__device__ BlockInfo()

in candle-flash-attn/kernels/block_info.h [15:25]

• 9 lines of code
• 14 McCabe index (conditional complexity)

    __device__ BlockInfo(const Params &params, const int bidb)
        : sum_s_q(!Varlen || params.cu_seqlens_q == nullptr ? -1 : params.cu_seqlens_q[bidb])
        , sum_s_k(!Varlen || params.cu_seqlens_k == nullptr || !params.is_seqlens_k_cumulative ? -1 : params.cu_seqlens_k[bidb])
        , actual_seqlen_q(!Varlen || params.cu_seqlens_q == nullptr ? params.seqlen_q : params.cu_seqlens_q[bidb + 1] - sum_s_q)
        // If is_seqlens_k_cumulative, then seqlen_k is cu_seqlens_k[bidb + 1] - cu_seqlens_k[bidb].
        // Otherwise it's cu_seqlens_k[bidb], i.e., we use cu_seqlens_k to store the sequence lengths of K.
        , leftpad_k(params.leftpad_k == nullptr ? 0 : params.leftpad_k[bidb])
        , seqlen_k_cache((!Varlen || params.cu_seqlens_k == nullptr ? params.seqlen_k : (params.is_seqlens_k_cumulative ? params.cu_seqlens_k[bidb + 1] - sum_s_k : params.cu_seqlens_k[bidb])) - leftpad_k)
        , actual_seqlen_k(params.seqused_k ? params.seqused_k[bidb] - leftpad_k : seqlen_k_cache + (params.knew_ptr == nullptr ? 0 : params.seqlen_knew))
        {
        }