Development

Development and Benchmark Tools

The SFFT library includes some useful tools for development and benchmarking. To enable them, you have to configure with the --develop flag. Then, the following programs will be built additionally:

sfft-cachemisses

Runs an SFFT on random input. The tool is handy when used with Valgrind’s cachegrind tool. The program includes some instructions to disable valgrind during the input-generation and planning phases. Thus, when the program is analyzed with cachegrind, only the execution phase will be observed.

sfft-instruction_count

Counts the floating point instructions of the specified SFFT call (configured with program parameters, see below) and prints them. When the configuration option --profile was defined, this will also print a profile of the SFFT call.

sfft-profiling

Another program that runs a configurable SFFT call. This program will be compiled with the profiling flags -pg, so that it can be analyzed with the gprof profiling tool.

sfft-timing

A program that accurately measures the runtime of the specified SFFT call. This can be used by benchmark scripts.

sfft-timing_many

Similar to sfft-timing, but measures the parallel execution of multiple SFFT calls.

sfft-verification

This program runs the specified SFFT call and checks that the output is correct. This is useful for testing.

All of the programs run one or many SFFT executions. Random input data is generated automatically. The programs share the following common options:

-n SIZE

The size of the input signal.

-k NUMBER

Number of frequencies generated in the random input signal.

-r REPETITIONS

NOT available for sfft-timing_many. Allows to compute multiple SFFTs. Default: 1. .

-i NUM

Only available for sfft-timing_many. Generate NUM inputs.

-s

Only available for sfft-timing_many. Do not share data between threads. This is slower.

-v VERSION

Selects the algorithm version to use. VERSION is either 1, 2, or 3. ``

-o

When -o is used, FFTW_MEASURE is used for FFTW calls instead of FFTW_ESTIMATE.

-h

Displays help.

An Overview of the Sourcecode

Here is an overview of the purpose of different sourcefiles:

cachemisses.cc, timing.cc, timing_many.cc, instruction_count.cc, verification.cc, simulation.[cc,h]

The main routines and some support code for all development tools are located in these files.

computefourier-1.0-2.0.[cc,h]

Algorithm sourcecode for SFFT v1 and v2.

computefourier-3.0.[cc,h]

Algorithm sourcecode for SFFT v3.

fft.h, common.[cc,h], utils.[cc,h]

Some common code and datatypes.

fftw.[cc,h]

Interface code for FFTW calls.

filters.[cc,h]

The routines to generate filter vectors are in here.

intrinsics.h

Some compiler-specific abstractions to include the correct intrinsics header.

parameters.[cc,h]

Parameter configuration for SFFT v1, v2.

profiling_tools.h

Some preprocessor tools to allow profiling, used when compiled with --profile.

roofline.cc

A program to use with the roofline tool perfplot. Can be built with tools/build-roofline.sh.

sfft.[cc,h]

User interface code and basic datastructures. The headerfile is to be included by users.

timer.[cc,h]

Functions for accurate timing, used by sfft-timing.

flopcount/

Files in this directory are used to count floating point operations, used by sfft-instruction_count.