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diff --git a/share/doc/gccint/Range-checks-on-poly_005fints.html b/share/doc/gccint/Range-checks-on-poly_005fints.html new file mode 100644 index 0000000..f96904e --- /dev/null +++ b/share/doc/gccint/Range-checks-on-poly_005fints.html @@ -0,0 +1,154 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- Copyright (C) 1988-2023 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>GNU Compiler Collection (GCC) Internals: Range checks on poly_ints</title> + +<meta name="description" content="GNU Compiler Collection (GCC) Internals: Range checks on poly_ints"> +<meta name="keywords" content="GNU Compiler Collection (GCC) Internals: Range checks on poly_ints"> +<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="Comparisons-involving-poly_005fint.html#Comparisons-involving-poly_005fint" rel="up" title="Comparisons involving poly_int"> +<link href="Sorting-poly_005fints.html#Sorting-poly_005fints" rel="next" title="Sorting poly_ints"> +<link href="Checking-for-a-poly_005fint-marker-value.html#Checking-for-a-poly_005fint-marker-value" rel="previous" title="Checking for a poly_int marker value"> +<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="Range-checks-on-poly_005fints"></a> +<div class="header"> +<p> +Next: <a href="Sorting-poly_005fints.html#Sorting-poly_005fints" accesskey="n" rel="next">Sorting <code>poly_int</code>s</a>, Previous: <a href="Checking-for-a-poly_005fint-marker-value.html#Checking-for-a-poly_005fint-marker-value" accesskey="p" rel="previous">Checking for a <code>poly_int</code> marker value</a>, Up: <a href="Comparisons-involving-poly_005fint.html#Comparisons-involving-poly_005fint" accesskey="u" rel="up">Comparisons involving <code>poly_int</code></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="Range-checks-on-poly_005fints-1"></a> +<h4 class="subsection">10.3.6 Range checks on <code>poly_int</code>s</h4> + +<p>As well as the core comparisons +(see <a href="Comparison-functions-for-poly_005fint.html#Comparison-functions-for-poly_005fint">Comparison functions for <code>poly_int</code></a>), <code>poly_int</code> provides +utilities for various kinds of range check. In each case the range +is represented by a start position and a size rather than a start +position and an end position; this is because the former is used +much more often than the latter in GCC. Also, the sizes can be +-1 (or all ones for unsigned sizes) to indicate a range with a known +start position but an unknown size. All other sizes must be nonnegative. +A range of size 0 does not contain anything or overlap anything. +</p> +<dl compact="compact"> +<dt>‘<samp>known_size_p (<var>size</var>)</samp>’</dt> +<dd><p>Return true if <var>size</var> represents a known range size, false if it +is -1 or all ones (for signed and unsigned types respectively). +</p> +</dd> +<dt>‘<samp>ranges_maybe_overlap_p (<var>pos1</var>, <var>size1</var>, <var>pos2</var>, <var>size2</var>)</samp>’</dt> +<dd><p>Return true if the range described by <var>pos1</var> and <var>size1</var> <em>might</em> +overlap the range described by <var>pos2</var> and <var>size2</var> (in other words, +return true if we cannot prove that the ranges are disjoint). +</p> +</dd> +<dt>‘<samp>ranges_known_overlap_p (<var>pos1</var>, <var>size1</var>, <var>pos2</var>, <var>size2</var>)</samp>’</dt> +<dd><p>Return true if the range described by <var>pos1</var> and <var>size1</var> is known to +overlap the range described by <var>pos2</var> and <var>size2</var>. +</p> +</dd> +<dt>‘<samp>known_subrange_p (<var>pos1</var>, <var>size1</var>, <var>pos2</var>, <var>size2</var>)</samp>’</dt> +<dd><p>Return true if the range described by <var>pos1</var> and <var>size1</var> is known to +be contained in the range described by <var>pos2</var> and <var>size2</var>. +</p> +</dd> +<dt>‘<samp>maybe_in_range_p (<var>value</var>, <var>pos</var>, <var>size</var>)</samp>’</dt> +<dd><p>Return true if <var>value</var> <em>might</em> be in the range described by +<var>pos</var> and <var>size</var> (in other words, return true if we cannot +prove that <var>value</var> is outside that range). +</p> +</dd> +<dt>‘<samp>known_in_range_p (<var>value</var>, <var>pos</var>, <var>size</var>)</samp>’</dt> +<dd><p>Return true if <var>value</var> is known to be in the range described +by <var>pos</var> and <var>size</var>. +</p> +</dd> +<dt>‘<samp>endpoint_representable_p (<var>pos</var>, <var>size</var>)</samp>’</dt> +<dd><p>Return true if the range described by <var>pos</var> and <var>size</var> is +open-ended or if the endpoint (<var>pos</var> + <var>size</var>) is representable +in the same type as <var>pos</var> and <var>size</var>. The function returns false +if adding <var>size</var> to <var>pos</var> makes conceptual sense but could overflow. +</p></dd> +</dl> + +<p>There is also a <code>poly_int</code> version of the <code>IN_RANGE_P</code> macro: +</p> +<dl compact="compact"> +<dt>‘<samp>coeffs_in_range_p (<var>x</var>, <var>lower</var>, <var>upper</var>)</samp>’</dt> +<dd><p>Return true if every coefficient of <var>x</var> is in the inclusive range +[<var>lower</var>, <var>upper</var>]. This function can be useful when testing +whether an operation would cause the values of coefficients to +overflow. +</p> +<p>Note that the function does not indicate whether <var>x</var> itself is in the +given range. <var>x</var> can be either a constant or a <code>poly_int</code>. +</p></dd> +</dl> + +<hr> +<div class="header"> +<p> +Next: <a href="Sorting-poly_005fints.html#Sorting-poly_005fints" accesskey="n" rel="next">Sorting <code>poly_int</code>s</a>, Previous: <a href="Checking-for-a-poly_005fint-marker-value.html#Checking-for-a-poly_005fint-marker-value" accesskey="p" rel="previous">Checking for a <code>poly_int</code> marker value</a>, Up: <a href="Comparisons-involving-poly_005fint.html#Comparisons-involving-poly_005fint" accesskey="u" rel="up">Comparisons involving <code>poly_int</code></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> |