FFTW FAQ - Section 5
This bug was fixed in FFTW 1.2. There was a bug in
rfftwnd causing an incorrect amount of memory to be allocated. The bug showed
up in Linux with libc-5.3.12 (and nowhere else that we know of).
These bugs were corrected in FFTW 1.2.1. The MPI transforms (really,
just the transpose routines) in FFTW 1.2 had bugs that could cause
errors in some situations.
This bug was fixed in FFTW 1.3. (Older versions of FFTW did
work in single precision, but the test programs didn't--the error
tolerances in the tests were set for double precision.)
This bug was fixed in FFTW 1.3. FFTW 1.2.1 produced the right answer,
but the test program was wrong. For large n, n*n in the naive
transform that we used for comparison overflows 32 bit integer
precision, breaking the test.
We had problems with glibc-2.0.5. The code should work with
This bug was fixed in FFTW 2.0.1. (There was a 32-bit integer
overflow due to a poorly-parenthesized expression.)
There was a bug in the complex transforms that could cause incorrect
results under (hopefully rare) circumstances for lengths with
intermediate-size prime factors (17-97). This bug was fixed in FFTW
This bug was fixed in FFTW 2.1.2. The 2.1/2.1.1 MPI test programs
crashed when using the MPICH implementation of MPI with the
ch_p4 device (TCP/IP); the transforms themselves worked fine.
This bug was fixed in FFTW 2.1.3. The multi-threaded transforms in
previous versions didn't work with AIX's
pthreads implementation, which idiosyncratically creates threads in detached
(non-joinable) mode by default.
This bug was fixed in FFTW 2.1.3. FFTW's complex-transform algorithm
for prime sizes (in versions 2.0 to 2.1.2) had an integer overflow
problem that caused incorrect results for many primes greater than
32768 (on 32-bit machines). (Sizes without large prime factors are
This bug was fixed in FFTW 2.1.4. (By default, Solaris creates
threads that do not parallelize over multiple processors, so one has
to request the proper behavior specifically.)
The FFTW 2.1.3
configure script picked incorrect compiler flags for the
xlc compiler on newer IBM processors. This
is fixed in FFTW 2.1.4.
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Matteo Frigo and Steven G. Johnson / firstname.lastname@example.org
- 04 March 2014
Extracted from FFTW Frequently Asked Questions with Answers,
Copyright © 2014 Matteo Frigo and Massachusetts Institute of Technology.