makarna/pkg/backend/cuda/cuda_dequant_q8k.cu

#include "cuda_common.cuh"

// ============================================================
// Q8_K Dequantization Kernel
// Each thread handles 1 element within a block
// ============================================================
__global__ void dequant_q8k_kernel(const BlockQ8_K* blocks, float* out, int numBlocks) {
    int blockIdx_q = blockIdx.x;
    int elemIdx = threadIdx.x; // 0-255
    
    if (blockIdx_q >= numBlocks) return;
    
    const BlockQ8_K* b = &blocks[blockIdx_q];
    float d = b->d;
    
    out[blockIdx_q * 256 + elemIdx] = d * (float)b->qs[elemIdx];
}

int cuda_dequant_q8k(const void* blocks, float* out, int numBlocks) {
    if (numBlocks == 0) return 0;
    dequant_q8k_kernel<<<numBlocks, 256>>>((const BlockQ8_K*)blocks, out, numBlocks);
    CHECK_CUDA(cudaGetLastError());
    return 0;
}