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| author | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
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| committer | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
| commit | abdaadbcae30fe0c9a66c7516798279fdfd97750 (patch) | |
| tree | 00a54a6e25601e43876d03c1a4a12a749d4a914c /share/doc/gfortran/SYSTEM_005fCLOCK.html | |
https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads
Change-Id: I7303388733328cd98ab9aa3c30236db67f2e9e9c
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diff --git a/share/doc/gfortran/SYSTEM_005fCLOCK.html b/share/doc/gfortran/SYSTEM_005fCLOCK.html new file mode 100644 index 0000000..d7dfb37 --- /dev/null +++ b/share/doc/gfortran/SYSTEM_005fCLOCK.html @@ -0,0 +1,171 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- Copyright (C) 1999-2023 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 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>The GNU Fortran Compiler: SYSTEM_CLOCK</title> + +<meta name="description" content="The GNU Fortran Compiler: SYSTEM_CLOCK"> +<meta name="keywords" content="The GNU Fortran Compiler: SYSTEM_CLOCK"> +<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="TAN.html#TAN" rel="next" title="TAN"> +<link href="SYSTEM.html#SYSTEM" rel="previous" title="SYSTEM"> +<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="SYSTEM_005fCLOCK"></a> +<div class="header"> +<p> +Next: <a href="TAN.html#TAN" accesskey="n" rel="next">TAN</a>, Previous: <a href="SYSTEM.html#SYSTEM" accesskey="p" rel="previous">SYSTEM</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="SYSTEM_005fCLOCK-_002d_002d_002d-Time-function"></a> +<h3 class="section">8.264 <code>SYSTEM_CLOCK</code> — Time function</h3> +<a name="index-SYSTEM_005fCLOCK"></a> +<a name="index-time_002c-clock-ticks-2"></a> +<a name="index-clock-ticks-2"></a> + +<dl compact="compact"> +<dt><em>Description</em>:</dt> +<dd><p>Determines the <var>COUNT</var> of a processor clock since an unspecified +time in the past modulo <var>COUNT_MAX</var>, <var>COUNT_RATE</var> determines +the number of clock ticks per second. If the platform supports a +monotonic clock, that clock is used and can, depending on the platform +clock implementation, provide up to nanosecond resolution. If a +monotonic clock is not available, the implementation falls back to a +realtime clock. +</p> +<p><var>COUNT_RATE</var> is system dependent and can vary depending on the kind of +the arguments. For <var>kind=4</var> arguments (and smaller integer kinds), +<var>COUNT</var> represents milliseconds, while for <var>kind=8</var> arguments (and +larger integer kinds), <var>COUNT</var> typically represents micro- or +nanoseconds depending on resolution of the underlying platform clock. +<var>COUNT_MAX</var> usually equals <code>HUGE(COUNT_MAX)</code>. Note that the +millisecond resolution of the <var>kind=4</var> version implies that the +<var>COUNT</var> will wrap around in roughly 25 days. In order to avoid issues +with the wrap around and for more precise timing, please use the +<var>kind=8</var> version. +</p> +<p>If there is no clock, or querying the clock fails, <var>COUNT</var> is set +to <code>-HUGE(COUNT)</code>, and <var>COUNT_RATE</var> and <var>COUNT_MAX</var> are +set to zero. +</p> +<p>When running on a platform using the GNU C library (glibc) version +2.16 or older, or a derivative thereof, the high resolution monotonic +clock is available only when linking with the <var>rt</var> library. This +can be done explicitly by adding the <code>-lrt</code> flag when linking the +application, but is also done implicitly when using OpenMP. +</p> +<p>On the Windows platform, the version with <var>kind=4</var> arguments uses +the <code>GetTickCount</code> function, whereas the <var>kind=8</var> version +uses <code>QueryPerformanceCounter</code> and +<code>QueryPerformanceCounterFrequency</code>. For more information, and +potential caveats, please see the platform documentation. +</p> +</dd> +<dt><em>Standard</em>:</dt> +<dd><p>Fortran 90 and later +</p> +</dd> +<dt><em>Class</em>:</dt> +<dd><p>Subroutine +</p> +</dd> +<dt><em>Syntax</em>:</dt> +<dd><p><code>CALL SYSTEM_CLOCK([COUNT, COUNT_RATE, COUNT_MAX])</code> +</p> +</dd> +<dt><em>Arguments</em>:</dt> +<dd><table> +<tr><td width="20%"><var>COUNT</var></td><td width="65%">(Optional) shall be a scalar of type +<code>INTEGER</code> with <code>INTENT(OUT)</code>.</td></tr> +<tr><td width="20%"><var>COUNT_RATE</var></td><td width="65%">(Optional) shall be a scalar of type +<code>INTEGER</code> or <code>REAL</code>, with <code>INTENT(OUT)</code>.</td></tr> +<tr><td width="20%"><var>COUNT_MAX</var></td><td width="65%">(Optional) shall be a scalar of type +<code>INTEGER</code> with <code>INTENT(OUT)</code>.</td></tr> +</table> + +</dd> +<dt><em>Example</em>:</dt> +<dd><div class="smallexample"> +<pre class="smallexample">PROGRAM test_system_clock + INTEGER :: count, count_rate, count_max + CALL SYSTEM_CLOCK(count, count_rate, count_max) + WRITE(*,*) count, count_rate, count_max +END PROGRAM +</pre></div> + +</dd> +<dt><em>See also</em>:</dt> +<dd><p><a href="DATE_005fAND_005fTIME.html#DATE_005fAND_005fTIME">DATE_AND_TIME</a>, <br> +<a href="CPU_005fTIME.html#CPU_005fTIME">CPU_TIME</a> +</p></dd> +</dl> + + + +<hr> +<div class="header"> +<p> +Next: <a href="TAN.html#TAN" accesskey="n" rel="next">TAN</a>, Previous: <a href="SYSTEM.html#SYSTEM" accesskey="p" rel="previous">SYSTEM</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> |