hip_minimal.hpp

// SPDX-License-Identifier: MIT


#ifndef HIP_MINIMAL_HPP
#define HIP_MINIMAL_HPP

/**
 * @file opus/hip_minimal.hpp
 * @brief Minimal HIP host-side declarations for kernel launch and device management.
 *
 * Replaces <hip/hip_runtime.h> (~100K+ preprocessed lines) for the HOST pass only.
 * For device-side intrinsics, use opus::thread_id_x(), opus::block_id_x(), etc. from opus.hpp.
 *
 * Usage (recommended separate host/device pattern):
 *   #ifdef __HIP_DEVICE_COMPILE__
 *   #include <opus/opus.hpp>        // device: template library + device intrinsics
 *   #else
 *   #include <opus/hip_minimal.hpp> // host: dim3, hipMalloc, hipLaunchKernelGGL, etc.
 *   #endif
 *
 * Compile: hipcc kernel.cu -I<aiter_root>/csrc/include -D__HIPCC_RTC__ ...
 */

// ========== Attribute keyword fallbacks (both passes) ==========
#ifndef __launch_bounds__
#define __launch_bounds_impl0__(requiredMaxThreadsPerBlock) \
    __attribute__((amdgpu_flat_work_group_size(1, requiredMaxThreadsPerBlock)))
#define __launch_bounds_impl1__(requiredMaxThreadsPerBlock, minBlocksPerMultiprocessor) \
    __attribute__((amdgpu_flat_work_group_size(1, requiredMaxThreadsPerBlock), \
                   amdgpu_waves_per_eu(minBlocksPerMultiprocessor)))
#define __launch_bounds_select__(_1, _2, impl_, ...) impl_
#define __launch_bounds__(...) \
    __launch_bounds_select__(__VA_ARGS__, __launch_bounds_impl1__, __launch_bounds_impl0__, )(__VA_ARGS__)
#endif
#ifndef __shared__
#define __shared__ __attribute__((shared))
#endif
#ifndef __device__
#define __device__ __attribute__((device))
#endif
#ifndef __global__
#define __global__ __attribute__((global))
#endif
#ifndef __host__
#define __host__ __attribute__((host))
#endif

// ========== Host-side declarations (guarded to coexist with <hip/hip_runtime.h>) ==========
#if !defined(HIP_INCLUDE_HIP_HIP_RUNTIME_API_H)

#include <cstddef>   // size_t

typedef int hipError_t;
typedef void* hipStream_t;
#define hipSuccess 0

struct dim3 {
    unsigned int x, y, z;
    constexpr dim3(unsigned int _x = 1, unsigned int _y = 1, unsigned int _z = 1)
        : x(_x), y(_y), z(_z) {}
};

// Error handling
extern "C" hipError_t hipGetLastError();
extern "C" hipError_t hipDeviceSynchronize();
extern "C" const char* hipGetErrorString(hipError_t error);

// Memory management
extern "C" hipError_t hipMalloc(void** ptr, size_t size);
extern "C" hipError_t hipFree(void* ptr);
extern "C" hipError_t hipMemset(void* dst, int value, size_t sizeBytes);
enum hipMemcpyKind { hipMemcpyHostToHost = 0, hipMemcpyHostToDevice = 1, hipMemcpyDeviceToHost = 2, hipMemcpyDeviceToDevice = 3, hipMemcpyDefault = 4 };
extern "C" hipError_t hipMemcpy(void* dst, const void* src, size_t sizeBytes, hipMemcpyKind kind);
template <typename T> inline hipError_t hipMalloc(T** ptr, size_t size) { return hipMalloc(reinterpret_cast<void**>(ptr), size); }

// Events (timing)
typedef void* hipEvent_t;
extern "C" hipError_t hipEventCreate(hipEvent_t* event);
extern "C" hipError_t hipEventDestroy(hipEvent_t event);
extern "C" hipError_t hipEventRecord(hipEvent_t event, hipStream_t stream = nullptr);
extern "C" hipError_t hipEventSynchronize(hipEvent_t event);
extern "C" hipError_t hipEventElapsedTime(float* ms, hipEvent_t start, hipEvent_t stop);

// Kernel launch (<<<>>> syntax)
extern "C" hipError_t __hipPushCallConfiguration(dim3 gridDim, dim3 blockDim, size_t sharedMem = 0, hipStream_t stream = nullptr);
extern "C" hipError_t __hipPopCallConfiguration(dim3* gridDim, dim3* blockDim, size_t* sharedMem, hipStream_t* stream);
extern "C" hipError_t hipLaunchKernel(const void* function_address, dim3 numBlocks, dim3 dimBlocks, void** args, size_t sharedMemBytes, hipStream_t stream);
#ifndef hipLaunchKernelGGL
#define hipLaunchKernelGGL(kernel, numBlocks, dimBlocks, sharedMemBytes, stream, ...) \
    kernel<<<numBlocks, dimBlocks, sharedMemBytes, stream>>>(__VA_ARGS__)
#endif

#endif // !HIP_INCLUDE_HIP_HIP_RUNTIME_API_H

#endif // HIP_MINIMAL_HPP