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Add FFTW 3.3.8 source, and a Linux build
author Chris Cannam
date Tue, 19 Nov 2019 14:52:55 +0000
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1 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
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3 <!-- This manual is for FFTW
4 (version 3.3.8, 24 May 2018).
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6 Copyright (C) 2003 Matteo Frigo.
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8 Copyright (C) 2003 Massachusetts Institute of Technology.
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24 <head>
25 <title>FFTW 3.3.8: Using MPI Plans</title>
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35 <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
36 <link href="FFTW-MPI-Reference.html#FFTW-MPI-Reference" rel="up" title="FFTW MPI Reference">
37 <link href="MPI-Data-Distribution-Functions.html#MPI-Data-Distribution-Functions" rel="next" title="MPI Data Distribution Functions">
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68 </head>
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70 <body lang="en">
71 <a name="Using-MPI-Plans"></a>
72 <div class="header">
73 <p>
74 Next: <a href="MPI-Data-Distribution-Functions.html#MPI-Data-Distribution-Functions" accesskey="n" rel="next">MPI Data Distribution Functions</a>, Previous: <a href="MPI-Initialization.html#MPI-Initialization" accesskey="p" rel="prev">MPI Initialization</a>, Up: <a href="FFTW-MPI-Reference.html#FFTW-MPI-Reference" accesskey="u" rel="up">FFTW MPI Reference</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
75 </div>
76 <hr>
77 <a name="Using-MPI-Plans-1"></a>
78 <h4 class="subsection">6.12.3 Using MPI Plans</h4>
79
80 <p>Once an MPI plan is created, you can execute and destroy it using
81 <code>fftw_execute</code>, <code>fftw_destroy_plan</code>, and the other functions
82 in the serial interface that operate on generic plans (see <a href="Using-Plans.html#Using-Plans">Using Plans</a>).
83 </p>
84 <a name="index-collective-function-3"></a>
85 <a name="index-MPI-communicator-1"></a>
86 <p>The <code>fftw_execute</code> and <code>fftw_destroy_plan</code> functions, applied to
87 MPI plans, are <em>collective</em> calls: they must be called for all processes
88 in the communicator that was used to create the plan.
89 </p>
90 <a name="index-new_002darray-execution-1"></a>
91 <p>You must <em>not</em> use the serial new-array plan-execution functions
92 <code>fftw_execute_dft</code> and so on (see <a href="New_002darray-Execute-Functions.html#New_002darray-Execute-Functions">New-array Execute Functions</a>) with MPI plans. Such functions are specialized to the
93 problem type, and there are specific new-array execute functions for MPI plans:
94 </p>
95 <a name="index-fftw_005fmpi_005fexecute_005fdft"></a>
96 <a name="index-fftw_005fmpi_005fexecute_005fdft_005fr2c"></a>
97 <a name="index-fftw_005fmpi_005fexecute_005fdft_005fc2r"></a>
98 <a name="index-fftw_005fmpi_005fexecute_005fr2r"></a>
99 <div class="example">
100 <pre class="example">void fftw_mpi_execute_dft(fftw_plan p, fftw_complex *in, fftw_complex *out);
101 void fftw_mpi_execute_dft_r2c(fftw_plan p, double *in, fftw_complex *out);
102 void fftw_mpi_execute_dft_c2r(fftw_plan p, fftw_complex *in, double *out);
103 void fftw_mpi_execute_r2r(fftw_plan p, double *in, double *out);
104 </pre></div>
105
106 <a name="index-alignment-3"></a>
107 <a name="index-fftw_005fmalloc-6"></a>
108 <p>These functions have the same restrictions as those of the serial
109 new-array execute functions. They are <em>always</em> safe to apply to
110 the <em>same</em> <code>in</code> and <code>out</code> arrays that were used to
111 create the plan. They can only be applied to new arrarys if those
112 arrays have the same types, dimensions, in-placeness, and alignment as
113 the original arrays, where the best way to ensure the same alignment
114 is to use FFTW&rsquo;s <code>fftw_malloc</code> and related allocation functions
115 for all arrays (see <a href="Memory-Allocation.html#Memory-Allocation">Memory Allocation</a>). Note that distributed
116 transposes (see <a href="FFTW-MPI-Transposes.html#FFTW-MPI-Transposes">FFTW MPI Transposes</a>) use
117 <code>fftw_mpi_execute_r2r</code>, since they count as rank-zero r2r plans
118 from FFTW&rsquo;s perspective.
119 </p>
120 <hr>
121 <div class="header">
122 <p>
123 Next: <a href="MPI-Data-Distribution-Functions.html#MPI-Data-Distribution-Functions" accesskey="n" rel="next">MPI Data Distribution Functions</a>, Previous: <a href="MPI-Initialization.html#MPI-Initialization" accesskey="p" rel="prev">MPI Initialization</a>, Up: <a href="FFTW-MPI-Reference.html#FFTW-MPI-Reference" accesskey="u" rel="up">FFTW MPI Reference</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
124 </div>
125
126
127
128 </body>
129 </html>