Your modification results in the inclusion of a bounds check in the inner loop: .LBB0_4: cmp rdx, rsi jae .LBB0_7 At `LBB0_7` is a call to `pani

Your modification results in the inclusion of a bounds check in the inner loop: .LBB0_4: cmp rdx, rsi jae .LBB0_7 At `LBB0_7` is a call to `panic_bounds_check`.