| <html lang="en"> |
| <head> |
| <title>MIPS ISA - Using as</title> |
| <meta http-equiv="Content-Type" content="text/html"> |
| <meta name="description" content="Using as"> |
| <meta name="generator" content="makeinfo 4.13"> |
| <link title="Top" rel="start" href="index.html#Top"> |
| <link rel="up" href="MIPS_002dDependent.html#MIPS_002dDependent" title="MIPS-Dependent"> |
| <link rel="prev" href="MIPS-Stabs.html#MIPS-Stabs" title="MIPS Stabs"> |
| <link rel="next" href="MIPS-symbol-sizes.html#MIPS-symbol-sizes" title="MIPS symbol sizes"> |
| <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> |
| <!-- |
| This file documents the GNU Assembler "as". |
| |
| Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, |
| 2000, 2001, 2002, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. |
| |
| Permission is granted to copy, distribute and/or modify this document |
| under the terms of the GNU Free Documentation License, Version 1.3 |
| or any later version published by the Free Software Foundation; |
| with no Invariant Sections, with no Front-Cover Texts, and with no |
| Back-Cover Texts. A copy of the license is included in the |
| section entitled ``GNU Free Documentation License''. |
| |
| --> |
| <meta http-equiv="Content-Style-Type" content="text/css"> |
| <style type="text/css"><!-- |
| pre.display { font-family:inherit } |
| pre.format { font-family:inherit } |
| pre.smalldisplay { font-family:inherit; font-size:smaller } |
| pre.smallformat { font-family:inherit; font-size:smaller } |
| pre.smallexample { font-size:smaller } |
| pre.smalllisp { font-size:smaller } |
| span.sc { font-variant:small-caps } |
| span.roman { font-family:serif; font-weight:normal; } |
| span.sansserif { font-family:sans-serif; font-weight:normal; } |
| --></style> |
| <link rel="stylesheet" type="text/css" href="../cs.css"> |
| </head> |
| <body> |
| <div class="node"> |
| <a name="MIPS-ISA"></a> |
| <p> |
| Next: <a rel="next" accesskey="n" href="MIPS-symbol-sizes.html#MIPS-symbol-sizes">MIPS symbol sizes</a>, |
| Previous: <a rel="previous" accesskey="p" href="MIPS-Stabs.html#MIPS-Stabs">MIPS Stabs</a>, |
| Up: <a rel="up" accesskey="u" href="MIPS_002dDependent.html#MIPS_002dDependent">MIPS-Dependent</a> |
| <hr> |
| </div> |
| |
| <h4 class="subsection">9.24.5 Directives to override the ISA level</h4> |
| |
| <p><a name="index-MIPS-ISA-override-1273"></a><a name="index-g_t_0040code_007b_002eset-mips_0040var_007bn_007d_007d-1274"></a><span class="sc">gnu</span> <code>as</code> supports an additional directive to change |
| the <span class="sc">mips</span> Instruction Set Architecture level on the fly: <code>.set |
| mips</code><var>n</var>. <var>n</var> should be a number from 0 to 5, or 32, 32r2, 64 |
| or 64r2. |
| The values other than 0 make the assembler accept instructions |
| for the corresponding <span class="sc">isa</span> level, from that point on in the |
| assembly. <code>.set mips</code><var>n</var> affects not only which instructions |
| are permitted, but also how certain macros are expanded. <code>.set |
| mips0</code> restores the <span class="sc">isa</span> level to its original level: either the |
| level you selected with command line options, or the default for your |
| configuration. You can use this feature to permit specific <span class="sc">mips3</span> |
| instructions while assembling in 32 bit mode. Use this directive with |
| care! |
| |
| <p><a name="index-MIPS-CPU-override-1275"></a><a name="index-g_t_0040code_007b_002eset-arch_003d_0040var_007bcpu_007d_007d-1276"></a>The <code>.set arch=</code><var>cpu</var> directive provides even finer control. |
| It changes the effective CPU target and allows the assembler to use |
| instructions specific to a particular CPU. All CPUs supported by the |
| ‘<samp><span class="samp">-march</span></samp>’ command line option are also selectable by this directive. |
| The original value is restored by <code>.set arch=default</code>. |
| |
| <p>The directive <code>.set mips16</code> puts the assembler into MIPS 16 mode, |
| in which it will assemble instructions for the MIPS 16 processor. Use |
| <code>.set nomips16</code> to return to normal 32 bit mode. |
| |
| <p>Traditional <span class="sc">mips</span> assemblers do not support this directive. |
| |
| <p>The directive <code>.set micromips</code> puts the assembler into microMIPS mode, |
| in which it will assemble instructions for the microMIPS processor. Use |
| <code>.set nomicromips</code> to return to normal 32 bit mode. |
| |
| <p>Traditional <span class="sc">mips</span> assemblers do not support this directive. |
| |
| </body></html> |
| |