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diff --git a/share/doc/gfortran/CO_005fREDUCE.html b/share/doc/gfortran/CO_005fREDUCE.html new file mode 100644 index 0000000..f54de97 --- /dev/null +++ b/share/doc/gfortran/CO_005fREDUCE.html @@ -0,0 +1,177 @@ +<!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). 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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: CO_REDUCE</title> + +<meta name="description" content="The GNU Fortran Compiler: CO_REDUCE"> +<meta name="keywords" content="The GNU Fortran Compiler: CO_REDUCE"> +<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="CO_005fSUM.html#CO_005fSUM" rel="next" title="CO_SUM"> +<link href="CO_005fMIN.html#CO_005fMIN" rel="previous" title="CO_MIN"> +<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="CO_005fREDUCE"></a> +<div class="header"> +<p> +Next: <a href="CO_005fSUM.html#CO_005fSUM" accesskey="n" rel="next">CO_SUM</a>, Previous: <a href="CO_005fMIN.html#CO_005fMIN" accesskey="p" rel="previous">CO_MIN</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="CO_005fREDUCE-_002d_002d_002d-Reduction-of-values-on-the-current-set-of-images"></a> +<h3 class="section">8.66 <code>CO_REDUCE</code> — Reduction of values on the current set of images</h3> +<a name="index-CO_005fREDUCE"></a> +<a name="index-Collectives_002c-generic-reduction"></a> + +<dl compact="compact"> +<dt><em>Description</em>:</dt> +<dd><p><code>CO_REDUCE</code> determines element-wise the reduction of the value of <var>A</var> +on all images of the current team. The pure function passed as <var>OPERATION</var> +is used to pairwise reduce the values of <var>A</var> by passing either the value +of <var>A</var> of different images or the result values of such a reduction as +argument. If <var>A</var> is an array, the deduction is done element wise. If +<var>RESULT_IMAGE</var> is present, the result values are returned in <var>A</var> on +the specified image only and the value of <var>A</var> on the other images become +undefined. If <var>RESULT_IMAGE</var> is not present, the value is returned on all +images. If the execution was successful and <var>STAT</var> is present, it is +assigned the value zero. If the execution failed, <var>STAT</var> gets assigned +a nonzero value and, if present, <var>ERRMSG</var> gets assigned a value describing +the occurred error. +</p> +</dd> +<dt><em>Standard</em>:</dt> +<dd><p>Technical Specification (TS) 18508 or later +</p> +</dd> +<dt><em>Class</em>:</dt> +<dd><p>Collective subroutine +</p> +</dd> +<dt><em>Syntax</em>:</dt> +<dd><p><code>CALL CO_REDUCE(A, OPERATION, [, RESULT_IMAGE, STAT, ERRMSG])</code> +</p> +</dd> +<dt><em>Arguments</em>:</dt> +<dd><table> +<tr><td width="20%"><var>A</var></td><td width="65%">is an <code>INTENT(INOUT)</code> argument and shall be +nonpolymorphic. If it is allocatable, it shall be allocated; if it is a pointer, +it shall be associated. <var>A</var> shall have the same type and type parameters on +all images of the team; if it is an array, it shall have the same shape on all +images.</td></tr> +<tr><td width="20%"><var>OPERATION</var></td><td width="65%">pure function with two scalar nonallocatable +arguments, which shall be nonpolymorphic and have the same type and type +parameters as <var>A</var>. The function shall return a nonallocatable scalar of +the same type and type parameters as <var>A</var>. The function shall be the same on +all images and with regards to the arguments mathematically commutative and +associative. Note that <var>OPERATION</var> may not be an elemental function, unless +it is an intrisic function.</td></tr> +<tr><td width="20%"><var>RESULT_IMAGE</var></td><td width="65%">(optional) a scalar integer expression; if +present, it shall have the same value on all images and refer to an +image of the current team.</td></tr> +<tr><td width="20%"><var>STAT</var></td><td width="65%">(optional) a scalar integer variable</td></tr> +<tr><td width="20%"><var>ERRMSG</var></td><td width="65%">(optional) a scalar character variable</td></tr> +</table> + +</dd> +<dt><em>Example</em>:</dt> +<dd><div class="smallexample"> +<pre class="smallexample">program test + integer :: val + val = this_image () + call co_reduce (val, result_image=1, operation=myprod) + if (this_image() == 1) then + write(*,*) "Product value", val ! prints num_images() factorial + end if +contains + pure function myprod(a, b) + integer, value :: a, b + integer :: myprod + myprod = a * b + end function myprod +end program test +</pre></div> + +</dd> +<dt><em>Note</em>:</dt> +<dd><p>While the rules permit in principle an intrinsic function, none of the +intrinsics in the standard fulfill the criteria of having a specific +function, which takes two arguments of the same type and returning that +type as result. +</p> +</dd> +<dt><em>See also</em>:</dt> +<dd><p><a href="CO_005fMIN.html#CO_005fMIN">CO_MIN</a>, <br> +<a href="CO_005fMAX.html#CO_005fMAX">CO_MAX</a>, <br> +<a href="CO_005fSUM.html#CO_005fSUM">CO_SUM</a>, <br> +<a href="CO_005fBROADCAST.html#CO_005fBROADCAST">CO_BROADCAST</a> +</p></dd> +</dl> + + + +<hr> +<div class="header"> +<p> +Next: <a href="CO_005fSUM.html#CO_005fSUM" accesskey="n" rel="next">CO_SUM</a>, Previous: <a href="CO_005fMIN.html#CO_005fMIN" accesskey="p" rel="previous">CO_MIN</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> |