/**
 * llama.cpp - commit 8962422b1c6f9b8b15f5aeaea42600bcc2d44177 - do not edit this file
 *
 * MIT License
 *
 * Copyright (c) 2023-2024 The ggml authors
 *
 * 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.
 */

#include "pad.cuh"

static __global__ void pad_f32(const float * x, float * dst, const int ne0, const int ne00, const int ne01, const int ne02, const int ne03) {
    // blockIdx.z: idx of ne2*ne3, aka ne02*ne03
    // blockIdx.y: idx of ne1
    // blockIDx.x: idx of ne0 / BLOCK_SIZE
    int nidx = threadIdx.x + blockIdx.x * blockDim.x;
    if (nidx >= ne0) {
        return;
    }

    // operation
    int offset_dst =
        nidx +
        blockIdx.y * ne0 +
        blockIdx.z * ne0 * gridDim.y;
    if (nidx < ne00 && blockIdx.y < ne01 && blockIdx.z < ne02*ne03) {
        int offset_src =
            nidx +
            blockIdx.y * ne00 +
            blockIdx.z * ne00 * ne01;
        dst[offset_dst] = x[offset_src];
    } else {
        dst[offset_dst] = 0.0f;
    }
}

static void pad_f32_cuda(const float * x, float * dst,
    const int ne00, const int ne01, const int ne02, const int ne03,
    const int ne0, const int ne1, const int ne2, const int ne3, cudaStream_t stream) {
    int num_blocks = (ne0 + CUDA_PAD_BLOCK_SIZE - 1) / CUDA_PAD_BLOCK_SIZE;
    dim3 gridDim(num_blocks, ne1, ne2*ne3);
    pad_f32<<<gridDim, CUDA_PAD_BLOCK_SIZE, 0, stream>>>(x, dst, ne0, ne00, ne01, ne02, ne03);
}

void ggml_cuda_op_pad(ggml_backend_cuda_context & ctx, ggml_tensor * dst) {
    const ggml_tensor * src0 = dst->src[0];
    const float * src0_d = (const float *)src0->data;
    float * dst_d = (float *)dst->data;
    cudaStream_t stream = ctx.stream();

    GGML_ASSERT(src0->type == GGML_TYPE_F32);
    GGML_ASSERT(dst->type == GGML_TYPE_F32);
    GGML_ASSERT(src0->ne[3] == 1 && dst->ne[3] == 1); // just 3D tensors

    pad_f32_cuda(src0_d, dst_d,
        src0->ne[0], src0->ne[1], src0->ne[2], src0->ne[3],
        dst->ne[0], dst->ne[1], dst->ne[2], dst->ne[3], stream);
}