| <html lang="en"> |
| <head> |
| <title>MIPS FP ABI History - 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-FP-ABIs.html#MIPS-FP-ABIs" title="MIPS FP ABIs"> |
| <link rel="next" href="MIPS-FP-ABI-Variants.html#MIPS-FP-ABI-Variants" title="MIPS FP ABI Variants"> |
| <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> |
| <!-- |
| This file documents the GNU Assembler "as". |
| |
| Copyright (C) 1991-2019 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> |
| </head> |
| <body> |
| <div class="node"> |
| <a name="MIPS-FP-ABI-History"></a> |
| <p> |
| Next: <a rel="next" accesskey="n" href="MIPS-FP-ABI-Variants.html#MIPS-FP-ABI-Variants">MIPS FP ABI Variants</a>, |
| Up: <a rel="up" accesskey="u" href="MIPS-FP-ABIs.html#MIPS-FP-ABIs">MIPS FP ABIs</a> |
| <hr> |
| </div> |
| |
| <h5 class="subsubsection">9.27.9.1 History of FP ABIs</h5> |
| |
| <p><a name="index-g_t_0040code_007b_002egnu_005fattribute-4_002c-_0040var_007bn_007d_007d-directive_002c-MIPS-1593"></a><a name="index-g_t_0040code_007b_002egnu_005fattribute-Tag_005fGNU_005fMIPS_005fABI_005fFP_002c-_0040var_007bn_007d_007d-directive_002c-MIPS-1594"></a>The MIPS ABIs support a variety of different floating-point extensions |
| where calling-convention and register sizes vary for floating-point data. |
| The extensions exist to support a wide variety of optional architecture |
| features. The resulting ABI variants are generally incompatible with each |
| other and must be tracked carefully. |
| |
| <p>Traditionally the use of an explicit <code>.gnu_attribute 4, </code><var>n</var> |
| directive is used to indicate which ABI is in use by a specific module. |
| It was then left to the user to ensure that command-line options and the |
| selected ABI were compatible with some potential for inconsistencies. |
| |
| </body></html> |
| |