cannam@127: <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
cannam@127: <html>
cannam@127: <!-- This manual is for FFTW
cannam@127: (version 3.3.5, 30 July 2016).
cannam@127:
cannam@127: Copyright (C) 2003 Matteo Frigo.
cannam@127:
cannam@127: Copyright (C) 2003 Massachusetts Institute of Technology.
cannam@127:
cannam@127: Permission is granted to make and distribute verbatim copies of this
cannam@127: manual provided the copyright notice and this permission notice are
cannam@127: preserved on all copies.
cannam@127:
cannam@127: Permission is granted to copy and distribute modified versions of this
cannam@127: manual under the conditions for verbatim copying, provided that the
cannam@127: entire resulting derived work is distributed under the terms of a
cannam@127: permission notice identical to this one.
cannam@127:
cannam@127: Permission is granted to copy and distribute translations of this manual
cannam@127: into another language, under the above conditions for modified versions,
cannam@127: except that this permission notice may be stated in a translation
cannam@127: approved by the Free Software Foundation. -->
cannam@127: <!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
cannam@127: <head>
cannam@127: <title>FFTW 3.3.5: Using MPI Plans</title>
cannam@127:
cannam@127: <meta name="description" content="FFTW 3.3.5: Using MPI Plans">
cannam@127: <meta name="keywords" content="FFTW 3.3.5: Using MPI Plans">
cannam@127: <meta name="resource-type" content="document">
cannam@127: <meta name="distribution" content="global">
cannam@127: <meta name="Generator" content="makeinfo">
cannam@127: <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
cannam@127: <link href="index.html#Top" rel="start" title="Top">
cannam@127: <link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index">
cannam@127: <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
cannam@127: <link href="FFTW-MPI-Reference.html#FFTW-MPI-Reference" rel="up" title="FFTW MPI Reference">
cannam@127: <link href="MPI-Data-Distribution-Functions.html#MPI-Data-Distribution-Functions" rel="next" title="MPI Data Distribution Functions">
cannam@127: <link href="MPI-Initialization.html#MPI-Initialization" rel="prev" title="MPI Initialization">
cannam@127: <style type="text/css">
cannam@127: <!--
cannam@127: a.summary-letter {text-decoration: none}
cannam@127: blockquote.smallquotation {font-size: smaller}
cannam@127: div.display {margin-left: 3.2em}
cannam@127: div.example {margin-left: 3.2em}
cannam@127: div.indentedblock {margin-left: 3.2em}
cannam@127: div.lisp {margin-left: 3.2em}
cannam@127: div.smalldisplay {margin-left: 3.2em}
cannam@127: div.smallexample {margin-left: 3.2em}
cannam@127: div.smallindentedblock {margin-left: 3.2em; font-size: smaller}
cannam@127: div.smalllisp {margin-left: 3.2em}
cannam@127: kbd {font-style:oblique}
cannam@127: pre.display {font-family: inherit}
cannam@127: pre.format {font-family: inherit}
cannam@127: pre.menu-comment {font-family: serif}
cannam@127: pre.menu-preformatted {font-family: serif}
cannam@127: pre.smalldisplay {font-family: inherit; font-size: smaller}
cannam@127: pre.smallexample {font-size: smaller}
cannam@127: pre.smallformat {font-family: inherit; font-size: smaller}
cannam@127: pre.smalllisp {font-size: smaller}
cannam@127: span.nocodebreak {white-space:nowrap}
cannam@127: span.nolinebreak {white-space:nowrap}
cannam@127: span.roman {font-family:serif; font-weight:normal}
cannam@127: span.sansserif {font-family:sans-serif; font-weight:normal}
cannam@127: ul.no-bullet {list-style: none}
cannam@127: -->
cannam@127: </style>
cannam@127:
cannam@127:
cannam@127: </head>
cannam@127:
cannam@127: <body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
cannam@127: <a name="Using-MPI-Plans"></a>
cannam@127: <div class="header">
cannam@127: <p>
cannam@127: 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> [<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>
cannam@127: </div>
cannam@127: <hr>
cannam@127: <a name="Using-MPI-Plans-1"></a>
cannam@127: <h4 class="subsection">6.12.3 Using MPI Plans</h4>
cannam@127:
cannam@127: <p>Once an MPI plan is created, you can execute and destroy it using
cannam@127: <code>fftw_execute</code>, <code>fftw_destroy_plan</code>, and the other functions
cannam@127: in the serial interface that operate on generic plans (see <a href="Using-Plans.html#Using-Plans">Using Plans</a>).
cannam@127: </p>
cannam@127: <a name="index-collective-function-3"></a>
cannam@127: <a name="index-MPI-communicator-1"></a>
cannam@127: <p>The <code>fftw_execute</code> and <code>fftw_destroy_plan</code> functions, applied to
cannam@127: MPI plans, are <em>collective</em> calls: they must be called for all processes
cannam@127: in the communicator that was used to create the plan.
cannam@127: </p>
cannam@127: <a name="index-new_002darray-execution-1"></a>
cannam@127: <p>You must <em>not</em> use the serial new-array plan-execution functions
cannam@127: <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
cannam@127: problem type, and there are specific new-array execute functions for MPI plans:
cannam@127: </p>
cannam@127: <a name="index-fftw_005fmpi_005fexecute_005fdft"></a>
cannam@127: <a name="index-fftw_005fmpi_005fexecute_005fdft_005fr2c"></a>
cannam@127: <a name="index-fftw_005fmpi_005fexecute_005fdft_005fc2r"></a>
cannam@127: <a name="index-fftw_005fmpi_005fexecute_005fr2r"></a>
cannam@127: <div class="example">
cannam@127: <pre class="example">void fftw_mpi_execute_dft(fftw_plan p, fftw_complex *in, fftw_complex *out);
cannam@127: void fftw_mpi_execute_dft_r2c(fftw_plan p, double *in, fftw_complex *out);
cannam@127: void fftw_mpi_execute_dft_c2r(fftw_plan p, fftw_complex *in, double *out);
cannam@127: void fftw_mpi_execute_r2r(fftw_plan p, double *in, double *out);
cannam@127: </pre></div>
cannam@127:
cannam@127: <a name="index-alignment-3"></a>
cannam@127: <a name="index-fftw_005fmalloc-6"></a>
cannam@127: <p>These functions have the same restrictions as those of the serial
cannam@127: new-array execute functions. They are <em>always</em> safe to apply to
cannam@127: the <em>same</em> <code>in</code> and <code>out</code> arrays that were used to
cannam@127: create the plan. They can only be applied to new arrarys if those
cannam@127: arrays have the same types, dimensions, in-placeness, and alignment as
cannam@127: the original arrays, where the best way to ensure the same alignment
cannam@127: is to use FFTW’s <code>fftw_malloc</code> and related allocation functions
cannam@127: for all arrays (see <a href="Memory-Allocation.html#Memory-Allocation">Memory Allocation</a>). Note that distributed
cannam@127: transposes (see <a href="FFTW-MPI-Transposes.html#FFTW-MPI-Transposes">FFTW MPI Transposes</a>) use
cannam@127: <code>fftw_mpi_execute_r2r</code>, since they count as rank-zero r2r plans
cannam@127: from FFTW’s perspective.
cannam@127: </p>
cannam@127: <hr>
cannam@127: <div class="header">
cannam@127: <p>
cannam@127: 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> [<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>
cannam@127: </div>
cannam@127:
cannam@127:
cannam@127:
cannam@127: </body>
cannam@127: </html>