mirror of
https://github.com/tildearrow/furnace.git
synced 2024-11-06 12:55:05 +00:00
120 lines
4.9 KiB
HTML
120 lines
4.9 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<html>
|
|
<!-- This manual is for FFTW
|
|
(version 3.3.10, 10 December 2020).
|
|
|
|
Copyright (C) 2003 Matteo Frigo.
|
|
|
|
Copyright (C) 2003 Massachusetts Institute of Technology.
|
|
|
|
Permission is granted to make and distribute verbatim copies of this
|
|
manual provided the copyright notice and this permission notice are
|
|
preserved on all copies.
|
|
|
|
Permission is granted to copy and distribute modified versions of this
|
|
manual under the conditions for verbatim copying, provided that the
|
|
entire resulting derived work is distributed under the terms of a
|
|
permission notice identical to this one.
|
|
|
|
Permission is granted to copy and distribute translations of this manual
|
|
into another language, under the above conditions for modified versions,
|
|
except that this permission notice may be stated in a translation
|
|
approved by the Free Software Foundation. -->
|
|
<!-- Created by GNU Texinfo 6.7, http://www.gnu.org/software/texinfo/ -->
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
|
<title>Memory Allocation (FFTW 3.3.10)</title>
|
|
|
|
<meta name="description" content="Memory Allocation (FFTW 3.3.10)">
|
|
<meta name="keywords" content="Memory Allocation (FFTW 3.3.10)">
|
|
<meta name="resource-type" content="document">
|
|
<meta name="distribution" content="global">
|
|
<meta name="Generator" content="makeinfo">
|
|
<link href="index.html" rel="start" title="Top">
|
|
<link href="Concept-Index.html" rel="index" title="Concept Index">
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
|
<link href="Data-Types-and-Files.html" rel="up" title="Data Types and Files">
|
|
<link href="Using-Plans.html" rel="next" title="Using Plans">
|
|
<link href="Precision.html" rel="prev" title="Precision">
|
|
<style type="text/css">
|
|
<!--
|
|
a.summary-letter {text-decoration: none}
|
|
blockquote.indentedblock {margin-right: 0em}
|
|
div.display {margin-left: 3.2em}
|
|
div.example {margin-left: 3.2em}
|
|
div.lisp {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}
|
|
span.nolinebreak {white-space: nowrap}
|
|
span.roman {font-family: initial; font-weight: normal}
|
|
span.sansserif {font-family: sans-serif; font-weight: normal}
|
|
ul.no-bullet {list-style: none}
|
|
-->
|
|
</style>
|
|
|
|
|
|
</head>
|
|
|
|
<body lang="en">
|
|
<span id="Memory-Allocation"></span><div class="header">
|
|
<p>
|
|
Previous: <a href="Precision.html" accesskey="p" rel="prev">Precision</a>, Up: <a href="Data-Types-and-Files.html" accesskey="u" rel="up">Data Types and Files</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html" title="Index" rel="index">Index</a>]</p>
|
|
</div>
|
|
<hr>
|
|
<span id="Memory-Allocation-1"></span><h4 class="subsection">4.1.3 Memory Allocation</h4>
|
|
|
|
<div class="example">
|
|
<pre class="example">void *fftw_malloc(size_t n);
|
|
void fftw_free(void *p);
|
|
</pre></div>
|
|
<span id="index-fftw_005fmalloc-3"></span>
|
|
<span id="index-fftw_005ffree-2"></span>
|
|
|
|
<p>These are functions that behave identically to <code>malloc</code> and
|
|
<code>free</code>, except that they guarantee that the returned pointer obeys
|
|
any special alignment restrictions imposed by any algorithm in FFTW
|
|
(e.g. for SIMD acceleration). See <a href="SIMD-alignment-and-fftw_005fmalloc.html">SIMD alignment and fftw_malloc</a>.
|
|
<span id="index-alignment"></span>
|
|
</p>
|
|
|
|
<p>Data allocated by <code>fftw_malloc</code> <em>must</em> be deallocated by
|
|
<code>fftw_free</code> and not by the ordinary <code>free</code>.
|
|
</p>
|
|
<p>These routines simply call through to your operating system’s
|
|
<code>malloc</code> or, if necessary, its aligned equivalent
|
|
(e.g. <code>memalign</code>), so you normally need not worry about any
|
|
significant time or space overhead. You are <em>not required</em> to use
|
|
them to allocate your data, but we strongly recommend it.
|
|
</p>
|
|
<p>Note: in C++, just as with ordinary <code>malloc</code>, you must typecast
|
|
the output of <code>fftw_malloc</code> to whatever pointer type you are
|
|
allocating.
|
|
<span id="index-C_002b_002b-4"></span>
|
|
</p>
|
|
|
|
<p>We also provide the following two convenience functions to allocate
|
|
real and complex arrays with <code>n</code> elements, which are equivalent
|
|
to <code>(double *) fftw_malloc(sizeof(double) * n)</code> and
|
|
<code>(fftw_complex *) fftw_malloc(sizeof(fftw_complex) * n)</code>,
|
|
respectively:
|
|
</p>
|
|
<div class="example">
|
|
<pre class="example">double *fftw_alloc_real(size_t n);
|
|
fftw_complex *fftw_alloc_complex(size_t n);
|
|
</pre></div>
|
|
<span id="index-fftw_005falloc_005freal-1"></span>
|
|
<span id="index-fftw_005falloc_005fcomplex-2"></span>
|
|
|
|
<p>The equivalent functions in other precisions allocate arrays of <code>n</code>
|
|
elements in that precision. e.g. <code>fftwf_alloc_real(n)</code> is
|
|
equivalent to <code>(float *) fftwf_malloc(sizeof(float) * n)</code>.
|
|
<span id="index-precision-4"></span>
|
|
</p>
|
|
|
|
|
|
|
|
</body>
|
|
</html>
|