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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) | |
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diff --git a/share/doc/gfortran/Evaluation-of-logical-expressions.html b/share/doc/gfortran/Evaluation-of-logical-expressions.html new file mode 100644 index 0000000..6132142 --- /dev/null +++ b/share/doc/gfortran/Evaluation-of-logical-expressions.html @@ -0,0 +1,94 @@ +<!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: Evaluation of logical expressions</title> + +<meta name="description" content="The GNU Fortran Compiler: Evaluation of logical expressions"> +<meta name="keywords" content="The GNU Fortran Compiler: Evaluation of logical expressions"> +<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="Compiler-Characteristics.html#Compiler-Characteristics" rel="up" title="Compiler Characteristics"> +<link href="MAX-and-MIN-intrinsics-with-REAL-NaN-arguments.html#MAX-and-MIN-intrinsics-with-REAL-NaN-arguments" rel="next" title="MAX and MIN intrinsics with REAL NaN arguments"> +<link href="Internal-representation-of-LOGICAL-variables.html#Internal-representation-of-LOGICAL-variables" rel="previous" title="Internal representation of LOGICAL variables"> +<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="Evaluation-of-logical-expressions"></a> +<div class="header"> +<p> +Next: <a href="MAX-and-MIN-intrinsics-with-REAL-NaN-arguments.html#MAX-and-MIN-intrinsics-with-REAL-NaN-arguments" accesskey="n" rel="next">MAX and MIN intrinsics with REAL NaN arguments</a>, Previous: <a href="Internal-representation-of-LOGICAL-variables.html#Internal-representation-of-LOGICAL-variables" accesskey="p" rel="previous">Internal representation of LOGICAL variables</a>, Up: <a href="Compiler-Characteristics.html#Compiler-Characteristics" accesskey="u" rel="up">Compiler Characteristics</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="Evaluation-of-logical-expressions-1"></a> +<h3 class="section">4.3 Evaluation of logical expressions</h3> + +<p>The Fortran standard does not require the compiler to evaluate all parts of an +expression, if they do not contribute to the final result. For logical +expressions with <code>.AND.</code> or <code>.OR.</code> operators, in particular, GNU +Fortran will optimize out function calls (even to impure functions) if the +result of the expression can be established without them. However, since not +all compilers do that, and such an optimization can potentially modify the +program flow and subsequent results, GNU Fortran throws warnings for such +situations with the <samp>-Wfunction-elimination</samp> flag. +</p> + + + + +</body> +</html> |