   auto &&CodeGen = [this, OutlinedFn, CapturedVars, Loc, &ThreadIDAddr](
2699                        CodeGenFunction &CGF, PrePostActionTy &Action) {
2700     Action.Enter(CGF);
2701
2702     Address ZeroAddr =
2703         CGF.CreateDefaultAlignTempAlloca(CGF.Int32Ty,
2704                                          /*Name=*/".bound.zero.addr");
2705     CGF.InitTempAlloca(ZeroAddr, CGF.Builder.getInt32(/*C*/ 0));
2706     llvm::SmallVector<llvm::Value *, 16> OutlinedFnArgs;
2707     OutlinedFnArgs.push_back(ThreadIDAddr.getPointer());
2708     OutlinedFnArgs.push_back(ZeroAddr.getPointer());
2709     OutlinedFnArgs.append(CapturedVars.begin(), CapturedVars.end());
2710     emitOutlinedFunctionCall(CGF, Loc, OutlinedFn, OutlinedFnArgs);
2711   };
2712   auto &&SeqGen = [this, &CodeGen, Loc](CodeGenFunction &CGF,
2713                                         PrePostActionTy &) {
2714
2715     RegionCodeGenTy RCG(CodeGen);
2716     llvm::Value *RTLoc = emitUpdateLocation(CGF, Loc);
2717     llvm::Value *ThreadID = getThreadID(CGF, Loc);
2718     llvm::Value *Args[] = {RTLoc, ThreadID};
2719
2720     NVPTXActionTy Action(
2721         createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_serialized_parallel),
2722         Args,
2723         createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_end_serialized_parallel),
2724         Args);
2725     RCG.setAction(Action);
2726     RCG(CGF);
2727   };
2728
2729   if (IsInTargetMasterThreadRegion) {
2730     // In the worker need to use the real thread id.
2731     ThreadIDAddr = emitThreadIDAddress(CGF, Loc);
2732     RegionCodeGenTy RCG(CodeGen);
2733     RCG(CGF);
2734   } else {
2735     // If we are not in the target region, it is definitely L2 parallelism or
2736     // more, because for SPMD mode we always has L1 parallel level, sowe don't
2737     // need to check for orphaned directives.
2738     RegionCodeGenTy RCG(SeqGen);
2739     RCG(CGF);
2740   }
2741 }
2742
2743 void CGOpenMPRuntimeNVPTX::syncCTAThreads(CodeGenFunction &CGF) {
2744   // Always emit simple barriers!
2745   if (!CGF.HaveInsertPoint())
2746     return;
2747   // Build call __kmpc_barrier_simple_spmd(nullptr, 0);
2748   // This function does not use parameters, so we can emit just default values.
2749   llvm::Value *Args[] = {
2750       llvm::ConstantPointerNull::get(
2751           cast<llvm::PointerType>(getIdentTyPointerTy())),
2752       llvm::ConstantInt::get(CGF.Int32Ty, /*V=*/0, /*isSigned=*/true)};
2753   llvm::CallInst *Call = CGF.EmitRuntimeCall(
2754       createNVPTXRuntimeFunction(OMPRTL__kmpc_barrier_simple_spmd), Args);
2755   Call->setConvergent();
2756 }
2757
2758 void CGOpenMPRuntimeNVPTX::emitBarrierCall(CodeGenFunction &CGF,
2759                                            SourceLocation Loc,
2760                                            OpenMPDirectiveKind Kind, bool,
2761                                            bool) {
2762   // Always emit simple barriers!
2763   if (!CGF.HaveInsertPoint())
2764     return;
2765   // Build call __kmpc_cancel_barrier(loc, thread_id);
2766   unsigned Flags = getDefaultFlagsForBarriers(Kind);
2767   llvm::Value *Args[] = {emitUpdateLocation(CGF, Loc, Flags),
2768                          getThreadID(CGF, Loc)};
2769   llvm::CallInst *Call = CGF.EmitRuntimeCall(
2770       createNVPTXRuntimeFunction(OMPRTL__kmpc_barrier), Args);
2771   Call->setConvergent();
2772 }
2773
2774 void CGOpenMPRuntimeNVPTX::emitCriticalRegion(
2775     CodeGenFunction &CGF, StringRef CriticalName,
2776     const RegionCodeGenTy &CriticalOpGen, SourceLocation Loc,
2777     const Expr *Hint) {
2778   llvm::BasicBlock *LoopBB = CGF.createBasicBlock("omp.critical.loop");
2779   llvm::BasicBlock *TestBB = CGF.createBasicBlock("omp.critical.test");
2780   llvm::BasicBlock *SyncBB = CGF.createBasicBlock("omp.critical.sync");
2781   llvm::BasicBlock *BodyBB = CGF.createBasicBlock("omp.critical.body");
2782   llvm::BasicBlock *ExitBB = CGF.createBasicBlock("omp.critical.exit");
2783
2784   // Get the mask of active threads in the warp.
2785   llvm::Value *Mask = CGF.EmitRuntimeCall(
2786       createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_warp_active_thread_mask));
2787   // Fetch team-local id of the thread.
2788   llvm::Value *ThreadID = getNVPTXThreadID(CGF);
2789
2790   // Get the width of the team.
2791   llvm::Value *TeamWidth = getNVPTXNumThreads(CGF);
2792
2793   // Initialize the counter variable for the loop.
2794   QualType Int32Ty =
2795       CGF.getContext().getIntTypeForBitwidth(/*DestWidth=*/32, /*Signed=*/0);
2796   Address Counter = CGF.CreateMemTemp(Int32Ty, "critical_counter");
2797   LValue CounterLVal = CGF.MakeAddrLValue(Counter, Int32Ty);
2798   CGF.EmitStoreOfScalar(llvm::Constant::getNullValue(CGM.Int32Ty), CounterLVal,
2799                         /*isInit=*/true);
2800
2801   // Block checks if loop counter exceeds upper bound.
2802   CGF.EmitBlock(LoopBB);
2803   llvm::Value *CounterVal = CGF.EmitLoadOfScalar(CounterLVal, Loc);
2804   llvm::Value *CmpLoopBound = CGF.Builder.CreateICmpSLT(CounterVal, TeamWidth);
2805   CGF.Builder.CreateCondBr(CmpLoopBound, TestBB, ExitBB);
2806
2807   // Block tests which single thread should execute region, and which threads
2808   // should go straight to synchronisation point.
2809   CGF.EmitBlock(TestBB);
2810   CounterVal = CGF.EmitLoadOfScalar(CounterLVal, Loc);
2811   llvm::Value *CmpThreadToCounter =
2812       CGF.Builder.CreateICmpEQ(ThreadID, CounterVal);
2813   CGF.Builder.CreateCondBr(CmpThreadToCounter, BodyBB, SyncBB);
2814
2815   // Block emits the body of the critical region.
2816   CGF.EmitBlock(BodyBB);
2817
2818   // Output the critical statement.
2819   CGOpenMPRuntime::emitCriticalRegion(CGF, CriticalName, CriticalOpGen, Loc,
2820                                       Hint);
2821
2822   // After the body surrounded by the critical region, the single executing
2823   // thread will jump to the synchronisation point.
2824   // Block waits for all threads in current team to finish then increments the
2825   // counter variable and returns to the loop.
2826   CGF.EmitBlock(SyncBB);
2827   // Reconverge active threads in the warp.
2828   (void)CGF.EmitRuntimeCall(
2829       createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_syncwarp), Mask);
2830
2831   llvm::Value *IncCounterVal =
2832       CGF.Builder.CreateNSWAdd(CounterVal, CGF.Builder.getInt32(1));
2833   CGF.EmitStoreOfScalar(IncCounterVal, CounterLVal);
2834   CGF.EmitBranch(LoopBB);
2835
2836   // Block that is reached when  all threads in the team complete the region.
2837   CGF.EmitBlock(ExitBB, /*IsFinished=*/true);
2838 }
2839
2840 /// Cast value to the specified type.
2841 static llvm::Value *castValueToType(CodeGenFunction &CGF, llvm::Value *Val,
2842                                     QualType ValTy, QualType CastTy,
2843                                     SourceLocation Loc) {
2844   assert(!CGF.getContext().getTypeSizeInChars(CastTy).isZero() &&
2845          "Cast type must sized.");
2846   assert(!CGF.getContext().getTypeSizeInChars(ValTy).isZero() &&
2847          "Val type must sized.");
2848   llvm::Type *LLVMCastTy = CGF.ConvertTypeForMem(CastTy);
2849   if (ValTy == CastTy)
2850     return Val;
2851   if (CGF.getContext().getTypeSizeInChars(ValTy) ==
2852       CGF.getContext().getTypeSizeInChars(CastTy))
2853     return CGF.Builder.CreateBitCast(Val, LLVMCastTy);
2854   if (CastTy->isIntegerType() && ValTy->isIntegerType())
2855     return CGF.Builder.CreateIntCast(Val, LLVMCastTy,
2856                                      CastTy->hasSignedIntegerRepresentation());
2857   Address CastItem = CGF.CreateMemTemp(CastTy);
2858   Address ValCastItem = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
2859       CastItem, Val->getType()->getPointerTo(CastItem.getAddressSpace()));
2860   CGF.EmitStoreOfScalar(Val, ValCastItem, /*Volatile=*/false, ValTy);
2861   return CGF.EmitLoadOfScalar(CastItem, /*Volatile=*/false, CastTy, Loc);
2862 }
2863
2864 /// This function creates calls to one of two shuffle functions to copy
2865 /// variables between lanes in a warp.
2866 static llvm::Value *createRuntimeShuffleFunction(CodeGenFunction &CGF,
2867                                                  llvm::Value *Elem,
2868                                                  QualType ElemType,
2869                                                  llvm::Value *Offset,
2870                                                  SourceLocation Loc) {
2871   CodeGenModule &CGM = CGF.CGM;
2872   CGBuilderTy &Bld = CGF.Builder;
2873   CGOpenMPRuntimeNVPTX &RT =
2874       *(static_cast<CGOpenMPRuntimeNVPTX *>(&CGM.getOpenMPRuntime()));
2875
2876   CharUnits Size = CGF.getContext().getTypeSizeInChars(ElemType);
2877   assert(Size.getQuantity() <= 8 &&
2878          "Unsupported bitwidth in shuffle instruction.");
2879
2880   OpenMPRTLFunctionNVPTX ShuffleFn = Size.getQuantity() <= 4
2881                                          ? OMPRTL_NVPTX__kmpc_shuffle_int32
2882                                          : OMPRTL_NVPTX__kmpc_shuffle_int64;
2883
2884   // Cast all types to 32- or 64-bit values before calling shuffle routines.
2885   QualType CastTy = CGF.getContext().getIntTypeForBitwidth(
2886       Size.getQuantity() <= 4 ? 32 : 64, /*Signed=*/1);
2887   llvm::Value *ElemCast = castValueToType(CGF, Elem, ElemType, CastTy, Loc);
2888   llvm::Value *WarpSize =
2889       Bld.CreateIntCast(getNVPTXWarpSize(CGF), CGM.Int16Ty, /*isSigned=*/true);
2890
2891   llvm::Value *ShuffledVal = CGF.EmitRuntimeCall(
2892       RT.createNVPTXRuntimeFunction(ShuffleFn), {ElemCast, Offset, WarpSize});
2893
2894   return castValueToType(CGF, ShuffledVal, CastTy, ElemType, Loc);
2895 }
2896
2897 static void shuffleAndStore(CodeGenFunction &CGF, Address SrcAddr,
2898                             Address DestAddr, QualType ElemType,
2899                             llvm::Value *Offset, SourceLocation Loc) {
2900   CGBuilderTy &Bld = CGF.Builder;
2901
2902   CharUnits Size = CGF.getContext().getTypeSizeInChars(ElemType);
2903   // Create the loop over the big sized data.
2904   // ptr = (void*)Elem;
2905   // ptrEnd = (void*) Elem + 1;
2906   // Step = 8;
2907   // while (ptr + Step < ptrEnd)
2908   //   shuffle((int64_t)*ptr);
2909   // Step = 4;
2910   // while (ptr + Step < ptrEnd)
2911   //   shuffle((int32_t)*ptr);
2912   // ...
2913   Address ElemPtr = DestAddr;
2914   Address Ptr = SrcAddr;
2915   Address PtrEnd = Bld.CreatePointerBitCastOrAddrSpaceCast(
2916       Bld.CreateConstGEP(SrcAddr, 1), CGF.VoidPtrTy);
2917   for (int IntSize = 8; IntSize >= 1; IntSize /= 2) {
2918     if (Size < CharUnits::fromQuantity(IntSize))
2919       continue;
2920     QualType IntType = CGF.getContext().getIntTypeForBitwidth(
2921         CGF.getContext().toBits(CharUnits::fromQuantity(IntSize)),
2922         /*Signed=*/1);
2923     llvm::Type *IntTy = CGF.ConvertTypeForMem(IntType);
2924     Ptr = Bld.CreatePointerBitCastOrAddrSpaceCast(Ptr, IntTy->getPointerTo());
2925     ElemPtr =
2926         Bld.CreatePointerBitCastOrAddrSpaceCast(ElemPtr, IntTy->getPointerTo());
2927     if (Size.getQuantity() / IntSize > 1) {
2928       llvm::BasicBlock *PreCondBB = CGF.createBasicBlock(".shuffle.pre_cond");
2929       llvm::BasicBlock *ThenBB = CGF.createBasicBlock(".shuffle.then");
2930       llvm::BasicBlock *ExitBB = CGF.createBasicBlock(".shuffle.exit");
2931       llvm::BasicBlock *CurrentBB = Bld.GetInsertBlock();
2932       CGF.EmitBlock(PreCondBB);
2933       llvm::PHINode *PhiSrc =
2934           Bld.CreatePHI(Ptr.getType(), /*NumReservedValues=*/2);
2935       PhiSrc->addIncoming(Ptr.getPointer(), CurrentBB);
2936       llvm::PHINode *PhiDest =
2937           Bld.CreatePHI(ElemPtr.getType(), /*NumReservedValues=*/2);
2938       PhiDest->addIncoming(ElemPtr.getPointer(), CurrentBB);
2939       Ptr = Address(PhiSrc, Ptr.getAlignment());
2940       ElemPtr = Address(PhiDest, ElemPtr.getAlignment());
2941       llvm::Value *PtrDiff = Bld.CreatePtrDiff(
2942           PtrEnd.getPointer(), Bld.CreatePointerBitCastOrAddrSpaceCast(
2943                                    Ptr.getPointer(), CGF.VoidPtrTy));
2944       Bld.CreateCondBr(Bld.CreateICmpSGT(PtrDiff, Bld.getInt64(IntSize - 1)),
2945                        ThenBB, ExitBB);
2946       CGF.EmitBlock(ThenBB);
2947       llvm::Value *Res = createRuntimeShuffleFunction(
2948           CGF, CGF.EmitLoadOfScalar(Ptr, /*Volatile=*/false, IntType, Loc),
2949           IntType, Offset, Loc);
2950       CGF.EmitStoreOfScalar(Res, ElemPtr, /*Volatile=*/false, IntType);
2951       Address LocalPtr = Bld.CreateConstGEP(Ptr, 1);
2952       Address LocalElemPtr = Bld.CreateConstGEP(ElemPtr, 1);
2953       PhiSrc->addIncoming(LocalPtr.getPointer(), ThenBB);
2954       PhiDest->addIncoming(LocalElemPtr.getPointer(), ThenBB);
2955       CGF.EmitBranch(PreCondBB);
2956       CGF.EmitBlock(ExitBB);
2957     } else {
2958       llvm::Value *Res = createRuntimeShuffleFunction(
2959           CGF, CGF.EmitLoadOfScalar(Ptr, /*Volatile=*/false, IntType, Loc),
2960           IntType, Offset, Loc);
2961       CGF.EmitStoreOfScalar(Res, ElemPtr, /*Volatile=*/false, IntType);
2962       Ptr = Bld.CreateConstGEP(Ptr, 1);
2963       ElemPtr = Bld.CreateConstGEP(ElemPtr, 1);
2964     }
2965     Size = Size % IntSize;
2966   }
2967 }
2968
2969 namespace {
2970 enum CopyAction : unsigned {
2971   // RemoteLaneToThread: Copy over a Reduce list from a remote lane in
2972   // the warp using shuffle instructions.
2973   RemoteLaneToThread,
2974   // ThreadCopy: Make a copy of a Reduce list on the thread's stack.
2975   ThreadCopy,
2976   // ThreadToScratchpad: Copy a team-reduced array to the scratchpad.
2977   ThreadToScratchpad,
2978   // ScratchpadToThread: Copy from a scratchpad array in global memory
2979   // containing team-reduced data to a thread's stack.
2980   ScratchpadToThread,
2981 };
2982 } // namespace
2983
2984 struct CopyOptionsTy {
2985   llvm::Value *RemoteLaneOffset;
2986   llvm::Value *ScratchpadIndex;
2987   llvm::Value *ScratchpadWidth;
2988 };
2989
2990 /// Emit instructions to copy a Reduce list, which contains partially
2991 /// aggregated values, in the specified direction.
2992 static void emitReductionListCopy(
2993     CopyAction Action, CodeGenFunction &CGF, QualType ReductionArrayTy,
2994     ArrayRef<const Expr *> Privates, Address SrcBase, Address DestBase,
2995     CopyOptionsTy CopyOptions = {nullptr, nullptr, nullptr}) {
2996
2997   CodeGenModule &CGM = CGF.CGM;
2998   ASTContext &C = CGM.getContext();
2999   CGBuilderTy &Bld = CGF.Builder;
3000
3001   llvm::Value *RemoteLaneOffset = CopyOptions.RemoteLaneOffset;
3002   llvm::Value *ScratchpadIndex = CopyOptions.ScratchpadIndex;
3003   llvm::Value *ScratchpadWidth = CopyOptions.ScratchpadWidth;
3004
3005   // Iterates, element-by-element, through the source Reduce list and
3006   // make a copy.
3007   unsigned Idx = 0;
3008   unsigned Size = Privates.size();
3009   for (const Expr *Private : Privates) {
3010     Address SrcElementAddr = Address::invalid();
3011     Address DestElementAddr = Address::invalid();
3012     Address DestElementPtrAddr = Address::invalid();
3013     // Should we shuffle in an element from a remote lane?
3014     bool ShuffleInElement = false;
3015     // Set to true to update the pointer in the dest Reduce list to a
3016     // newly created element.
3017     bool UpdateDestListPtr = false;
3018     // Increment the src or dest pointer to the scratchpad, for each
3019     // new element.
3020     bool IncrScratchpadSrc = false;
3021     bool IncrScratchpadDest = false;
3022
3023     switch (Action) {
3024     case RemoteLaneToThread: {
3025       // Step 1.1: Get the address for the src element in the Reduce list.
3026       Address SrcElementPtrAddr = Bld.CreateConstArrayGEP(SrcBase, Idx);
3027       SrcElementAddr = CGF.EmitLoadOfPointer(
3028           SrcElementPtrAddr,
3029           C.getPointerType(Private->getType())->castAs<PointerType>());
3030
3031       // Step 1.2: Create a temporary to store the element in the destination
3032       // Reduce list.
3033       DestElementPtrAddr = Bld.CreateConstArrayGEP(DestBase, Idx);
3034       DestElementAddr =
3035           CGF.CreateMemTemp(Private->getType(), ".omp.reduction.element");
3036       ShuffleInElement = true;
3037       UpdateDestListPtr = true;
3038       break;
3039     }
3040     case ThreadCopy: {
3041       // Step 1.1: Get the address for the src element in the Reduce list.
3042       Address SrcElementPtrAddr = Bld.CreateConstArrayGEP(SrcBase, Idx);
3043       SrcElementAddr = CGF.EmitLoadOfPointer(
3044           SrcElementPtrAddr,
3045           C.getPointerType(Private->getType())->castAs<PointerType>());
3046
3047       // Step 1.2: Get the address for dest element.  The destination
3048       // element has already been created on the thread's stack.
3049       DestElementPtrAddr = Bld.CreateConstArrayGEP(DestBase, Idx);
3050       DestElementAddr = CGF.EmitLoadOfPointer(
3051           DestElementPtrAddr,
3052           C.getPointerType(Private->getType())->castAs<PointerType>());
3053       break;
3054     }
3055     case ThreadToScratchpad: {
3056       // Step 1.1: Get the address for the src element in the Reduce list.
3057       Address SrcElementPtrAddr = Bld.CreateConstArrayGEP(SrcBase, Idx);
3058       SrcElementAddr = CGF.EmitLoadOfPointer(
3059           SrcElementPtrAddr,
3060           C.getPointerType(Private->getType())->castAs<PointerType>());
3061
3062       // Step 1.2: Get the address for dest element:
3063       // address = base + index * ElementSizeInChars.
3064       llvm::Value *ElementSizeInChars = CGF.getTypeSize(Private->getType());
3065       llvm::Value *CurrentOffset =
3066           Bld.CreateNUWMul(ElementSizeInChars, ScratchpadIndex);
3067       llvm::Value *ScratchPadElemAbsolutePtrVal =
3068           Bld.CreateNUWAdd(DestBase.getPointer(), CurrentOffset);
3069       ScratchPadElemAbsolutePtrVal =
3070           Bld.CreateIntToPtr(ScratchPadElemAbsolutePtrVal, CGF.VoidPtrTy);
3071       DestElementAddr = Address(ScratchPadElemAbsolutePtrVal,
3072                                 C.getTypeAlignInChars(Private->getType()));
3073       IncrScratchpadDest = true;
3074       break;
3075     }
3076     case ScratchpadToThread: {
3077       // Step 1.1: Get the address for the src element in the scratchpad.
3078       // address = base + index * ElementSizeInChars.
3079       llvm::Value *ElementSizeInChars = CGF.getTypeSize(Private->getType());
3080       llvm::Value *CurrentOffset =
3081           Bld.CreateNUWMul(ElementSizeInChars, ScratchpadIndex);
3082       llvm::Value *ScratchPadElemAbsolutePtrVal =
3083           Bld.CreateNUWAdd(SrcBase.getPointer(), CurrentOffset);
3084       ScratchPadElemAbsolutePtrVal =
3085           Bld.CreateIntToPtr(ScratchPadElemAbsolutePtrVal, CGF.VoidPtrTy);
3086       SrcElementAddr = Address(ScratchPadElemAbsolutePtrVal,
3087                                C.getTypeAlignInChars(Private->getType()));
3088       IncrScratchpadSrc = true;
3089
3090       // Step 1.2: Create a temporary to store the element in the destination
3091       // Reduce list.
3092       DestElementPtrAddr = Bld.CreateConstArrayGEP(DestBase, Idx);
3093       DestElementAddr =
3094           CGF.CreateMemTemp(Private->getType(), ".omp.reduction.element");
3095       UpdateDestListPtr = true;
3096       break;
3097     }
3098     }
3099
3100     // Regardless of src and dest of copy, we emit the load of src
3101     // element as this is required in all directions
3102     SrcElementAddr = Bld.CreateElementBitCast(
3103         SrcElementAddr, CGF.ConvertTypeForMem(Private->getType()));
3104     DestElementAddr = Bld.CreateElementBitCast(DestElementAddr,
3105                                                SrcElementAddr.getElementType());
3106
3107     // Now that all active lanes have read the element in the
3108     // Reduce list, shuffle over the value from the remote lane.
3109     if (ShuffleInElement) {
3110       shuffleAndStore(CGF, SrcElementAddr, DestElementAddr, Private->getType(),
3111                       RemoteLaneOffset, Private->getExprLoc());
3112     } else {
3113       switch (CGF.getEvaluationKind(Private->getType())) {
3114       case TEK_Scalar: {
3115         llvm::Value *Elem =
3116             CGF.EmitLoadOfScalar(SrcElementAddr, /*Volatile=*/false,
3117                                  Private->getType(), Private->getExprLoc());
3118         // Store the source element value to the dest element address.
3119         CGF.EmitStoreOfScalar(Elem, DestElementAddr, /*Volatile=*/false,
3120                               Private->getType());
3121         break;
3122       }
3123       case TEK_Complex: {
3124         CodeGenFunction::ComplexPairTy Elem = CGF.EmitLoadOfComplex(
3125             CGF.MakeAddrLValue(SrcElementAddr, Private->getType()),
3126             Private->getExprLoc());
3127         CGF.EmitStoreOfComplex(
3128             Elem, CGF.MakeAddrLValue(DestElementAddr, Private->getType()),
3129             /*isInit=*/false);
3130         break;
3131       }
3132       case TEK_Aggregate:
3133         CGF.EmitAggregateCopy(
3134             CGF.MakeAddrLValue(DestElementAddr, Private->getType()),
3135             CGF.MakeAddrLValue(SrcElementAddr, Private->getType()),
3136             Private->getType(), AggValueSlot::DoesNotOverlap);
3137         break;
3138       }
3139     }
3140
3141     // Step 3.1: Modify reference in dest Reduce list as needed.
3142     // Modifying the reference in Reduce list to point to the newly
3143     // created element.  The element is live in the current function
3144     // scope and that of functions it invokes (i.e., reduce_function).
3145     // RemoteReduceData[i] = (void*)&RemoteElem
3146     if (UpdateDestListPtr) {
3147       CGF.EmitStoreOfScalar(Bld.CreatePointerBitCastOrAddrSpaceCast(
3148                                 DestElementAddr.getPointer(), CGF.VoidPtrTy),
3149                             DestElementPtrAddr, /*Volatile=*/false,
3150                             C.VoidPtrTy);
3151     }
3152
3153     // Step 4.1: Increment SrcBase/DestBase so that it points to the starting
3154     // address of the next element in scratchpad memory, unless we're currently
3155     // processing the last one.  Memory alignment is also taken care of here.
3156     if ((IncrScratchpadDest || IncrScratchpadSrc) && (Idx + 1 < Size)) {
3157       llvm::Value *ScratchpadBasePtr =
3158           IncrScratchpadDest ? DestBase.getPointer() : SrcBase.getPointer();
3159       llvm::Value *ElementSizeInChars = CGF.getTypeSize(Private->getType());
3160       ScratchpadBasePtr = Bld.CreateNUWAdd(
3161           ScratchpadBasePtr,
3162           Bld.CreateNUWMul(ScratchpadWidth, ElementSizeInChars));
3163
3164       // Take care of global memory alignment for performance
3165       ScratchpadBasePtr = Bld.CreateNUWSub(
3166           ScratchpadBasePtr, llvm::ConstantInt::get(CGM.SizeTy, 1));
3167       ScratchpadBasePtr = Bld.CreateUDiv(
3168           ScratchpadBasePtr,
3169           llvm::ConstantInt::get(CGM.SizeTy, GlobalMemoryAlignment));
3170       ScratchpadBasePtr = Bld.CreateNUWAdd(
3171           ScratchpadBasePtr, llvm::ConstantInt::get(CGM.SizeTy, 1));
3172       ScratchpadBasePtr = Bld.CreateNUWMul(
3173           ScratchpadBasePtr,
3174           llvm::ConstantInt::get(CGM.SizeTy, GlobalMemoryAlignment));
3175
3176       if (IncrScratchpadDest)
3177         DestBase = Address(ScratchpadBasePtr, CGF.getPointerAlign());
3178       else /* IncrScratchpadSrc = true */
3179         SrcBase = Address(ScratchpadBasePtr, CGF.getPointerAlign());
3180     }
3181
3182     ++Idx;
3183   }
3184 }
3185
3186 /// This function emits a helper that gathers Reduce lists from the first
3187 /// lane of every active warp to lanes in the first warp.
3188 ///
3189 /// void inter_warp_copy_func(void* reduce_data, num_warps)
3190 ///   shared smem[warp_size];
3191 ///   For all data entries D in reduce_data:
3192 ///     sync
3193 ///     If (I am the first lane in each warp)
3194 ///       Copy my local D to smem[warp_id]
3195 ///     sync
3196 ///     if (I am the first warp)
3197 ///       Copy smem[thread_id] to my local D
3198 static llvm::Value *emitInterWarpCopyFunction(CodeGenModule &CGM,
3199                                               ArrayRef<const Expr *> Privates,
3200                                               QualType ReductionArrayTy,
3201                                               SourceLocation Loc) {
3202   ASTContext &C = CGM.getContext();
3203   llvm::Module &M = CGM.getModule();
3204
3205   // ReduceList: thread local Reduce list.
3206   // At the stage of the computation when this function is called, partially
3207   // aggregated values reside in the first lane of every active warp.
3208   ImplicitParamDecl ReduceListArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
3209                                   C.VoidPtrTy, ImplicitParamDecl::Other);
3210   // NumWarps: number of warps active in the parallel region.  This could
3211   // be smaller than 32 (max warps in a CTA) for partial block reduction.
3212   ImplicitParamDecl NumWarpsArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
3213                                 C.getIntTypeForBitwidth(32, /* Signed */ true),
3214                                 ImplicitParamDecl::Other);
3215   FunctionArgList Args;
3216   Args.push_back(&ReduceListArg);
3217   Args.push_back(&NumWarpsArg);
3218
3219   const CGFunctionInfo &CGFI =
3220       CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, Args);
3221   auto *Fn = llvm::Function::Create(CGM.getTypes().GetFunctionType(CGFI),
3222                                     llvm::GlobalValue::InternalLinkage,
3223                                     "_omp_reduction_inter_warp_copy_func", &M);
3224   CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, CGFI);
3225   Fn->setDoesNotRecurse();
3226   CodeGenFunction CGF(CGM);
3227   CGF.StartFunction(GlobalDecl(), C.VoidTy, Fn, CGFI, Args, Loc, Loc);
3228
3229   CGBuilderTy &Bld = CGF.Builder;
3230
3231   // This array is used as a medium to transfer, one reduce element at a time,
3232   // the data from the first lane of every warp to lanes in the first warp
3233   // in order to perform the final step of a reduction in a parallel region
3234   // (reduction across warps).  The array is placed in NVPTX __shared__ memory
3235   // for reduced latency, as well as to have a distinct copy for concurrently
3236   // executing target regions.  The array is declared with common linkage so
3237   // as to be shared across compilation units.
3238   StringRef TransferMediumName =
3239       "__openmp_nvptx_data_transfer_temporary_storage";
3240   llvm::GlobalVariable *TransferMedium =
3241       M.getGlobalVariable(TransferMediumName);
3242   if (!TransferMedium) {
3243     auto *Ty = llvm::ArrayType::get(CGM.Int32Ty, WarpSize);
3244     unsigned SharedAddressSpace = C.getTargetAddressSpace(LangAS::cuda_shared);
3245     TransferMedium = new llvm::GlobalVariable(
3246         M, Ty, /*isConstant=*/false, llvm::GlobalVariable::CommonLinkage,
3247         llvm::Constant::getNullValue(Ty), TransferMediumName,
3248         /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal,
3249         SharedAddressSpace);
3250     CGM.addCompilerUsedGlobal(TransferMedium);
3251   }
3252
3253   // Get the CUDA thread id of the current OpenMP thread on the GPU.
3254   llvm::Value *ThreadID = getNVPTXThreadID(CGF);
3255   // nvptx_lane_id = nvptx_id % warpsize
3256   llvm::Value *LaneID = getNVPTXLaneID(CGF);
3257   // nvptx_warp_id = nvptx_id / warpsize
3258   llvm::Value *WarpID = getNVPTXWarpID(CGF);
3259
3260   Address AddrReduceListArg = CGF.GetAddrOfLocalVar(&ReduceListArg);
3261   Address LocalReduceList(
3262       Bld.CreatePointerBitCastOrAddrSpaceCast(
3263           CGF.EmitLoadOfScalar(AddrReduceListArg, /*Volatile=*/false,
3264                                C.VoidPtrTy, Loc),
3265           CGF.ConvertTypeForMem(ReductionArrayTy)->getPointerTo()),
3266       CGF.getPointerAlign());
3267
3268   unsigned Idx = 0;
3269   for (const Expr *Private : Privates) {
3270     //
3271     // Warp master copies reduce element to transfer medium in __shared__
3272     // memory.
3273     //
3274     unsigned RealTySize =
3275         C.getTypeSizeInChars(Private->getType())
3276             .alignTo(C.getTypeAlignInChars(Private->getType()))
3277             .getQuantity();
3278     for (unsigned TySize = 4; TySize > 0 && RealTySize > 0; TySize /=2) {
3279       unsigned NumIters = RealTySize / TySize;
3280       if (NumIters == 0)
3281         continue;
3282       QualType CType = C.getIntTypeForBitwidth(
3283           C.toBits(CharUnits::fromQuantity(TySize)), /*Signed=*/1);
3284       llvm::Type *CopyType = CGF.ConvertTypeForMem(CType);
3285       CharUnits Align = CharUnits::fromQuantity(TySize);
3286       llvm::Value *Cnt = nullptr;
3287       Address CntAddr = Address::invalid();
3288       llvm::BasicBlock *PrecondBB = nullptr;
3289       llvm::BasicBlock *ExitBB = nullptr;
3290       if (NumIters > 1) {
3291         CntAddr = CGF.CreateMemTemp(C.IntTy, ".cnt.addr");
3292         CGF.EmitStoreOfScalar(llvm::Constant::getNullValue(CGM.IntTy), CntAddr,
3293                               /*Volatile=*/false, C.IntTy);
3294         PrecondBB = CGF.createBasicBlock("precond");
3295         ExitBB = CGF.createBasicBlock("exit");
3296         llvm::BasicBlock *BodyBB = CGF.createBasicBlock("body");
3297         // There is no need to emit line number for unconditional branch.
3298         (void)ApplyDebugLocation::CreateEmpty(CGF);
3299         CGF.EmitBlock(PrecondBB);
3300         Cnt = CGF.EmitLoadOfScalar(CntAddr, /*Volatile=*/false, C.IntTy, Loc);
3301         llvm::Value *Cmp =
3302             Bld.CreateICmpULT(Cnt, llvm::ConstantInt::get(CGM.IntTy, NumIters));
3303         Bld.CreateCondBr(Cmp, BodyBB, ExitBB);
3304         CGF.EmitBlock(BodyBB);
3305       }
3306       // kmpc_barrier.
3307       CGM.getOpenMPRuntime().emitBarrierCall(CGF, Loc, OMPD_unknown,
3308                                              /*EmitChecks=*/false,
3309                                              /*ForceSimpleCall=*/true);
3310       llvm::BasicBlock *ThenBB = CGF.createBasicBlock("then");
3311       llvm::BasicBlock *ElseBB = CGF.createBasicBlock("else");
3312       llvm::BasicBlock *MergeBB = CGF.createBasicBlock("ifcont");
3313
3314       // if (lane_id == 0)
3315       llvm::Value *IsWarpMaster = Bld.CreateIsNull(LaneID, "warp_master");
3316       Bld.CreateCondBr(IsWarpMaster, ThenBB, ElseBB);
3317       CGF.EmitBlock(ThenBB);
3318
3319       // Reduce element = LocalReduceList[i]
3320       Address ElemPtrPtrAddr = Bld.CreateConstArrayGEP(LocalReduceList, Idx);
3321       llvm::Value *ElemPtrPtr = CGF.EmitLoadOfScalar(
3322           ElemPtrPtrAddr, /*Volatile=*/false, C.VoidPtrTy, SourceLocation());
3323       // elemptr = ((CopyType*)(elemptrptr)) + I
3324       Address ElemPtr = Address(ElemPtrPtr, Align);
3325       ElemPtr = Bld.CreateElementBitCast(ElemPtr, CopyType);
3326       if (NumIters > 1) {
3327         ElemPtr = Address(Bld.CreateGEP(ElemPtr.getPointer(), Cnt),
3328                           ElemPtr.getAlignment());
3329       }
3330
3331       // Get pointer to location in transfer medium.
3332       // MediumPtr = &medium[warp_id]
3333       llvm::Value *MediumPtrVal = Bld.CreateInBoundsGEP(
3334           TransferMedium, {llvm::Constant::getNullValue(CGM.Int64Ty), WarpID});
3335       Address MediumPtr(MediumPtrVal, Align);
3336       // Casting to actual data type.
3337       // MediumPtr = (CopyType*)MediumPtrAddr;
3338       MediumPtr = Bld.CreateElementBitCast(MediumPtr, CopyType);
3339
3340       // elem = *elemptr
3341       //*MediumPtr = elem
3342       llvm::Value *Elem =
3343           CGF.EmitLoadOfScalar(ElemPtr, /*Volatile=*/false, CType, Loc);
3344       // Store the source element value to the dest element address.
3345       CGF.EmitStoreOfScalar(Elem, MediumPtr, /*Volatile=*/true, CType);
3346
3347       Bld.CreateBr(MergeBB);
3348
3349       CGF.EmitBlock(ElseBB);
3350       Bld.CreateBr(MergeBB);
3351
3352       CGF.EmitBlock(MergeBB);
3353
3354       // kmpc_barrier.
3355       CGM.getOpenMPRuntime().emitBarrierCall(CGF, Loc, OMPD_unknown,
3356                                              /*EmitChecks=*/false,
3357                                              /*ForceSimpleCall=*/true);
3358
3359       //
3360       // Warp 0 copies reduce element from transfer medium.
3361       //
3362       llvm::BasicBlock *W0ThenBB = CGF.createBasicBlock("then");
3363       llvm::BasicBlock *W0ElseBB = CGF.createBasicBlock("else");
3364       llvm::BasicBlock *W0MergeBB = CGF.createBasicBlock("ifcont");
3365
3366       Address AddrNumWarpsArg = CGF.GetAddrOfLocalVar(&NumWarpsArg);
3367       llvm::Value *NumWarpsVal = CGF.EmitLoadOfScalar(
3368           AddrNumWarpsArg, /*Volatile=*/false, C.IntTy, Loc);
3369
3370       // Up to 32 threads in warp 0 are active.
3371       llvm::Value *IsActiveThread =
3372           Bld.CreateICmpULT(ThreadID, NumWarpsVal, "is_active_thread");
3373       Bld.CreateCondBr(IsActiveThread, W0ThenBB, W0ElseBB);
3374
3375       CGF.EmitBlock(W0ThenBB);
3376
3377       // SrcMediumPtr = &medium[tid]
3378       llvm::Value *SrcMediumPtrVal = Bld.CreateInBoundsGEP(
3379           TransferMedium,
3380           {llvm::Constant::getNullValue(CGM.Int64Ty), ThreadID});
3381       Address SrcMediumPtr(SrcMediumPtrVal, Align);
3382       // SrcMediumVal = *SrcMediumPtr;
3383       SrcMediumPtr = Bld.CreateElementBitCast(SrcMediumPtr, CopyType);
3384
3385       // TargetElemPtr = (CopyType*)(SrcDataAddr[i]) + I
3386       Address TargetElemPtrPtr = Bld.CreateConstArrayGEP(LocalReduceList, Idx);
3387       llvm::Value *TargetElemPtrVal = CGF.EmitLoadOfScalar(
3388           TargetElemPtrPtr, /*Volatile=*/false, C.VoidPtrTy, Loc);
3389       Address TargetElemPtr = Address(TargetElemPtrVal, Align);
3390       TargetElemPtr = Bld.CreateElementBitCast(TargetElemPtr, CopyType);
3391       if (NumIters > 1) {
3392         TargetElemPtr = Address(Bld.CreateGEP(TargetElemPtr.getPointer(), Cnt),
3393                                 TargetElemPtr.getAlignment());
3394       }
3395
3396       // *TargetElemPtr = SrcMediumVal;
3397       llvm::Value *SrcMediumValue =
3398           CGF.EmitLoadOfScalar(SrcMediumPtr, /*Volatile=*/true, CType, Loc);
3399       CGF.EmitStoreOfScalar(SrcMediumValue, TargetElemPtr, /*Volatile=*/false,
3400                             CType);
3401       Bld.CreateBr(W0MergeBB);
3402
3403       CGF.EmitBlock(W0ElseBB);
3404       Bld.CreateBr(W0MergeBB);
3405
3406       CGF.EmitBlock(W0MergeBB);
3407
3408       if (NumIters > 1) {
3409         Cnt = Bld.CreateNSWAdd(Cnt, llvm::ConstantInt::get(CGM.IntTy, /*V=*/1));
3410         CGF.EmitStoreOfScalar(Cnt, CntAddr, /*Volatile=*/false, C.IntTy);
3411         CGF.EmitBranch(PrecondBB);
3412         (void)ApplyDebugLocation::CreateEmpty(CGF);
3413         CGF.EmitBlock(ExitBB);
3414       }
3415       RealTySize %= TySize;
3416     }
3417     ++Idx;
3418   }
3419
3420   CGF.FinishFunction();
3421   return Fn;
3422 }
3423
3424 /// Emit a helper that reduces data across two OpenMP threads (lanes)
3425 /// in the same warp.  It uses shuffle instructions to copy over data from
3426 /// a remote lane's stack.  The reduction algorithm performed is specified
3427 /// by the fourth parameter.
3428 ///
3429 /// Algorithm Versions.
3430 /// Full Warp Reduce (argument value 0):
3431 ///   This algorithm assumes that all 32 lanes are active and gathers
3432 ///   data from these 32 lanes, producing a single resultant value.
3433 /// Contiguous Partial Warp Reduce (argument value 1):
3434 ///   This algorithm assumes that only a *contiguous* subset of lanes
3435 ///   are active.  This happens for the last warp in a parallel region
3436 ///   when the user specified num_threads is not an integer multiple of
3437 ///   32.  This contiguous subset always starts with the zeroth lane.
3438 /// Partial Warp Reduce (argument value 2):
3439 ///   This algorithm gathers data from any number of lanes at any position.
3440 /// All reduced values are stored in the lowest possible lane.  The set
3441 /// of problems every algorithm addresses is a super set of those
3442 /// addressable by algorithms with a lower version number.  Overhead
3443 /// increases as algorithm version increases.
3444 ///
3445 /// Terminology
3446 /// Reduce element:
3447 ///   Reduce element refers to the individual data field with primitive
3448 ///   data types to be combined and reduced across threads.
3449 /// Reduce list:
3450 ///   Reduce list refers to a collection of local, thread-private
3451 ///   reduce elements.
3452 /// Remote Reduce list:
3453 ///   Remote Reduce list refers to a collection of remote (relative to
3454 ///   the current thread) reduce elements.
3455 ///
3456 /// We distinguish between three states of threads that are important to
3457 /// the implementation of this function.
3458 /// Alive threads:
3459 ///   Threads in a warp executing the SIMT instruction, as distinguished from
3460 ///   threads that are inactive due to divergent control flow.
3461 /// Active threads:
3462 ///   The minimal set of threads that has to be alive upon entry to this
3463 ///   function.  The computation is correct iff active threads are alive.
3464 ///   Some threads are alive but they are not active because they do not
3465 ///   contribute to the computation in any useful manner.  Turning them off
3466 ///   may introduce control flow overheads without any tangible benefits.
3467 /// Effective threads:
3468 ///   In order to comply with the argument requirements of the shuffle
3469 ///   function, we must keep all lanes holding data alive.  But at most
3470 ///   half of them perform value aggregation; we refer to this half of
3471 ///   threads as effective. The other half is simply handing off their
3472 ///   data.
3473 ///
3474 /// Procedure
3475 /// Value shuffle:
3476 ///   In this step active threads transfer data from higher lane positions
3477 ///   in the warp to lower lane positions, creating Remote Reduce list.
3478 /// Value aggregation:
3479 ///   In this step, effective threads combine their thread local Reduce list
3480 ///   with Remote Reduce list and store the result in the thread local
3481 ///   Reduce list.
3482 /// Value copy:
3483 ///   In this step, we deal with the assumption made by algorithm 2
3484 ///   (i.e. contiguity assumption).  When we have an odd number of lanes
3485 ///   active, say 2k+1, only k threads will be effective and therefore k
3486 ///   new values will be produced.  However, the Reduce list owned by the
3487 ///   (2k+1)th thread is ignored in the value aggregation.  Therefore
3488 ///   we copy the Reduce list from the (2k+1)th lane to (k+1)th lane so
3489 ///   that the contiguity assumption still holds.
3490 static llvm::Function *emitShuffleAndReduceFunction(
3491     CodeGenModule &CGM, ArrayRef<const Expr *> Privates,
3492     QualType ReductionArrayTy, llvm::Function *ReduceFn, SourceLocation Loc) {
3493   ASTContext &C = CGM.getContext();
3494
3495   // Thread local Reduce list used to host the values of data to be reduced.
3496   ImplicitParamDecl ReduceListArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
3497                                   C.VoidPtrTy, ImplicitParamDecl::Other);
3498   // Current lane id; could be logical.
3499   ImplicitParamDecl LaneIDArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr, C.ShortTy,
3500                               ImplicitParamDecl::Other);
3501   // Offset of the remote source lane relative to the current lane.
3502   ImplicitParamDecl RemoteLaneOffsetArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
3503                                         C.ShortTy, ImplicitParamDecl::Other);
3504   // Algorithm version.  This is expected to be known at compile time.
3505   ImplicitParamDecl AlgoVerArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
3506                                C.ShortTy, ImplicitParamDecl::Other);
3507   FunctionArgList Args;
3508   Args.push_back(&ReduceListArg);
3509   Args.push_back(&LaneIDArg);
3510   Args.push_back(&RemoteLaneOffsetArg);
3511   Args.push_back(&AlgoVerArg);
3512
3513   const CGFunctionInfo &CGFI =
3514       CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, Args);
3515   auto *Fn = llvm::Function::Create(
3516       CGM.getTypes().GetFunctionType(CGFI), llvm::GlobalValue::InternalLinkage,
3517       "_omp_reduction_shuffle_and_reduce_func", &CGM.getModule());
3518   CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, CGFI);
3519   Fn->setDoesNotRecurse();
3520   if (CGM.getLangOpts().Optimize) {
3521     Fn->removeFnAttr(llvm::Attribute::NoInline);
3522     Fn->removeFnAttr(llvm::Attribute::OptimizeNone);
3523     Fn->addFnAttr(llvm::Attribute::AlwaysInline);
3524   }
3525
3526   CodeGenFunction CGF(CGM);
3527   CGF.StartFunction(GlobalDecl(), C.VoidTy, Fn, CGFI, Args, Loc, Loc);
3528
3529   CGBuilderTy &Bld = CGF.Builder;
3530
3531   Address AddrReduceListArg = CGF.GetAddrOfLocalVar(&ReduceListArg);
3532   Address LocalReduceList(
3533       Bld.CreatePointerBitCastOrAddrSpaceCast(
3534           CGF.EmitLoadOfScalar(AddrReduceListArg, /*Volatile=*/false,
3535                                C.VoidPtrTy, SourceLocation()),
3536           CGF.ConvertTypeForMem(ReductionArrayTy)->getPointerTo()),
3537       CGF.getPointerAlign());
3538
3539   Address AddrLaneIDArg = CGF.GetAddrOfLocalVar(&LaneIDArg);
3540   llvm::Value *LaneIDArgVal = CGF.EmitLoadOfScalar(
3541       AddrLaneIDArg, /*Volatile=*/false, C.ShortTy, SourceLocation());
3542
3543   Address AddrRemoteLaneOffsetArg = CGF.GetAddrOfLocalVar(&RemoteLaneOffsetArg);
3544   llvm::Value *RemoteLaneOffsetArgVal = CGF.EmitLoadOfScalar(
3545       AddrRemoteLaneOffsetArg, /*Volatile=*/false, C.ShortTy, SourceLocation());
3546
3547   Address AddrAlgoVerArg = CGF.GetAddrOfLocalVar(&AlgoVerArg);
3548   llvm::Value *AlgoVerArgVal = CGF.EmitLoadOfScalar(
3549       AddrAlgoVerArg, /*Volatile=*/false, C.ShortTy, SourceLocation());
3550
3551   // Create a local thread-private variable to host the Reduce list
3552   // from a remote lane.
3553   Address RemoteReduceList =
3554       CGF.CreateMemTemp(ReductionArrayTy, ".omp.reduction.remote_reduce_list");
3555
3556   // This loop iterates through the list of reduce elements and copies,
3557   // element by element, from a remote lane in the warp to RemoteReduceList,
3558   // hosted on the thread's stack.
3559   emitReductionListCopy(RemoteLaneToThread, CGF, ReductionArrayTy, Privates,
3560                         LocalReduceList, RemoteReduceList,
3561                         {/*RemoteLaneOffset=*/RemoteLaneOffsetArgVal,
3562                          /*ScratchpadIndex=*/nullptr,
3563                          /*ScratchpadWidth=*/nullptr});
3564
3565   // The actions to be performed on the Remote Reduce list is dependent
3566   // on the algorithm version.
3567   //
3568   //  if (AlgoVer==0) || (AlgoVer==1 && (LaneId < Offset)) || (AlgoVer==2 &&
3569   //  LaneId % 2 == 0 && Offset > 0):
3570   //    do the reduction value aggregation
3571   //
3572   //  The thread local variable Reduce list is mutated in place to host the
3573   //  reduced data, which is the aggregated value produced from local and
3574   //  remote lanes.
3575   //
3576   //  Note that AlgoVer is expected to be a constant integer known at compile
3577   //  time.
3578   //  When AlgoVer==0, the first conjunction evaluates to true, making
3579   //    the entire predicate true during compile time.
3580   //  When AlgoVer==1, the second conjunction has only the second part to be
3581   //    evaluated during runtime.  Other conjunctions evaluates to false
3582   //    during compile time.
3583   //  When AlgoVer==2, the third conjunction has only the second part to be
3584   //    evaluated during runtime.  Other conjunctions evaluates to false
3585   //    during compile time.
3586   llvm::Value *CondAlgo0 = Bld.CreateIsNull(AlgoVerArgVal);
3587
3588   llvm::Value *Algo1 = Bld.CreateICmpEQ(AlgoVerArgVal, Bld.getInt16(1));
3589   llvm::Value *CondAlgo1 = Bld.CreateAnd(
3590       Algo1, Bld.CreateICmpULT(LaneIDArgVal, RemoteLaneOffsetArgVal));
3591
3592   llvm::Value *Algo2 = Bld.CreateICmpEQ(AlgoVerArgVal, Bld.getInt16(2));
3593   llvm::Value *CondAlgo2 = Bld.CreateAnd(
3594       Algo2, Bld.CreateIsNull(Bld.CreateAnd(LaneIDArgVal, Bld.getInt16(1))));
3595   CondAlgo2 = Bld.CreateAnd(
3596       CondAlgo2, Bld.CreateICmpSGT(RemoteLaneOffsetArgVal, Bld.getInt16(0)));
3597
3598   llvm::Value *CondReduce = Bld.CreateOr(CondAlgo0, CondAlgo1);
3599   CondReduce = Bld.CreateOr(CondReduce, CondAlgo2);
3600
3601   llvm::BasicBlock *ThenBB = CGF.createBasicBlock("then");
3602   llvm::BasicBlock *ElseBB = CGF.createBasicBlock("else");
3603   llvm::BasicBlock *MergeBB = CGF.createBasicBlock("ifcont");
3604   Bld.CreateCondBr(CondReduce, ThenBB, ElseBB);
3605
3606   CGF.EmitBlock(ThenBB);
3607   // reduce_function(LocalReduceList, RemoteReduceList)
3608   llvm::Value *LocalReduceListPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
3609       LocalReduceList.getPointer(), CGF.VoidPtrTy);
3610   llvm::Value *RemoteReduceListPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
3611       RemoteReduceList.getPointer(), CGF.VoidPtrTy);
3612   CGM.getOpenMPRuntime().emitOutlinedFunctionCall(
3613       CGF, Loc, ReduceFn, {LocalReduceListPtr, RemoteReduceListPtr});
3614   Bld.CreateBr(MergeBB);
3615
3616   CGF.EmitBlock(ElseBB);
3617   Bld.CreateBr(MergeBB);
3618
3619   CGF.EmitBlock(MergeBB);
3620
3621   // if (AlgoVer==1 && (LaneId >= Offset)) copy Remote Reduce list to local
3622   // Reduce list.
3623   Algo1 = Bld.CreateICmpEQ(AlgoVerArgVal, Bld.getInt16(1));
3624   llvm::Value *CondCopy = Bld.CreateAnd(
3625       Algo1, Bld.CreateICmpUGE(LaneIDArgVal, RemoteLaneOffsetArgVal));
3626
3627   llvm::BasicBlock *CpyThenBB = CGF.createBasicBlock("then");
3628   llvm::BasicBlock *CpyElseBB = CGF.createBasicBlock("else");
3629   llvm::BasicBlock *CpyMergeBB = CGF.createBasicBlock("ifcont");
3630   Bld.CreateCondBr(CondCopy, CpyThenBB, CpyElseBB);
3631
3632   CGF.EmitBlock(CpyThenBB);
3633   emitReductionListCopy(ThreadCopy, CGF, ReductionArrayTy, Privates,
3634                         RemoteReduceList, LocalReduceList);
3635   Bld.CreateBr(CpyMergeBB);
3636
3637   CGF.EmitBlock(CpyElseBB);
3638   Bld.CreateBr(CpyMergeBB);
3639
3640   CGF.EmitBlock(CpyMergeBB);
3641
3642   CGF.FinishFunction();
3643   return Fn;
3644 }
3645
3646 /// This function emits a helper that copies all the reduction variables from
3647 /// the team into the provided global buffer for the reduction variables.
3648 ///
3649 /// void list_to_global_copy_func(void *buffer, int Idx, void *reduce_data)
3650 ///   For all data entries D in reduce_data:
3651 ///     Copy local D to buffer.D[Idx]
3652 static llvm::Value *emitListToGlobalCopyFunction(
3653     CodeGenModule &CGM, ArrayRef<const Expr *> Privates,
3654     QualType ReductionArrayTy, SourceLocation Loc,
3655     const RecordDecl *TeamReductionRec,
3656     const llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *>
3657         &VarFieldMap) {
3658   ASTContext &C = CGM.getContext();
3659
3660   // Buffer: global reduction buffer.
3661   ImplicitParamDecl BufferArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
3662                               C.VoidPtrTy, ImplicitParamDecl::Other);
3663   // Idx: index of the buffer.
3664   ImplicitParamDecl IdxArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr, C.IntTy,
3665                            ImplicitParamDecl::Other);
3666   // ReduceList: thread local Reduce list.
3667   ImplicitParamDecl ReduceListArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
3668                                   C.VoidPtrTy, ImplicitParamDecl::Other);
3669   FunctionArgList Args;
3670   Args.push_back(&BufferArg);
3671   Args.push_back(&IdxArg);
3672   Args.push_back(&ReduceListArg);
3673
3674   const CGFunctionInfo &CGFI =
3675       CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, Args);
3676   auto *Fn = llvm::Function::Create(
3677       CGM.getTypes().GetFunctionType(CGFI), llvm::GlobalValue::InternalLinkage,
3678       "_omp_reduction_list_to_global_copy_func", &CGM.getModule());
3679   CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, CGFI);
3680   Fn->setDoesNotRecurse();
3681   CodeGenFunction CGF(CGM);
3682   CGF.StartFunction(GlobalDecl(), C.VoidTy, Fn, CGFI, Args, Loc, Loc);
3683
3684   CGBuilderTy &Bld = CGF.Builder;
3685
3686   Address AddrReduceListArg = CGF.GetAddrOfLocalVar(&ReduceListArg);
3687   Address AddrBufferArg = CGF.GetAddrOfLocalVar(&BufferArg);
3688   Address LocalReduceList(
3689       Bld.CreatePointerBitCastOrAddrSpaceCast(
3690           CGF.EmitLoadOfScalar(AddrReduceListArg, /*Volatile=*/false,
3691                                C.VoidPtrTy, Loc),
3692           CGF.ConvertTypeForMem(ReductionArrayTy)->getPointerTo()),
3693       CGF.getPointerAlign());
3694   QualType StaticTy = C.getRecordType(TeamReductionRec);
3695   llvm::Type *LLVMReductionsBufferTy =
3696       CGM.getTypes().ConvertTypeForMem(StaticTy);
3697   llvm::Value *BufferArrPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
3698       CGF.EmitLoadOfScalar(AddrBufferArg, /*Volatile=*/false, C.VoidPtrTy, Loc),
3699       LLVMReductionsBufferTy->getPointerTo());
3700   llvm::Value *Idxs[] = {llvm::ConstantInt::getNullValue(CGF.Int32Ty),
3701                          CGF.EmitLoadOfScalar(CGF.GetAddrOfLocalVar(&IdxArg),
3702                                               /*Volatile=*/false, C.IntTy,
3703                                               Loc)};
3704   unsigned Idx = 0;
3705   for (const Expr *Private : Privates) {
3706     // Reduce element = LocalReduceList[i]
3707     Address ElemPtrPtrAddr = Bld.CreateConstArrayGEP(LocalReduceList, Idx);
3708     llvm::Value *ElemPtrPtr = CGF.EmitLoadOfScalar(
3709         ElemPtrPtrAddr, /*Volatile=*/false, C.VoidPtrTy, SourceLocation());
3710     // elemptr = ((CopyType*)(elemptrptr)) + I
3711     ElemPtrPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
3712         ElemPtrPtr, CGF.ConvertTypeForMem(Private->getType())->getPointerTo());
3713     Address ElemPtr =
3714         Address(ElemPtrPtr, C.getTypeAlignInChars(Private->getType()));
3715     const ValueDecl *VD = cast<DeclRefExpr>(Private)->getDecl();
3716     // Global = Buffer.VD[Idx];
3717     const FieldDecl *FD = VarFieldMap.lookup(VD);
3718     LValue GlobLVal = CGF.EmitLValueForField(
3719         CGF.MakeNaturalAlignAddrLValue(BufferArrPtr, StaticTy), FD);
3720     llvm::Value *BufferPtr =
3721         Bld.CreateInBoundsGEP(GlobLVal.getPointer(CGF), Idxs);
3722     GlobLVal.setAddress(Address(BufferPtr, GlobLVal.getAlignment()));
3723     switch (CGF.getEvaluationKind(Private->getType())) {
3724     case TEK_Scalar: {
3725       llvm::Value *V = CGF.EmitLoadOfScalar(ElemPtr, /*Volatile=*/false,
3726                                             Private->getType(), Loc);
3727       CGF.EmitStoreOfScalar(V, GlobLVal);
3728       break;
3729     }
3730     case TEK_Complex: {
3731       CodeGenFunction::ComplexPairTy V = CGF.EmitLoadOfComplex(
3732           CGF.MakeAddrLValue(ElemPtr, Private->getType()), Loc);
3733       CGF.EmitStoreOfComplex(V, GlobLVal, /*isInit=*/false);
3734       break;
3735     }
3736     case TEK_Aggregate:
3737       CGF.EmitAggregateCopy(GlobLVal,
3738                             CGF.MakeAddrLValue(ElemPtr, Private->getType()),
3739                             Private->getType(), AggValueSlot::DoesNotOverlap);
3740       break;
3741     }
3742     ++Idx;
3743   }
3744
3745   CGF.FinishFunction();
3746   return Fn;
3747 }
3748
3749 /// This function emits a helper that reduces all the reduction variables from
3750 /// the team into the provided global buffer for the reduction variables.
3751 ///
3752 /// void list_to_global_reduce_func(void *buffer, int Idx, void *reduce_data)
3753 ///  void *GlobPtrs[];
3754 ///  GlobPtrs[0] = (void*)&buffer.D0[Idx];
3755 ///  ...
3756 ///  GlobPtrs[N] = (void*)&buffer.DN[Idx];
3757 ///  reduce_function(GlobPtrs, reduce_data);
3758 static llvm::Value *emitListToGlobalReduceFunction(
3759     CodeGenModule &CGM, ArrayRef<const Expr *> Privates,
3760     QualType ReductionArrayTy, SourceLocation Loc,
3761     const RecordDecl *TeamReductionRec,
3762     const llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *>
3763         &VarFieldMap,
3764     llvm::Function *ReduceFn) {
3765   ASTContext &C = CGM.getContext();
3766
3767   // Buffer: global reduction buffer.
3768   ImplicitParamDecl BufferArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
3769                               C.VoidPtrTy, ImplicitParamDecl::Other);
3770   // Idx: index of the buffer.
3771   ImplicitParamDecl IdxArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr, C.IntTy,
3772                            ImplicitParamDecl::Other);
3773   // ReduceList: thread local Reduce list.
3774   ImplicitParamDecl ReduceListArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
3775                                   C.VoidPtrTy, ImplicitParamDecl::Other);
3776   FunctionArgList Args;
3777   Args.push_back(&BufferArg);
3778   Args.push_back(&IdxArg);
3779   Args.push_back(&ReduceListArg);
3780
3781   const CGFunctionInfo &CGFI =
3782       CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, Args);
3783   auto *Fn = llvm::Function::Create(
3784       CGM.getTypes().GetFunctionType(CGFI), llvm::GlobalValue::InternalLinkage,
3785       "_omp_reduction_list_to_global_reduce_func", &CGM.getModule());
3786   CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, CGFI);
3787   Fn->setDoesNotRecurse();
3788   CodeGenFunction CGF(CGM);
3789   CGF.StartFunction(GlobalDecl(), C.VoidTy, Fn, CGFI, Args, Loc, Loc);
3790
3791   CGBuilderTy &Bld = CGF.Builder;
3792
3793   Address AddrBufferArg = CGF.GetAddrOfLocalVar(&BufferArg);
3794   QualType StaticTy = C.getRecordType(TeamReductionRec);
3795   llvm::Type *LLVMReductionsBufferTy =
3796       CGM.getTypes().ConvertTypeForMem(StaticTy);
3797   llvm::Value *BufferArrPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
3798       CGF.EmitLoadOfScalar(AddrBufferArg, /*Volatile=*/false, C.VoidPtrTy, Loc),
3799       LLVMReductionsBufferTy->getPointerTo());
3800
3801   // 1. Build a list of reduction variables.
3802   // void *RedList[<n>] = {<ReductionVars>[0], ..., <ReductionVars>[<n>-1]};
3803   Address ReductionList =
3804       CGF.CreateMemTemp(ReductionArrayTy, ".omp.reduction.red_list");
3805   auto IPriv = Privates.begin();
3806   llvm::Value *Idxs[] = {llvm::ConstantInt::getNullValue(CGF.Int32Ty),
3807                          CGF.EmitLoadOfScalar(CGF.GetAddrOfLocalVar(&IdxArg),
3808                                               /*Volatile=*/false, C.IntTy,
3809                                               Loc)};
3810   unsigned Idx = 0;
3811   for (unsigned I = 0, E = Privates.size(); I < E; ++I, ++IPriv, ++Idx) {
3812     Address Elem = CGF.Builder.CreateConstArrayGEP(ReductionList, Idx);
3813     // Global = Buffer.VD[Idx];
3814     const ValueDecl *VD = cast<DeclRefExpr>(*IPriv)->getDecl();
3815     const FieldDecl *FD = VarFieldMap.lookup(VD);
3816     LValue GlobLVal = CGF.EmitLValueForField(
3817         CGF.MakeNaturalAlignAddrLValue(BufferArrPtr, StaticTy), FD);
3818     llvm::Value *BufferPtr =
3819         Bld.CreateInBoundsGEP(GlobLVal.getPointer(CGF), Idxs);
3820     llvm::Value *Ptr = CGF.EmitCastToVoidPtr(BufferPtr);
3821     CGF.EmitStoreOfScalar(Ptr, Elem, /*Volatile=*/false, C.VoidPtrTy);
3822     if ((*IPriv)->getType()->isVariablyModifiedType()) {
3823       // Store array size.
3824       ++Idx;
3825       Elem = CGF.Builder.CreateConstArrayGEP(ReductionList, Idx);
3826       llvm::Value *Size = CGF.Builder.CreateIntCast(
3827           CGF.getVLASize(
3828                  CGF.getContext().getAsVariableArrayType((*IPriv)->getType()))
3829               .NumElts,
3830           CGF.SizeTy, /*isSigned=*/false);
3831       CGF.Builder.CreateStore(CGF.Builder.CreateIntToPtr(Size, CGF.VoidPtrTy),
3832                               Elem);
3833     }
3834   }
3835
3836   // Call reduce_function(GlobalReduceList, ReduceList)
3837   llvm::Value *GlobalReduceList =
3838       CGF.EmitCastToVoidPtr(ReductionList.getPointer());
3839   Address AddrReduceListArg = CGF.GetAddrOfLocalVar(&ReduceListArg);
3840   llvm::Value *ReducedPtr = CGF.EmitLoadOfScalar(
3841       AddrReduceListArg, /*Volatile=*/false, C.VoidPtrTy, Loc);
3842   CGM.getOpenMPRuntime().emitOutlinedFunctionCall(
3843       CGF, Loc, ReduceFn, {GlobalReduceList, ReducedPtr});
3844   CGF.FinishFunction();
3845   return Fn;
3846 }
3847
3848 /// This function emits a helper that copies all the reduction variables from
3849 /// the team into the provided global buffer for the reduction variables.
3850 ///
3851 /// void list_to_global_copy_func(void *buffer, int Idx, void *reduce_data)
3852 ///   For all data entries D in reduce_data:
3853 ///     Copy buffer.D[Idx] to local D;
3854 static llvm::Value *emitGlobalToListCopyFunction(
3855     CodeGenModule &CGM, ArrayRef<const Expr *> Privates,
3856     QualType ReductionArrayTy, SourceLocation Loc,
3857     const RecordDecl *TeamReductionRec,
3858     const llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *>
3859         &VarFieldMap) {
3860   ASTContext &C = CGM.getContext();
3861
3862   // Buffer: global reduction buffer.
3863   ImplicitParamDecl BufferArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
3864                               C.VoidPtrTy, ImplicitParamDecl::Other);
3865   // Idx: index of the buffer.
3866   ImplicitParamDecl IdxArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr, C.IntTy,
3867                            ImplicitParamDecl::Other);
3868   // ReduceList: thread local Reduce list.
3869   ImplicitParamDecl ReduceListArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
3870                                   C.VoidPtrTy, ImplicitParamDecl::Other);
3871   FunctionArgList Args;
3872   Args.push_back(&BufferArg);
3873   Args.push_back(&IdxArg);
3874   Args.push_back(&ReduceListArg);
3875
3876   const CGFunctionInfo &CGFI =
3877       CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, Args);
3878   auto *Fn = llvm::Function::Create(
3879       CGM.getTypes().GetFunctionType(CGFI), llvm::GlobalValue::InternalLinkage,
3880       "_omp_reduction_global_to_list_copy_func", &CGM.getModule());
3881   CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, CGFI);
3882   Fn->setDoesNotRecurse();
3883   CodeGenFunction CGF(CGM);
3884   CGF.StartFunction(GlobalDecl(), C.VoidTy, Fn, CGFI, Args, Loc, Loc);
3885
3886   CGBuilderTy &Bld = CGF.Builder;
3887
3888   Address AddrReduceListArg = CGF.GetAddrOfLocalVar(&ReduceListArg);
3889   Address AddrBufferArg = CGF.GetAddrOfLocalVar(&BufferArg);
3890   Address LocalReduceList(
3891       Bld.CreatePointerBitCastOrAddrSpaceCast(
3892           CGF.EmitLoadOfScalar(AddrReduceListArg, /*Volatile=*/false,
3893                                C.VoidPtrTy, Loc),
3894           CGF.ConvertTypeForMem(ReductionArrayTy)->getPointerTo()),
3895       CGF.getPointerAlign());
3896   QualType StaticTy = C.getRecordType(TeamReductionRec);
3897   llvm::Type *LLVMReductionsBufferTy =
3898       CGM.getTypes().ConvertTypeForMem(StaticTy);
3899   llvm::Value *BufferArrPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
3900       CGF.EmitLoadOfScalar(AddrBufferArg, /*Volatile=*/false, C.VoidPtrTy, Loc),
3901       LLVMReductionsBufferTy->getPointerTo());
3902
3903   llvm::Value *Idxs[] = {llvm::ConstantInt::getNullValue(CGF.Int32Ty),
3904                          CGF.EmitLoadOfScalar(CGF.GetAddrOfLocalVar(&IdxArg),
3905                                               /*Volatile=*/false, C.IntTy,
3906                                               Loc)};
3907   unsigned Idx = 0;
3908   for (const Expr *Private : Privates) {
3909     // Reduce element = LocalReduceList[i]
3910     Address ElemPtrPtrAddr = Bld.CreateConstArrayGEP(LocalReduceList, Idx);
3911     llvm::Value *ElemPtrPtr = CGF.EmitLoadOfScalar(
3912         ElemPtrPtrAddr, /*Volatile=*/false, C.VoidPtrTy, SourceLocation());
3913     // elemptr = ((CopyType*)(elemptrptr)) + I
3914     ElemPtrPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
3915         ElemPtrPtr, CGF.ConvertTypeForMem(Private->getType())->getPointerTo());
3916     Address ElemPtr =
3917         Address(ElemPtrPtr, C.getTypeAlignInChars(Private->getType()));
3918     const ValueDecl *VD = cast<DeclRefExpr>(Private)->getDecl();
3919     // Global = Buffer.VD[Idx];
3920     const FieldDecl *FD = VarFieldMap.lookup(VD);
3921     LValue GlobLVal = CGF.EmitLValueForField(
3922         CGF.MakeNaturalAlignAddrLValue(BufferArrPtr, StaticTy), FD);
3923     llvm::Value *BufferPtr =
3924         Bld.CreateInBoundsGEP(GlobLVal.getPointer(CGF), Idxs);
3925     GlobLVal.setAddress(Address(BufferPtr, GlobLVal.getAlignment()));
3926     switch (CGF.getEvaluationKind(Private->getType())) {
3927     case TEK_Scalar: {
3928       llvm::Value *V = CGF.EmitLoadOfScalar(GlobLVal, Loc);
3929       CGF.EmitStoreOfScalar(V, ElemPtr, /*Volatile=*/false, Private->getType());
3930       break;
3931     }
3932     case TEK_Complex: {
3933       CodeGenFunction::ComplexPairTy V = CGF.EmitLoadOfComplex(GlobLVal, Loc);
3934       CGF.EmitStoreOfComplex(V, CGF.MakeAddrLValue(ElemPtr, Private->getType()),
3935                              /*isInit=*/false);
3936       break;
3937     }
3938     case TEK_Aggregate:
3939       CGF.EmitAggregateCopy(CGF.MakeAddrLValue(ElemPtr, Private->getType()),
3940                             GlobLVal, Private->getType(),
3941                             AggValueSlot::DoesNotOverlap);
3942       break;
3943     }
3944     ++Idx;
3945   }
3946
3947   CGF.FinishFunction();
3948   return Fn;
3949 }
3950
3951 /// This function emits a helper that reduces all the reduction variables from
3952 /// the team into the provided global buffer for the reduction variables.
3953 ///
3954 /// void global_to_list_reduce_func(void *buffer, int Idx, void *reduce_data)
3955 ///  void *GlobPtrs[];
3956 ///  GlobPtrs[0] = (void*)&buffer.D0[Idx];
3957 ///  ...
3958 ///  GlobPtrs[N] = (void*)&buffer.DN[Idx];
3959 ///  reduce_function(reduce_data, GlobPtrs);
3960 static llvm::Value *emitGlobalToListReduceFunction(
3961     CodeGenModule &CGM, ArrayRef<const Expr *> Privates,
3962     QualType ReductionArrayTy, SourceLocation Loc,
3963     const RecordDecl *TeamReductionRec,
3964     const llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *>
3965         &VarFieldMap,
3966     llvm::Function *ReduceFn) {
3967   ASTContext &C = CGM.getContext();
3968
3969   // Buffer: global reduction buffer.
3970   ImplicitParamDecl BufferArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
3971                               C.VoidPtrTy, ImplicitParamDecl::Other);
3972   // Idx: index of the buffer.
3973   ImplicitParamDecl IdxArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr, C.IntTy,
3974                            ImplicitParamDecl::Other);
3975   // ReduceList: thread local Reduce list.
3976   ImplicitParamDecl ReduceListArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
3977                                   C.VoidPtrTy, ImplicitParamDecl::Other);
3978   FunctionArgList Args;
3979   Args.push_back(&BufferArg);
3980   Args.push_back(&IdxArg);
3981   Args.push_back(&ReduceListArg);
3982
3983   const CGFunctionInfo &CGFI =
3984       CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, Args);
3985   auto *Fn = llvm::Function::Create(
3986       CGM.getTypes().GetFunctionType(CGFI), llvm::GlobalValue::InternalLinkage,
3987       "_omp_reduction_global_to_list_reduce_func", &CGM.getModule());
3988   CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, CGFI);
3989   Fn->setDoesNotRecurse();
3990   CodeGenFunction CGF(CGM);
3991   CGF.StartFunction(GlobalDecl(), C.VoidTy, Fn, CGFI, Args, Loc, Loc);
3992
3993   CGBuilderTy &Bld = CGF.Builder;
3994
3995   Address AddrBufferArg = CGF.GetAddrOfLocalVar(&BufferArg);
3996   QualType StaticTy = C.getRecordType(TeamReductionRec);
3997   llvm::Type *LLVMReductionsBufferTy =
3998       CGM.getTypes().ConvertTypeForMem(StaticTy);
3999   llvm::Value *BufferArrPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
4000       CGF.EmitLoadOfScalar(AddrBufferArg, /*Volatile=*/false, C.VoidPtrTy, Loc),
4001       LLVMReductionsBufferTy->getPointerTo());
4002
4003   // 1. Build a list of reduction variables.
4004   // void *RedList[<n>] = {<ReductionVars>[0], ..., <ReductionVars>[<n>-1]};
4005   Address ReductionList =
4006       CGF.CreateMemTemp(ReductionArrayTy, ".omp.reduction.red_list");
4007   auto IPriv = Privates.begin();
4008   llvm::Value *Idxs[] = {llvm::ConstantInt::getNullValue(CGF.Int32Ty),
4009                          CGF.EmitLoadOfScalar(CGF.GetAddrOfLocalVar(&IdxArg),
4010                                               /*Volatile=*/false, C.IntTy,
4011                                               Loc)};
4012   unsigned Idx = 0;
4013   for (unsigned I = 0, E = Privates.size(); I < E; ++I, ++IPriv, ++Idx) {
4014     Address Elem = CGF.Builder.CreateConstArrayGEP(ReductionList, Idx);
4015     // Global = Buffer.VD[Idx];
4016     const ValueDecl *VD = cast<DeclRefExpr>(*IPriv)->getDecl();
4017     const FieldDecl *FD = VarFieldMap.lookup(VD);
4018     LValue GlobLVal = CGF.EmitLValueForField(
4019         CGF.MakeNaturalAlignAddrLValue(BufferArrPtr, StaticTy), FD);
4020     llvm::Value *BufferPtr =
4021         Bld.CreateInBoundsGEP(GlobLVal.getPointer(CGF), Idxs);
4022     llvm::Value *Ptr = CGF.EmitCastToVoidPtr(BufferPtr);
4023     CGF.EmitStoreOfScalar(Ptr, Elem, /*Volatile=*/false, C.VoidPtrTy);
4024     if ((*IPriv)->getType()->isVariablyModifiedType()) {
4025       // Store array size.
4026       ++Idx;
4027       Elem = CGF.Builder.CreateConstArrayGEP(ReductionList, Idx);
4028       llvm::Value *Size = CGF.Builder.CreateIntCast(
4029           CGF.getVLASize(
4030                  CGF.getContext().getAsVariableArrayType((*IPriv)->getType()))
4031               .NumElts,
4032           CGF.SizeTy, /*isSigned=*/false);
4033       CGF.Builder.CreateStore(CGF.Builder.CreateIntToPtr(Size, CGF.VoidPtrTy),
4034                               Elem);
4035     }
4036   }
4037
4038   // Call reduce_function(ReduceList, GlobalReduceList)
4039   llvm::Value *GlobalReduceList =
4040       CGF.EmitCastToVoidPtr(ReductionList.getPointer());
4041   Address AddrReduceListArg = CGF.GetAddrOfLocalVar(&ReduceListArg);
4042   llvm::Value *ReducedPtr = CGF.EmitLoadOfScalar(
4043       AddrReduceListArg, /*Volatile=*/false, C.VoidPtrTy, Loc);
4044   CGM.getOpenMPRuntime().emitOutlinedFunctionCall(
4045       CGF, Loc, ReduceFn, {ReducedPtr, GlobalReduceList});
4046   CGF.FinishFunction();
4047   return Fn;
4048 }
4049
4050 ///
4051 /// Design of OpenMP reductions on the GPU
4052 ///
4053 /// Consider a typical OpenMP program with one or more reduction
4054 /// clauses:
4055 ///
4056 /// float foo;
4057 /// double bar;
4058 /// #pragma omp target teams distribute parallel for \
4059 ///             reduction(+:foo) reduction(*:bar)
4060 /// for (int i = 0; i < N; i++) {
4061 ///   foo += A[i]; bar *= B[i];
4062 /// }
4063 ///
4064 /// where 'foo' and 'bar' are reduced across all OpenMP threads in
4065 /// all teams.  In our OpenMP implementation on the NVPTX device an
4066 /// OpenMP team is mapped to a CUDA threadblock and OpenMP threads
4067 /// within a team are mapped to CUDA threads within a threadblock.
4068 /// Our goal is to efficiently aggregate values across all OpenMP
4069 /// threads such that:
4070 ///
4071 ///   - the compiler and runtime are logically concise, and
4072 ///   - the reduction is performed efficiently in a hierarchical
4073 ///     manner as follows: within OpenMP threads in the same warp,
4074 ///     across warps in a threadblock, and finally across teams on
4075 ///     the NVPTX device.
4076 ///
4077 /// Introduction to Decoupling
4078 ///
4079 /// We would like to decouple the compiler and the runtime so that the
4080 /// latter is ignorant of the reduction variables (number, data types)
4081 /// and the reduction operators.  This allows a simpler interface
4082 /// and implementation while still attaining good performance.
4083 ///
4084 /// Pseudocode for the aforementioned OpenMP program generated by the
4085 /// compiler is as follows:
4086 ///
4087 /// 1. Create private copies of reduction variables on each OpenMP
4088 ///    thread: 'foo_private', 'bar_private'
4089 /// 2. Each OpenMP thread reduces the chunk of 'A' and 'B' assigned
4090 ///    to it and writes the result in 'foo_private' and 'bar_private'
4091 ///    respectively.
4092 /// 3. Call the OpenMP runtime on the GPU to reduce within a team
4093 ///    and store the result on the team master:
4094 ///
4095 ///     __kmpc_nvptx_parallel_reduce_nowait_v2(...,
4096 ///        reduceData, shuffleReduceFn, interWarpCpyFn)
4097 ///
4098 ///     where:
4099 ///       struct ReduceData {
4100 ///         double *foo;
4101 ///         double *bar;
4102 ///       } reduceData
4103 ///       reduceData.foo = &foo_private
4104 ///       reduceData.bar = &bar_private
4105 ///
4106 ///     'shuffleReduceFn' and 'interWarpCpyFn' are pointers to two
4107 ///     auxiliary functions generated by the compiler that operate on
4108 ///     variables of type 'ReduceData'.  They aid the runtime perform
4109 ///     algorithmic steps in a data agnostic manner.
4110 ///
4111 ///     'shuffleReduceFn' is a pointer to a function that reduces data
4112 ///     of type 'ReduceData' across two OpenMP threads (lanes) in the
4113 ///     same warp.  It takes the following arguments as input:
4114 ///
4115 ///     a. variable of type 'ReduceData' on the calling lane,
4116 ///     b. its lane_id,
4117 ///     c. an offset relative to the current lane_id to generate a
4118 ///        remote_lane_id.  The remote lane contains the second
4119 ///        variable of type 'ReduceData' that is to be reduced.
4120 ///     d. an algorithm version parameter determining which reduction
4121 ///        algorithm to use.
4122 ///
4123 ///     'shuffleReduceFn' retrieves data from the remote lane using
4124 ///     efficient GPU shuffle intrinsics and reduces, using the
4125 ///     algorithm specified by the 4th parameter, the two operands
4126 ///     element-wise.  The result is written to the first operand.
4127 ///
4128 ///     Different reduction algorithms are implemented in different
4129 ///     runtime functions, all calling 'shuffleReduceFn' to perform
4130 ///     the essential reduction step.  Therefore, based on the 4th
4131 ///     parameter, this function behaves slightly differently to
4132 ///     cooperate with the runtime to ensure correctness under
4133 ///     different circumstances.
4134 ///
4135 ///     'InterWarpCpyFn' is a pointer to a function that transfers
4136 ///     reduced variables across warps.  It tunnels, through CUDA
4137 ///     shared memory, the thread-private data of type 'ReduceData'
4138 ///     from lane 0 of each warp to a lane in the first warp.
4139 /// 4. Call the OpenMP runtime on the GPU to reduce across teams.
4140 ///    The last team writes the global reduced value to memory.
4141 ///
4142 ///     ret = __kmpc_nvptx_teams_reduce_nowait(...,
4143 ///             reduceData, shuffleReduceFn, interWarpCpyFn,
4144 ///             scratchpadCopyFn, loadAndReduceFn)
4145 ///
4146 ///     'scratchpadCopyFn' is a helper that stores reduced
4147 ///     data from the team master to a scratchpad array in
4148 ///     global memory.
4149 ///
4150 ///     'loadAndReduceFn' is a helper that loads data from
4151 ///     the scratchpad array and reduces it with the input
4152 ///     operand.
4153 ///
4154 ///     These compiler generated functions hide address
4155 ///     calculation and alignment information from the runtime.
4156 /// 5. if ret == 1:
4157 ///     The team master of the last team stores the reduced
4158 ///     result to the globals in memory.
4159 ///     foo += reduceData.foo; bar *= reduceData.bar
4160 ///
4161 ///
4162 /// Warp Reduction Algorithms
4163 ///
4164 /// On the warp level, we have three algorithms implemented in the
4165 /// OpenMP runtime depending on the number of active lanes:
4166 ///
4167 /// Full Warp Reduction
4168 ///
4169 /// The reduce algorithm within a warp where all lanes are active
4170 /// is implemented in the runtime as follows:
4171 ///
4172 /// full_warp_reduce(void *reduce_data,
4173 ///                  kmp_ShuffleReductFctPtr ShuffleReduceFn) {
4174 ///   for (int offset = WARPSIZE/2; offset > 0; offset /= 2)
4175 ///     ShuffleReduceFn(reduce_data, 0, offset, 0);
4176 /// }
4177 ///
4178 /// The algorithm completes in log(2, WARPSIZE) steps.
4179 ///
4180 /// 'ShuffleReduceFn' is used here with lane_id set to 0 because it is
4181 /// not used therefore we save instructions by not retrieving lane_id
4182 /// from the corresponding special registers.  The 4th parameter, which
4183 /// represents the version of the algorithm being used, is set to 0 to
4184 /// signify full warp reduction.
4185 ///
4186 /// In this version, 'ShuffleReduceFn' behaves, per element, as follows:
4187 ///
4188 /// #reduce_elem refers to an element in the local lane's data structure
4189 /// #remote_elem is retrieved from a remote lane
4190 /// remote_elem = shuffle_down(reduce_elem, offset, WARPSIZE);
4191 /// reduce_elem = reduce_elem REDUCE_OP remote_elem;
4192 ///
4193 /// Contiguous Partial Warp Reduction
4194 ///
4195 /// This reduce algorithm is used within a warp where only the first
4196 /// 'n' (n <= WARPSIZE) lanes are active.  It is typically used when the
4197 /// number of OpenMP threads in a parallel region is not a multiple of
4198 /// WARPSIZE.  The algorithm is implemented in the runtime as follows:
4199 ///
4200 /// void
4201 /// contiguous_partial_reduce(void *reduce_data,
4202 ///                           kmp_ShuffleReductFctPtr ShuffleReduceFn,
4203 ///                           int size, int lane_id) {
4204 ///   int curr_size;
4205 ///   int offset;
4206 ///   curr_size = size;
4207 ///   mask = curr_size/2;
4208 ///   while (offset>0) {
4209 ///     ShuffleReduceFn(reduce_data, lane_id, offset, 1);
4210 ///     curr_size = (curr_size+1)/2;
4211 ///     offset = curr_size/2;
4212 ///   }
4213 /// }
4214 ///
4215 /// In this version, 'ShuffleReduceFn' behaves, per element, as follows:
4216 ///
4217 /// remote_elem = shuffle_down(reduce_elem, offset, WARPSIZE);
4218 /// if (lane_id < offset)
4219 ///     reduce_elem = reduce_elem REDUCE_OP remote_elem
4220 /// else
4221 ///     reduce_elem = remote_elem
4222 ///
4223 /// This algorithm assumes that the data to be reduced are located in a
4224 /// contiguous subset of lanes starting from the first.  When there is
4225 /// an odd number of active lanes, the data in the last lane is not
4226 /// aggregated with any other lane's dat but is instead copied over.
4227 ///
4228 /// Dispersed Partial Warp Reduction
4229 ///
4230 /// This algorithm is used within a warp when any discontiguous subset of
4231 /// lanes are active.  It is used to implement the reduction operation
4232 /// across lanes in an OpenMP simd region or in a nested parallel region.
4233 ///
4234 /// void
4235 /// dispersed_partial_reduce(void *reduce_data,
4236 ///                          kmp_ShuffleReductFctPtr ShuffleReduceFn) {
4237 ///   int size, remote_id;
4238 ///   int logical_lane_id = number_of_active_lanes_before_me() * 2;
4239 ///   do {
4240 ///       remote_id = next_active_lane_id_right_after_me();
4241 ///       # the above function returns 0 of no active lane
4242 ///       # is present right after the current lane.
4243 ///       size = number_of_active_lanes_in_this_warp();
4244 ///       logical_lane_id /= 2;
4245 ///       ShuffleReduceFn(reduce_data, logical_lane_id,
4246 ///                       remote_id-1-threadIdx.x, 2);
4247 ///   } while (logical_lane_id % 2 == 0 && size > 1);
4248 /// }
4249 ///
4250 /// There is no assumption made about the initial state of the reduction.
4251 /// Any number of lanes (>=1) could be active at any position.  The reduction
4252 /// result is returned in the first active lane.
4253 ///
4254 /// In this version, 'ShuffleReduceFn' behaves, per element, as follows:
4255 ///
4256 /// remote_elem = shuffle_down(reduce_elem, offset, WARPSIZE);
4257 /// if (lane_id % 2 == 0 && offset > 0)
4258 ///     reduce_elem = reduce_elem REDUCE_OP remote_elem
4259 /// else
4260 ///     reduce_elem = remote_elem
4261 ///
4262 ///
4263 /// Intra-Team Reduction
4264 ///
4265 /// This function, as implemented in the runtime call
4266 /// '__kmpc_nvptx_parallel_reduce_nowait_v2', aggregates data across OpenMP
4267 /// threads in a team.  It first reduces within a warp using the
4268 /// aforementioned algorithms.  We then proceed to gather all such
4269 /// reduced values at the first warp.
4270 ///
4271 /// The runtime makes use of the function 'InterWarpCpyFn', which copies
4272 /// data from each of the "warp master" (zeroth lane of each warp, where
4273 /// warp-reduced data is held) to the zeroth warp.  This step reduces (in
4274 /// a mathematical sense) the problem of reduction across warp masters in
4275 /// a block to the problem of warp reduction.
4276 ///
4277 ///
4278 /// Inter-Team Reduction
4279 ///
4280 /// Once a team has reduced its data to a single value, it is stored in
4281 /// a global scratchpad array.  Since each team has a distinct slot, this
4282 /// can be done without locking.
4283 ///
4284 /// The last team to write to the scratchpad array proceeds to reduce the
4285 /// scratchpad array.  One or more workers in the last team use the helper
4286 /// 'loadAndReduceDataFn' to load and reduce values from the array, i.e.,
4287 /// the k'th worker reduces every k'th element.
4288 ///
4289 /// Finally, a call is made to '__kmpc_nvptx_parallel_reduce_nowait_v2' to
4290 /// reduce across workers and compute a globally reduced value.
4291 ///
4292 void CGOpenMPRuntimeNVPTX::emitReduction(
4293     CodeGenFunction &CGF, SourceLocation Loc, ArrayRef<const Expr *> Privates,
4294     ArrayRef<const Expr *> LHSExprs, ArrayRef<const Expr *> RHSExprs,
4295     ArrayRef<const Expr *> ReductionOps, ReductionOptionsTy Options) {
4296   if (!CGF.HaveInsertPoint())
4297     return;
4298
4299   bool ParallelReduction = isOpenMPParallelDirective(Options.ReductionKind);
4300 #ifndef NDEBUG
4301   bool TeamsReduction = isOpenMPTeamsDirective(Options.ReductionKind);
4302 #endif
4303
4304   if (Options.SimpleReduction) {
4305     assert(!TeamsReduction && !ParallelReduction &&
4306            "Invalid reduction selection in emitReduction.");
4307     CGOpenMPRuntime::emitReduction(CGF, Loc, Privates, LHSExprs, RHSExprs,
4308                                    ReductionOps, Options);
4309     return;
4310   }
4311
4312   assert((TeamsReduction || ParallelReduction) &&
4313          "Invalid reduction selection in emitReduction.");
4314
4315   // Build res = __kmpc_reduce{_nowait}(<gtid>, <n>, sizeof(RedList),
4316   // RedList, shuffle_reduce_func, interwarp_copy_func);
4317   // or
4318   // Build res = __kmpc_reduce_teams_nowait_simple(<loc>, <gtid>, <lck>);
4319   llvm::Value *RTLoc = emitUpdateLocation(CGF, Loc);
4320   llvm::Value *ThreadId = getThreadID(CGF, Loc);
4321
4322   llvm::Value *Res;
4323   ASTContext &C = CGM.getContext();
4324   // 1. Build a list of reduction variables.
4325   // void *RedList[<n>] = {<ReductionVars>[0], ..., <ReductionVars>[<n>-1]};
4326   auto Size = RHSExprs.size();
4327   for (const Expr *E : Privates) {
4328     if (E->getType()->isVariablyModifiedType())
4329       // Reserve place for array size.
4330       ++Size;
4331   }
4332   llvm::APInt ArraySize(/*unsigned int numBits=*/32, Size);
4333   QualType ReductionArrayTy =
4334       C.getConstantArrayType(C.VoidPtrTy, ArraySize, nullptr, ArrayType::Normal,
4335                              /*IndexTypeQuals=*/0);
4336   Address ReductionList =
4337       CGF.CreateMemTemp(ReductionArrayTy, ".omp.reduction.red_list");
4338   auto IPriv = Privates.begin();
4339   unsigned Idx = 0;
4340   for (unsigned I = 0, E = RHSExprs.size(); I < E; ++I, ++IPriv, ++Idx) {
4341     Address Elem = CGF.Builder.CreateConstArrayGEP(ReductionList, Idx);
4342     CGF.Builder.CreateStore(
4343         CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
4344             CGF.EmitLValue(RHSExprs[I]).getPointer(CGF), CGF.VoidPtrTy),
4345         Elem);
4346     if ((*IPriv)->getType()->isVariablyModifiedType()) {
4347       // Store array size.
4348       ++Idx;
4349       Elem = CGF.Builder.CreateConstArrayGEP(ReductionList, Idx);
4350       llvm::Value *Size = CGF.Builder.CreateIntCast(
4351           CGF.getVLASize(
4352                  CGF.getContext().getAsVariableArrayType((*IPriv)->getType()))
4353               .NumElts,
4354           CGF.SizeTy, /*isSigned=*/false);
4355       CGF.Builder.CreateStore(CGF.Builder.CreateIntToPtr(Size, CGF.VoidPtrTy),
4356                               Elem);
4357     }
4358   }
4359
4360   llvm::Value *RL = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
4361       ReductionList.getPointer(), CGF.VoidPtrTy);
4362   llvm::Function *ReductionFn = emitReductionFunction(
4363       Loc, CGF.ConvertTypeForMem(ReductionArrayTy)->getPointerTo(), Privates,
4364       LHSExprs, RHSExprs, ReductionOps);
4365   llvm::Value *ReductionArrayTySize = CGF.getTypeSize(ReductionArrayTy);
4366   llvm::Function *ShuffleAndReduceFn = emitShuffleAndReduceFunction(
4367       CGM, Privates, ReductionArrayTy, ReductionFn, Loc);
4368   llvm::Value *InterWarpCopyFn =
4369       emitInterWarpCopyFunction(CGM, Privates, ReductionArrayTy, Loc);
4370
4371   if (ParallelReduction) {
4372     llvm::Value *Args[] = {RTLoc,
4373                            ThreadId,
4374                            CGF.Builder.getInt32(RHSExprs.size()),
4375                            ReductionArrayTySize,
4376                            RL,
4377                            ShuffleAndReduceFn,
4378                            InterWarpCopyFn};
4379
4380     Res = CGF.EmitRuntimeCall(
4381         createNVPTXRuntimeFunction(
4382             OMPRTL_NVPTX__kmpc_nvptx_parallel_reduce_nowait_v2),
4383         Args);
4384   } else {
4385     assert(TeamsReduction && "expected teams reduction.");
4386     llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *> VarFieldMap;
4387     llvm::SmallVector<const ValueDecl *, 4> PrivatesReductions(Privates.size());
4388     int Cnt = 0;
4389     for (const Expr *DRE : Privates) {
4390       PrivatesReductions[Cnt] = cast<DeclRefExpr>(DRE)->getDecl();
4391       ++Cnt;
4392     }
4393     const RecordDecl *TeamReductionRec = ::buildRecordForGlobalizedVars(
4394         CGM.getContext(), PrivatesReductions, llvm::None, VarFieldMap,
4395         C.getLangOpts().OpenMPCUDAReductionBufNum);
4396     TeamsReductions.push_back(TeamReductionRec);
4397     if (!KernelTeamsReductionPtr) {
4398       KernelTeamsReductionPtr = new llvm::GlobalVariable(
4399           CGM.getModule(), CGM.VoidPtrTy, /*isConstant=*/true,
4400           llvm::GlobalValue::InternalLinkage, nullptr,
4401           "_openmp_teams_reductions_buffer_$_$ptr");
4402     }
4403     llvm::Value *GlobalBufferPtr = CGF.EmitLoadOfScalar(
4404         Address(KernelTeamsReductionPtr, CGM.getPointerAlign()),
4405         /*Volatile=*/false, C.getPointerType(C.VoidPtrTy), Loc);
4406     llvm::Value *GlobalToBufferCpyFn = ::emitListToGlobalCopyFunction(
4407         CGM, Privates, ReductionArrayTy, Loc, TeamReductionRec, VarFieldMap);
4408     llvm::Value *GlobalToBufferRedFn = ::emitListToGlobalReduceFunction(
4409         CGM, Privates, ReductionArrayTy, Loc, TeamReductionRec, VarFieldMap,
4410         ReductionFn);
4411     llvm::Value *BufferToGlobalCpyFn = ::emitGlobalToListCopyFunction(
4412         CGM, Privates, ReductionArrayTy, Loc, TeamReductionRec, VarFieldMap);
4413     llvm::Value *BufferToGlobalRedFn = ::emitGlobalToListReduceFunction(
4414         CGM, Privates, ReductionArrayTy, Loc, TeamReductionRec, VarFieldMap,
4415         ReductionFn);
4416
4417     llvm::Value *Args[] = {
4418         RTLoc,
4419         ThreadId,
4420         GlobalBufferPtr,
4421         CGF.Builder.getInt32(C.getLangOpts().OpenMPCUDAReductionBufNum),
4422         RL,
4423         ShuffleAndReduceFn,
4424         InterWarpCopyFn,
4425         GlobalToBufferCpyFn,
4426         GlobalToBufferRedFn,
4427         BufferToGlobalCpyFn,
4428         BufferToGlobalRedFn};
4429
4430     Res = CGF.EmitRuntimeCall(
4431         createNVPTXRuntimeFunction(
4432             OMPRTL_NVPTX__kmpc_nvptx_teams_reduce_nowait_v2),
4433         Args);
4434   }
4435
4436   // 5. Build if (res == 1)
4437   llvm::BasicBlock *ExitBB = CGF.createBasicBlock(".omp.reduction.done");
4438   llvm::BasicBlock *ThenBB = CGF.createBasicBlock(".omp.reduction.then");
4439   llvm::Value *Cond = CGF.Builder.CreateICmpEQ(
4440       Res, llvm::ConstantInt::get(CGM.Int32Ty, /*V=*/1));
4441   CGF.Builder.CreateCondBr(Cond, ThenBB, ExitBB);
4442
4443   // 6. Build then branch: where we have reduced values in the master
4444   //    thread in each team.
4445   //    __kmpc_end_reduce{_nowait}(<gtid>);
4446   //    break;
4447   CGF.EmitBlock(ThenBB);
4448
4449   // Add emission of __kmpc_end_reduce{_nowait}(<gtid>);
4450   auto &&CodeGen = [Privates, LHSExprs, RHSExprs, ReductionOps,
4451                     this](CodeGenFunction &CGF, PrePostActionTy &Action) {
4452     auto IPriv = Privates.begin();
4453     auto ILHS = LHSExprs.begin();
4454     auto IRHS = RHSExprs.begin();
4455     for (const Expr *E : ReductionOps) {
4456       emitSingleReductionCombiner(CGF, E, *IPriv, cast<DeclRefExpr>(*ILHS),
4457                                   cast<DeclRefExpr>(*IRHS));
4458       ++IPriv;
4459       ++ILHS;
4460       ++IRHS;
4461     }
4462   };
4463   llvm::Value *EndArgs[] = {ThreadId};
4464   RegionCodeGenTy RCG(CodeGen);
4465   NVPTXActionTy Action(
4466       nullptr, llvm::None,
4467       createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_end_reduce_nowait),
4468       EndArgs);
4469   RCG.setAction(Action);
4470   RCG(CGF);
4471   // There is no need to emit line number for unconditional branch.
4472   (void)ApplyDebugLocation::CreateEmpty(CGF);
4473   CGF.EmitBlock(ExitBB, /*IsFinished=*/true);
4474 }
4475
4476 const VarDecl *
4477 CGOpenMPRuntimeNVPTX::translateParameter(const FieldDecl *FD,
4478                                          const VarDecl *NativeParam) const {
4479   if (!NativeParam->getType()->isReferenceType())
4480     return NativeParam;
4481   QualType ArgType = NativeParam->getType();
4482   QualifierCollector QC;
4483   const Type *NonQualTy = QC.strip(ArgType);
4484   QualType PointeeTy = cast<ReferenceType>(NonQualTy)->getPointeeType();
4485   if (const auto *Attr = FD->getAttr<OMPCaptureKindAttr>()) {
4486     if (Attr->getCaptureKind() == OMPC_map) {
4487       PointeeTy = CGM.getContext().getAddrSpaceQualType(PointeeTy,
4488                                                         LangAS::opencl_global);
4489     } else if (Attr->getCaptureKind() == OMPC_firstprivate &&
4490                PointeeTy.isConstant(CGM.getContext())) {
4491       PointeeTy = CGM.getContext().getAddrSpaceQualType(PointeeTy,
4492                                                         LangAS::opencl_generic);
4493     }
4494   }
4495   ArgType = CGM.getContext().getPointerType(PointeeTy);
4496   QC.addRestrict();
4497   enum { NVPTX_local_addr = 5 };
4498   QC.addAddressSpace(getLangASFromTargetAS(NVPTX_local_addr));
4499   ArgType = QC.apply(CGM.getContext(), ArgType);
4500   if (isa<ImplicitParamDecl>(NativeParam))
4501     return ImplicitParamDecl::Create(
4502         CGM.getContext(), /*DC=*/nullptr, NativeParam->getLocation(),
4503         NativeParam->getIdentifier(), ArgType, ImplicitParamDecl::Other);
4504   return ParmVarDecl::Create(
4505       CGM.getContext(),
4506       const_cast<DeclContext *>(NativeParam->getDeclContext()),
4507       NativeParam->getBeginLoc(), NativeParam->getLocation(),
4508       NativeParam->getIdentifier(), ArgType,
4509       /*TInfo=*/nullptr, SC_None, /*DefArg=*/nullptr);
4510 }
4511
4512 Address
4513 CGOpenMPRuntimeNVPTX::getParameterAddress(CodeGenFunction &CGF,
4514                                           const VarDecl *NativeParam,
4515                                           const VarDecl *TargetParam) const {
4516   assert(NativeParam != TargetParam &&
4517          NativeParam->getType()->isReferenceType() &&
4518          "Native arg must not be the same as target arg.");
4519   Address LocalAddr = CGF.GetAddrOfLocalVar(TargetParam);
4520   QualType NativeParamType = NativeParam->getType();
4521   QualifierCollector QC;
4522   const Type *NonQualTy = QC.strip(NativeParamType);
4523   QualType NativePointeeTy = cast<ReferenceType>(NonQualTy)->getPointeeType();
4524   unsigned NativePointeeAddrSpace =
4525       CGF.getContext().getTargetAddressSpace(NativePointeeTy);
4526   QualType TargetTy = TargetParam->getType();
4527   llvm::Value *TargetAddr = CGF.EmitLoadOfScalar(
4528       LocalAddr, /*Volatile=*/false, TargetTy, SourceLocation());
4529   // First cast to generic.
4530   TargetAddr = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
4531       TargetAddr, TargetAddr->getType()->getPointerElementType()->getPointerTo(
4532                       /*AddrSpace=*/0));
4533   // Cast from generic to native address space.
4534   TargetAddr = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
4535       TargetAddr, TargetAddr->getType()->getPointerElementType()->getPointerTo(
4536                       NativePointeeAddrSpace));
4537   Address NativeParamAddr = CGF.CreateMemTemp(NativeParamType);
4538   CGF.EmitStoreOfScalar(TargetAddr, NativeParamAddr, /*Volatile=*/false,
4539                         NativeParamType);
4540   return NativeParamAddr;
4541 }
4542
4543 void CGOpenMPRuntimeNVPTX::emitOutlinedFunctionCall(
4544     CodeGenFunction &CGF, SourceLocation Loc, llvm::FunctionCallee OutlinedFn,
4545     ArrayRef<llvm::Value *> Args) const {
4546   SmallVector<llvm::Value *, 4> TargetArgs;
4547   TargetArgs.reserve(Args.size());
4548   auto *FnType = OutlinedFn.getFunctionType();
4549   for (unsigned I = 0, E = Args.size(); I < E; ++I) {
4550     if (FnType->isVarArg() && FnType->getNumParams() <= I) {
4551       TargetArgs.append(std::next(Args.begin(), I), Args.end());
4552       break;
4553     }
4554     llvm::Type *TargetType = FnType->getParamType(I);
4555     llvm::Value *NativeArg = Args[I];
4556     if (!TargetType->isPointerTy()) {
4557       TargetArgs.emplace_back(NativeArg);
4558       continue;
4559     }
4560     llvm::Value *TargetArg = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
4561         NativeArg,
4562         NativeArg->getType()->getPointerElementType()->getPointerTo());
4563     TargetArgs.emplace_back(
4564         CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(TargetArg, TargetType));
4565   }
4566   CGOpenMPRuntime::emitOutlinedFunctionCall(CGF, Loc, OutlinedFn, TargetArgs);
4567 }
4568
4569 /// Emit function which wraps the outline parallel region
4570 /// and controls the arguments which are passed to this function.
4571 /// The wrapper ensures that the outlined function is called
4572 /// with the correct arguments when data is shared.
4573 llvm::Function *CGOpenMPRuntimeNVPTX::createParallelDataSharingWrapper(
4574     llvm::Function *OutlinedParallelFn, const OMPExecutableDirective &D) {
4575   ASTContext &Ctx = CGM.getContext();
4576   const auto &CS = *D.getCapturedStmt(OMPD_parallel);
4577
4578   // Create a function that takes as argument the source thread.
4579   FunctionArgList WrapperArgs;
4580   QualType Int16QTy =
4581       Ctx.getIntTypeForBitwidth(/*DestWidth=*/16, /*Signed=*/false);
4582   QualType Int32QTy =
4583       Ctx.getIntTypeForBitwidth(/*DestWidth=*/32, /*Signed=*/false);
4584   ImplicitParamDecl ParallelLevelArg(Ctx, /*DC=*/nullptr, D.getBeginLoc(),
4585                                      /*Id=*/nullptr, Int16QTy,
4586                                      ImplicitParamDecl::Other);
4587   ImplicitParamDecl WrapperArg(Ctx, /*DC=*/nullptr, D.getBeginLoc(),
4588                                /*Id=*/nullptr, Int32QTy,
4589                                ImplicitParamDecl::Other);
4590   WrapperArgs.emplace_back(&ParallelLevelArg);
4591   WrapperArgs.emplace_back(&WrapperArg);
4592
4593   const CGFunctionInfo &CGFI =
4594       CGM.getTypes().arrangeBuiltinFunctionDeclaration(Ctx.VoidTy, WrapperArgs);
4595
4596   auto *Fn = llvm::Function::Create(
4597       CGM.getTypes().GetFunctionType(CGFI), llvm::GlobalValue::InternalLinkage,
4598       Twine(OutlinedParallelFn->getName(), "_wrapper"), &CGM.getModule());
4599   CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, CGFI);
4600   Fn->setLinkage(llvm::GlobalValue::InternalLinkage);
4601   Fn->setDoesNotRecurse();
4602
4603   CodeGenFunction CGF(CGM, /*suppressNewContext=*/true);
4604   CGF.StartFunction(GlobalDecl(), Ctx.VoidTy, Fn, CGFI, WrapperArgs,
4605                     D.getBeginLoc(), D.getBeginLoc());
4606
4607   const auto *RD = CS.getCapturedRecordDecl();
4608   auto CurField = RD->field_begin();
4609
4610   Address ZeroAddr = CGF.CreateDefaultAlignTempAlloca(CGF.Int32Ty,
4611                                                       /*Name=*/".zero.addr");
4612   CGF.InitTempAlloca(ZeroAddr, CGF.Builder.getInt32(/*C*/ 0));
4613   // Get the array of arguments.
4614   SmallVector<llvm::Value *, 8> Args;
4615
4616   Args.emplace_back(CGF.GetAddrOfLocalVar(&WrapperArg).getPointer());
4617   Args.emplace_back(ZeroAddr.getPointer());
4618
4619   CGBuilderTy &Bld = CGF.Builder;
4620   auto CI = CS.capture_begin();
4621
4622   // Use global memory for data sharing.
4623   // Handle passing of global args to workers.
4624   Address GlobalArgs =
4625       CGF.CreateDefaultAlignTempAlloca(CGF.VoidPtrPtrTy, "global_args");
4626   llvm::Value *GlobalArgsPtr = GlobalArgs.getPointer();
4627   llvm::Value *DataSharingArgs[] = {GlobalArgsPtr};
4628   CGF.EmitRuntimeCall(
4629       createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_get_shared_variables),
4630       DataSharingArgs);
4631
4632   // Retrieve the shared variables from the list of references returned
4633   // by the runtime. Pass the variables to the outlined function.
4634   Address SharedArgListAddress = Address::invalid();
4635   if (CS.capture_size() > 0 ||
4636       isOpenMPLoopBoundSharingDirective(D.getDirectiveKind())) {
4637     SharedArgListAddress = CGF.EmitLoadOfPointer(
4638         GlobalArgs, CGF.getContext()
4639                         .getPointerType(CGF.getContext().getPointerType(
4640                             CGF.getContext().VoidPtrTy))
4641                         .castAs<PointerType>());
4642   }
4643   unsigned Idx = 0;
4644   if (isOpenMPLoopBoundSharingDirective(D.getDirectiveKind())) {
4645     Address Src = Bld.CreateConstInBoundsGEP(SharedArgListAddress, Idx);
4646     Address TypedAddress = Bld.CreatePointerBitCastOrAddrSpaceCast(
4647         Src, CGF.SizeTy->getPointerTo());
4648     llvm::Value *LB = CGF.EmitLoadOfScalar(
4649         TypedAddress,
4650         /*Volatile=*/false,
4651         CGF.getContext().getPointerType(CGF.getContext().getSizeType()),
4652         cast<OMPLoopDirective>(D).getLowerBoundVariable()->getExprLoc());
4653     Args.emplace_back(LB);
4654     ++Idx;
4655     Src = Bld.CreateConstInBoundsGEP(SharedArgListAddress, Idx);
4656     TypedAddress = Bld.CreatePointerBitCastOrAddrSpaceCast(
4657         Src, CGF.SizeTy->getPointerTo());
4658     llvm::Value *UB = CGF.EmitLoadOfScalar(
4659         TypedAddress,
4660         /*Volatile=*/false,
4661         CGF.getContext().getPointerType(CGF.getContext().getSizeType()),
4662         cast<OMPLoopDirective>(D).getUpperBoundVariable()->getExprLoc());
4663     Args.emplace_back(UB);
4664     ++Idx;
4665   }
4666   if (CS.capture_size() > 0) {
4667     ASTContext &CGFContext = CGF.getContext();
4668     for (unsigned I = 0, E = CS.capture_size(); I < E; ++I, ++CI, ++CurField) {
4669       QualType ElemTy = CurField->getType();
4670       Address Src = Bld.CreateConstInBoundsGEP(SharedArgListAddress, I + Idx);
4671       Address TypedAddress = Bld.CreatePointerBitCastOrAddrSpaceCast(
4672           Src, CGF.ConvertTypeForMem(CGFContext.getPointerType(ElemTy)));
4673       llvm::Value *Arg = CGF.EmitLoadOfScalar(TypedAddress,
4674                                               /*Volatile=*/false,
4675                                               CGFContext.getPointerType(ElemTy),
4676                                               CI->getLocation());
4677       if (CI->capturesVariableByCopy() &&
4678           !CI->getCapturedVar()->getType()->isAnyPointerType()) {
4679         Arg = castValueToType(CGF, Arg, ElemTy, CGFContext.getUIntPtrType(),
4680                               CI->getLocation());
4681       }
4682       Args.emplace_back(Arg);
4683     }
4684   }
4685
4686   emitOutlinedFunctionCall(CGF, D.getBeginLoc(), OutlinedParallelFn, Args);
4687   CGF.FinishFunction();
4688   return Fn;
4689 }
4690
4691 void CGOpenMPRuntimeNVPTX::emitFunctionProlog(CodeGenFunction &CGF,
4692                                               const Decl *D) {
4693   if (getDataSharingMode(CGM) != CGOpenMPRuntimeNVPTX::Generic)
4694     return;
4695
4696   assert(D && "Expected function or captured|block decl.");
4697   assert(FunctionGlobalizedDecls.count(CGF.CurFn) == 0 &&
4698          "Function is registered already.");
4699   assert((!TeamAndReductions.first || TeamAndReductions.first == D) &&
4700          "Team is set but not processed.");
4701   const Stmt *Body = nullptr;
4702   bool NeedToDelayGlobalization = false;
4703   if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
4704     Body = FD->getBody();
4705   } else if (const auto *BD = dyn_cast<BlockDecl>(D)) {
4706     Body = BD->getBody();
4707   } else if (const auto *CD = dyn_cast<CapturedDecl>(D)) {
4708     Body = CD->getBody();
4709     NeedToDelayGlobalization = CGF.CapturedStmtInfo->getKind() == CR_OpenMP;
4710     if (NeedToDelayGlobalization &&
4711         getExecutionMode() == CGOpenMPRuntimeNVPTX::EM_SPMD)
4712       return;
4713   }
4714   if (!Body)
4715     return;
4716   CheckVarsEscapingDeclContext VarChecker(CGF, TeamAndReductions.second);
4717   VarChecker.Visit(Body);
4718   const RecordDecl *GlobalizedVarsRecord =
4719       VarChecker.getGlobalizedRecord(IsInTTDRegion);
4720   TeamAndReductions.first = nullptr;
4721   TeamAndReductions.second.clear();
4722   ArrayRef<const ValueDecl *> EscapedVariableLengthDecls =
4723       VarChecker.getEscapedVariableLengthDecls();
4724   if (!GlobalizedVarsRecord && EscapedVariableLengthDecls.empty())
4725     return;
4726   auto I = FunctionGlobalizedDecls.try_emplace(CGF.CurFn).first;
4727   I->getSecond().MappedParams =
4728       std::make_unique<CodeGenFunction::OMPMapVars>();
4729   I->getSecond().GlobalRecord = GlobalizedVarsRecord;
4730   I->getSecond().EscapedParameters.insert(
4731       VarChecker.getEscapedParameters().begin(),
4732       VarChecker.getEscapedParameters().end());
4733   I->getSecond().EscapedVariableLengthDecls.append(
4734       EscapedVariableLengthDecls.begin(), EscapedVariableLengthDecls.end());
4735   DeclToAddrMapTy &Data = I->getSecond().LocalVarData;
4736   for (const ValueDecl *VD : VarChecker.getEscapedDecls()) {
4737     assert(VD->isCanonicalDecl() && "Expected canonical declaration");
4738     const FieldDecl *FD = VarChecker.getFieldForGlobalizedVar(VD);
4739     Data.insert(std::make_pair(VD, MappedVarData(FD, IsInTTDRegion)));
4740   }
4741   if (!IsInTTDRegion && !NeedToDelayGlobalization && !IsInParallelRegion) {
4742     CheckVarsEscapingDeclContext VarChecker(CGF, llvm::None);
4743     VarChecker.Visit(Body);
4744     I->getSecond().SecondaryGlobalRecord =
4745         VarChecker.getGlobalizedRecord(/*IsInTTDRegion=*/true);
4746     I->getSecond().SecondaryLocalVarData.emplace();
4747     DeclToAddrMapTy &Data = I->getSecond().SecondaryLocalVarData.getValue();
4748     for (const ValueDecl *VD : VarChecker.getEscapedDecls()) {
4749       assert(VD->isCanonicalDecl() && "Expected canonical declaration");
4750       const FieldDecl *FD = VarChecker.getFieldForGlobalizedVar(VD);
4751       Data.insert(
4752           std::make_pair(VD, MappedVarData(FD, /*IsInTTDRegion=*/true)));
4753     }
4754   }
4755   if (!NeedToDelayGlobalization) {
4756     emitGenericVarsProlog(CGF, D->getBeginLoc(), /*WithSPMDCheck=*/true);
4757     struct GlobalizationScope final : EHScopeStack::Cleanup {
4758       GlobalizationScope() = default;
4759
4760       void Emit(CodeGenFunction &CGF, Flags flags) override {
4761         static_cast<CGOpenMPRuntimeNVPTX &>(CGF.CGM.getOpenMPRuntime())
4762             .emitGenericVarsEpilog(CGF, /*WithSPMDCheck=*/true);
4763       }
4764     };
4765     CGF.EHStack.pushCleanup<GlobalizationScope>(NormalAndEHCleanup);
4766   }
4767 }
4768
4769 Address CGOpenMPRuntimeNVPTX::getAddressOfLocalVariable(CodeGenFunction &CGF,
4770                                                         const VarDecl *VD) {
4771   if (VD && VD->hasAttr<OMPAllocateDeclAttr>()) {
4772     const auto *A = VD->getAttr<OMPAllocateDeclAttr>();
4773     auto AS = LangAS::Default;
4774     switch (A->getAllocatorType()) {
4775       // Use the default allocator here as by default local vars are
4776       // threadlocal.
4777     case OMPAllocateDeclAttr::OMPNullMemAlloc:
4778     case OMPAllocateDeclAttr::OMPDefaultMemAlloc:
4779     case OMPAllocateDeclAttr::OMPThreadMemAlloc:
4780     case OMPAllocateDeclAttr::OMPHighBWMemAlloc:
4781     case OMPAllocateDeclAttr::OMPLowLatMemAlloc:
4782       // Follow the user decision - use default allocation.
4783       return Address::invalid();
4784     case OMPAllocateDeclAttr::OMPUserDefinedMemAlloc:
4785       // TODO: implement aupport for user-defined allocators.
4786       return Address::invalid();
4787     case OMPAllocateDeclAttr::OMPConstMemAlloc:
4788       AS = LangAS::cuda_constant;
4789       break;
4790     case OMPAllocateDeclAttr::OMPPTeamMemAlloc:
4791       AS = LangAS::cuda_shared;
4792       break;
4793     case OMPAllocateDeclAttr::OMPLargeCapMemAlloc:
4794     case OMPAllocateDeclAttr::OMPCGroupMemAlloc:
4795       break;
4796     }
4797     llvm::Type *VarTy = CGF.ConvertTypeForMem(VD->getType());
4798     auto *GV = new llvm::GlobalVariable(
4799         CGM.getModule(), VarTy, /*isConstant=*/false,
4800         llvm::GlobalValue::InternalLinkage, llvm::Constant::getNullValue(VarTy),
4801         VD->getName(),
4802         /*InsertBefore=*/nullptr, llvm::GlobalValue::NotThreadLocal,
4803         CGM.getContext().getTargetAddressSpace(AS));
4804     CharUnits Align = CGM.getContext().getDeclAlign(VD);
4805     GV->setAlignment(Align.getAsAlign());
4806     return Address(
4807         CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
4808             GV, VarTy->getPointerTo(CGM.getContext().getTargetAddressSpace(
4809                     VD->getType().getAddressSpace()))),
4810         Align);
4811   }
4812
4813   if (getDataSharingMode(CGM) != CGOpenMPRuntimeNVPTX::Generic)
4814     return Address::invalid();
4815
4816   VD = VD->getCanonicalDecl();
4817   auto I = FunctionGlobalizedDecls.find(CGF.CurFn);
4818   if (I == FunctionGlobalizedDecls.end())
4819     return Address::invalid();
4820   auto VDI = I->getSecond().LocalVarData.find(VD);
4821   if (VDI != I->getSecond().LocalVarData.end())
4822     return VDI->second.PrivateAddr;
4823   if (VD->hasAttrs()) {
4824     for (specific_attr_iterator<OMPReferencedVarAttr> IT(VD->attr_begin()),
4825          E(VD->attr_end());
4826          IT != E; ++IT) {
4827       auto VDI = I->getSecond().LocalVarData.find(
4828           cast<VarDecl>(cast<DeclRefExpr>(IT->getRef())->getDecl())
4829               ->getCanonicalDecl());
4830       if (VDI != I->getSecond().LocalVarData.end())
4831         return VDI->second.PrivateAddr;
4832     }
4833   }
4834
4835   return Address::invalid();
4836 }
4837
4838 void CGOpenMPRuntimeNVPTX::functionFinished(CodeGenFunction &CGF) {
4839   FunctionGlobalizedDecls.erase(CGF.CurFn);
4840   CGOpenMPRuntime::functionFinished(CGF);
4841 }
4842
4843 void CGOpenMPRuntimeNVPTX::getDefaultDistScheduleAndChunk(
4844     CodeGenFunction &CGF, const OMPLoopDirective &S,
4845     OpenMPDistScheduleClauseKind &ScheduleKind,
4846     llvm::Value *&Chunk) const {
4847   if (getExecutionMode() == CGOpenMPRuntimeNVPTX::EM_SPMD) {
4848     ScheduleKind = OMPC_DIST_SCHEDULE_static;
4849     Chunk = CGF.EmitScalarConversion(getNVPTXNumThreads(CGF),
4850         CGF.getContext().getIntTypeForBitwidth(32, /*Signed=*/0),
4851         S.getIterationVariable()->getType(), S.getBeginLoc());
4852     return;
4853   }
4854   CGOpenMPRuntime::getDefaultDistScheduleAndChunk(
4855       CGF, S, ScheduleKind, Chunk);
4856 }
4857
4858 void CGOpenMPRuntimeNVPTX::getDefaultScheduleAndChunk(
4859     CodeGenFunction &CGF, const OMPLoopDirective &S,
4860     OpenMPScheduleClauseKind &ScheduleKind,
4861     const Expr *&ChunkExpr) const {
4862   ScheduleKind = OMPC_SCHEDULE_static;
4863   // Chunk size is 1 in this case.
4864   llvm::APInt ChunkSize(32, 1);
4865   ChunkExpr = IntegerLiteral::Create(CGF.getContext(), ChunkSize,
4866       CGF.getContext().getIntTypeForBitwidth(32, /*Signed=*/0),
4867       SourceLocation());
4868 }
4869
4870 void CGOpenMPRuntimeNVPTX::adjustTargetSpecificDataForLambdas(
4871     CodeGenFunction &CGF, const OMPExecutableDirective &D) const {
4872   assert(isOpenMPTargetExecutionDirective(D.getDirectiveKind()) &&
4873          " Expected target-based directive.");
4874   const CapturedStmt *CS = D.getCapturedStmt(OMPD_target);
4875   for (const CapturedStmt::Capture &C : CS->captures()) {
4876     // Capture variables captured by reference in lambdas for target-based
4877     // directives.
4878     if (!C.capturesVariable())
4879       continue;
4880     const VarDecl *VD = C.getCapturedVar();
4881     const auto *RD = VD->getType()
4882                          .getCanonicalType()
4883                          .getNonReferenceType()
4884                          ->getAsCXXRecordDecl();
4885     if (!RD || !RD->isLambda())
4886       continue;
4887     Address VDAddr = CGF.GetAddrOfLocalVar(VD);
4888     LValue VDLVal;
4889     if (VD->getType().getCanonicalType()->isReferenceType())
4890       VDLVal = CGF.EmitLoadOfReferenceLValue(VDAddr, VD->getType());
4891     else
4892       VDLVal = CGF.MakeAddrLValue(
4893           VDAddr, VD->getType().getCanonicalType().getNonReferenceType());
4894     llvm::DenseMap<const VarDecl *, FieldDecl *> Captures;
4895     FieldDecl *ThisCapture = nullptr;
4896     RD->getCaptureFields(Captures, ThisCapture);
4897     if (ThisCapture && CGF.CapturedStmtInfo->isCXXThisExprCaptured()) {
4898       LValue ThisLVal =
4899           CGF.EmitLValueForFieldInitialization(VDLVal, ThisCapture);
4900       llvm::Value *CXXThis = CGF.LoadCXXThis();
4901       CGF.EmitStoreOfScalar(CXXThis, ThisLVal);
4902     }
4903     for (const LambdaCapture &LC : RD->captures()) {
4904       if (LC.getCaptureKind() != LCK_ByRef)
4905         continue;
4906       const VarDecl *VD = LC.getCapturedVar();
4907       if (!CS->capturesVariable(VD))
4908         continue;
4909       auto It = Captures.find(VD);
4910       assert(It != Captures.end() && "Found lambda capture without field.");
4911       LValue VarLVal = CGF.EmitLValueForFieldInitialization(VDLVal, It->second);
4912       Address VDAddr = CGF.GetAddrOfLocalVar(VD);
4913       if (VD->getType().getCanonicalType()->isReferenceType())
4914         VDAddr = CGF.EmitLoadOfReferenceLValue(VDAddr,
4915                                                VD->getType().getCanonicalType())
4916                      .getAddress(CGF);
4917       CGF.EmitStoreOfScalar(VDAddr.getPointer(), VarLVal);
4918     }
4919   }
4920 }
4921
4922 unsigned CGOpenMPRuntimeNVPTX::getDefaultFirstprivateAddressSpace() const {
4923   return CGM.getContext().getTargetAddressSpace(LangAS::cuda_constant);
4924 }
4925
4926 bool CGOpenMPRuntimeNVPTX::hasAllocateAttributeForGlobalVar(const VarDecl *VD,
4927                                                             LangAS &AS) {
4928   if (!VD || !VD->hasAttr<OMPAllocateDeclAttr>())
4929     return false;
4930   const auto *A = VD->getAttr<OMPAllocateDeclAttr>();
4931   switch(A->getAllocatorType()) {
4932   case OMPAllocateDeclAttr::OMPNullMemAlloc:
4933   case OMPAllocateDeclAttr::OMPDefaultMemAlloc:
4934   // Not supported, fallback to the default mem space.
4935   case OMPAllocateDeclAttr::OMPThreadMemAlloc:
4936   case OMPAllocateDeclAttr::OMPLargeCapMemAlloc:
4937   case OMPAllocateDeclAttr::OMPCGroupMemAlloc:
4938   case OMPAllocateDeclAttr::OMPHighBWMemAlloc:
4939   case OMPAllocateDeclAttr::OMPLowLatMemAlloc:
4940     AS = LangAS::Default;
4941     return true;
4942   case OMPAllocateDeclAttr::OMPConstMemAlloc:
4943     AS = LangAS::cuda_constant;
4944     return true;
4945   case OMPAllocateDeclAttr::OMPPTeamMemAlloc:
4946     AS = LangAS::cuda_shared;
4947     return true;
4948   case OMPAllocateDeclAttr::OMPUserDefinedMemAlloc:
4949     llvm_unreachable("Expected predefined allocator for the variables with the "
4950                      "static storage.");
4951   }
4952   return false;
4953 }
4954
4955 // Get current CudaArch and ignore any unknown values
4956 static CudaArch getCudaArch(CodeGenModule &CGM) {
4957   if (!CGM.getTarget().hasFeature("ptx"))
4958     return CudaArch::UNKNOWN;
4959   for (const auto &Feature : CGM.getTarget().getTargetOpts().FeatureMap) {
4960     if (Feature.getValue()) {
4961       CudaArch Arch = StringToCudaArch(Feature.getKey());
4962       if (Arch != CudaArch::UNKNOWN)
4963         return Arch;
4964     }
4965   }
4966   return CudaArch::UNKNOWN;
4967 }
4968
4969 /// Check to see if target architecture supports unified addressing which is
4970 /// a restriction for OpenMP requires clause "unified_shared_memory".
4971 void CGOpenMPRuntimeNVPTX::processRequiresDirective(
4972     const OMPRequiresDecl *D) {
4973   for (const OMPClause *Clause : D->clauselists()) {
4974     if (Clause->getClauseKind() == OMPC_unified_shared_memory) {
4975       CudaArch Arch = getCudaArch(CGM);
4976       switch (Arch) {
4977       case CudaArch::SM_20:
4978       case CudaArch::SM_21:
4979       case CudaArch::SM_30:
4980       case CudaArch::SM_32:
4981       case CudaArch::SM_35:
4982       case CudaArch::SM_37:
4983       case CudaArch::SM_50:
4984       case CudaArch::SM_52:
4985       case CudaArch::SM_53:
4986       case CudaArch::SM_60:
4987       case CudaArch::SM_61:
4988       case CudaArch::SM_62: {
4989         SmallString<256> Buffer;
4990         llvm::raw_svector_ostream Out(Buffer);
4991         Out << "Target architecture " << CudaArchToString(Arch)
4992             << " does not support unified addressing";
4993         CGM.Error(Clause->getBeginLoc(), Out.str());
4994         return;
4995       }
4996       case CudaArch::SM_70:
4997       case CudaArch::SM_72:
4998       case CudaArch::SM_75:
4999       case CudaArch::SM_80:
5000       case CudaArch::GFX600:
5001       case CudaArch::GFX601:
5002       case CudaArch::GFX700:
5003       case CudaArch::GFX701:
5004       case CudaArch::GFX702:
5005       case CudaArch::GFX703:
5006       case CudaArch::GFX704:
5007       case CudaArch::GFX801:
5008       case CudaArch::GFX802:
5009       case CudaArch::GFX803:
5010       case CudaArch::GFX810:
5011       case CudaArch::GFX900:
5012       case CudaArch::GFX902:
5013       case CudaArch::GFX904:
5014       case CudaArch::GFX906:
5015       case CudaArch::GFX908:
5016       case CudaArch::GFX909:
5017       case CudaArch::GFX1010:
5018       case CudaArch::GFX1011:
5019       case CudaArch::GFX1012:
5020       case CudaArch::GFX1030:
5021       case CudaArch::UNKNOWN:
5022         break;
5023       case CudaArch::LAST:
5024         llvm_unreachable("Unexpected Cuda arch.");
5025       }
5026     }
5027   }
5028   CGOpenMPRuntime::processRequiresDirective(D);
5029 }
5030
5031 /// Get number of SMs and number of blocks per SM.
5032 static std::pair<unsigned, unsigned> getSMsBlocksPerSM(CodeGenModule &CGM) {
5033   std::pair<unsigned, unsigned> Data;
5034   if (CGM.getLangOpts().OpenMPCUDANumSMs)
5035     Data.first = CGM.getLangOpts().OpenMPCUDANumSMs;
5036   if (CGM.getLangOpts().OpenMPCUDABlocksPerSM)
5037     Data.second = CGM.getLangOpts().OpenMPCUDABlocksPerSM;
5038   if (Data.first && Data.second)
5039     return Data;
5040   switch (getCudaArch(CGM)) {
5041   case CudaArch::SM_20:
5042   case CudaArch::SM_21:
5043   case CudaArch::SM_30:
5044   case CudaArch::SM_32:
5045   case CudaArch::SM_35:
5046   case CudaArch::SM_37:
5047   case CudaArch::SM_50:
5048   case CudaArch::SM_52:
5049   case CudaArch::SM_53:
5050     return {16, 16};
5051   case CudaArch::SM_60:
5052   case CudaArch::SM_61:
5053   case CudaArch::SM_62:
5054     return {56, 32};
5055   case CudaArch::SM_70:
5056   case CudaArch::SM_72:
5057   case CudaArch::SM_75:
5058   case CudaArch::SM_80:
5059     return {84, 32};
5060   case CudaArch::GFX600:
5061   case CudaArch::GFX601:
5062   case CudaArch::GFX700:
5063   case CudaArch::GFX701:
5064   case CudaArch::GFX702:
5065   case CudaArch::GFX703:
5066   case CudaArch::GFX704:
5067   case CudaArch::GFX801:
5068   case CudaArch::GFX802:
5069   case CudaArch::GFX803:
5070   case CudaArch::GFX810:
5071   case CudaArch::GFX900:
5072   case CudaArch::GFX902:
5073   case CudaArch::GFX904:
5074   case CudaArch::GFX906:
5075   case CudaArch::GFX908:
5076   case CudaArch::GFX909:
5077   case CudaArch::GFX1010:
5078   case CudaArch::GFX1011:
5079   case CudaArch::GFX1012:
5080   case CudaArch::GFX1030:
5081   case CudaArch::UNKNOWN:
5082     break;
5083   case CudaArch::LAST:
5084     llvm_unreachable("Unexpected Cuda arch.");
5085   }
5086   llvm_unreachable("Unexpected NVPTX target without ptx feature.");
5087 }
5088
5089 void CGOpenMPRuntimeNVPTX::clear() {
5090   if (!GlobalizedRecords.empty() &&
5091       !CGM.getLangOpts().OpenMPCUDATargetParallel) {
5092     ASTContext &C = CGM.getContext();
5093     llvm::SmallVector<const GlobalPtrSizeRecsTy *, 4> GlobalRecs;
5094     llvm::SmallVector<const GlobalPtrSizeRecsTy *, 4> SharedRecs;
5095     RecordDecl *StaticRD = C.buildImplicitRecord(
5096         "_openmp_static_memory_type_$_", RecordDecl::TagKind::TTK_Union);
5097     StaticRD->startDefinition();
5098     RecordDecl *SharedStaticRD = C.buildImplicitRecord(
5099         "_shared_openmp_static_memory_type_$_", RecordDecl::TagKind::TTK_Union);
5100     SharedStaticRD->startDefinition();
5101     for (const GlobalPtrSizeRecsTy &Records : GlobalizedRecords) {
5102       if (Records.Records.empty())
5103         continue;
5104       unsigned Size = 0;
5105       unsigned RecAlignment = 0;
5106       for (const RecordDecl *RD : Records.Records) {
5107         QualType RDTy = C.getRecordType(RD);
5108         unsigned Alignment = C.getTypeAlignInChars(RDTy).getQuantity();
5109         RecAlignment = std::max(RecAlignment, Alignment);
5110         unsigned RecSize = C.getTypeSizeInChars(RDTy).getQuantity();
5111         Size =
5112             llvm::alignTo(llvm::alignTo(Size, Alignment) + RecSize, Alignment);
5113       }
5114       Size = llvm::alignTo(Size, RecAlignment);
5115       llvm::APInt ArySize(/*numBits=*/64, Size);
5116       QualType SubTy = C.getConstantArrayType(
5117           C.CharTy, ArySize, nullptr, ArrayType::Normal, /*IndexTypeQuals=*/0);
5118       const bool UseSharedMemory = Size <= SharedMemorySize;
5119       auto *Field =
5120           FieldDecl::Create(C, UseSharedMemory ? SharedStaticRD : StaticRD,
5121                             SourceLocation(), SourceLocation(), nullptr, SubTy,
5122                             C.getTrivialTypeSourceInfo(SubTy, SourceLocation()),
5123                             /*BW=*/nullptr, /*Mutable=*/false,
5124                             /*InitStyle=*/ICIS_NoInit);
5125       Field->setAccess(AS_public);
5126       if (UseSharedMemory) {
5127         SharedStaticRD->addDecl(Field);
5128         SharedRecs.push_back(&Records);
5129       } else {
5130         StaticRD->addDecl(Field);
5131         GlobalRecs.push_back(&Records);
5132       }
5133       Records.RecSize->setInitializer(llvm::ConstantInt::get(CGM.SizeTy, Size));
5134       Records.UseSharedMemory->setInitializer(
5135           llvm::ConstantInt::get(CGM.Int16Ty, UseSharedMemory ? 1 : 0));
5136     }
5137     // Allocate SharedMemorySize buffer for the shared memory.
5138     // FIXME: nvlink does not handle weak linkage correctly (object with the
5139     // different size are reported as erroneous).
5140     // Restore this code as sson as nvlink is fixed.
5141     if (!SharedStaticRD->field_empty()) {
5142       llvm::APInt ArySize(/*numBits=*/64, SharedMemorySize);
5143       QualType SubTy = C.getConstantArrayType(
5144           C.CharTy, ArySize, nullptr, ArrayType::Normal, /*IndexTypeQuals=*/0);
5145       auto *Field = FieldDecl::Create(
5146           C, SharedStaticRD, SourceLocation(), SourceLocation(), nullptr, SubTy,
5147           C.getTrivialTypeSourceInfo(SubTy, SourceLocation()),
5148           /*BW=*/nullptr, /*Mutable=*/false,
5149           /*InitStyle=*/ICIS_NoInit);
5150       Field->setAccess(AS_public);
5151       SharedStaticRD->addDecl(Field);
5152     }
5153     SharedStaticRD->completeDefinition();
5154     if (!SharedStaticRD->field_empty()) {
5155       QualType StaticTy = C.getRecordType(SharedStaticRD);
5156       llvm::Type *LLVMStaticTy = CGM.getTypes().ConvertTypeForMem(StaticTy);
5157       auto *GV = new llvm::GlobalVariable(
5158           CGM.getModule(), LLVMStaticTy,
5159           /*isConstant=*/false, llvm::GlobalValue::CommonLinkage,
5160           llvm::Constant::getNullValue(LLVMStaticTy),
5161           "_openmp_shared_static_glob_rd_$_", /*InsertBefore=*/nullptr,
5162           llvm::GlobalValue::NotThreadLocal,
5163           C.getTargetAddressSpace(LangAS::cuda_shared));
5164       auto *Replacement = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
5165           GV, CGM.VoidPtrTy);
5166       for (const GlobalPtrSizeRecsTy *Rec : SharedRecs) {
5167         Rec->Buffer->replaceAllUsesWith(Replacement);
5168         Rec->Buffer->eraseFromParent();
5169       }
5170     }
5171     StaticRD->completeDefinition();
5172     if (!StaticRD->field_empty()) {
5173       QualType StaticTy = C.getRecordType(StaticRD);
5174       std::pair<unsigned, unsigned> SMsBlockPerSM = getSMsBlocksPerSM(CGM);
5175       llvm::APInt Size1(32, SMsBlockPerSM.second);
5176       QualType Arr1Ty =
5177           C.getConstantArrayType(StaticTy, Size1, nullptr, ArrayType::Normal,
5178                                  /*IndexTypeQuals=*/0);
5179       llvm::APInt Size2(32, SMsBlockPerSM.first);
5180       QualType Arr2Ty =
5181           C.getConstantArrayType(Arr1Ty, Size2, nullptr, ArrayType::Normal,
5182                                  /*IndexTypeQuals=*/0);
5183       llvm::Type *LLVMArr2Ty = CGM.getTypes().ConvertTypeForMem(Arr2Ty);
5184       // FIXME: nvlink does not handle weak linkage correctly (object with the
5185       // different size are reported as erroneous).
5186       // Restore CommonLinkage as soon as nvlink is fixed.
5187       auto *GV = new llvm::GlobalVariable(
5188           CGM.getModule(), LLVMArr2Ty,
5189           /*isConstant=*/false, llvm::GlobalValue::InternalLinkage,
5190           llvm::Constant::getNullValue(LLVMArr2Ty),
5191           "_openmp_static_glob_rd_$_");
5192       auto *Replacement = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
5193           GV, CGM.VoidPtrTy);
5194       for (const GlobalPtrSizeRecsTy *Rec : GlobalRecs) {
5195         Rec->Buffer->replaceAllUsesWith(Replacement);
5196         Rec->Buffer->eraseFromParent();
5197       }
5198     }
5199   }
5200   if (!TeamsReductions.empty()) {
5201     ASTContext &C = CGM.getContext();
5202     RecordDecl *StaticRD = C.buildImplicitRecord(
5203         "_openmp_teams_reduction_type_$_", RecordDecl::TagKind::TTK_Union);
5204     StaticRD->startDefinition();
5205     for (const RecordDecl *TeamReductionRec : TeamsReductions) {
5206       QualType RecTy = C.getRecordType(TeamReductionRec);
5207       auto *Field = FieldDecl::Create(
5208           C, StaticRD, SourceLocation(), SourceLocation(), nullptr, RecTy,
5209           C.getTrivialTypeSourceInfo(RecTy, SourceLocation()),
5210           /*BW=*/nullptr, /*Mutable=*/false,
5211           /*InitStyle=*/ICIS_NoInit);
5212       Field->setAccess(AS_public);
5213       StaticRD->addDecl(Field);
5214     }
5215     StaticRD->completeDefinition();
5216     QualType StaticTy = C.getRecordType(StaticRD);
5217     llvm::Type *LLVMReductionsBufferTy =
5218         CGM.getTypes().ConvertTypeForMem(StaticTy);
5219     // FIXME: nvlink does not handle weak linkage correctly (object with the
5220     // different size are reported as erroneous).
5221     // Restore CommonLinkage as soon as nvlink is fixed.
5222     auto *GV = new llvm::GlobalVariable(
5223         CGM.getModule(), LLVMReductionsBufferTy,
5224         /*isConstant=*/false, llvm::GlobalValue::InternalLinkage,
5225         llvm::Constant::getNullValue(LLVMReductionsBufferTy),
5226         "_openmp_teams_reductions_buffer_$_");
5227     KernelTeamsReductionPtr->setInitializer(
5228         llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV,
5229                                                              CGM.VoidPtrTy));
5230   }
5231   CGOpenMPRuntime::clear();
5232 }