llvm-project/openmp/libomptarget/include/omptarget.h

//===-------- omptarget.h - Target independent OpenMP target RTL -- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Interface to be used by Clang during the codegen of a
// target region.
//
//===----------------------------------------------------------------------===//

#ifndef _OMPTARGET_H_
#define _OMPTARGET_H_

#include <deque>
#include <stddef.h>
#include <stdint.h>

#include <SourceInfo.h>

#define OFFLOAD_SUCCESS (0)
#define OFFLOAD_FAIL (~0)

#define OFFLOAD_DEVICE_DEFAULT -1

// Don't format out enums and structs.
// clang-format off

/// return flags of __tgt_target_XXX public APIs
enum __tgt_target_return_t : int {
  /// successful offload executed on a target device
  OMP_TGT_SUCCESS = 0,
  /// offload may not execute on the requested target device
  /// this scenario can be caused by the device not available or unsupported
  /// as described in the Execution Model in the specifcation
  /// this status may not be used for target device execution failure
  /// which should be handled internally in libomptarget
  OMP_TGT_FAIL = ~0
};

/// Data attributes for each data reference used in an OpenMP target region.
enum tgt_map_type {
  // No flags
  OMP_TGT_MAPTYPE_NONE            = 0x000,
  // copy data from host to device
  OMP_TGT_MAPTYPE_TO              = 0x001,
  // copy data from device to host
  OMP_TGT_MAPTYPE_FROM            = 0x002,
  // copy regardless of the reference count
  OMP_TGT_MAPTYPE_ALWAYS          = 0x004,
  // force unmapping of data
  OMP_TGT_MAPTYPE_DELETE          = 0x008,
  // map the pointer as well as the pointee
  OMP_TGT_MAPTYPE_PTR_AND_OBJ     = 0x010,
  // pass device base address to kernel
  OMP_TGT_MAPTYPE_TARGET_PARAM    = 0x020,
  // return base device address of mapped data
  OMP_TGT_MAPTYPE_RETURN_PARAM    = 0x040,
  // private variable - not mapped
  OMP_TGT_MAPTYPE_PRIVATE         = 0x080,
  // copy by value - not mapped
  OMP_TGT_MAPTYPE_LITERAL         = 0x100,
  // mapping is implicit
  OMP_TGT_MAPTYPE_IMPLICIT        = 0x200,
  // copy data to device
  OMP_TGT_MAPTYPE_CLOSE           = 0x400,
  // runtime error if not already allocated
  OMP_TGT_MAPTYPE_PRESENT         = 0x1000,
  // use a separate reference counter so that the data cannot be unmapped within
  // the structured region
  // This is an OpenMP extension for the sake of OpenACC support.
  OMP_TGT_MAPTYPE_OMPX_HOLD       = 0x2000,
  // descriptor for non-contiguous target-update
  OMP_TGT_MAPTYPE_NON_CONTIG      = 0x100000000000,
  // member of struct, member given by [16 MSBs] - 1
  OMP_TGT_MAPTYPE_MEMBER_OF       = 0xffff000000000000
};

enum OpenMPOffloadingDeclareTargetFlags {
  /// Mark the entry as having a 'link' attribute.
  OMP_DECLARE_TARGET_LINK = 0x01,
  /// Mark the entry as being a global constructor.
  OMP_DECLARE_TARGET_CTOR = 0x02,
  /// Mark the entry as being a global destructor.
  OMP_DECLARE_TARGET_DTOR = 0x04
};

enum OpenMPOffloadingRequiresDirFlags {
  /// flag undefined.
  OMP_REQ_UNDEFINED               = 0x000,
  /// no requires directive present.
  OMP_REQ_NONE                    = 0x001,
  /// reverse_offload clause.
  OMP_REQ_REVERSE_OFFLOAD         = 0x002,
  /// unified_address clause.
  OMP_REQ_UNIFIED_ADDRESS         = 0x004,
  /// unified_shared_memory clause.
  OMP_REQ_UNIFIED_SHARED_MEMORY   = 0x008,
  /// dynamic_allocators clause.
  OMP_REQ_DYNAMIC_ALLOCATORS      = 0x010
};

enum TargetAllocTy : int32_t {
  TARGET_ALLOC_DEVICE = 0,
  TARGET_ALLOC_HOST,
  TARGET_ALLOC_SHARED,
  TARGET_ALLOC_DEFAULT
};

/// This struct is a record of an entry point or global. For a function
/// entry point the size is expected to be zero
struct __tgt_offload_entry {
  void *addr;   // Pointer to the offload entry info (function or global)
  char *name;   // Name of the function or global
  size_t size;  // Size of the entry info (0 if it is a function)
  int32_t flags; // Flags associated with the entry, e.g. 'link'.
  int32_t reserved; // Reserved, to be used by the runtime library.
};

/// This struct is a record of the device image information
struct __tgt_device_image {
  void *ImageStart;                  // Pointer to the target code start
  void *ImageEnd;                    // Pointer to the target code end
  __tgt_offload_entry *EntriesBegin; // Begin of table with all target entries
  __tgt_offload_entry *EntriesEnd;   // End of table (non inclusive)
};

/// This struct is a record of all the host code that may be offloaded to a
/// target.
struct __tgt_bin_desc {
  int32_t NumDeviceImages;           // Number of device types supported
  __tgt_device_image *DeviceImages;  // Array of device images (1 per dev. type)
  __tgt_offload_entry *HostEntriesBegin; // Begin of table with all host entries
  __tgt_offload_entry *HostEntriesEnd;   // End of table (non inclusive)
};

/// This struct contains the offload entries identified by the target runtime
struct __tgt_target_table {
  __tgt_offload_entry *EntriesBegin; // Begin of the table with all the entries
  __tgt_offload_entry
      *EntriesEnd; // End of the table with all the entries (non inclusive)
};

// clang-format on

/// This struct contains information exchanged between different asynchronous
/// operations for device-dependent optimization and potential synchronization
struct __tgt_async_info {
  // A pointer to a queue-like structure where offloading operations are issued.
  // We assume to use this structure to do synchronization. In CUDA backend, it
  // is CUstream.
  void *Queue = nullptr;
};

struct DeviceTy;

/// The libomptarget wrapper around a __tgt_async_info object directly
/// associated with a libomptarget layer device. RAII semantics to avoid
/// mistakes.
class AsyncInfoTy {
  /// Locations we used in (potentially) asynchronous calls which should live
  /// as long as this AsyncInfoTy object.
  std::deque<void *> BufferLocations;

  __tgt_async_info AsyncInfo;
  DeviceTy &Device;

public:
  AsyncInfoTy(DeviceTy &Device) : Device(Device) {}
  ~AsyncInfoTy() { synchronize(); }

  /// Implicit conversion to the __tgt_async_info which is used in the
  /// plugin interface.
  operator __tgt_async_info *() { return &AsyncInfo; }

  /// Synchronize all pending actions.
  ///
  /// \returns OFFLOAD_FAIL or OFFLOAD_SUCCESS appropriately.
  int synchronize();

  /// Return a void* reference with a lifetime that is at least as long as this
  /// AsyncInfoTy object. The location can be used as intermediate buffer.
  void *&getVoidPtrLocation();
};

/// This struct is a record of non-contiguous information
struct __tgt_target_non_contig {
  uint64_t Offset;
  uint64_t Count;
  uint64_t Stride;
};

#ifdef __cplusplus
extern "C" {
#endif

int omp_get_num_devices(void);
int omp_get_initial_device(void);
void *omp_target_alloc(size_t size, int device_num);
void omp_target_free(void *device_ptr, int device_num);
int omp_target_is_present(const void *ptr, int device_num);
int omp_target_memcpy(void *dst, const void *src, size_t length,
                      size_t dst_offset, size_t src_offset, int dst_device,
                      int src_device);
int omp_target_memcpy_rect(void *dst, const void *src, size_t element_size,
                           int num_dims, const size_t *volume,
                           const size_t *dst_offsets, const size_t *src_offsets,
                           const size_t *dst_dimensions,
                           const size_t *src_dimensions, int dst_device,
                           int src_device);
int omp_target_associate_ptr(const void *host_ptr, const void *device_ptr,
                             size_t size, size_t device_offset, int device_num);
int omp_target_disassociate_ptr(const void *host_ptr, int device_num);

/// Explicit target memory allocators
/// Using the llvm_ prefix until they become part of the OpenMP standard.
void *llvm_omp_target_alloc_device(size_t size, int device_num);
void *llvm_omp_target_alloc_host(size_t size, int device_num);
void *llvm_omp_target_alloc_shared(size_t size, int device_num);

/// Dummy target so we have a symbol for generating host fallback.
void *llvm_omp_get_dynamic_shared();

/// add the clauses of the requires directives in a given file
void __tgt_register_requires(int64_t flags);

/// adds a target shared library to the target execution image
void __tgt_register_lib(__tgt_bin_desc *desc);

/// Initialize all RTLs at once
void __tgt_init_all_rtls();

/// removes a target shared library from the target execution image
void __tgt_unregister_lib(__tgt_bin_desc *desc);

// creates the host to target data mapping, stores it in the
// libomptarget.so internal structure (an entry in a stack of data maps) and
// passes the data to the device;
void __tgt_target_data_begin(int64_t device_id, int32_t arg_num,
                             void **args_base, void **args, int64_t *arg_sizes,
                             int64_t *arg_types);
void __tgt_target_data_begin_nowait(int64_t device_id, int32_t arg_num,
                                    void **args_base, void **args,
                                    int64_t *arg_sizes, int64_t *arg_types,
                                    int32_t depNum, void *depList,
                                    int32_t noAliasDepNum,
                                    void *noAliasDepList);
void __tgt_target_data_begin_mapper(ident_t *loc, int64_t device_id,
                                    int32_t arg_num, void **args_base,
                                    void **args, int64_t *arg_sizes,
                                    int64_t *arg_types,
                                    map_var_info_t *arg_names,
                                    void **arg_mappers);
void __tgt_target_data_begin_nowait_mapper(
    ident_t *loc, int64_t device_id, int32_t arg_num, void **args_base,
    void **args, int64_t *arg_sizes, int64_t *arg_types,
    map_var_info_t *arg_names, void **arg_mappers, int32_t depNum,
    void *depList, int32_t noAliasDepNum, void *noAliasDepList);

// passes data from the target, release target memory and destroys the
// host-target mapping (top entry from the stack of data maps) created by
// the last __tgt_target_data_begin
void __tgt_target_data_end(int64_t device_id, int32_t arg_num, void **args_base,
                           void **args, int64_t *arg_sizes, int64_t *arg_types);
void __tgt_target_data_end_nowait(int64_t device_id, int32_t arg_num,
                                  void **args_base, void **args,
                                  int64_t *arg_sizes, int64_t *arg_types,
                                  int32_t depNum, void *depList,
                                  int32_t noAliasDepNum, void *noAliasDepList);
void __tgt_target_data_end_mapper(ident_t *loc, int64_t device_id,
                                  int32_t arg_num, void **args_base,
                                  void **args, int64_t *arg_sizes,
                                  int64_t *arg_types, map_var_info_t *arg_names,
                                  void **arg_mappers);
void __tgt_target_data_end_nowait_mapper(
    ident_t *loc, int64_t device_id, int32_t arg_num, void **args_base,
    void **args, int64_t *arg_sizes, int64_t *arg_types,
    map_var_info_t *arg_names, void **arg_mappers, int32_t depNum,
    void *depList, int32_t noAliasDepNum, void *noAliasDepList);

/// passes data to/from the target
void __tgt_target_data_update(int64_t device_id, int32_t arg_num,
                              void **args_base, void **args, int64_t *arg_sizes,
                              int64_t *arg_types);
void __tgt_target_data_update_nowait(int64_t device_id, int32_t arg_num,
                                     void **args_base, void **args,
                                     int64_t *arg_sizes, int64_t *arg_types,
                                     int32_t depNum, void *depList,
                                     int32_t noAliasDepNum,
                                     void *noAliasDepList);
void __tgt_target_data_update_mapper(ident_t *loc, int64_t device_id,
                                     int32_t arg_num, void **args_base,
                                     void **args, int64_t *arg_sizes,
                                     int64_t *arg_types,
                                     map_var_info_t *arg_names,
                                     void **arg_mappers);
void __tgt_target_data_update_nowait_mapper(
    ident_t *loc, int64_t device_id, int32_t arg_num, void **args_base,
    void **args, int64_t *arg_sizes, int64_t *arg_types,
    map_var_info_t *arg_names, void **arg_mappers, int32_t depNum,
    void *depList, int32_t noAliasDepNum, void *noAliasDepList);

// Performs the same actions as data_begin in case arg_num is non-zero
// and initiates run of offloaded region on target platform; if arg_num
// is non-zero after the region execution is done it also performs the
// same action as data_end above. The following types are used; this
// function returns 0 if it was able to transfer the execution to a
// target and an int different from zero otherwise.
int __tgt_target(int64_t device_id, void *host_ptr, int32_t arg_num,
                 void **args_base, void **args, int64_t *arg_sizes,
                 int64_t *arg_types);
int __tgt_target_nowait(int64_t device_id, void *host_ptr, int32_t arg_num,
                        void **args_base, void **args, int64_t *arg_sizes,
                        int64_t *arg_types, int32_t depNum, void *depList,
                        int32_t noAliasDepNum, void *noAliasDepList);
int __tgt_target_mapper(ident_t *loc, int64_t device_id, void *host_ptr,
                        int32_t arg_num, void **args_base, void **args,
                        int64_t *arg_sizes, int64_t *arg_types,
                        map_var_info_t *arg_names, void **arg_mappers);
int __tgt_target_nowait_mapper(ident_t *loc, int64_t device_id, void *host_ptr,
                               int32_t arg_num, void **args_base, void **args,
                               int64_t *arg_sizes, int64_t *arg_types,
                               map_var_info_t *arg_names, void **arg_mappers,
                               int32_t depNum, void *depList,
                               int32_t noAliasDepNum, void *noAliasDepList);

int __tgt_target_teams(int64_t device_id, void *host_ptr, int32_t arg_num,
                       void **args_base, void **args, int64_t *arg_sizes,
                       int64_t *arg_types, int32_t num_teams,
                       int32_t thread_limit);
int __tgt_target_teams_nowait(int64_t device_id, void *host_ptr,
                              int32_t arg_num, void **args_base, void **args,
                              int64_t *arg_sizes, int64_t *arg_types,
                              int32_t num_teams, int32_t thread_limit,
                              int32_t depNum, void *depList,
                              int32_t noAliasDepNum, void *noAliasDepList);
int __tgt_target_teams_mapper(ident_t *loc, int64_t device_id, void *host_ptr,
                              int32_t arg_num, void **args_base, void **args,
                              int64_t *arg_sizes, int64_t *arg_types,
                              map_var_info_t *arg_names, void **arg_mappers,
                              int32_t num_teams, int32_t thread_limit);
int __tgt_target_teams_nowait_mapper(
    ident_t *loc, int64_t device_id, void *host_ptr, int32_t arg_num,
    void **args_base, void **args, int64_t *arg_sizes, int64_t *arg_types,
    map_var_info_t *arg_names, void **arg_mappers, int32_t num_teams,
    int32_t thread_limit, int32_t depNum, void *depList, int32_t noAliasDepNum,
    void *noAliasDepList);

void __kmpc_push_target_tripcount(int64_t device_id, uint64_t loop_tripcount);

void __kmpc_push_target_tripcount_mapper(ident_t *loc, int64_t device_id,
                                         uint64_t loop_tripcount);

void __tgt_set_info_flag(uint32_t);

int __tgt_print_device_info(int64_t device_id);
#ifdef __cplusplus
}
#endif

#ifdef __cplusplus
#define EXTERN extern "C"
#else
#define EXTERN extern
#endif

#endif // _OMPTARGET_H_