fn f()

in candle-core/src/cpu_backend/mod.rs [676:735]
60 lines of code
11 McCabe index (conditional complexity)

    fn f<T: WithDType>(&self, v1: &[T], l1: &Layout, src: &[T], src_l: &Layout) -> Result<Vec<T>> {
        let dst_len = l1.shape().elem_count();
        let mut dst = vec![T::zero(); dst_len];
        copy_strided_src_(v1, &mut dst, 0, l1);
        let src = match src_l.contiguous_offsets() {
            None => Err(Error::RequiresContiguous { op: "index-add" }.bt())?,
            Some((o1, o2)) => &src[o1..o2],
        };
        let dim = self.dim;
        let max_idx = l1.dims()[dim];
        let pre_dim = src_l.dims()[..dim].iter().product::<usize>();
        let src_dim_sz = src_l.dims()[dim];
        let post_dim = src_l.dims()[dim + 1..].iter().product::<usize>();
        if dim == 0 {
            for (src_idx, dst_idx) in self.ids.iter().enumerate() {
                if *dst_idx == I::max_value() {
                    continue;
                }
                let dst_idx = dst_idx.as_usize();
                if dst_idx >= max_idx {
                    Err(Error::InvalidIndex {
                        index: dst_idx,
                        op: "index-add",
                        size: max_idx,
                    })?
                }
                let src_idx = src_idx * post_dim;
                let dst_idx = dst_idx * post_dim;
                let src = &src[src_idx..src_idx + post_dim];
                let dst = &mut dst[dst_idx..dst_idx + post_dim];
                for (d, &s) in dst.iter_mut().zip(src.iter()) {
                    *d += s
                }
            }
        } else {
            for (src_idx, dst_idx) in self.ids.iter().enumerate() {
                if *dst_idx == I::max_value() {
                    continue;
                }
                let dst_idx = dst_idx.as_usize();
                if dst_idx >= max_idx {
                    Err(Error::InvalidIndex {
                        index: dst_idx,
                        op: "index-add",
                        size: max_idx,
                    })?
                }
                for pre_i in 0..pre_dim {
                    let pre_src_i = (pre_i * src_dim_sz + src_idx) * post_dim;
                    let pre_dst_i = (pre_i * max_idx + dst_idx) * post_dim;
                    let src = &src[pre_src_i..pre_src_i + post_dim];
                    let dst = &mut dst[pre_dst_i..pre_dst_i + post_dim];
                    for (d, &s) in dst.iter_mut().zip(src.iter()) {
                        *d += s
                    }
                }
            }
        }
        Ok(dst)
    }