aphrodite-engine/kernels/quantization/exl2/compat.cuh

/*
 * Adapted from https://github.com/turboderp/exllamav2
 * Copyright (c) 2024 turboderp
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#ifndef _compat_cuh
#define _compat_cuh


namespace aphrodite {
namespace exl2 {

// atomicAdd for half types, to support CC < 7.x

__device__ __forceinline__ void atomicAdd_half(half* address, half val)
{
    unsigned int * address_as_ui = (unsigned int *) ((char *)address - ((size_t)address & 2));
    unsigned int old = *address_as_ui;
    unsigned int assumed;

    do
    {
        assumed = old;
        __half_raw hsum;
        hsum.x = (size_t)address & 2 ? (old >> 16) : (old & 0xffff);
        half tmpres = __hadd(hsum, val);
        hsum = __half_raw(tmpres);
        old = (size_t)address & 2 ? (old & 0xffff) | (hsum.x << 16) : (old & 0xffff0000) | hsum.x;
        old = atomicCAS(address_as_ui, assumed, old);
    }
    while (assumed != old);
}

// atomicAdd for half2 types

__device__ __forceinline__ void atomicAdd_half2(half2* address, half2 val)
{
    unsigned int* address_as_ui = (unsigned int*)address;
    unsigned int old = *address_as_ui;
    unsigned int assumed;
    do
    {
        assumed = old;
        half2 old_val = *((half2*)&old);
        half2 new_val = __hadd2(old_val, val);
        old = atomicCAS(address_as_ui, assumed, *((unsigned int*)&new_val));
    }
    while (assumed != old);
}

//

#if defined(__CUDA_ARCH__) || defined(USE_ROCM)
#if __CUDA_ARCH__ < 700 || defined(USE_ROCM)

__device__ __forceinline__ void atomicAdd(half* address, half val) { atomicAdd_half(address, val); }

#if __CUDA_ARCH__ < 600 || defined(USE_ROCM)
__device__ __forceinline__ void atomicAdd(half2* address, half2 val) { atomicAdd_half2(address, val); }
#endif

#endif
#endif

#endif

}  // namespace exl2
}  // namespace aphrodite