Date: 2026-03-01T05:24:34+00:00

Actual source code: cupminterface.hpp

      1: #pragma once

      3: #include <petscdevice_cupm.h>

      5: #include <petsc/private/cpputil.hpp>
      6: #include <petsc/private/petscadvancedmacros.h>

      8: #include <petsc/private/cpp/array.hpp>

     10: namespace Petsc
     11: {

     13: namespace device
     14: {

     16: namespace cupm
     17: {

     19: // enum describing available cupm devices, this is used as the template parameter to any
     20: // class subclassing the Interface or using it as a member variable
     21: enum class DeviceType : int {
     22:   CUDA,
     23:   HIP
     24: };

     26: // clang-format off
     27: static constexpr std::array<const char *const, 5> DeviceTypes = {
     28:   "cuda",
     29:   "hip",
     30:   "Petsc::device::cupm::DeviceType",
     31:   "Petsc::device::cupm::DeviceType::",
     32:   nullptr
     33: };
     34: // clang-format on

     36: namespace impl
     37: {

     39: #define PetscCallCUPM_(__abort_fn__, __comm__, ...) \
     40:   do { \
     41:     PetscStackUpdateLine; \
     42:     const cupmError_t cerr_p_ = __VA_ARGS__; \
     43:     __abort_fn__(cerr_p_ == cupmSuccess, __comm__, PETSC_ERR_GPU, "%s error %d (%s) : %s", cupmName(), static_cast<PetscErrorCode>(cerr_p_), cupmGetErrorName(cerr_p_), cupmGetErrorString(cerr_p_)); \
     44:   } while (0)

     46: // A backend agnostic PetscCallCUPM() function, this will only work inside the member
     47: // functions of a class inheriting from CUPM::Interface. Thanks to __VA_ARGS__ templated
     48: // functions can also be wrapped inline:
     49: //
     50: // PetscCallCUPM(foo());
     51: #define PetscCallCUPM(...)             PetscCallCUPM_(PetscCheck, PETSC_COMM_SELF, __VA_ARGS__)
     52: #define PetscCallCUPMAbort(comm_, ...) PetscCallCUPM_(PetscCheckAbort, comm_, __VA_ARGS__)

     54: // PETSC_CUPM_ALIAS_FUNCTION() - declaration to alias a cuda/hip function
     55: //
     56: // input params:
     57: // our_name   - the name of the alias
     58: // their_name - the name of the function being aliased
     59: //
     60: // notes:
     61: // see PETSC_ALIAS_FUNCTION() for the exact nature of the expansion
     62: //
     63: // example usage:
     64: // PETSC_CUPM_ALIAS_FUNCTION(cupmMalloc, cudaMalloc) ->
     65: // template
     66: // static constexpr auto cupmMalloc(T&&... args) *noexcept and trailing return type deduction*
     67: // {
     68: //   return cudaMalloc(std::forward(args)...);
     69: // }
     70: //
     71: // PETSC_CUPM_ALIAS_FUNCTION(cupmMalloc, hipMalloc) ->
     72: // template
     73: // static constexpr auto cupmMalloc(T&&... args) *noexcept and trailing return type deduction*
     74: // {
     75: //   return hipMalloc(std::forward(args)...);
     76: // }
     77: #define PETSC_CUPM_ALIAS_FUNCTION(our_name, their_name) PETSC_ALIAS_FUNCTION(static our_name, their_name)

     79: // PETSC_CUPM_ALIAS_FUNCTION_GOBBLE() - declaration to alias a cuda/hip function but
     80: // discard the last N arguments
     81: //
     82: // input params:
     83: // our_name   - the name of the alias
     84: // their_name - the name of the function being aliased
     85: // N          - integer constant [0, INT_MAX) dictating how many arguments to chop off the end
     86: //
     87: // notes:
     88: // see PETSC_ALIAS_FUNCTION_GOBBLE_NTH_LAST_ARGS() for the exact nature of the expansion
     89: //
     90: // example use:
     91: // PETSC_CUPM_ALIAS_FUNCTION_GOBBLE_COMMON(cupmMallocAsync, cudaMalloc, 1) ->
     92: // template
     93: // static constexpr auto cupmMallocAsync(T&&... args, Tend argend) *noexcept and trailing
     94: // return type deduction*
     95: // {
     96: //   (void)argend;
     97: //   return cudaMalloc(std::forward(args)...);
     98: // }
     99: #define PETSC_CUPM_ALIAS_FUNCTION_GOBBLE(our_name, their_name, N) PETSC_ALIAS_FUNCTION_GOBBLE_NTH_LAST_ARGS(static our_name, their_name, N)

    101: // Base class that holds functions and variables that don't require CUDA or HIP to be present
    102: // on the system
    103: template <DeviceType T>
    104: struct InterfaceBase {
    105:   static const DeviceType type = T;

    107:   PETSC_NODISCARD static constexpr const char *cupmName() noexcept
    108:   {
    109:     static_assert(util::to_underlying(DeviceType::CUDA) == 0, "");
    110:     static_assert(util::to_underlying(DeviceType::HIP) == 1, "");
    111:     return std::get<util::to_underlying(T)>(DeviceTypes);
    112:   }

    114:   PETSC_NODISCARD static constexpr const char *cupmNAME() noexcept { return T == DeviceType::CUDA ? "CUDA" : "HIP"; }

    116:   PETSC_NODISCARD static constexpr PetscDeviceType PETSC_DEVICE_CUPM() noexcept { return T == DeviceType::CUDA ? PETSC_DEVICE_CUDA : PETSC_DEVICE_HIP; }

    118:   PETSC_NODISCARD static constexpr PetscMemType PETSC_MEMTYPE_CUPM() noexcept { return T == DeviceType::CUDA ? PETSC_MEMTYPE_CUDA : PETSC_MEMTYPE_HIP; }
    119: };

    121: // declare the base class static member variables
    122: template <DeviceType T>
    123: const DeviceType InterfaceBase<T>::type;

    125: #define PETSC_CUPM_BASE_CLASS_HEADER(T) \
    126:   using ::Petsc::device::cupm::impl::InterfaceBase<T>::type; \
    127:   using ::Petsc::device::cupm::impl::InterfaceBase<T>::cupmName; \
    128:   using ::Petsc::device::cupm::impl::InterfaceBase<T>::cupmNAME; \
    129:   using ::Petsc::device::cupm::impl::InterfaceBase<T>::PETSC_DEVICE_CUPM; \
    130:   using ::Petsc::device::cupm::impl::InterfaceBase<T>::PETSC_MEMTYPE_CUPM

    132: // A templated C++ struct that defines the entire CUPM interface. Use of templating vs
    133: // preprocessor macros allows us to use both interfaces simultaneously as well as easily
    134: // import them into classes.
    135: template <DeviceType>
    136: struct InterfaceImpl;

    138: #if PetscDefined(HAVE_CUDA)
    139: template <>
    140: struct InterfaceImpl<DeviceType::CUDA> : InterfaceBase<DeviceType::CUDA> {
    141:   PETSC_CUPM_BASE_CLASS_HEADER(DeviceType::CUDA);

    143:   // typedefs
    144:   using cupmError_t             = cudaError_t;
    145:   using cupmEvent_t             = cudaEvent_t;
    146:   using cupmStream_t            = cudaStream_t;
    147:   using cupmDeviceProp_t        = cudaDeviceProp;
    148:   using cupmMemcpyKind_t        = cudaMemcpyKind;
    149:   using cupmDeviceAttr_t        = cudaDeviceAttr;
    150:   using cupmComplex_t           = util::conditional_t<PetscDefined(USE_REAL_SINGLE), cuComplex, cuDoubleComplex>;
    151:   using cupmPointerAttributes_t = cudaPointerAttributes;
    152:   using cupmMemoryType_t        = enum cudaMemoryType;
    153:   using cupmDim3                = dim3;
    154:   using cupmHostFn_t            = cudaHostFn_t;
    155:   #if PETSC_PKG_CUDA_VERSION_GE(11, 2, 0)
    156:   using cupmMemPool_t   = cudaMemPool_t;
    157:   using cupmMemPoolAttr = cudaMemPoolAttr;
    158:   #else
    159:   using cupmMemPool_t   = void *;
    160:   using cupmMemPoolAttr = unsigned int;
    161:   #endif

    163:   // values
    164:   static const auto cupmSuccess                 = cudaSuccess;
    165:   static const auto cupmErrorNotReady           = cudaErrorNotReady;
    166:   static const auto cupmErrorDeviceAlreadyInUse = cudaErrorDeviceAlreadyInUse;
    167:   static const auto cupmErrorSetOnActiveProcess = cudaErrorSetOnActiveProcess;
    168:   static const auto cupmErrorStubLibrary =
    169:   #if PETSC_PKG_CUDA_VERSION_GE(11, 1, 0)
    170:     cudaErrorStubLibrary;
    171:   #else
    172:     cudaErrorInsufficientDriver;
    173:   #endif

    175:   static const auto cupmErrorNoDevice          = cudaErrorNoDevice;
    176:   static const auto cupmStreamDefault          = cudaStreamDefault;
    177:   static const auto cupmStreamNonBlocking      = cudaStreamNonBlocking;
    178:   static const auto cupmDeviceMapHost          = cudaDeviceMapHost;
    179:   static const auto cupmMemcpyHostToDevice     = cudaMemcpyHostToDevice;
    180:   static const auto cupmMemcpyDeviceToHost     = cudaMemcpyDeviceToHost;
    181:   static const auto cupmMemcpyDeviceToDevice   = cudaMemcpyDeviceToDevice;
    182:   static const auto cupmMemcpyHostToHost       = cudaMemcpyHostToHost;
    183:   static const auto cupmMemcpyDefault          = cudaMemcpyDefault;
    184:   static const auto cupmMemoryTypeHost         = cudaMemoryTypeHost;
    185:   static const auto cupmMemoryTypeDevice       = cudaMemoryTypeDevice;
    186:   static const auto cupmMemoryTypeManaged      = cudaMemoryTypeManaged;
    187:   static const auto cupmEventDisableTiming     = cudaEventDisableTiming;
    188:   static const auto cupmHostAllocDefault       = cudaHostAllocDefault;
    189:   static const auto cupmHostAllocWriteCombined = cudaHostAllocWriteCombined;
    190:   static const auto cupmMemPoolAttrReleaseThreshold =
    191:   #if PETSC_PKG_CUDA_VERSION_GE(11, 2, 0)
    192:     cudaMemPoolAttrReleaseThreshold;
    193:   #else
    194:     cupmMemPoolAttr{0};
    195:   #endif
    196:   static const auto cupmDevAttrClockRate       = cudaDevAttrClockRate;
    197:   static const auto cupmDevAttrMemoryClockRate = cudaDevAttrMemoryClockRate;

    199:   // error functions
    200:   PETSC_CUPM_ALIAS_FUNCTION(cupmGetErrorName, cudaGetErrorName)
    201:   PETSC_CUPM_ALIAS_FUNCTION(cupmGetErrorString, cudaGetErrorString)
    202:   PETSC_CUPM_ALIAS_FUNCTION(cupmGetLastError, cudaGetLastError)

    204:   // device management
    205:   PETSC_CUPM_ALIAS_FUNCTION(cupmGetDeviceCount, cudaGetDeviceCount)
    206:   PETSC_CUPM_ALIAS_FUNCTION(cupmGetDeviceProperties, cudaGetDeviceProperties)
    207:   PETSC_CUPM_ALIAS_FUNCTION(cupmDeviceGetAttribute, cudaDeviceGetAttribute)
    208:   PETSC_CUPM_ALIAS_FUNCTION(cupmGetDevice, cudaGetDevice)
    209:   PETSC_CUPM_ALIAS_FUNCTION(cupmSetDevice, cudaSetDevice)
    210:   PETSC_CUPM_ALIAS_FUNCTION(cupmGetDeviceFlags, cudaGetDeviceFlags)
    211:   PETSC_CUPM_ALIAS_FUNCTION(cupmSetDeviceFlags, cudaSetDeviceFlags)
    212:   PETSC_CUPM_ALIAS_FUNCTION(cupmPointerGetAttributes, cudaPointerGetAttributes)
    213:   #if PETSC_PKG_CUDA_VERSION_GE(11, 2, 0)
    214:   PETSC_CUPM_ALIAS_FUNCTION(cupmDeviceGetMemPool, cudaDeviceGetMemPool)
    215:   PETSC_CUPM_ALIAS_FUNCTION(cupmMemPoolSetAttribute, cudaMemPoolSetAttribute)
    216:   #else
    217:   PETSC_NODISCARD static cupmError_t cupmDeviceGetMemPool(cupmMemPool_t *pool, int) noexcept
    218:   {
    219:     *pool = nullptr;
    220:     return cupmSuccess;
    221:   }

    223:   PETSC_NODISCARD static cupmError_t cupmMemPoolSetAttribute(cupmMemPool_t, cupmMemPoolAttr, void *) noexcept { return cupmSuccess; }
    224:   #endif
    225:   // CUDA has no cudaInit() to match hipInit()
    226:   PETSC_NODISCARD static cupmError_t cupmInit(unsigned int) noexcept { return cudaFree(nullptr); }

    228:   // stream management
    229:   PETSC_CUPM_ALIAS_FUNCTION(cupmEventCreate, cudaEventCreate)
    230:   PETSC_CUPM_ALIAS_FUNCTION(cupmEventCreateWithFlags, cudaEventCreateWithFlags)
    231:   PETSC_CUPM_ALIAS_FUNCTION(cupmEventDestroy, cudaEventDestroy)
    232:   PETSC_CUPM_ALIAS_FUNCTION(cupmEventRecord, cudaEventRecord)
    233:   PETSC_CUPM_ALIAS_FUNCTION(cupmEventSynchronize, cudaEventSynchronize)
    234:   PETSC_CUPM_ALIAS_FUNCTION(cupmEventElapsedTime, cudaEventElapsedTime)
    235:   PETSC_CUPM_ALIAS_FUNCTION(cupmEventQuery, cudaEventQuery)
    236:   PETSC_CUPM_ALIAS_FUNCTION(cupmStreamCreate, cudaStreamCreate)
    237:   PETSC_CUPM_ALIAS_FUNCTION(cupmStreamCreateWithFlags, cudaStreamCreateWithFlags)
    238:   PETSC_CUPM_ALIAS_FUNCTION(cupmStreamGetFlags, cudaStreamGetFlags)
    239:   PETSC_CUPM_ALIAS_FUNCTION(cupmStreamDestroy, cudaStreamDestroy)
    240:   PETSC_CUPM_ALIAS_FUNCTION(cupmStreamWaitEvent, cudaStreamWaitEvent)
    241:   PETSC_CUPM_ALIAS_FUNCTION(cupmStreamQuery, cudaStreamQuery)
    242:   PETSC_CUPM_ALIAS_FUNCTION(cupmStreamSynchronize, cudaStreamSynchronize)
    243:   PETSC_CUPM_ALIAS_FUNCTION(cupmDeviceSynchronize, cudaDeviceSynchronize)
    244:   PETSC_CUPM_ALIAS_FUNCTION(cupmGetSymbolAddress, cudaGetSymbolAddress)

    246:   // memory management
    247:   PETSC_CUPM_ALIAS_FUNCTION(cupmFree, cudaFree)
    248:   PETSC_CUPM_ALIAS_FUNCTION(cupmMalloc, cudaMalloc)
    249:   #if PETSC_PKG_CUDA_VERSION_GE(11, 2, 0)
    250:   PETSC_CUPM_ALIAS_FUNCTION(cupmFreeAsync, cudaFreeAsync)
    251:   PETSC_CUPM_ALIAS_FUNCTION(cupmMallocAsync, cudaMallocAsync)
    252:   #else
    253:   PETSC_CUPM_ALIAS_FUNCTION_GOBBLE(cupmFreeAsync, cudaFree, 1)
    254:   PETSC_CUPM_ALIAS_FUNCTION_GOBBLE(cupmMallocAsync, cudaMalloc, 1)
    255:   #endif
    256:   PETSC_CUPM_ALIAS_FUNCTION(cupmMemcpy, cudaMemcpy)
    257:   PETSC_CUPM_ALIAS_FUNCTION(cupmMemcpyAsync, cudaMemcpyAsync)
    258:   PETSC_CUPM_ALIAS_FUNCTION(cupmMallocHost, cudaMallocHost)
    259:   PETSC_CUPM_ALIAS_FUNCTION(cupmFreeHost, cudaFreeHost)
    260:   PETSC_CUPM_ALIAS_FUNCTION(cupmMemset, cudaMemset)
    261:   #if PETSC_PKG_CUDA_VERSION_GE(11, 2, 0)
    262:   PETSC_CUPM_ALIAS_FUNCTION(cupmMemsetAsync, cudaMemsetAsync)
    263:   #else
    264:   PETSC_CUPM_ALIAS_FUNCTION_GOBBLE(cupmMemsetAsync, cudaMemset, 1)
    265:   #endif
    266:   PETSC_CUPM_ALIAS_FUNCTION(cupmMemcpy2D, cudaMemcpy2D)
    267:   PETSC_CUPM_ALIAS_FUNCTION_GOBBLE(cupmMemcpy2DAsync, cudaMemcpy2DAsync, 1)
    268:   PETSC_CUPM_ALIAS_FUNCTION(cupmMemset2D, cudaMemset2D)
    269:   PETSC_CUPM_ALIAS_FUNCTION_GOBBLE(cupmMemset2DAsync, cudaMemset2DAsync, 1)

    271:   // launch control
    272:   PETSC_CUPM_ALIAS_FUNCTION(cupmLaunchHostFunc, cudaLaunchHostFunc)
    273:   template <typename FunctionT, typename... KernelArgsT>
    274:   PETSC_NODISCARD static cudaError_t cupmLaunchKernel(FunctionT &&func, dim3 gridDim, dim3 blockDim, std::size_t sharedMem, cudaStream_t stream, KernelArgsT &&...kernelArgs) noexcept
    275:   {
    276:     static_assert(!std::is_pointer<FunctionT>::value, "kernel function must not be passed by pointer");
    277:     void *args[] = {(void *)std::addressof(kernelArgs)...};

    279:     return cudaLaunchKernel<util::remove_reference_t<FunctionT>>(std::addressof(func), std::move(gridDim), std::move(blockDim), args, sharedMem, std::move(stream));
    280:   }
    281: };
    282: #endif // PetscDefined(HAVE_CUDA)

    284: #if PetscDefined(HAVE_HIP)
    285: template <>
    286: struct InterfaceImpl<DeviceType::HIP> : InterfaceBase<DeviceType::HIP> {
    287:   PETSC_CUPM_BASE_CLASS_HEADER(DeviceType::HIP);

    289:   // typedefs
    290:   using cupmError_t             = hipError_t;
    291:   using cupmEvent_t             = hipEvent_t;
    292:   using cupmStream_t            = hipStream_t;
    293:   using cupmDeviceProp_t        = hipDeviceProp_t;
    294:   using cupmMemcpyKind_t        = hipMemcpyKind;
    295:   using cupmDeviceAttr_t        = hipDeviceAttribute_t;
    296:   using cupmComplex_t           = util::conditional_t<PetscDefined(USE_REAL_SINGLE), hipComplex, hipDoubleComplex>;
    297:   using cupmPointerAttributes_t = hipPointerAttribute_t;
    298:   using cupmMemoryType_t        = enum hipMemoryType;
    299:   using cupmDim3                = dim3;
    300:   #if PETSC_PKG_HIP_VERSION_GE(5, 2, 0)
    301:   using cupmHostFn_t    = hipHostFn_t;
    302:   using cupmMemPool_t   = hipMemPool_t;
    303:   using cupmMemPoolAttr = hipMemPoolAttr;
    304:   #else
    305:   using cupmHostFn_t    = void (*)(void *);
    306:   using cupmMemPool_t   = void *;
    307:   using cupmMemPoolAttr = unsigned int;
    308:   #endif

    310:   // values
    311:   static const auto cupmSuccess       = hipSuccess;
    312:   static const auto cupmErrorNotReady = hipErrorNotReady;
    313:   // see https://github.com/ROCm-Developer-Tools/HIP/blob/develop/bin/hipify-perl
    314:   static const auto cupmErrorDeviceAlreadyInUse = hipErrorContextAlreadyInUse;
    315:   static const auto cupmErrorSetOnActiveProcess = hipErrorSetOnActiveProcess;
    316:   // as of HIP v4.2 cudaErrorStubLibrary has no HIP equivalent
    317:   static const auto cupmErrorStubLibrary     = hipErrorInsufficientDriver;
    318:   static const auto cupmErrorNoDevice        = hipErrorNoDevice;
    319:   static const auto cupmStreamDefault        = hipStreamDefault;
    320:   static const auto cupmStreamNonBlocking    = hipStreamNonBlocking;
    321:   static const auto cupmDeviceMapHost        = hipDeviceMapHost;
    322:   static const auto cupmMemcpyHostToDevice   = hipMemcpyHostToDevice;
    323:   static const auto cupmMemcpyDeviceToHost   = hipMemcpyDeviceToHost;
    324:   static const auto cupmMemcpyDeviceToDevice = hipMemcpyDeviceToDevice;
    325:   static const auto cupmMemcpyHostToHost     = hipMemcpyHostToHost;
    326:   static const auto cupmMemcpyDefault        = hipMemcpyDefault;
    327:   static const auto cupmMemoryTypeHost       = hipMemoryTypeHost;
    328:   static const auto cupmMemoryTypeDevice     = hipMemoryTypeDevice;
    329:   // see
    330:   // https://github.com/ROCm-Developer-Tools/HIP/blob/develop/include/hip/hip_runtime_api.h#L156
    331:   static const auto cupmMemoryTypeManaged      = hipMemoryTypeUnified;
    332:   static const auto cupmEventDisableTiming     = hipEventDisableTiming;
    333:   static const auto cupmHostAllocDefault       = hipHostMallocDefault;
    334:   static const auto cupmHostAllocWriteCombined = hipHostMallocWriteCombined;
    335:   static const auto cupmMemPoolAttrReleaseThreshold =
    336:   #if PETSC_PKG_HIP_VERSION_GE(5, 2, 0)
    337:     hipMemPoolAttrReleaseThreshold;
    338:   #else
    339:     cupmMemPoolAttr{0};
    340:   #endif
    341:   static const auto cupmDevAttrClockRate       = hipDeviceAttributeClockRate;
    342:   static const auto cupmDevAttrMemoryClockRate = hipDeviceAttributeMemoryClockRate;

    344:   // error functions
    345:   PETSC_CUPM_ALIAS_FUNCTION(cupmGetErrorName, hipGetErrorName)
    346:   PETSC_CUPM_ALIAS_FUNCTION(cupmGetErrorString, hipGetErrorString)
    347:   PETSC_CUPM_ALIAS_FUNCTION(cupmGetLastError, hipGetLastError)

    349:   // device management
    350:   PETSC_CUPM_ALIAS_FUNCTION(cupmGetDeviceCount, hipGetDeviceCount)
    351:   PETSC_CUPM_ALIAS_FUNCTION(cupmGetDeviceProperties, hipGetDeviceProperties)
    352:   PETSC_CUPM_ALIAS_FUNCTION(cupmDeviceGetAttribute, hipDeviceGetAttribute)
    353:   PETSC_CUPM_ALIAS_FUNCTION(cupmGetDevice, hipGetDevice)
    354:   PETSC_CUPM_ALIAS_FUNCTION(cupmSetDevice, hipSetDevice)
    355:   PETSC_CUPM_ALIAS_FUNCTION(cupmGetDeviceFlags, hipGetDeviceFlags)
    356:   PETSC_CUPM_ALIAS_FUNCTION(cupmSetDeviceFlags, hipSetDeviceFlags)
    357:   PETSC_CUPM_ALIAS_FUNCTION(cupmPointerGetAttributes, hipPointerGetAttributes)
    358:   #if PETSC_PKG_HIP_VERSION_GE(5, 2, 0)
    359:   PETSC_CUPM_ALIAS_FUNCTION(cupmDeviceGetMemPool, hipDeviceGetMemPool)
    360:   PETSC_CUPM_ALIAS_FUNCTION(cupmMemPoolSetAttribute, hipMemPoolSetAttribute)
    361:   #else
    362:   PETSC_NODISCARD static cupmError_t cupmDeviceGetMemPool(cupmMemPool_t *pool, int) noexcept
    363:   {
    364:     *pool = nullptr;
    365:     return cupmSuccess;
    366:   }

    368:   PETSC_NODISCARD static cupmError_t cupmMemPoolSetAttribute(cupmMemPool_t, cupmMemPoolAttr, void *) noexcept { return cupmSuccess; }
    369:   #endif
    370:   PETSC_CUPM_ALIAS_FUNCTION(cupmInit, hipInit)

    372:   // stream management
    373:   PETSC_CUPM_ALIAS_FUNCTION(cupmEventCreate, hipEventCreate)
    374:   PETSC_CUPM_ALIAS_FUNCTION(cupmEventCreateWithFlags, hipEventCreateWithFlags)
    375:   PETSC_CUPM_ALIAS_FUNCTION(cupmEventDestroy, hipEventDestroy)
    376:   PETSC_CUPM_ALIAS_FUNCTION(cupmEventRecord, hipEventRecord)
    377:   PETSC_CUPM_ALIAS_FUNCTION(cupmEventSynchronize, hipEventSynchronize)
    378:   PETSC_CUPM_ALIAS_FUNCTION(cupmEventElapsedTime, hipEventElapsedTime)
    379:   PETSC_CUPM_ALIAS_FUNCTION(cupmEventQuery, hipEventQuery)
    380:   PETSC_CUPM_ALIAS_FUNCTION(cupmStreamCreate, hipStreamCreate)
    381:   PETSC_CUPM_ALIAS_FUNCTION(cupmStreamCreateWithFlags, hipStreamCreateWithFlags)
    382:   PETSC_CUPM_ALIAS_FUNCTION(cupmStreamGetFlags, hipStreamGetFlags)
    383:   PETSC_CUPM_ALIAS_FUNCTION(cupmStreamDestroy, hipStreamDestroy)
    384:   PETSC_CUPM_ALIAS_FUNCTION(cupmStreamWaitEvent, hipStreamWaitEvent)
    385:   PETSC_CUPM_ALIAS_FUNCTION(cupmStreamQuery, hipStreamQuery)
    386:   PETSC_CUPM_ALIAS_FUNCTION(cupmStreamSynchronize, hipStreamSynchronize)
    387:   PETSC_CUPM_ALIAS_FUNCTION(cupmDeviceSynchronize, hipDeviceSynchronize)
    388:   PETSC_CUPM_ALIAS_FUNCTION(cupmGetSymbolAddress, hipGetSymbolAddress)

    390:   // memory management
    391:   PETSC_CUPM_ALIAS_FUNCTION(cupmFree, hipFree)
    392:   PETSC_CUPM_ALIAS_FUNCTION(cupmMalloc, hipMalloc)
    393:   #if PETSC_PKG_HIP_VERSION_GE(5, 2, 0)
    394:   PETSC_CUPM_ALIAS_FUNCTION(cupmMallocAsync, hipMallocAsync)
    395:   PETSC_CUPM_ALIAS_FUNCTION(cupmFreeAsync, hipFreeAsync)
    396:   #else
    397:   PETSC_CUPM_ALIAS_FUNCTION_GOBBLE(cupmMallocAsync, hipMalloc, 1)
    398:   PETSC_CUPM_ALIAS_FUNCTION_GOBBLE(cupmFreeAsync, hipFree, 1)
    399:   #endif
    400:   PETSC_CUPM_ALIAS_FUNCTION(cupmMemcpy, hipMemcpy)
    401:   PETSC_CUPM_ALIAS_FUNCTION(cupmMemcpyAsync, hipMemcpyAsync)
    402:   // hipMallocHost is deprecated
    403:   PETSC_CUPM_ALIAS_FUNCTION(cupmMallocHost, hipHostMalloc)
    404:   // hipFreeHost is deprecated
    405:   PETSC_CUPM_ALIAS_FUNCTION(cupmFreeHost, hipHostFree)
    406:   PETSC_CUPM_ALIAS_FUNCTION(cupmMemset, hipMemset)
    407:   PETSC_CUPM_ALIAS_FUNCTION(cupmMemsetAsync, hipMemsetAsync)
    408:   PETSC_CUPM_ALIAS_FUNCTION(cupmMemcpy2D, hipMemcpy2D)
    409:   PETSC_CUPM_ALIAS_FUNCTION_GOBBLE(cupmMemcpy2DAsync, hipMemcpy2DAsync, 1)
    410:   PETSC_CUPM_ALIAS_FUNCTION(cupmMemset2D, hipMemset2D)
    411:   PETSC_CUPM_ALIAS_FUNCTION_GOBBLE(cupmMemset2DAsync, hipMemset2DAsync, 1)

    413:   // launch control
    414:   // HIP appears to only have hipLaunchHostFunc from 5.2.0 onwards
    415:   // https://github.com/ROCm-Developer-Tools/HIPIFY/blob/master/doc/markdown/CUDA_Runtime_API_functions_supported_by_HIP.md#7-execution-control=
    416:   #if PETSC_PKG_HIP_VERSION_GE(5, 2, 0)
    417:   PETSC_CUPM_ALIAS_FUNCTION(cupmLaunchHostFunc, hipLaunchHostFunc)
    418:   #else
    419:   PETSC_NODISCARD static hipError_t cupmLaunchHostFunc(hipStream_t stream, cupmHostFn_t fn, void *ctx) noexcept
    420:   {
    421:     // the only correct way to spoof this function is to do it synchronously...
    422:     auto herr = hipStreamSynchronize(stream);
    423:     if (PetscUnlikely(herr != hipSuccess)) return herr;
    424:     fn(ctx);
    425:     return herr;
    426:   }
    427:   #endif

    429:   template <typename FunctionT, typename... KernelArgsT>
    430:   PETSC_NODISCARD static hipError_t cupmLaunchKernel(FunctionT &&func, dim3 gridDim, dim3 blockDim, std::size_t sharedMem, hipStream_t stream, KernelArgsT &&...kernelArgs) noexcept
    431:   {
    432:     void *args[] = {(void *)std::addressof(kernelArgs)...};

    434:     return hipLaunchKernel((void *)func, std::move(gridDim), std::move(blockDim), args, sharedMem, std::move(stream));
    435:   }
    436: };
    437: #endif // PetscDefined(HAVE_HIP)

    439: // shorthand for bringing all of the typedefs from the base Interface class into your own,
    440: // it's annoying that c++ doesn't have a way to do this automatically
    441: #define PETSC_CUPM_IMPL_CLASS_HEADER(T) \
    442:   PETSC_CUPM_BASE_CLASS_HEADER(T); \
    443:   /* types */ \
    444:   using cupmError_t             = typename ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmError_t; \
    445:   using cupmEvent_t             = typename ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmEvent_t; \
    446:   using cupmStream_t            = typename ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmStream_t; \
    447:   using cupmDeviceProp_t        = typename ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmDeviceProp_t; \
    448:   using cupmMemcpyKind_t        = typename ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemcpyKind_t; \
    449:   using cupmDeviceAttr_t        = typename ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmDeviceAttr_t; \
    450:   using cupmComplex_t           = typename ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmComplex_t; \
    451:   using cupmPointerAttributes_t = typename ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmPointerAttributes_t; \
    452:   using cupmMemoryType_t        = typename ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemoryType_t; \
    453:   using cupmDim3                = typename ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmDim3; \
    454:   using cupmHostFn_t            = typename ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmHostFn_t; \
    455:   using cupmMemPool_t           = typename ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemPool_t; \
    456:   using cupmMemPoolAttr         = typename ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemPoolAttr; \
    457:   /* variables */ \
    458:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmSuccess; \
    459:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmErrorNotReady; \
    460:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmErrorDeviceAlreadyInUse; \
    461:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmErrorSetOnActiveProcess; \
    462:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmErrorStubLibrary; \
    463:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmErrorNoDevice; \
    464:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmStreamDefault; \
    465:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmStreamNonBlocking; \
    466:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmDeviceMapHost; \
    467:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemcpyHostToDevice; \
    468:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemcpyDeviceToHost; \
    469:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemcpyDeviceToDevice; \
    470:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemcpyHostToHost; \
    471:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemcpyDefault; \
    472:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemoryTypeHost; \
    473:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemoryTypeDevice; \
    474:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemoryTypeManaged; \
    475:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmEventDisableTiming; \
    476:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmHostAllocDefault; \
    477:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmHostAllocWriteCombined; \
    478:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemPoolAttrReleaseThreshold; \
    479:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmDevAttrClockRate; \
    480:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmDevAttrMemoryClockRate; \
    481:   /* functions */ \
    482:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmGetErrorName; \
    483:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmGetErrorString; \
    484:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmGetLastError; \
    485:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmGetDeviceCount; \
    486:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmGetDeviceProperties; \
    487:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmDeviceGetAttribute; \
    488:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmGetDevice; \
    489:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmSetDevice; \
    490:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmGetDeviceFlags; \
    491:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmSetDeviceFlags; \
    492:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmPointerGetAttributes; \
    493:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmDeviceGetMemPool; \
    494:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemPoolSetAttribute; \
    495:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmInit; \
    496:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmEventCreate; \
    497:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmEventCreateWithFlags; \
    498:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmEventDestroy; \
    499:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmEventRecord; \
    500:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmEventSynchronize; \
    501:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmEventElapsedTime; \
    502:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmEventQuery; \
    503:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmStreamCreate; \
    504:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmStreamCreateWithFlags; \
    505:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmStreamGetFlags; \
    506:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmStreamDestroy; \
    507:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmStreamWaitEvent; \
    508:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmStreamQuery; \
    509:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmStreamSynchronize; \
    510:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmDeviceSynchronize; \
    511:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmGetSymbolAddress; \
    512:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMalloc; \
    513:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMallocAsync; \
    514:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemcpy; \
    515:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemcpyAsync; \
    516:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMallocHost; \
    517:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemset; \
    518:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemsetAsync; \
    519:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemcpy2D; \
    520:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemcpy2DAsync; \
    521:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemset2D; \
    522:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmMemset2DAsync; \
    523:   using ::Petsc::device::cupm::impl::InterfaceImpl<T>::cupmLaunchHostFunc

    525: #if PetscHasAttribute(always_inline)
    526:   // https://gcc.gnu.org/bugzilla//show_bug.cgi?id=109464
    527:   #define PETSC_GCC_LINKER_UNDEFINED_REFERENCE_BUG_WORKAROUND __attribute__((always_inline))
    528: #else
    529:   #define PETSC_GCC_LINKER_UNDEFINED_REFERENCE_BUG_WORKAROUND
    530: #endif

    532: // The actual interface class
    533: template <DeviceType T>
    534: struct Interface : InterfaceImpl<T> {
    535: private:
    536:   using interface_type = InterfaceImpl<T>;

    538: public:
    539:   PETSC_CUPM_IMPL_CLASS_HEADER(T);

    541:   using cupmReal_t   = util::conditional_t<PetscDefined(USE_REAL_SINGLE), float, double>;
    542:   using cupmScalar_t = util::conditional_t<PetscDefined(USE_COMPLEX), cupmComplex_t, cupmReal_t>;

    544:   PETSC_NODISCARD PETSC_GCC_LINKER_UNDEFINED_REFERENCE_BUG_WORKAROUND static constexpr cupmScalar_t cupmScalarCast(PetscScalar s) noexcept
    545:   {
    546: #if PetscDefined(USE_COMPLEX)
    547:     return cupmComplex_t{PetscRealPart(s), PetscImaginaryPart(s)};
    548: #else
    549:     return static_cast<cupmScalar_t>(s);
    550: #endif
    551:   }

    553:   PETSC_NODISCARD PETSC_GCC_LINKER_UNDEFINED_REFERENCE_BUG_WORKAROUND static constexpr const cupmScalar_t *cupmScalarPtrCast(const PetscScalar *s) noexcept { return reinterpret_cast<const cupmScalar_t *>(s); }

    555:   PETSC_NODISCARD PETSC_GCC_LINKER_UNDEFINED_REFERENCE_BUG_WORKAROUND static constexpr cupmScalar_t *cupmScalarPtrCast(PetscScalar *s) noexcept { return reinterpret_cast<cupmScalar_t *>(s); }

    557:   PETSC_NODISCARD PETSC_GCC_LINKER_UNDEFINED_REFERENCE_BUG_WORKAROUND static constexpr const cupmReal_t *cupmRealPtrCast(const PetscReal *s) noexcept { return reinterpret_cast<const cupmReal_t *>(s); }

    559:   PETSC_NODISCARD PETSC_GCC_LINKER_UNDEFINED_REFERENCE_BUG_WORKAROUND static constexpr cupmReal_t *cupmRealPtrCast(PetscReal *s) noexcept { return reinterpret_cast<cupmReal_t *>(s); }

    561: #if !defined(PETSC_PKG_CUDA_VERSION_GE)
    562:   #define PETSC_PKG_CUDA_VERSION_GE(...) 0
    563:   #define CUPM_DEFINED_PETSC_PKG_CUDA_VERSION_GE
    564: #endif

    566: #if !defined(PETSC_PKG_HIP_VERSION_LT)
    567:   #define PETSC_PKG_HIP_VERSION_LT(...) 0
    568:   #define CUPM_DEFINED_PETSC_PKG_HIP_VERSION_LT
    569: #endif

    571:   static PetscErrorCode PetscCUPMGetMemType(const void *data, PetscMemType *type, PetscBool *registered = nullptr, PetscBool *managed = nullptr) noexcept
    572:   {
    573:     cupmPointerAttributes_t attr;
    574:     cupmError_t             cerr;

    576:     PetscFunctionBegin;
    577:     if (type) PetscAssertPointer(type, 2);
    578:     if (registered) {
    579:       PetscAssertPointer(registered, 3);
    580:       *registered = PETSC_FALSE;
    581:     }
    582:     if (managed) {
    583:       PetscAssertPointer(managed, 4);
    584:       *managed = PETSC_FALSE;
    585:     }
    586:     // Do not check error, instead reset it via GetLastError() since before CUDA 11.0, passing
    587:     // a host pointer returns cudaErrorInvalidValue
    588:     cerr = cupmPointerGetAttributes(&attr, data);
    589:     cerr = cupmGetLastError();
    590:     // HIP seems to always have used memoryType though
    591: #if (defined(CUDART_VERSION) && (CUDART_VERSION < 10000)) || (defined(__HIP_PLATFORM_HCC__) && PETSC_PKG_HIP_VERSION_LT(5, 5, 0))
    592:     const auto mtype = attr.memoryType;
    593:     if (managed) *managed = static_cast<PetscBool>((cerr == cupmSuccess) && attr.isManaged);
    594: #else
    595:     if (PETSC_PKG_CUDA_VERSION_GE(11, 0, 0) && (T == DeviceType::CUDA)) PetscCallCUPM(cerr);
    596:     const auto mtype = attr.type;
    597:     if (managed) *managed = static_cast<PetscBool>(mtype == cupmMemoryTypeManaged);
    598: #endif // CUDART_VERSION && CUDART_VERSION < 10000 || (defined(__HIP_PLATFORM_HCC__) && PETSC_PKG_HIP_VERSION_LT(5, 5, 0))
    599:     if (type) *type = ((cerr == cupmSuccess) && (mtype == cupmMemoryTypeDevice)) ? PETSC_MEMTYPE_CUPM() : PETSC_MEMTYPE_HOST;
    600:     if (registered && (cerr == cupmSuccess) && (mtype == cupmMemoryTypeHost)) *registered = PETSC_TRUE;
    601:     PetscFunctionReturn(PETSC_SUCCESS);
    602:   }
    603: #if defined(CUPM_DEFINED_PETSC_PKG_CUDA_VERSION_GE)
    604:   #undef PETSC_PKG_CUDA_VERSION_GE
    605: #endif
    606: #if defined(CUPM_DEFINED_PETSC_PKG_HIP_VERSION_LT)
    607:   #undef PETSC_PKG_HIP_VERSION_LT
    608: #endif

    610:   PETSC_NODISCARD static PETSC_CONSTEXPR_14 cupmMemcpyKind_t PetscDeviceCopyModeToCUPMMemcpyKind(PetscDeviceCopyMode mode) noexcept
    611:   {
    612:     switch (mode) {
    613:     case PETSC_DEVICE_COPY_HTOH:
    614:       return cupmMemcpyHostToHost;
    615:     case PETSC_DEVICE_COPY_HTOD:
    616:       return cupmMemcpyHostToDevice;
    617:     case PETSC_DEVICE_COPY_DTOD:
    618:       return cupmMemcpyDeviceToDevice;
    619:     case PETSC_DEVICE_COPY_DTOH:
    620:       return cupmMemcpyDeviceToHost;
    621:     case PETSC_DEVICE_COPY_AUTO:
    622:       return cupmMemcpyDefault;
    623:     }
    624:     PetscUnreachable();
    625:     return cupmMemcpyDefault;
    626:   }

    628:   // these change what the arguments mean, so need to namespace these
    629:   template <typename M>
    630:   static PetscErrorCode PetscCUPMMallocAsync(M **ptr, std::size_t n, cupmStream_t stream = nullptr) noexcept
    631:   {
    632:     static_assert(!std::is_void<M>::value, "");

    634:     PetscFunctionBegin;
    635:     PetscAssertPointer(ptr, 1);
    636:     *ptr = nullptr;
    637:     if (n) {
    638:       const auto bytes = n * sizeof(M);
    639:       // https://developer.nvidia.com/blog/using-cuda-stream-ordered-memory-allocator-part-2/
    640:       //
    641:       // TLD;DR: cudaMallocAsync() does not work with NVIDIA GPUDirect which OPENMPI uses to
    642:       // underpin its cuda-aware MPI implementation, so we cannot just async allocate
    643:       // blindly...
    644:       if (stream) {
    645:         PetscCallCUPM(cupmMallocAsync(reinterpret_cast<void **>(ptr), bytes, stream));
    646:       } else {
    647:         PetscCallCUPM(cupmMalloc(reinterpret_cast<void **>(ptr), bytes));
    648:       }
    649:     }
    650:     PetscFunctionReturn(PETSC_SUCCESS);
    651:   }

    653:   template <typename M>
    654:   static PetscErrorCode PetscCUPMMalloc(M **ptr, std::size_t n) noexcept
    655:   {
    656:     PetscFunctionBegin;
    657:     PetscCall(PetscCUPMMallocAsync(ptr, n));
    658:     PetscFunctionReturn(PETSC_SUCCESS);
    659:   }

    661:   template <typename M>
    662:   static PetscErrorCode PetscCUPMMallocHost(M **ptr, std::size_t n, unsigned int flags = cupmHostAllocDefault) noexcept
    663:   {
    664:     static_assert(!std::is_void<M>::value, "");

    666:     PetscFunctionBegin;
    667:     PetscAssertPointer(ptr, 1);
    668:     *ptr = nullptr;
    669:     if (n) PetscCallCUPM(cupmMallocHost(reinterpret_cast<void **>(ptr), n * sizeof(M), flags));
    670:     PetscFunctionReturn(PETSC_SUCCESS);
    671:   }

    673:   template <typename D>
    674:   static PetscErrorCode PetscCUPMMemcpyAsync(D *dest, const util::type_identity_t<D> *src, std::size_t n, cupmMemcpyKind_t kind, cupmStream_t stream = nullptr, bool use_async = false) noexcept
    675:   {
    676:     static_assert(!std::is_void<D>::value, "");
    677:     const auto size = n * sizeof(D);

    679:     PetscFunctionBegin;
    680:     if (PetscUnlikely(!n)) PetscFunctionReturn(PETSC_SUCCESS);
    681:     // cannot dereference (i.e. cannot call PetscAssertPointer() here)
    682:     PetscCheck(dest, PETSC_COMM_SELF, PETSC_ERR_POINTER, "Trying to copy to a NULL pointer");
    683:     PetscCheck(src, PETSC_COMM_SELF, PETSC_ERR_POINTER, "Trying to copy from a NULL pointer");
    684:     // do early return after nullptr check since we need to check that they are not both nullptrs
    685:     if (PetscUnlikely(dest == src)) PetscFunctionReturn(PETSC_SUCCESS);
    686:     if (kind == cupmMemcpyHostToHost) {
    687:       // If we are HTOH it is cheaper to check if the stream is idle and do a basic mempcy()
    688:       // than it is to just call the vendor functions. This assumes of course that the stream
    689:       // accounts for both memory regions being "idle"
    690:       if (cupmStreamQuery(stream) == cupmSuccess) {
    691:         PetscCall(PetscMemcpy(dest, src, size));
    692:         PetscFunctionReturn(PETSC_SUCCESS);
    693:       }
    694:       // need to clear the potential cupmErrorNotReady generated by query above...
    695:       auto cerr = cupmGetLastError();

    697:       if (PetscUnlikely(cerr != cupmErrorNotReady)) PetscCallCUPM(cerr);
    698:     }
    699:     if (use_async || stream || (kind != cupmMemcpyDeviceToHost)) {
    700:       PetscCallCUPM(cupmMemcpyAsync(dest, src, size, kind, stream));
    701:     } else {
    702:       PetscCallCUPM(cupmMemcpy(dest, src, size, kind));
    703:     }
    704:     PetscCall(PetscLogCUPMMemcpyTransfer(kind, size));
    705:     PetscFunctionReturn(PETSC_SUCCESS);
    706:   }

    708:   template <typename D>
    709:   static PetscErrorCode PetscCUPMMemcpy(D *dest, const util::type_identity_t<D> *src, std::size_t n, cupmMemcpyKind_t kind) noexcept
    710:   {
    711:     PetscFunctionBegin;
    712:     PetscCall(PetscCUPMMemcpyAsync(dest, src, n, kind));
    713:     PetscFunctionReturn(PETSC_SUCCESS);
    714:   }

    716:   template <typename D>
    717:   static PetscErrorCode PetscCUPMMemcpy2DAsync(D *dest, std::size_t dest_pitch, const util::type_identity_t<D> *src, std::size_t src_pitch, std::size_t width, std::size_t height, cupmMemcpyKind_t kind, cupmStream_t stream = nullptr)
    718:   {
    719:     static_assert(!std::is_void<D>::value, "");
    720:     const auto dest_pitch_bytes = dest_pitch * sizeof(D);
    721:     const auto src_pitch_bytes  = src_pitch * sizeof(D);
    722:     const auto width_bytes      = width * sizeof(D);
    723:     const auto size             = height * width_bytes;

    725:     PetscFunctionBegin;
    726:     if (PetscUnlikely(!size)) PetscFunctionReturn(PETSC_SUCCESS);
    727:     PetscCheck(dest, PETSC_COMM_SELF, PETSC_ERR_POINTER, "Trying to copy to a NULL pointer");
    728:     PetscCheck(src, PETSC_COMM_SELF, PETSC_ERR_POINTER, "Trying to copy from a NULL pointer");
    729:     if (stream || (kind != cupmMemcpyDeviceToHost)) {
    730:       PetscCallCUPM(cupmMemcpy2DAsync(dest, dest_pitch_bytes, src, src_pitch_bytes, width_bytes, height, kind, stream));
    731:     } else {
    732:       PetscCallCUPM(cupmMemcpy2D(dest, dest_pitch_bytes, src, src_pitch_bytes, width_bytes, height, kind));
    733:     }
    734:     PetscCall(PetscLogCUPMMemcpyTransfer(kind, size));
    735:     PetscFunctionReturn(PETSC_SUCCESS);
    736:   }

    738:   template <typename D>
    739:   static PetscErrorCode PetscCUPMMemcpy2D(D *dest, std::size_t dest_pitch, const util::type_identity_t<D> *src, std::size_t src_pitch, std::size_t width, std::size_t height, cupmMemcpyKind_t kind)
    740:   {
    741:     PetscFunctionBegin;
    742:     PetscCall(PetscCUPMMemcpy2DAsync(dest, dest_pitch, src, src_pitch, width, height, kind));
    743:     PetscFunctionReturn(PETSC_SUCCESS);
    744:   }

    746:   template <typename M>
    747:   static PetscErrorCode PetscCUPMMemsetAsync(M *ptr, int value, std::size_t n, cupmStream_t stream = nullptr, bool use_async = false) noexcept
    748:   {
    749:     static_assert(!std::is_void<M>::value, "");

    751:     PetscFunctionBegin;
    752:     if (PetscLikely(n)) {
    753:       const auto bytes = n * sizeof(M);

    755:       PetscCheck(ptr, PETSC_COMM_SELF, PETSC_ERR_POINTER, "Trying to memset a NULL pointer with size %zu != 0", n);
    756:       if (stream || use_async) {
    757:         PetscCallCUPM(cupmMemsetAsync(ptr, value, bytes, stream));
    758:       } else {
    759:         PetscCallCUPM(cupmMemset(ptr, value, bytes));
    760:       }
    761:     }
    762:     PetscFunctionReturn(PETSC_SUCCESS);
    763:   }

    765:   template <typename M>
    766:   static PetscErrorCode PetscCUPMMemset(M *ptr, int value, std::size_t n) noexcept
    767:   {
    768:     PetscFunctionBegin;
    769:     PetscCall(PetscCUPMMemsetAsync(ptr, value, n));
    770:     PetscFunctionReturn(PETSC_SUCCESS);
    771:   }

    773:   template <typename D>
    774:   static PetscErrorCode PetscCUPMMemset2DAsync(D *ptr, std::size_t pitch, int value, std::size_t width, std::size_t height, cupmStream_t stream = nullptr)
    775:   {
    776:     static_assert(!std::is_void<D>::value, "");
    777:     const auto pitch_bytes = pitch * sizeof(D);
    778:     const auto width_bytes = width * sizeof(D);
    779:     const auto size        = width_bytes * height;

    781:     PetscFunctionBegin;
    782:     if (PetscUnlikely(!size)) PetscFunctionReturn(PETSC_SUCCESS);
    783:     PetscAssert(ptr, PETSC_COMM_SELF, PETSC_ERR_POINTER, "Trying to memset a NULL pointer with size %zu != 0", size);
    784:     if (stream) {
    785:       PetscCallCUPM(cupmMemset2DAsync(ptr, pitch_bytes, value, width_bytes, height, stream));
    786:     } else {
    787:       PetscCallCUPM(cupmMemset2D(ptr, pitch_bytes, value, width_bytes, height));
    788:     }
    789:     PetscFunctionReturn(PETSC_SUCCESS);
    790:   }

    792:   // these we can transparently wrap, no need to namespace it to Petsc
    793:   template <typename M>
    794:   PETSC_NODISCARD static cupmError_t cupmFreeAsync(M &ptr, cupmStream_t stream = nullptr) noexcept
    795:   {
    796:     static_assert(std::is_pointer<util::decay_t<M>>::value, "");
    797:     static_assert(!std::is_const<M>::value, "");

    799:     if (ptr) {
    800:       auto cerr = interface_type::cupmFreeAsync(std::forward<M>(ptr), stream);

    802:       ptr = nullptr;
    803:       if (PetscUnlikely(cerr != cupmSuccess)) return cerr;
    804:     }
    805:     return cupmSuccess;
    806:   }

    808:   PETSC_NODISCARD static cupmError_t cupmFreeAsync(std::nullptr_t ptr, cupmStream_t stream = nullptr) { return interface_type::cupmFreeAsync(ptr, stream); }

    810:   template <typename M>
    811:   PETSC_NODISCARD static cupmError_t cupmFree(M &ptr) noexcept
    812:   {
    813:     return cupmFreeAsync(ptr);
    814:   }

    816:   PETSC_NODISCARD static cupmError_t cupmFree(std::nullptr_t ptr) { return cupmFreeAsync(ptr); }

    818:   template <typename M>
    819:   PETSC_NODISCARD static cupmError_t cupmFreeHost(M &ptr) noexcept
    820:   {
    821:     static_assert(std::is_pointer<util::decay_t<M>>::value, "");
    822:     const auto cerr = interface_type::cupmFreeHost(std::forward<M>(ptr));
    823:     ptr             = nullptr;
    824:     return cerr;
    825:   }

    827:   PETSC_NODISCARD static cupmError_t cupmFreeHost(std::nullptr_t ptr) { return interface_type::cupmFreeHost(ptr); }

    829:   // specific wrapper for device launch function, as the real function is a C routine and
    830:   // doesn't have variable arguments. The actual mechanics of this are a bit complicated but
    831:   // boils down to the fact that ultimately we pass a
    832:   //
    833:   // void *args[] = {(void*)&kernel_args...};
    834:   //
    835:   // to the kernel launcher. Since we pass void* this means implicit conversion does **not**
    836:   // happen to the kernel arguments so we must do it ourselves here. This function does this in
    837:   // 3 stages:
    838:   // 1. Enumerate the kernel arguments (cupmLaunchKernel)
    839:   // 2. Deduce the signature of func() and static_cast the kernel arguments to the type
    840:   //    expected by func() using the enumeration above (deduceKernelCall)
    841:   // 3. Form the void* array with the converted arguments and call cuda/hipLaunchKernel with
    842:   //    it. (interface_type::cupmLaunchKernel)
    843:   template <typename F, typename... Args>
    844:   PETSC_NODISCARD static cupmError_t cupmLaunchKernel(F &&func, cupmDim3 gridDim, cupmDim3 blockDim, std::size_t sharedMem, cupmStream_t stream, Args &&...kernelArgs) noexcept
    845:   {
    846:     return deduceKernelCall(util::index_sequence_for<Args...>{}, std::forward<F>(func), std::move(gridDim), std::move(blockDim), std::move(sharedMem), std::move(stream), std::forward<Args>(kernelArgs)...);
    847:   }

    849:   template <std::size_t block_size = 256, std::size_t warp_size = 32, typename F, typename... Args>
    850:   static PetscErrorCode PetscCUPMLaunchKernel1D(std::size_t n, std::size_t sharedMem, cupmStream_t stream, F &&func, Args &&...kernelArgs) noexcept
    851:   {
    852:     static_assert(block_size > 0, "");
    853:     static_assert(warp_size > 0, "");
    854:     // want block_size to be a multiple of the warp_size
    855:     static_assert(block_size % warp_size == 0, "");
    856:     const auto nthread = std::min(n, block_size);
    857:     const auto nblock  = (n + block_size - 1) / block_size;

    859:     PetscFunctionBegin;
    860:     // if n = 0 then nthread = 0, which is not allowed. rather than letting the user try to
    861:     // decipher cryptic 'cuda/hipErrorLaunchFailure' we explicitly check for zero here
    862:     PetscAssert(nthread, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Trying to launch kernel with grid/block size 0");
    863:     PetscCallCUPM(cupmLaunchKernel(std::forward<F>(func), (unsigned int)nblock, (unsigned int)nthread, sharedMem, stream, std::forward<Args>(kernelArgs)...));
    864:     PetscFunctionReturn(PETSC_SUCCESS);
    865:   }

    867: private:
    868:   template <typename S, typename D, typename = void>
    869:   struct is_static_castable : std::false_type { };

    871:   template <typename S, typename D>
    872:   struct is_static_castable<S, D, util::void_t<decltype(static_cast<D>(std::declval<S>()))>> : std::true_type { };

    874:   template <typename D, typename S>
    875:   static constexpr util::enable_if_t<is_static_castable<S, D>::value, D> cast_to(S &&src) noexcept
    876:   {
    877:     return static_cast<D>(std::forward<S>(src));
    878:   }

    880:   template <typename D, typename S>
    881:   static constexpr util::enable_if_t<!is_static_castable<S, D>::value, D> cast_to(S &&src) noexcept
    882:   {
    883:     return const_cast<D>(std::forward<S>(src));
    884:   }

    886:   template <typename F, typename... Args, std::size_t... Idx>
    887:   PETSC_NODISCARD static cupmError_t deduceKernelCall(util::index_sequence<Idx...>, F &&func, cupmDim3 gridDim, cupmDim3 blockDim, std::size_t sharedMem, cupmStream_t stream, Args &&...kernelArgs) noexcept
    888:   {
    889:     // clang-format off
    890:     return interface_type::cupmLaunchKernel(
    891:       std::forward<F>(func),
    892:       std::move(gridDim), std::move(blockDim), std::move(sharedMem), std::move(stream),
    893:       // can't static_cast() here since the function argument type may be cv-qualified, in
    894:       // which case we would need to const_cast(). But you can only const_cast() indirect types
    895:       // (pointers, references). So we need a SFINAE monster that is a static_cast() if
    896:       // possible, and a const_cast() if not. We could just use a C-style cast which *would*
    897:       // work here since it tries the following and uses the first one that succeeds:
    898:       //
    899:       // 1. const_cast()
    900:       // 2. static_cast()
    901:       // 3. static_cast() then const_cast()
    902:       // 4. reinterpret_cast()...
    903:       //
    904:       // the issue however is the final reinterpret_cast(). We absolutely cannot get there
    905:       // because doing so would silently hide a ton of bugs, for example casting a PetscScalar
    906:       // * to double * in complex builds, a PetscInt * to int * in 64idx builds, etc.
    907:       cast_to<typename util::func_traits<F>::template arg<Idx>::type>(std::forward<Args>(kernelArgs))...
    908:     );
    909:     // clang-format on
    910:   }

    912:   static PetscErrorCode PetscLogCUPMMemcpyTransfer(cupmMemcpyKind_t kind, std::size_t size) noexcept
    913:   {
    914:     PetscFunctionBegin;
    915:     // only the explicit HTOD or DTOH are handled, since we either don't log the other cases
    916:     // (yet) or don't know the direction
    917:     if (kind == cupmMemcpyDeviceToHost) PetscCall(PetscLogGpuToCpu(static_cast<PetscLogDouble>(size)));
    918:     else if (kind == cupmMemcpyHostToDevice) PetscCall(PetscLogCpuToGpu(static_cast<PetscLogDouble>(size)));
    919:     else (void)size;
    920:     PetscFunctionReturn(PETSC_SUCCESS);
    921:   }
    922: };

    924: #undef PETSC_GCC_LINKER_UNDEFINED_REFERENCE_BUG_WORKAROUND

    926: #define PETSC_CUPM_INHERIT_INTERFACE_TYPEDEFS_USING(T) \
    927:   PETSC_CUPM_IMPL_CLASS_HEADER(T); \
    928:   using cupmReal_t   = typename ::Petsc::device::cupm::impl::Interface<T>::cupmReal_t; \
    929:   using cupmScalar_t = typename ::Petsc::device::cupm::impl::Interface<T>::cupmScalar_t; \
    930:   using ::Petsc::device::cupm::impl::Interface<T>::cupmScalarCast; \
    931:   using ::Petsc::device::cupm::impl::Interface<T>::cupmScalarPtrCast; \
    932:   using ::Petsc::device::cupm::impl::Interface<T>::cupmRealPtrCast; \
    933:   using ::Petsc::device::cupm::impl::Interface<T>::PetscCUPMGetMemType; \
    934:   using ::Petsc::device::cupm::impl::Interface<T>::PetscCUPMMemset; \
    935:   using ::Petsc::device::cupm::impl::Interface<T>::PetscCUPMMemsetAsync; \
    936:   using ::Petsc::device::cupm::impl::Interface<T>::PetscCUPMMalloc; \
    937:   using ::Petsc::device::cupm::impl::Interface<T>::PetscCUPMMallocAsync; \
    938:   using ::Petsc::device::cupm::impl::Interface<T>::PetscCUPMMallocHost; \
    939:   using ::Petsc::device::cupm::impl::Interface<T>::PetscCUPMMemcpy; \
    940:   using ::Petsc::device::cupm::impl::Interface<T>::PetscCUPMMemcpyAsync; \
    941:   using ::Petsc::device::cupm::impl::Interface<T>::PetscCUPMMemcpy2D; \
    942:   using ::Petsc::device::cupm::impl::Interface<T>::PetscCUPMMemcpy2DAsync; \
    943:   using ::Petsc::device::cupm::impl::Interface<T>::PetscCUPMMemset2DAsync; \
    944:   using ::Petsc::device::cupm::impl::Interface<T>::cupmFree; \
    945:   using ::Petsc::device::cupm::impl::Interface<T>::cupmFreeAsync; \
    946:   using ::Petsc::device::cupm::impl::Interface<T>::cupmFreeHost; \
    947:   using ::Petsc::device::cupm::impl::Interface<T>::cupmLaunchKernel; \
    948:   using ::Petsc::device::cupm::impl::Interface<T>::PetscCUPMLaunchKernel1D; \
    949:   using ::Petsc::device::cupm::impl::Interface<T>::PetscDeviceCopyModeToCUPMMemcpyKind

    951: #if PetscDefined(HAVE_CUDA)
    952: extern template struct PETSC_SINGLE_LIBRARY_VISIBILITY_INTERNAL Interface<DeviceType::CUDA>;
    953: #endif

    955: #if PetscDefined(HAVE_HIP)
    956: extern template struct PETSC_SINGLE_LIBRARY_VISIBILITY_INTERNAL Interface<DeviceType::HIP>;
    957: #endif

    959: } // namespace impl

    961: } // namespace cupm

    963: } // namespace device

    965: } // namespace Petsc