FFTW 3.3 * Changes since 3.3-beta1: - Compiling OpenMP support (--enable-openmp) now installs a fftw3_omp library, instead of fftw3_threads, so that OpenMP and POSIX threads (--enable-threads) libraries can be built and installed at the same time. - Various minor compilation fixes, corrections of manual typos, and improvements to the benchmark test program. * Add support for the AVX extensions to x86 and x86-64. The AVX code works with 16-byte alignment (as opposed to 32-byte alignment), so there is no ABI change compared to FFTW 3.2.2. * Added Fortran 2003 interface, which should be usable on most modern Fortran compilers (e.g. gfortran) and provides type-checked access to the the C FFTW interface. (The legacy Fortran-77 interface is still included also.) * Added MPI distributed-memory transforms. Compared to 3.3alpha, the major changes in the MPI transforms are: - Fixed some deadlock and crashing bugs. - Added Fortran 2003 interface. - Added new-array execute functions for MPI plans. - Eliminated use of large MPI tags, since Cray MPI requires tags < 2^24; thanks to Jonathan Bentz for the bug report. - Expanded documentation. - 'make check' now runs MPI tests - Some ABI changes - not binary-compatible with 3.3alpha MPI. * Add support for quad-precision __float128 in gcc 4.6 or later (on x86. x86-64, and Itanium). The new routines use the fftwq_ prefix. * Removed support for MIPS paired-single instructions due to lack of available hardware for testing. Users who want this functionality should continue using FFTW 3.2.x. (Note that FFTW 3.3 still works on MIPS; this only concerns special instructions available on some MIPS chips.) * Removed support for the Cell Broadband Engine. Cell users should use FFTW 3.2.x. * New convenience functions fftw_alloc_real and fftw_alloc_complex to use fftw_malloc for real and complex arrays without typecasts or sizeof. * New convenience functions fftw_export_wisdom_to_filename and fftw_import_wisdom_from_filename that export/import wisdom to a file, which don't require you to open/close the file yourself. * New function fftw_cost to return FFTW's internal cost metric for a given plan; thanks to Rhys Ulerich and Nathanael Schaeffer for the suggestion. * The --enable-sse2 configure flag now works in both double and single precision (and is equivalent to --enable-sse in the latter case). * Remove --enable-portable-binary flag: we new produce portable binaries by default. * Remove the automatic detection of native architecture flag for gcc which was introduced in fftw-3.1, since new gcc supports -mtune=native. Remove the --with-gcc-arch flag; if you want to specify a particlar arch to configure, use ./configure CC="gcc -mtune=...". * --with-our-malloc16 configure flag is now renamed --with-our-malloc. * Fixed build problem failure when srand48 declaration is missing; thanks to Ralf Wildenhues for the bug report. * Fixed bug in fftw_set_timelimit: ensure that a negative timelimit is equivalent to no timelimit in all cases. Thanks to William Andrew Burnson for the bug report. * Fixed stack-overflow problem on OpenBSD caused by using alloca with too large a buffer. FFTW 3.2.2 * Improve performance of some copy operations of complex arrays on x86 machines. * Add configure flag to disable alloca(), which is broken in mingw64. * Planning in FFTW_ESTIMATE mode for r2r transforms became slower between fftw-3.1.3 and 3.2. This regression has now been fixed. FFTW 3.2.1 * Performance improvements for some multidimensional r2c/c2r transforms; thanks to Eugene Miloslavsky for his benchmark reports. * Compile with icc on MacOS X, use better icc compiler flags. * Compilation fixes for systems where snprintf is defined as a macro; thanks to Marcus Mae for the bug report. * Fortran documentation now recommends not using dfftw_execute, because of reports of problems with various Fortran compilers; it is better to use dfftw_execute_dft etcetera. * Some documentation clarifications, e.g. of fact that --enable-openmp and --enable-threads are mutually exclusive (thanks to Long To), and document slightly odd behavior of plan_guru_r2r in Fortran (thanks to Alexander Pozdneev). * FAQ was accidentally omitted from 3.2 tarball. * Remove some extraneous (harmless) files accidentally included in a subdirectory of the 3.2 tarball. FFTW 3.2 * Worked around apparent glibc bug that leads to rare hangs when freeing semaphores. * Fixed segfault due to unaligned access in certain obscure problems that use SSE and multiple threads. * MPI transforms not included, as they are still in alpha; the alpha versions of the MPI transforms have been moved to FFTW 3.3alpha1. FFTW 3.2alpha3 * Performance improvements for sizes with factors of 5 and 10. * Documented FFTW_WISDOM_ONLY flag, at the suggestion of Mario Emmenlauer and Phil Dumont. * Port Cell code to SDK2.1 (libspe2), as opposed to the old libspe1 code. * Performance improvements in Cell code for N < 32k, thanks to Jan Wagner for the suggestions. * Cycle counter for Sun x86_64 compiler, and compilation fix in cycle counter for AIX/xlc (thanks to Jeff Haferman for the bug report). * Fixed incorrect type prefix in MPI code that prevented wisdom routines from working in single precision (thanks to Eric A. Borisch for the report). * Added 'make check' for MPI code (which still fails in a couple corner cases, but should be much better than in alpha2). * Many other small fixes. FFTW 3.2alpha2 * Support for the Cell processor, donated by IBM Research; see README.Cell and the Cell section of the manual. * New 64-bit API: for every "plan_guru" function there is a new "plan_guru64" function with the same semantics, but which takes fftw_iodim64 instead of fftw_iodim. fftw_iodim64 is the same as fftw_iodim, except that it takes ptrdiff_t integer types as parameters, which is a 64-bit type on 64-bit machines. This is only useful for specifying very large transforms on 64-bit machines. (Internally, FFTW uses ptrdiff_t everywhere regardless of what API you choose.) * Experimental MPI support. Complex one- and multi-dimensional FFTs, multi-dimensional r2r, multi-dimensional r2c/c2r transforms, and distributed transpose operations, with 1d block distributions. (This is an alpha preview: routines have not been exhaustively tested, documentation is incomplete, and some functionality is missing, e.g. Fortran support.) See mpi/README and also the MPI section of the manual. * Significantly faster r2c/c2r transforms, especially on machines with SIMD. * Rewritten multi-threaded support for better performance by re-using a fixed pool of threads rather than continually respawning and joining (which nowadays is much slower). * Support for MIPS paired-single SIMD instructions, donated by Codesourcery. * FFTW_WISDOM_ONLY planner flag, to create plan only if wisdom is available and return NULL otherwise. * Removed k7 support, which only worked in 32-bit mode and is becoming obsolete. Use --enable-sse instead. * Added --with-g77-wrappers configure option to force inclusion of g77 wrappers, in addition to whatever is needed for the detected Fortran compilers. This is mainly intended for GNU/Linux distros switching to gfortran that wish to include both gfortran and g77 support in FFTW. * In manual, renamed "guru execute" functions to "new-array execute" functions, to reduce confusion with the guru planner interface. (The programming interface is unchanged.) * Add missing __declspec attribute to threads API functions when compiling for Windows; thanks to Robert O. Morris for the bug report. * Fixed missing return value from dfftw_init_threads in Fortran; thanks to Markus Wetzstein for the bug report. FFTW 3.1.1 * Performance improvements for Intel EMT64. * Performance improvements for large-size transforms with SIMD. * Cycle counter support for Intel icc and Visual C++ on x86-64. * In fftw-wisdom tool, replaced obsolete --impatient with --measure. * Fixed compilation failure with AIX/xlc; thanks to Joseph Thomas. * Windows DLL support for Fortran API (added missing __declspec(dllexport)). * SSE/SSE2 code works properly (i.e. disables itself) on older 386 and 486 CPUs lacking a CPUID instruction; thanks to Eric Korpela. FFTW 3.1 * Faster FFTW_ESTIMATE planner. * New (faster) algorithm for REDFT00/RODFT00 (type-I DCT/DST) of odd size. * "4-step" algorithm for faster FFTs of very large sizes (> 2^18). * Faster in-place real-data DFTs (for R2HC and HC2R r2r formats). * Faster in-place non-square transpositions (FFTW uses these internally for in-place FFTs, and you can also perform them explicitly using the guru interface). * Faster prime-size DFTs: implemented Bluestein's algorithm, as well as a zero-padded Rader variant to limit recursive use of Rader's algorithm. * SIMD support for split complex arrays. * Much faster Altivec/VMX performance. * New fftw_set_timelimit function to specify a (rough) upper bound to the planning time (does not affect ESTIMATE mode). * Removed --enable-3dnow support; use --enable-k7 instead. * FMA (fused multiply-add) version is now included in "standard" FFTW, and is enabled with --enable-fma (the default on PowerPC and Itanium). * Automatic detection of native architecture flag for gcc. New configure options: --enable-portable-binary and --with-gcc-arch=, for people distributing compiled binaries of FFTW (see manual). * Automatic detection of Altivec under Linux with gcc 3.4 (so that same binary should work on both Altivec and non-Altivec PowerPCs). * Compiler-specific tweaks/flags/workarounds for gcc 3.4, xlc, HP/UX, Solaris/Intel. * Various documentation clarifications. * 64-bit clean. (Fixes a bug affecting the split guru planner on 64-bit machines, reported by David Necas.) * Fixed Debian bug #259612: inadvertent use of SSE instructions on non-SSE machines (causing a crash) for --enable-sse binaries. * Fixed bug that caused HC2R transforms to destroy the input in certain cases, even if the user specified FFTW_PRESERVE_INPUT. * Fixed bug where wisdom would be lost under rare circumstances, causing excessive planning time. * FAQ notes bug in gcc-3.4.[1-3] that causes FFTW to crash with SSE/SSE2. * Fixed accidentally exported symbol that prohibited simultaneous linking to double/single multithreaded FFTW (thanks to Alessio Massaro). * Support Win32 threads under MinGW (thanks to Alessio Massaro). * Fixed problem with building DLL under Cygwin; thanks to Stephane Fillod. * Fix build failure if no Fortran compiler is found (thanks to Charles Radley for the bug report). * Fixed compilation failure with icc 8.0 and SSE/SSE2. Automatic detection of icc architecture flag (e.g. -xW). * Fixed compilation with OpenMP on AIX (thanks to Greg Bauer). * Fixed compilation failure on x86-64 with gcc (thanks to Orion Poplawski). * Incorporated patch from FreeBSD ports (FreeBSD does not have memalign, but its malloc is 16-byte aligned). * Cycle-counter compilation fixes for Itanium, Alpha, x86-64, Sparc, MacOS (thanks to Matt Boman, John Bowman, and James A. Treacy for reports/fixes). Added x86-64 cycle counter for PGI compilers, courtesy Cristiano Calonaci. * Fix compilation problem in test program due to C99 conflict. * Portability fix for import_system_wisdom with djgpp (thanks to Juan Manuel Guerrero). * Fixed compilation failure on MacOS 10.3 due to getopt conflict. * Work around Visual C++ (version 6/7) bug in SSE compilation; thanks to Eddie Yee for his detailed report. Changes from FFTW 3.1 beta 2: * Several minor compilation fixes. * Eliminate FFTW_TIMELIMIT flag and replace fftw_timelimit global with fftw_set_timelimit function. Make wisdom work with time-limited plans. Changes from FFTW 3.1 beta 1: * Fixes for creating DLLs under Windows; thanks to John Pavel for his feedback. * Fixed more 64-bit problems, thanks to John Pavel for the bug report. * Further speed improvements for Altivec/VMX. * Further speed improvements for non-square transpositions. * Many minor tweaks. FFTW 3.0.1 * Some speed improvements in SIMD code. * --without-cycle-counter option is removed. If no cycle counter is found, then the estimator is always used. A --with-slow-timer option is provided to force the use of lower-resolution timers. * Several fixes for compilation under Visual C++, with help from Stefane Ruel. * Added x86 cycle counter for Visual C++, with help from Morten Nissov. * Added S390 cycle counter, courtesy of James Treacy. * Added missing static keyword that prevented simultaneous linkage of different-precision versions; thanks to Rasmus Larsen for the bug report. * Corrected accidental omission of f77_wisdom.f file; thanks to Alan Watson. * Support -xopenmp flag for SunOS; thanks to John Lou for the bug report. * Compilation with HP/UX cc requires -Wp,-H128000 flag to increase preprocessor limits; thanks to Peter Vouras for the bug report. * Removed non-portable use of 'tempfile' in fftw-wisdom-to-conf script; thanks to Nicolas Decoster for the patch. * Added 'make smallcheck' target in tests/ directory, at the request of James Treacy. FFTW 3.0 Major goals of this release: * Speed: often 20% or more faster than FFTW 2.x, even without SIMD (see below). * Complete rewrite, to make it easier to add new algorithms and transforms. * New API, to support more general semantics. Other enhancements: * SIMD acceleration on supporting CPUs (SSE, SSE2, 3DNow!, and AltiVec). (With special thanks to Franz Franchetti for many experimental prototypes and to Stefan Kral for the vectorizing generator from fftwgel.) * True in-place 1d transforms of large sizes (as well as compressed twiddle tables for additional memory/cache savings). * More arbitrary placement of real & imaginary data, e.g. including interleaved (as in FFTW 2.x) as well as separate real/imag arrays. * Efficient prime-size transforms of real data. * Multidimensional transforms can operate on a subset of a larger matrix, and/or transform selected dimensions of a multidimensional array. * By popular demand, simultaneous linking to double precision (fftw), single precision (fftwf), and long-double precision (fftwl) versions of FFTW is now supported. * Cycle counters (on all modern CPUs) are exploited to speed planning. * Efficient transforms of real even/odd arrays, a.k.a. discrete cosine/sine transforms (types I-IV). (Currently work via pre/post processing of real transforms, ala FFTPACK, so are not optimal.) * DHTs (Discrete Hartley Transforms), again via post-processing of real transforms (and thus suboptimal, for now). * Support for linking to just those parts of FFTW that you need, greatly reducing the size of statically linked programs when only a limited set of transform sizes/types are required. * Canonical global wisdom file (/etc/fftw/wisdom) on Unix, along with a command-line tool (fftw-wisdom) to generate/update it. * Fortran API can be used with both g77 and non-g77 compilers simultaneously. * Multi-threaded version has optional OpenMP support. * Authors' good looks have greatly improved with age. Changes from 3.0beta3: * Separate FMA distribution to better exploit fused multiply-add instructions on PowerPC (and possibly other) architectures. * Performance improvements via some inlining tweaks. * fftw_flops now returns double arguments, not int, to avoid overflows for large sizes. * Workarounds for automake bugs. Changes from 3.0beta2: * The standard REDFT00/RODFT00 (DCT-I/DST-I) algorithm (used in FFTPACK, NR, etcetera) turns out to have poor numerical accuracy, so we replaced it with a slower routine that is more accurate. * The guru planner and execute functions now have two variants, one that takes complex arguments and one that takes separate real/imag pointers. * Execute and planner routines now automatically align the stack on x86, in case the calling program is misaligned. * README file for test program. * Fixed bugs in the combination of SIMD with multi-threaded transforms. * Eliminated internal fftw_threads_init function, which some people were calling accidentally instead of the fftw_init_threads API function. * Check for -openmp flag (Intel C compiler) when --enable-openmp is used. * Support AMD x86-64 SIMD and cycle counter. * Support SSE2 intrinsics in forthcoming gcc 3.3. Changes from 3.0beta1: * Faster in-place 1d transforms of non-power-of-two sizes. * SIMD improvements for in-place, multi-dimensional, and/or non-FFTW_PATIENT transforms. * Added support for hard-coded DCT/DST/DHT codelets of small sizes; the default distribution only includes hard-coded size-8 DCT-II/III, however. * Many minor improvements to the manual. Added section on using the codelet generator to customize and enhance FFTW. * The default 'make check' should now only take a few minutes; for more strenuous tests (which may take a day or so), do 'cd tests; make bigcheck'. * fftw_print_plan is split into fftw_fprint_plan and fftw_print_plan, where the latter uses stdout. * Fixed ability to compile with a C++ compiler. * Fixed support for C99 complex type under glibc. * Fixed problems with alloca under MinGW, AIX. * Workaround for gcc/SPARC bug. * Fixed multi-threaded initialization failure on IRIX due to lack of user-accessible PTHREAD_SCOPE_SYSTEM there.