Function strided_out_extent_elems 

pub fn strided_out_extent_elems(m_pad: u32, ldc: u32, n: u32) -> usize

2026-09-25: Elements from the start of the output to one past the last element a cuBLASLt GEMM writes when its m_pad output rows of n elements are ldc elements apart: (m_pad - 1) * ldc + n. Pass the padded row count, because the pad rows are written too. The strided call sites bound their buffers with it.