This directory contains a benchmarking and testing program for FFTS. This is a fork of test program used by FFTW.

The `bench' program has a zillion options, because we use it for benchmarking other FFT libraries as well. This file only documents the basic usage of bench.

Usage: bench

where each command is as follows:

-s --speed

Benchmarks the speed of <problem>.

The syntax for problems is [i|o][r|c][f|b]<size>, where

  i/o means in-place or out-of-place.  Out of place is the default.
  r/c means real or complex transform.  Complex is the default.
  f/b means forward or backward transform.  Forward is the default.
  <size> is an arbitrary multidimensional sequence of integers
    separated by the character 'x'.

(The syntax for problems is actually richer, but we do not document
it here.  See the man page for fftw-wisdom for more information.)

Example:

    ib256 : in-place backward complex transform of size 256
    32x64 : out-of-place forward complex 2D transform of 32 rows
            and 64 columns.

-y --verify

Verify that FFTW is computing the correct answer.

The program does not output anything unless an error occurs or verbosity is at least one.

-v

Set verbosity to , or 1 if is omitted. -v2 will output the created plans with fftw_print_plan.

-oestimate -opatient -oexhaustive

Plan with FFTW_ESTIMATE, FFTW_PATIENT, or FFTW_EXHAUSTIVE, respectively. The default is FFTW_MEASURE.

If you benchmark FFTW, please use -opatient.

-onthreads=N

Use N threads, if FFTW was compiled with --enable-threads. N must be a positive integer; the default is N=1.

-onosimd

Disable SIMD instructions (e.g. SSE or SSE2).

-ounaligned

Plan with the FFTW_UNALIGNED flag.

-owisdom

On startup, read wisdom from a file wis.dat in the current directory (if it exists). On completion, write accumulated wisdom to wis.dat (overwriting any existing file of that name).