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  1. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
  2. <html>
  3. <!-- This file documents the GNU Assembler "as".
  4. Copyright (C) 1991-2020 Free Software Foundation, Inc.
  5. Permission is granted to copy, distribute and/or modify this document
  6. under the terms of the GNU Free Documentation License, Version 1.3
  7. or any later version published by the Free Software Foundation;
  8. with no Invariant Sections, with no Front-Cover Texts, and with no
  9. Back-Cover Texts. A copy of the license is included in the
  10. section entitled "GNU Free Documentation License".
  11. -->
  12. <!-- Created by GNU Texinfo 6.5, http://www.gnu.org/software/texinfo/ -->
  13. <head>
  14. <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
  15. <title>Previous (Using as)</title>
  16. <meta name="description" content="Previous (Using as)">
  17. <meta name="keywords" content="Previous (Using as)">
  18. <meta name="resource-type" content="document">
  19. <meta name="distribution" content="global">
  20. <meta name="Generator" content="makeinfo">
  21. <link href="index.html#Top" rel="start" title="Top">
  22. <link href="AS-Index.html#AS-Index" rel="index" title="AS Index">
  23. <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
  24. <link href="Pseudo-Ops.html#Pseudo-Ops" rel="up" title="Pseudo Ops">
  25. <link href="Print.html#Print" rel="next" title="Print">
  26. <link href="PopSection.html#PopSection" rel="prev" title="PopSection">
  27. <style type="text/css">
  28. <!--
  29. a.summary-letter {text-decoration: none}
  30. blockquote.indentedblock {margin-right: 0em}
  31. blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
  32. blockquote.smallquotation {font-size: smaller}
  33. div.display {margin-left: 3.2em}
  34. div.example {margin-left: 3.2em}
  35. div.lisp {margin-left: 3.2em}
  36. div.smalldisplay {margin-left: 3.2em}
  37. div.smallexample {margin-left: 3.2em}
  38. div.smalllisp {margin-left: 3.2em}
  39. kbd {font-style: oblique}
  40. pre.display {font-family: inherit}
  41. pre.format {font-family: inherit}
  42. pre.menu-comment {font-family: serif}
  43. pre.menu-preformatted {font-family: serif}
  44. pre.smalldisplay {font-family: inherit; font-size: smaller}
  45. pre.smallexample {font-size: smaller}
  46. pre.smallformat {font-family: inherit; font-size: smaller}
  47. pre.smalllisp {font-size: smaller}
  48. span.nolinebreak {white-space: nowrap}
  49. span.roman {font-family: initial; font-weight: normal}
  50. span.sansserif {font-family: sans-serif; font-weight: normal}
  51. ul.no-bullet {list-style: none}
  52. -->
  53. </style>
  54. </head>
  55. <body lang="en">
  56. <a name="Previous"></a>
  57. <div class="header">
  58. <p>
  59. Next: <a href="Print.html#Print" accesskey="n" rel="next">Print</a>, Previous: <a href="PopSection.html#PopSection" accesskey="p" rel="prev">PopSection</a>, Up: <a href="Pseudo-Ops.html#Pseudo-Ops" accesskey="u" rel="up">Pseudo Ops</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
  60. </div>
  61. <hr>
  62. <a name="g_t_002eprevious"></a>
  63. <h3 class="section">7.72 <code>.previous</code></h3>
  64. <a name="index-previous-directive"></a>
  65. <a name="index-Section-Stack-1"></a>
  66. <p>This is one of the ELF section stack manipulation directives. The others are
  67. <code>.section</code> (see <a href="Section.html#Section">Section</a>), <code>.subsection</code> (see <a href="SubSection.html#SubSection">SubSection</a>),
  68. <code>.pushsection</code> (see <a href="PushSection.html#PushSection">PushSection</a>), and <code>.popsection</code>
  69. (see <a href="PopSection.html#PopSection">PopSection</a>).
  70. </p>
  71. <p>This directive swaps the current section (and subsection) with most recently
  72. referenced section/subsection pair prior to this one. Multiple
  73. <code>.previous</code> directives in a row will flip between two sections (and their
  74. subsections). For example:
  75. </p>
  76. <div class="smallexample">
  77. <pre class="smallexample">.section A
  78. .subsection 1
  79. .word 0x1234
  80. .subsection 2
  81. .word 0x5678
  82. .previous
  83. .word 0x9abc
  84. </pre></div>
  85. <p>Will place 0x1234 and 0x9abc into subsection 1 and 0x5678 into subsection 2 of
  86. section A. Whilst:
  87. </p>
  88. <div class="smallexample">
  89. <pre class="smallexample">.section A
  90. .subsection 1
  91. # Now in section A subsection 1
  92. .word 0x1234
  93. .section B
  94. .subsection 0
  95. # Now in section B subsection 0
  96. .word 0x5678
  97. .subsection 1
  98. # Now in section B subsection 1
  99. .word 0x9abc
  100. .previous
  101. # Now in section B subsection 0
  102. .word 0xdef0
  103. </pre></div>
  104. <p>Will place 0x1234 into section A, 0x5678 and 0xdef0 into subsection 0 of
  105. section B and 0x9abc into subsection 1 of section B.
  106. </p>
  107. <p>In terms of the section stack, this directive swaps the current section with
  108. the top section on the section stack.
  109. </p>
  110. </body>
  111. </html>