129 lines
6.2 KiB
HTML
129 lines
6.2 KiB
HTML
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
||
|
|
<html>
|
||
|
|
<!-- Copyright (C) 1999-2016 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 the
|
||
|
|
Invariant Sections being "Funding Free Software", the Front-Cover
|
||
|
|
Texts being (a) (see below), and with the Back-Cover Texts being (b)
|
||
|
|
(see below). A copy of the license is included in the section entitled
|
||
|
|
"GNU Free Documentation License".
|
||
|
|
|
||
|
|
(a) The FSF's Front-Cover Text is:
|
||
|
|
|
||
|
|
A GNU Manual
|
||
|
|
|
||
|
|
(b) The FSF's Back-Cover Text is:
|
||
|
|
|
||
|
|
You have freedom to copy and modify this GNU Manual, like GNU
|
||
|
|
software. Copies published by the Free Software Foundation raise
|
||
|
|
funds for GNU development. -->
|
||
|
|
<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
|
||
|
|
<head>
|
||
|
|
<title>The GNU Fortran Compiler: Introduction to Intrinsics</title>
|
||
|
|
|
||
|
|
<meta name="description" content="The GNU Fortran Compiler: Introduction to Intrinsics">
|
||
|
|
<meta name="keywords" content="The GNU Fortran Compiler: Introduction to Intrinsics">
|
||
|
|
<meta name="resource-type" content="document">
|
||
|
|
<meta name="distribution" content="global">
|
||
|
|
<meta name="Generator" content="makeinfo">
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
||
|
|
<link href="index.html#Top" rel="start" title="Top">
|
||
|
|
<link href="Option-Index.html#Option-Index" rel="index" title="Option Index">
|
||
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
||
|
|
<link href="Intrinsic-Procedures.html#Intrinsic-Procedures" rel="up" title="Intrinsic Procedures">
|
||
|
|
<link href="ABORT.html#ABORT" rel="next" title="ABORT">
|
||
|
|
<link href="Intrinsic-Procedures.html#Intrinsic-Procedures" rel="prev" title="Intrinsic Procedures">
|
||
|
|
<style type="text/css">
|
||
|
|
<!--
|
||
|
|
a.summary-letter {text-decoration: none}
|
||
|
|
blockquote.smallquotation {font-size: smaller}
|
||
|
|
div.display {margin-left: 3.2em}
|
||
|
|
div.example {margin-left: 3.2em}
|
||
|
|
div.indentedblock {margin-left: 3.2em}
|
||
|
|
div.lisp {margin-left: 3.2em}
|
||
|
|
div.smalldisplay {margin-left: 3.2em}
|
||
|
|
div.smallexample {margin-left: 3.2em}
|
||
|
|
div.smallindentedblock {margin-left: 3.2em; font-size: smaller}
|
||
|
|
div.smalllisp {margin-left: 3.2em}
|
||
|
|
kbd {font-style:oblique}
|
||
|
|
pre.display {font-family: inherit}
|
||
|
|
pre.format {font-family: inherit}
|
||
|
|
pre.menu-comment {font-family: serif}
|
||
|
|
pre.menu-preformatted {font-family: serif}
|
||
|
|
pre.smalldisplay {font-family: inherit; font-size: smaller}
|
||
|
|
pre.smallexample {font-size: smaller}
|
||
|
|
pre.smallformat {font-family: inherit; font-size: smaller}
|
||
|
|
pre.smalllisp {font-size: smaller}
|
||
|
|
span.nocodebreak {white-space:nowrap}
|
||
|
|
span.nolinebreak {white-space:nowrap}
|
||
|
|
span.roman {font-family:serif; font-weight:normal}
|
||
|
|
span.sansserif {font-family:sans-serif; font-weight:normal}
|
||
|
|
ul.no-bullet {list-style: none}
|
||
|
|
-->
|
||
|
|
</style>
|
||
|
|
|
||
|
|
|
||
|
|
</head>
|
||
|
|
|
||
|
|
<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
|
||
|
|
<a name="Introduction-to-Intrinsics"></a>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="ABORT.html#ABORT" accesskey="n" rel="next">ABORT</a>, Up: <a href="Intrinsic-Procedures.html#Intrinsic-Procedures" accesskey="u" rel="up">Intrinsic Procedures</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
|
||
|
|
</div>
|
||
|
|
<hr>
|
||
|
|
<a name="Introduction-to-intrinsic-procedures"></a>
|
||
|
|
<h3 class="section">9.1 Introduction to intrinsic procedures</h3>
|
||
|
|
|
||
|
|
<p>The intrinsic procedures provided by GNU Fortran include all of the
|
||
|
|
intrinsic procedures required by the Fortran 95 standard, a set of
|
||
|
|
intrinsic procedures for backwards compatibility with G77, and a
|
||
|
|
selection of intrinsic procedures from the Fortran 2003 and Fortran 2008
|
||
|
|
standards. Any conflict between a description here and a description in
|
||
|
|
either the Fortran 95 standard, the Fortran 2003 standard or the Fortran
|
||
|
|
2008 standard is unintentional, and the standard(s) should be considered
|
||
|
|
authoritative.
|
||
|
|
</p>
|
||
|
|
<p>The enumeration of the <code>KIND</code> type parameter is processor defined in
|
||
|
|
the Fortran 95 standard. GNU Fortran defines the default integer type and
|
||
|
|
default real type by <code>INTEGER(KIND=4)</code> and <code>REAL(KIND=4)</code>,
|
||
|
|
respectively. The standard mandates that both data types shall have
|
||
|
|
another kind, which have more precision. On typical target architectures
|
||
|
|
supported by <code>gfortran</code>, this kind type parameter is <code>KIND=8</code>.
|
||
|
|
Hence, <code>REAL(KIND=8)</code> and <code>DOUBLE PRECISION</code> are equivalent.
|
||
|
|
In the description of generic intrinsic procedures, the kind type parameter
|
||
|
|
will be specified by <code>KIND=*</code>, and in the description of specific
|
||
|
|
names for an intrinsic procedure the kind type parameter will be explicitly
|
||
|
|
given (e.g., <code>REAL(KIND=4)</code> or <code>REAL(KIND=8)</code>). Finally, for
|
||
|
|
brevity the optional <code>KIND=</code> syntax will be omitted.
|
||
|
|
</p>
|
||
|
|
<p>Many of the intrinsic procedures take one or more optional arguments.
|
||
|
|
This document follows the convention used in the Fortran 95 standard,
|
||
|
|
and denotes such arguments by square brackets.
|
||
|
|
</p>
|
||
|
|
<p>GNU Fortran offers the <samp>-std=f95</samp> and <samp>-std=gnu</samp> options,
|
||
|
|
which can be used to restrict the set of intrinsic procedures to a
|
||
|
|
given standard. By default, <code>gfortran</code> sets the <samp>-std=gnu</samp>
|
||
|
|
option, and so all intrinsic procedures described here are accepted. There
|
||
|
|
is one caveat. For a select group of intrinsic procedures, <code>g77</code>
|
||
|
|
implemented both a function and a subroutine. Both classes
|
||
|
|
have been implemented in <code>gfortran</code> for backwards compatibility
|
||
|
|
with <code>g77</code>. It is noted here that these functions and subroutines
|
||
|
|
cannot be intermixed in a given subprogram. In the descriptions that follow,
|
||
|
|
the applicable standard for each intrinsic procedure is noted.
|
||
|
|
</p>
|
||
|
|
|
||
|
|
|
||
|
|
<hr>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="ABORT.html#ABORT" accesskey="n" rel="next">ABORT</a>, Up: <a href="Intrinsic-Procedures.html#Intrinsic-Procedures" accesskey="u" rel="up">Intrinsic Procedures</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
</body>
|
||
|
|
</html>
|