Instructions to install GMP-ECM:
0) you first need to install the GNU MP (GMP) library.
GNU MP is available from <http://gmplib.org/>.
Remark: GNU MP is already installed in most Linux distributions.
However it is often an old version, moreover without processor-specific
optimizations. If you care about efficiency, be sure to install the
latest version of GNU MP (6.1.0 as of February 2016), and to compile it
for your particular processor.
Warning: make sure you have only one version of GMP installed on your
system at a given time. Frequently, after compiling GMP from source
and installing it without removing the distribution's GMP package,
later attempts to build software that uses GMP find the GMP header
file from the distribution's GMP package and the library from the
newly compiled GMP (or vice versa). GMP-ECM tries to detect this by
comparing the version number from header and library; if this test
fails, you should remove the obsolete GMP installation.
1) check your configuration with:
The configure script accepts several options (see ./configure --help).
In particular you can specify the GMP installation directory with:
$ ./configure --with-gmp=<gmpdir>
where <gmpdir>/include contains the header file gmp.h, and <gmpdir>/lib
contains the static or dynamic libraries (libgmp.a, libgmp.so, libgmp.lib).
To compile the GMP-ECM library as a shared library, use the
--enable-shared parameter for ./configure. Building a shared library is
disabled by default.
Note: the configure script will first search for a static GMP library, which
makes GMP-ECM more efficient. When only a dynamic library is available, make
sure to correctly set your dynamic libraries search path (LD_LIBRARY_PATH
on Unix systems), otherwise the configure script may fail.
Warning: it is recommended to use the same compiler and options as those
used to compile GMP, otherwise the compilation may fail, or you may get
poor performance. In the GMP build directory, simply type:
$ egrep -w '(CC|CFLAGS)' config.log
to see which compiler and options were used to build GMP. For example
on a Sparc v9 you may have to type:
$ ./configure CC=cc CFLAGS="-fast -fns=no -fsimple=1 -xarch=v9"
Note 2: On x86, x86-64, and 64 bit PowerPC systems, using GMP-ECM's
own modular multiplication code usually gives better performance than
the GMP-based functions. On these systems, configure enables it by
default. If the system is not identified correctly, you can enable
it by adding the command line parameter "--enable-asm-redc" to
configure. To disable it, add "--disable-asm-redc".
On 32-bit x86 systems that have SSE2 (e.g., Pentium 4, some Celeron,
some Sempron, Via C7), use of SSE2 instructions in stage 2 of P-1, P+1,
and ECM is enabled by default. You can enable it manually by adding the
command line parameter "--enable-sse2" and disable it by adding
"--disable-sse2" to ./configure. The SSE2 code is not used in 64-bit
builds, regardless of these parameters.
Note 3: If you want to use George Woltman's GWNUM library for speeding up
factoring base 2 numbers, obtain the source file from
<ftp://mersenne.org/gimps/> (on December 2011 the latest source is
source272.zip), build the gwnum library for your operating system, then use
$ ./configure --with-gwnum=<gwnum directory>
The directory must include the gwnum.a or gwnum.lib file as well as
gwnum.h and related header files. The source file of the gwnum library
is available at <http://www.mersenne.org/source.htm>.
2) compile the program with:
This will create the 'libecm.a' library, the 'libecm.so' shared
library if --enable-shared was used, the 'ecm' binary file,
the 'ecmfactor' binary file (sample use of libecm.a), and 'tune',
a tuning program.
3) to check that the program works correctly, type:
$ make check
This will run several tests for P+1, P-1, ECM. These tests take a few
minutes. It should normally end with "All ECM tests are ok."
4) (optional) to tune GMP-ECM, simply type:
$ make ecm-params; make
See also README ("How to get the best of GMP-ECM?"). Note: if your machine
has not enough memory for the tune program, you can run it manually with
./tune -max_log2_len 16 for example (the default is 18).
5) (optional) you can then install the ecm binary and its man page:
$ make install
By default, installation will be done in /usr/local.
You can change with the --prefix option of configure at step 1:
$ ./configure --prefix=<my_installation_directory>
The ecm binary will go in <my_installation_directory>/bin,
its man page in <my_installation_directory>/share/man/man1,
the ecm library in <my_installation_directory>/lib,
and the corresponding header file in <my_installation_directory>/include.
You can also do "make uninstall" to remove those files.
6) If you like GMP-ECM, please help us factoring Cunningham numbers. First
download "cunningham.in" on <http://www.loria.fr/~zimmerma/ecmnet/>, then
perform one ecm test with B1=110e6 on each number of this file:
$ ./ecm 110e6 < cunningham.in > cunningham.out &
If you find any factor (grep found cunningham.out), please submit it
using the report form on <http://www.loria.fr/~zimmerma/ecmnet/>.
To install GMP-ECM with support of NVIDIA Graphics Cards: see README.gpu
* [reported by Sam Rawlins] with MinGW under Windows XP (32-bit), the
compilation fails in spv.c. A fix seems to add -msse2 to CFLAGS.
* GCC 4.4 might miscompile GMP-ECM on Sparc,
see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45559 for more details.
The problem is due in fact to a bug in the Linux kernel. A fix is to use
-mcpu=v8 with GCC 4.4 if the bug occurs.
For Windows users:
Windows users have two options for building GMP-ECM: (a) the use of a
number of Unix on Windows environments, or (b) the use of Microsoft
Visual Studio C/C++ 2008. The former is described here while the latter
is described in the readme.txt file within the build.vc10 subdirectory.
(a) For Windows users with a Unix-like environment:
Before you can compile GMP-ECM, you will need a compiler. Several suitable
compilers are freely available, for example as part of MinGW, CygWin and
Microsoft's Services for Unix (SFU). We recommend MinGW as it is a smaller
download than the others and generates binaries that run on any Windows
system, even if they don't have MinGW installed themselves.
Step-by-step instructions, courtesy of Jes Hansen:
1) Download the current MinGW from
and MSYS from http://prdownloads.sf.net/mingw/MSYS-1.0.10.exe?download
2) Create a folder, for example C:\GNU, and install MinGW (execute the
MinGW-3.1.0-1.exe file) into C:\GNU\MinGW
3) Install MSYS (execute the MSYS-1.0.10.exe file) into C:\GNU\msys
Now you get an icon on the desktop where you can start the MinSys. Do
this, because is creates your home folder. Then exit it again.
4) Download the latest version of GMP in .tar.gz format from
http://gmplib.org/ and place it in your newly created home folder.
The home folder is in C:\GNU\msys\home and has the same name as your
Windows login name.
5) Download GMP-ECM (if you do not have it already) from
http://ecm.gforge.inria.fr/ and place it in your home folder as well.
6) Start the MinSys up again from the desktop and type
tar -xvzf gmp-6.1.0.tar.gz
7) You are back in your home directory. Now type
tar -xvzf ecm-x.y.z.tar.gz
8) Four executables should have appeared. The main application is ecm.exe,
which can be run from the Windows command line.
In case of a problem, report it to us, with:
- the output of the config.log file
- the versions of GMP-ECM and GMP used (first output line), for example:
GMP-ECM x.y.z [configured with GMP u.v.w, --enable-asm-redc] [P+1]
- the detailed input enabling us to reproduce the problem, for example:
$ echo 328006342451 | ./ecm -pp1 -x0 5 120 7043
- the output you get.
Then send your bug report at <email@example.com>.
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