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 5Copyright (C) 1991-2021 Free Software Foundation, Inc. 6 7Permission is granted to copy, distribute and/or modify this document 8under the terms of the GNU Free Documentation License, Version 1.3 9or any later version published by the Free Software Foundation; 10with no Invariant Sections, with no Front-Cover Texts, and with no 11Back-Cover Texts. A copy of the license is included in the 12section entitled "GNU Free Documentation License". 13 --> 14<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ --> 15<head> 16<title>Using as: AVR Pseudo Instructions</title> 17 18<meta name="description" content="Using as: AVR Pseudo Instructions"> 19<meta name="keywords" content="Using as: AVR Pseudo Instructions"> 20<meta name="resource-type" content="document"> 21<meta name="distribution" content="global"> 22<meta name="Generator" content="makeinfo"> 23<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> 24<link href="index.html#Top" rel="start" title="Top"> 25<link href="AS-Index.html#AS-Index" rel="index" title="AS Index"> 26<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> 27<link href="AVR_002dDependent.html#AVR_002dDependent" rel="up" title="AVR-Dependent"> 28<link href="Blackfin_002dDependent.html#Blackfin_002dDependent" rel="next" title="Blackfin-Dependent"> 29<link href="AVR-Opcodes.html#AVR-Opcodes" rel="previous" title="AVR Opcodes"> 30<style type="text/css"> 31<!-- 32a.summary-letter {text-decoration: none} 33blockquote.smallquotation {font-size: smaller} 34div.display {margin-left: 3.2em} 35div.example {margin-left: 3.2em} 36div.indentedblock {margin-left: 3.2em} 37div.lisp {margin-left: 3.2em} 38div.smalldisplay {margin-left: 3.2em} 39div.smallexample {margin-left: 3.2em} 40div.smallindentedblock {margin-left: 3.2em; font-size: smaller} 41div.smalllisp {margin-left: 3.2em} 42kbd {font-style:oblique} 43pre.display {font-family: inherit} 44pre.format {font-family: inherit} 45pre.menu-comment {font-family: serif} 46pre.menu-preformatted {font-family: serif} 47pre.smalldisplay {font-family: inherit; font-size: smaller} 48pre.smallexample {font-size: smaller} 49pre.smallformat {font-family: inherit; font-size: smaller} 50pre.smalllisp {font-size: smaller} 51span.nocodebreak {white-space:nowrap} 52span.nolinebreak {white-space:nowrap} 53span.roman {font-family:serif; font-weight:normal} 54span.sansserif {font-family:sans-serif; font-weight:normal} 55ul.no-bullet {list-style: none} 56--> 57</style> 58 59 60</head> 61 62<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> 63<a name="AVR-Pseudo-Instructions"></a> 64<div class="header"> 65<p> 66Previous: <a href="AVR-Opcodes.html#AVR-Opcodes" accesskey="p" rel="previous">AVR Opcodes</a>, Up: <a href="AVR_002dDependent.html#AVR_002dDependent" accesskey="u" rel="up">AVR-Dependent</a> [<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> 67</div> 68<hr> 69<a name="Pseudo-Instructions"></a> 70<h4 class="subsection">9.5.4 Pseudo Instructions</h4> 71 72<p>The only available pseudo-instruction <code>__gcc_isr</code> can be activated by 73option <samp>-mgcc-isr</samp>. 74</p> 75<dl compact="compact"> 76<dt><code>__gcc_isr 1</code></dt> 77<dd><p>Emit code chunk to be used in avr-gcc ISR prologue. 78It will expand to at most six 1-word instructions, all optional: 79push of <code>tmp_reg</code>, push of <code>SREG</code>, 80push and clear of <code>zero_reg</code>, push of <var>Reg</var>. 81</p> 82</dd> 83<dt><code>__gcc_isr 2</code></dt> 84<dd><p>Emit code chunk to be used in an avr-gcc ISR epilogue. 85It will expand to at most five 1-word instructions, all optional: 86pop of <var>Reg</var>, pop of <code>zero_reg</code>, 87pop of <code>SREG</code>, pop of <code>tmp_reg</code>. 88</p> 89</dd> 90<dt><code>__gcc_isr 0, <var>Reg</var></code></dt> 91<dd><p>Finish avr-gcc ISR function. Scan code since the last prologue 92for usage of: <code>SREG</code>, <code>tmp_reg</code>, <code>zero_reg</code>. 93Prologue chunk and epilogue chunks will be replaced by appropriate code 94to save / restore <code>SREG</code>, <code>tmp_reg</code>, <code>zero_reg</code> and <var>Reg</var>. 95</p> 96</dd> 97</dl> 98 99<p>Example input: 100</p> 101<div class="example"> 102<pre class="example">__vector1: 103 __gcc_isr 1 104 lds r24, var 105 inc r24 106 sts var, r24 107 __gcc_isr 2 108 reti 109 __gcc_isr 0, r24 110</pre></div> 111 112<p>Example output: 113</p> 114<div class="example"> 115<pre class="example">00000000 <__vector1>: 116 0: 8f 93 push r24 117 2: 8f b7 in r24, 0x3f 118 4: 8f 93 push r24 119 6: 80 91 60 00 lds r24, 0x0060 ; 0x800060 <var> 120 a: 83 95 inc r24 121 c: 80 93 60 00 sts 0x0060, r24 ; 0x800060 <var> 122 10: 8f 91 pop r24 123 12: 8f bf out 0x3f, r24 124 14: 8f 91 pop r24 125 16: 18 95 reti 126</pre></div> 127 128 129 130 131 132</body> 133</html> 134