### 7.71 `.previous`

This is one of the ELF section stack manipulation directives. The others are `.section` (see Section), `.subsection` (see SubSection), `.pushsection` (see PushSection), and `.popsection` (see PopSection).

This directive swaps the current section (and subsection) with most recently referenced section/subsection pair prior to this one. Multiple `.previous` directives in a row will flip between two sections (and their subsections). For example:

    .section A
     .subsection 1
      .word 0x1234
     .subsection 2
      .word 0x5678
    .previous
     .word 0x9abc

Will place 0x1234 and 0x9abc into subsection 1 and 0x5678 into subsection 2 of section A. Whilst:

    .section A
    .subsection 1
      # Now in section A subsection 1
      .word 0x1234
    .section B
    .subsection 0
      # Now in section B subsection 0
      .word 0x5678
    .subsection 1
      # Now in section B subsection 1
      .word 0x9abc
    .previous
      # Now in section B subsection 0
      .word 0xdef0

Will place 0x1234 into section A, 0x5678 and 0xdef0 into subsection 0 of section B and 0x9abc into subsection 1 of section B.

In terms of the section stack, this directive swaps the current section with the top section on the section stack.