Function inner_product_f32 

pub fn inner_product_f32<Idx: Copy + Ord>(
    x_idx: &[Idx],
    x_val: &[f32],
    y_idx: &[Idx],
    y_val: &[f32],
) -> Result<f32, LengthMismatch>

Σ x·y over matching indices for f32 operands.