offload/DeviceRTL/src/Synchronization.cpp

   1 //===- Synchronization.cpp - OpenMP Device synchronization API ---- c++ -*-===//
   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 // Include all synchronization.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "Synchronization.h"
  14
  15 #include "Debug.h"
  16 #include "DeviceTypes.h"
  17 #include "DeviceUtils.h"
  18 #include "Interface.h"
  19 #include "Mapping.h"
  20 #include "State.h"
  21
  22 #pragma omp begin declare target device_type(nohost)
  23
  24 using namespace ompx;
  25
  26 namespace impl {
  27
  28 /// Atomics
  29 ///
  30 ///{
  31 /// NOTE: This function needs to be implemented by every target.
  32 uint32_t atomicInc(uint32_t *Address, uint32_t Val, atomic::OrderingTy Ordering,
  33                    atomic::MemScopeTy MemScope);
  34
  35 template <typename Ty>
  36 Ty atomicAdd(Ty *Address, Ty Val, atomic::OrderingTy Ordering) {
  37   return __scoped_atomic_fetch_add(Address, Val, Ordering,
  38                                    __MEMORY_SCOPE_DEVICE);
  39 }
  40
  41 template <typename Ty>
  42 Ty atomicMul(Ty *Address, Ty V, atomic::OrderingTy Ordering) {
  43   Ty TypedCurrentVal, TypedResultVal, TypedNewVal;
  44   bool Success;
  45   do {
  46     TypedCurrentVal = atomic::load(Address, Ordering);
  47     TypedNewVal = TypedCurrentVal * V;
  48     Success = atomic::cas(Address, TypedCurrentVal, TypedNewVal, Ordering,
  49                           atomic::relaxed);
  50   } while (!Success);
  51   return TypedResultVal;
  52 }
  53
  54 template <typename Ty> Ty atomicLoad(Ty *Address, atomic::OrderingTy Ordering) {
  55   return atomicAdd(Address, Ty(0), Ordering);
  56 }
  57
  58 template <typename Ty>
  59 void atomicStore(Ty *Address, Ty Val, atomic::OrderingTy Ordering) {
  60   __scoped_atomic_store_n(Address, Val, Ordering, __MEMORY_SCOPE_DEVICE);
  61 }
  62
  63 template <typename Ty>
  64 bool atomicCAS(Ty *Address, Ty ExpectedV, Ty DesiredV,
  65                atomic::OrderingTy OrderingSucc,
  66                atomic::OrderingTy OrderingFail) {
  67   return __scoped_atomic_compare_exchange(Address, &ExpectedV, &DesiredV, false,
  68                                           OrderingSucc, OrderingFail,
  69                                           __MEMORY_SCOPE_DEVICE);
  70 }
  71
  72 template <typename Ty>
  73 Ty atomicMin(Ty *Address, Ty Val, atomic::OrderingTy Ordering) {
  74   return __scoped_atomic_fetch_min(Address, Val, Ordering,
  75                                    __MEMORY_SCOPE_DEVICE);
  76 }
  77
  78 template <typename Ty>
  79 Ty atomicMax(Ty *Address, Ty Val, atomic::OrderingTy Ordering) {
  80   return __scoped_atomic_fetch_max(Address, Val, Ordering,
  81                                    __MEMORY_SCOPE_DEVICE);
  82 }
  83
  84 // TODO: Implement this with __atomic_fetch_max and remove the duplication.
  85 template <typename Ty, typename STy, typename UTy>
  86 Ty atomicMinFP(Ty *Address, Ty Val, atomic::OrderingTy Ordering) {
  87   if (Val >= 0)
  88     return atomicMin((STy *)Address, utils::convertViaPun<STy>(Val), Ordering);
  89   return atomicMax((UTy *)Address, utils::convertViaPun<UTy>(Val), Ordering);
  90 }
  91
  92 template <typename Ty, typename STy, typename UTy>
  93 Ty atomicMaxFP(Ty *Address, Ty Val, atomic::OrderingTy Ordering) {
  94   if (Val >= 0)
  95     return atomicMax((STy *)Address, utils::convertViaPun<STy>(Val), Ordering);
  96   return atomicMin((UTy *)Address, utils::convertViaPun<UTy>(Val), Ordering);
  97 }
  98
  99 template <typename Ty>
 100 Ty atomicOr(Ty *Address, Ty Val, atomic::OrderingTy Ordering) {
 101   return __scoped_atomic_fetch_or(Address, Val, Ordering,
 102                                   __MEMORY_SCOPE_DEVICE);
 103 }
 104
 105 template <typename Ty>
 106 Ty atomicAnd(Ty *Address, Ty Val, atomic::OrderingTy Ordering) {
 107   return __scoped_atomic_fetch_and(Address, Val, Ordering,
 108                                    __MEMORY_SCOPE_DEVICE);
 109 }
 110
 111 template <typename Ty>
 112 Ty atomicXOr(Ty *Address, Ty Val, atomic::OrderingTy Ordering) {
 113   return __scoped_atomic_fetch_xor(Address, Val, Ordering,
 114                                    __MEMORY_SCOPE_DEVICE);
 115 }
 116
 117 uint32_t atomicExchange(uint32_t *Address, uint32_t Val,
 118                         atomic::OrderingTy Ordering) {
 119   uint32_t R;
 120   __scoped_atomic_exchange(Address, &Val, &R, Ordering, __MEMORY_SCOPE_DEVICE);
 121   return R;
 122 }
 123 ///}
 124
 125 // Forward declarations defined to be defined for AMDGCN and NVPTX.
 126 uint32_t atomicInc(uint32_t *A, uint32_t V, atomic::OrderingTy Ordering,
 127                    atomic::MemScopeTy MemScope);
 128 void namedBarrierInit();
 129 void namedBarrier();
 130 void fenceTeam(atomic::OrderingTy Ordering);
 131 void fenceKernel(atomic::OrderingTy Ordering);
 132 void fenceSystem(atomic::OrderingTy Ordering);
 133 void syncWarp(__kmpc_impl_lanemask_t);
 134 void syncThreads(atomic::OrderingTy Ordering);
 135 void syncThreadsAligned(atomic::OrderingTy Ordering) { syncThreads(Ordering); }
 136 void unsetLock(omp_lock_t *);
 137 int testLock(omp_lock_t *);
 138 void initLock(omp_lock_t *);
 139 void destroyLock(omp_lock_t *);
 140 void setLock(omp_lock_t *);
 141 void unsetCriticalLock(omp_lock_t *);
 142 void setCriticalLock(omp_lock_t *);
 143
 144 /// AMDGCN Implementation
 145 ///
 146 ///{
 147 #pragma omp begin declare variant match(device = {arch(amdgcn)})
 148
 149 uint32_t atomicInc(uint32_t *A, uint32_t V, atomic::OrderingTy Ordering,
 150                    atomic::MemScopeTy MemScope) {
 151   // builtin_amdgcn_atomic_inc32 should expand to this switch when
 152   // passed a runtime value, but does not do so yet. Workaround here.
 153
 154 #define ScopeSwitch(ORDER)                                                     \
 155   switch (MemScope) {                                                          \
 156   case atomic::MemScopeTy::all:                                                \
 157     return __builtin_amdgcn_atomic_inc32(A, V, ORDER, "");                     \
 158   case atomic::MemScopeTy::device:                                             \
 159     return __builtin_amdgcn_atomic_inc32(A, V, ORDER, "agent");                \
 160   case atomic::MemScopeTy::cgroup:                                             \
 161     return __builtin_amdgcn_atomic_inc32(A, V, ORDER, "workgroup");            \
 162   }
 163
 164 #define Case(ORDER)                                                            \
 165   case ORDER:                                                                  \
 166     ScopeSwitch(ORDER)
 167
 168   switch (Ordering) {
 169   default:
 170     __builtin_unreachable();
 171     Case(atomic::relaxed);
 172     Case(atomic::aquire);
 173     Case(atomic::release);
 174     Case(atomic::acq_rel);
 175     Case(atomic::seq_cst);
 176 #undef Case
 177 #undef ScopeSwitch
 178   }
 179 }
 180
 181 uint32_t SHARED(namedBarrierTracker);
 182
 183 void namedBarrierInit() {
 184   // Don't have global ctors, and shared memory is not zero init
 185   atomic::store(&namedBarrierTracker, 0u, atomic::release);
 186 }
 187
 188 void namedBarrier() {
 189   uint32_t NumThreads = omp_get_num_threads();
 190   // assert(NumThreads % 32 == 0);
 191
 192   uint32_t WarpSize = mapping::getWarpSize();
 193   uint32_t NumWaves = NumThreads / WarpSize;
 194
 195   fence::team(atomic::aquire);
 196
 197   // named barrier implementation for amdgcn.
 198   // Uses two 16 bit unsigned counters. One for the number of waves to have
 199   // reached the barrier, and one to count how many times the barrier has been
 200   // passed. These are packed in a single atomically accessed 32 bit integer.
 201   // Low bits for the number of waves, assumed zero before this call.
 202   // High bits to count the number of times the barrier has been passed.
 203
 204   // precondition: NumWaves != 0;
 205   // invariant: NumWaves * WarpSize == NumThreads;
 206   // precondition: NumWaves < 0xffffu;
 207
 208   // Increment the low 16 bits once, using the lowest active thread.
 209   if (mapping::isLeaderInWarp()) {
 210     uint32_t load = atomic::add(&namedBarrierTracker, 1,
 211                                 atomic::relaxed); // commutative
 212
 213     // Record the number of times the barrier has been passed
 214     uint32_t generation = load & 0xffff0000u;
 215
 216     if ((load & 0x0000ffffu) == (NumWaves - 1)) {
 217       // Reached NumWaves in low bits so this is the last wave.
 218       // Set low bits to zero and increment high bits
 219       load += 0x00010000u; // wrap is safe
 220       load &= 0xffff0000u; // because bits zeroed second
 221
 222       // Reset the wave counter and release the waiting waves
 223       atomic::store(&namedBarrierTracker, load, atomic::relaxed);
 224     } else {
 225       // more waves still to go, spin until generation counter changes
 226       do {
 227         __builtin_amdgcn_s_sleep(0);
 228         load = atomic::load(&namedBarrierTracker, atomic::relaxed);
 229       } while ((load & 0xffff0000u) == generation);
 230     }
 231   }
 232   fence::team(atomic::release);
 233 }
 234
 235 // sema checking of amdgcn_fence is aggressive. Intention is to patch clang
 236 // so that it is usable within a template environment and so that a runtime
 237 // value of the memory order is expanded to this switch within clang/llvm.
 238 void fenceTeam(atomic::OrderingTy Ordering) {
 239   switch (Ordering) {
 240   default:
 241     __builtin_unreachable();
 242   case atomic::aquire:
 243     return __builtin_amdgcn_fence(atomic::aquire, "workgroup");
 244   case atomic::release:
 245     return __builtin_amdgcn_fence(atomic::release, "workgroup");
 246   case atomic::acq_rel:
 247     return __builtin_amdgcn_fence(atomic::acq_rel, "workgroup");
 248   case atomic::seq_cst:
 249     return __builtin_amdgcn_fence(atomic::seq_cst, "workgroup");
 250   }
 251 }
 252 void fenceKernel(atomic::OrderingTy Ordering) {
 253   switch (Ordering) {
 254   default:
 255     __builtin_unreachable();
 256   case atomic::aquire:
 257     return __builtin_amdgcn_fence(atomic::aquire, "agent");
 258   case atomic::release:
 259     return __builtin_amdgcn_fence(atomic::release, "agent");
 260   case atomic::acq_rel:
 261     return __builtin_amdgcn_fence(atomic::acq_rel, "agent");
 262   case atomic::seq_cst:
 263     return __builtin_amdgcn_fence(atomic::seq_cst, "agent");
 264   }
 265 }
 266 void fenceSystem(atomic::OrderingTy Ordering) {
 267   switch (Ordering) {
 268   default:
 269     __builtin_unreachable();
 270   case atomic::aquire:
 271     return __builtin_amdgcn_fence(atomic::aquire, "");
 272   case atomic::release:
 273     return __builtin_amdgcn_fence(atomic::release, "");
 274   case atomic::acq_rel:
 275     return __builtin_amdgcn_fence(atomic::acq_rel, "");
 276   case atomic::seq_cst:
 277     return __builtin_amdgcn_fence(atomic::seq_cst, "");
 278   }
 279 }
 280
 281 void syncWarp(__kmpc_impl_lanemask_t) {
 282   // This is a no-op on current AMDGPU hardware but it is used by the optimizer
 283   // to enforce convergent behaviour between control flow graphs.
 284   __builtin_amdgcn_wave_barrier();
 285 }
 286
 287 void syncThreads(atomic::OrderingTy Ordering) {
 288   if (Ordering != atomic::relaxed)
 289     fenceTeam(Ordering == atomic::acq_rel ? atomic::release : atomic::seq_cst);
 290
 291   __builtin_amdgcn_s_barrier();
 292
 293   if (Ordering != atomic::relaxed)
 294     fenceTeam(Ordering == atomic::acq_rel ? atomic::aquire : atomic::seq_cst);
 295 }
 296 void syncThreadsAligned(atomic::OrderingTy Ordering) { syncThreads(Ordering); }
 297
 298 // TODO: Don't have wavefront lane locks. Possibly can't have them.
 299 void unsetLock(omp_lock_t *) { __builtin_trap(); }
 300 int testLock(omp_lock_t *) { __builtin_trap(); }
 301 void initLock(omp_lock_t *) { __builtin_trap(); }
 302 void destroyLock(omp_lock_t *) { __builtin_trap(); }
 303 void setLock(omp_lock_t *) { __builtin_trap(); }
 304
 305 constexpr uint32_t UNSET = 0;
 306 constexpr uint32_t SET = 1;
 307
 308 void unsetCriticalLock(omp_lock_t *Lock) {
 309   (void)atomicExchange((uint32_t *)Lock, UNSET, atomic::acq_rel);
 310 }
 311
 312 void setCriticalLock(omp_lock_t *Lock) {
 313   uint64_t LowestActiveThread = utils::ffs(mapping::activemask()) - 1;
 314   if (mapping::getThreadIdInWarp() == LowestActiveThread) {
 315     fenceKernel(atomic::release);
 316     while (!atomicCAS((uint32_t *)Lock, UNSET, SET, atomic::relaxed,
 317                       atomic::relaxed)) {
 318       __builtin_amdgcn_s_sleep(32);
 319     }
 320     fenceKernel(atomic::aquire);
 321   }
 322 }
 323
 324 #pragma omp end declare variant
 325 ///}
 326
 327 /// NVPTX Implementation
 328 ///
 329 ///{
 330 #pragma omp begin declare variant match(                                       \
 331         device = {arch(nvptx, nvptx64)},                                       \
 332             implementation = {extension(match_any)})
 333
 334 uint32_t atomicInc(uint32_t *Address, uint32_t Val, atomic::OrderingTy Ordering,
 335                    atomic::MemScopeTy MemScope) {
 336   return __nvvm_atom_inc_gen_ui(Address, Val);
 337 }
 338
 339 void namedBarrierInit() {}
 340
 341 void namedBarrier() {
 342   uint32_t NumThreads = omp_get_num_threads();
 343   ASSERT(NumThreads % 32 == 0, nullptr);
 344
 345   // The named barrier for active parallel threads of a team in an L1 parallel
 346   // region to synchronize with each other.
 347   constexpr int BarrierNo = 7;
 348   __nvvm_barrier_sync_cnt(BarrierNo, NumThreads);
 349 }
 350
 351 void fenceTeam(atomic::OrderingTy) { __nvvm_membar_cta(); }
 352
 353 void fenceKernel(atomic::OrderingTy) { __nvvm_membar_gl(); }
 354
 355 void fenceSystem(atomic::OrderingTy) { __nvvm_membar_sys(); }
 356
 357 void syncWarp(__kmpc_impl_lanemask_t Mask) { __nvvm_bar_warp_sync(Mask); }
 358
 359 void syncThreads(atomic::OrderingTy Ordering) {
 360   constexpr int BarrierNo = 8;
 361   __nvvm_barrier_sync(BarrierNo);
 362 }
 363
 364 void syncThreadsAligned(atomic::OrderingTy Ordering) { __syncthreads(); }
 365
 366 constexpr uint32_t OMP_SPIN = 1000;
 367 constexpr uint32_t UNSET = 0;
 368 constexpr uint32_t SET = 1;
 369
 370 // TODO: This seems to hide a bug in the declare variant handling. If it is
 371 // called before it is defined
 372 //       here the overload won't happen. Investigate lalter!
 373 void unsetLock(omp_lock_t *Lock) {
 374   (void)atomicExchange((uint32_t *)Lock, UNSET, atomic::seq_cst);
 375 }
 376
 377 int testLock(omp_lock_t *Lock) {
 378   return atomicAdd((uint32_t *)Lock, 0u, atomic::seq_cst);
 379 }
 380
 381 void initLock(omp_lock_t *Lock) { unsetLock(Lock); }
 382
 383 void destroyLock(omp_lock_t *Lock) { unsetLock(Lock); }
 384
 385 void setLock(omp_lock_t *Lock) {
 386   // TODO: not sure spinning is a good idea here..
 387   while (atomicCAS((uint32_t *)Lock, UNSET, SET, atomic::seq_cst,
 388                    atomic::seq_cst) != UNSET) {
 389     int32_t start = __nvvm_read_ptx_sreg_clock();
 390     int32_t now;
 391     for (;;) {
 392       now = __nvvm_read_ptx_sreg_clock();
 393       int32_t cycles = now > start ? now - start : now + (0xffffffff - start);
 394       if (cycles >= OMP_SPIN * mapping::getBlockIdInKernel()) {
 395         break;
 396       }
 397     }
 398   } // wait for 0 to be the read value
 399 }
 400
 401 void unsetCriticalLock(omp_lock_t *Lock) { unsetLock(Lock); }
 402
 403 void setCriticalLock(omp_lock_t *Lock) { setLock(Lock); }
 404
 405 #pragma omp end declare variant
 406 ///}
 407
 408 } // namespace impl
 409
 410 void synchronize::init(bool IsSPMD) {
 411   if (!IsSPMD)
 412     impl::namedBarrierInit();
 413 }
 414
 415 void synchronize::warp(LaneMaskTy Mask) { impl::syncWarp(Mask); }
 416
 417 void synchronize::threads(atomic::OrderingTy Ordering) {
 418   impl::syncThreads(Ordering);
 419 }
 420
 421 void synchronize::threadsAligned(atomic::OrderingTy Ordering) {
 422   impl::syncThreadsAligned(Ordering);
 423 }
 424
 425 void fence::team(atomic::OrderingTy Ordering) { impl::fenceTeam(Ordering); }
 426
 427 void fence::kernel(atomic::OrderingTy Ordering) { impl::fenceKernel(Ordering); }
 428
 429 void fence::system(atomic::OrderingTy Ordering) { impl::fenceSystem(Ordering); }
 430
 431 #define ATOMIC_COMMON_OP(TY)                                                   \
 432   TY atomic::add(TY *Addr, TY V, atomic::OrderingTy Ordering) {                \
 433     return impl::atomicAdd(Addr, V, Ordering);                                 \
 434   }                                                                            \
 435   TY atomic::mul(TY *Addr, TY V, atomic::OrderingTy Ordering) {                \
 436     return impl::atomicMul(Addr, V, Ordering);                                 \
 437   }                                                                            \
 438   TY atomic::load(TY *Addr, atomic::OrderingTy Ordering) {                     \
 439     return impl::atomicLoad(Addr, Ordering);                                   \
 440   }                                                                            \
 441   bool atomic::cas(TY *Addr, TY ExpectedV, TY DesiredV,                        \
 442                    atomic::OrderingTy OrderingSucc,                            \
 443                    atomic::OrderingTy OrderingFail) {                          \
 444     return impl::atomicCAS(Addr, ExpectedV, DesiredV, OrderingSucc,            \
 445                            OrderingFail);                                      \
 446   }
 447
 448 #define ATOMIC_FP_ONLY_OP(TY, STY, UTY)                                        \
 449   TY atomic::min(TY *Addr, TY V, atomic::OrderingTy Ordering) {                \
 450     return impl::atomicMinFP<TY, STY, UTY>(Addr, V, Ordering);                 \
 451   }                                                                            \
 452   TY atomic::max(TY *Addr, TY V, atomic::OrderingTy Ordering) {                \
 453     return impl::atomicMaxFP<TY, STY, UTY>(Addr, V, Ordering);                 \
 454   }                                                                            \
 455   void atomic::store(TY *Addr, TY V, atomic::OrderingTy Ordering) {            \
 456     impl::atomicStore(reinterpret_cast<UTY *>(Addr),                           \
 457                       utils::convertViaPun<UTY>(V), Ordering);                 \
 458   }
 459
 460 #define ATOMIC_INT_ONLY_OP(TY)                                                 \
 461   TY atomic::min(TY *Addr, TY V, atomic::OrderingTy Ordering) {                \
 462     return impl::atomicMin<TY>(Addr, V, Ordering);                             \
 463   }                                                                            \
 464   TY atomic::max(TY *Addr, TY V, atomic::OrderingTy Ordering) {                \
 465     return impl::atomicMax<TY>(Addr, V, Ordering);                             \
 466   }                                                                            \
 467   TY atomic::bit_or(TY *Addr, TY V, atomic::OrderingTy Ordering) {             \
 468     return impl::atomicOr(Addr, V, Ordering);                                  \
 469   }                                                                            \
 470   TY atomic::bit_and(TY *Addr, TY V, atomic::OrderingTy Ordering) {            \
 471     return impl::atomicAnd(Addr, V, Ordering);                                 \
 472   }                                                                            \
 473   TY atomic::bit_xor(TY *Addr, TY V, atomic::OrderingTy Ordering) {            \
 474     return impl::atomicXOr(Addr, V, Ordering);                                 \
 475   }                                                                            \
 476   void atomic::store(TY *Addr, TY V, atomic::OrderingTy Ordering) {            \
 477     impl::atomicStore(Addr, V, Ordering);                                      \
 478   }
 479
 480 #define ATOMIC_FP_OP(TY, STY, UTY)                                             \
 481   ATOMIC_FP_ONLY_OP(TY, STY, UTY)                                              \
 482   ATOMIC_COMMON_OP(TY)
 483
 484 #define ATOMIC_INT_OP(TY)                                                      \
 485   ATOMIC_INT_ONLY_OP(TY)                                                       \
 486   ATOMIC_COMMON_OP(TY)
 487
 488 // This needs to be kept in sync with the header. Also the reason we don't use
 489 // templates here.
 490 ATOMIC_INT_OP(int8_t)
 491 ATOMIC_INT_OP(int16_t)
 492 ATOMIC_INT_OP(int32_t)
 493 ATOMIC_INT_OP(int64_t)
 494 ATOMIC_INT_OP(uint8_t)
 495 ATOMIC_INT_OP(uint16_t)
 496 ATOMIC_INT_OP(uint32_t)
 497 ATOMIC_INT_OP(uint64_t)
 498 ATOMIC_FP_OP(float, int32_t, uint32_t)
 499 ATOMIC_FP_OP(double, int64_t, uint64_t)
 500
 501 #undef ATOMIC_INT_ONLY_OP
 502 #undef ATOMIC_FP_ONLY_OP
 503 #undef ATOMIC_COMMON_OP
 504 #undef ATOMIC_INT_OP
 505 #undef ATOMIC_FP_OP
 506
 507 uint32_t atomic::inc(uint32_t *Addr, uint32_t V, atomic::OrderingTy Ordering,
 508                      atomic::MemScopeTy MemScope) {
 509   return impl::atomicInc(Addr, V, Ordering, MemScope);
 510 }
 511
 512 void unsetCriticalLock(omp_lock_t *Lock) { impl::unsetLock(Lock); }
 513
 514 void setCriticalLock(omp_lock_t *Lock) { impl::setLock(Lock); }
 515
 516 extern "C" {
 517 void __kmpc_ordered(IdentTy *Loc, int32_t TId) {}
 518
 519 void __kmpc_end_ordered(IdentTy *Loc, int32_t TId) {}
 520
 521 int32_t __kmpc_cancel_barrier(IdentTy *Loc, int32_t TId) {
 522   __kmpc_barrier(Loc, TId);
 523   return 0;
 524 }
 525
 526 void __kmpc_barrier(IdentTy *Loc, int32_t TId) {
 527   if (mapping::isMainThreadInGenericMode())
 528     return __kmpc_flush(Loc);
 529
 530   if (mapping::isSPMDMode())
 531     return __kmpc_barrier_simple_spmd(Loc, TId);
 532
 533   impl::namedBarrier();
 534 }
 535
 536 [[clang::noinline]] void __kmpc_barrier_simple_spmd(IdentTy *Loc, int32_t TId) {
 537   synchronize::threadsAligned(atomic::OrderingTy::seq_cst);
 538 }
 539
 540 [[clang::noinline]] void __kmpc_barrier_simple_generic(IdentTy *Loc,
 541                                                        int32_t TId) {
 542   synchronize::threads(atomic::OrderingTy::seq_cst);
 543 }
 544
 545 int32_t __kmpc_master(IdentTy *Loc, int32_t TId) {
 546   return omp_get_thread_num() == 0;
 547 }
 548
 549 void __kmpc_end_master(IdentTy *Loc, int32_t TId) {}
 550
 551 int32_t __kmpc_masked(IdentTy *Loc, int32_t TId, int32_t Filter) {
 552   return omp_get_thread_num() == Filter;
 553 }
 554
 555 void __kmpc_end_masked(IdentTy *Loc, int32_t TId) {}
 556
 557 int32_t __kmpc_single(IdentTy *Loc, int32_t TId) {
 558   return __kmpc_master(Loc, TId);
 559 }
 560
 561 void __kmpc_end_single(IdentTy *Loc, int32_t TId) {
 562   // The barrier is explicitly called.
 563 }
 564
 565 void __kmpc_flush(IdentTy *Loc) { fence::kernel(atomic::seq_cst); }
 566
 567 uint64_t __kmpc_warp_active_thread_mask(void) { return mapping::activemask(); }
 568
 569 void __kmpc_syncwarp(uint64_t Mask) { synchronize::warp(Mask); }
 570
 571 void __kmpc_critical(IdentTy *Loc, int32_t TId, CriticalNameTy *Name) {
 572   impl::setCriticalLock(reinterpret_cast<omp_lock_t *>(Name));
 573 }
 574
 575 void __kmpc_end_critical(IdentTy *Loc, int32_t TId, CriticalNameTy *Name) {
 576   impl::unsetCriticalLock(reinterpret_cast<omp_lock_t *>(Name));
 577 }
 578
 579 void omp_init_lock(omp_lock_t *Lock) { impl::initLock(Lock); }
 580
 581 void omp_destroy_lock(omp_lock_t *Lock) { impl::destroyLock(Lock); }
 582
 583 void omp_set_lock(omp_lock_t *Lock) { impl::setLock(Lock); }
 584
 585 void omp_unset_lock(omp_lock_t *Lock) { impl::unsetLock(Lock); }
 586
 587 int omp_test_lock(omp_lock_t *Lock) { return impl::testLock(Lock); }
 588
 589 void ompx_sync_block(int Ordering) {
 590   impl::syncThreadsAligned(atomic::OrderingTy(Ordering));
 591 }
 592 void ompx_sync_block_acq_rel() {
 593   impl::syncThreadsAligned(atomic::OrderingTy::acq_rel);
 594 }
 595 void ompx_sync_block_divergent(int Ordering) {
 596   impl::syncThreads(atomic::OrderingTy(Ordering));
 597 }
 598 } // extern "C"
 599
 600 #pragma omp end declare target