Is there any effect to an align directive immediately following another?

Question

How does it works exactly? does the last align override the behavior of the previously one making its effect null or does it do something when used together? I found this from a large assembly source code and I'm asking this because I don't think it's just a typo.

align 64
align 4

Answer 1

align inserts NOPs to bring the current section offset to a multiple of the specified value. (You can also explicitly specify a value other than NOP to insert, such as NULL padding). It does also implicitly call SECTALIGN to set the section's alignment attribute.

See NASM manual section 4.12.12.

So it's a typo -- the second align will do nothing since the first one already padded up to 64-byte alignment. And the implicit SECTALIGN also has no effect since the manual specifies the alignment attribute can only be increased, never decreased.