Copyright 2000-2023 Free Software Foundation, Inc. Contributed by the AriC and Caramba projects, INRIA. This file is part of the GNU MPFR Library. The GNU MPFR Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. The GNU MPFR Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. ############################################################################## Changes from versions 4.1.* to version 4.2.0: - The "fondue savoyarde" release. - Binary compatible with MPFR 4.0.* and 4.1.*, though some minor changes in the behavior of the formatted output functions may be visible, regarded as underspecified behavior or bug fixes (see below). - New functions mpfr_cosu, mpfr_sinu, mpfr_tanu, mpfr_acosu, mpfr_asinu, mpfr_atanu and mpfr_atan2u. - New functions mpfr_cospi, mpfr_sinpi, mpfr_tanpi, mpfr_acospi, mpfr_asinpi, mpfr_atanpi and mpfr_atan2pi. - New functions mpfr_log2p1, mpfr_log10p1, mpfr_exp2m1, mpfr_exp10m1 and mpfr_compound_si. - New functions mpfr_fmod_ui, mpfr_powr, mpfr_pown, mpfr_pow_uj, mpfr_pow_sj and mpfr_rootn_si (mpfr_pown is actually a macro defined as an alias for mpfr_pow_sj). - Bug fixes. In particular, for the formatted output functions (mpfr_printf, etc.), the case where the precision consists only of a period has been fixed to be like ".0" as specified in the ISO C standard, and the manual has been corrected and clarified. The macros of the custom interface have also been fixed: they now behave like functions (except a minor limitation for mpfr_custom_init_set). Changes from versions 4.0.* to version 4.1.0: - The "épinards à la crème" release. - Binary compatible with MPFR 4.0.*, though some minor changes in the behavior of the formatted output functions may be visible, regarded as underspecified behavior or bug fixes (see below). - New --enable-formally-proven-code configure option, to use (when available) formally proven code. - Improved __GMP_CC and __GMP_CFLAGS retrieval (in particular for MS Windows). - Option -pedantic is now always removed from __GMP_CFLAGS (see INSTALL). - Changed __float128 to the type _Float128 specified in ISO/IEC TS 18661. __float128 is used as a fallback if _Float128 is not supported. - New function mpfr_get_str_ndigits about conversion to a string of digits. - New function mpfr_dot for the dot product (incomplete, experimental). - New functions mpfr_get_decimal128 and mpfr_set_decimal128 (available only when MPFR has been built with decimal float support). - New function mpfr_cmpabs_ui. - New function mpfr_total_order_p for the IEEE 754 totalOrder predicate. - The mpfr_out_str function now accepts bases from -2 to -36, in order to follow mpfr_get_str and GMP's mpf_out_str functions (these cases gave an assertion failure, as with other invalid bases). - Shared caches: cleanup; really detect lock failures (abort in this case). - The behavior of the formatted output functions (mpfr_printf, etc.) with an empty precision field has improved: trailing zeros are kept in a way similar to the formatted output functions from C. - Improved mpfr_add and mpfr_sub when all operands have a precision equal to twice the number of bits per word, e.g., 128 bits on a 64-bit platform. - Optimized the tuning parameters for various architectures. - Improved test coverage to 98.6% of code for x86_64. - Bug fixes. - MPFR manual: corrected/completed the mpfr_get_str description in order to follow the historical behavior and GMP's mpf_get_str function. - New: optional "make check-exported-symbols", mainly for the MPFR developers and binary distributions, to check that MPFR does not define symbols with a GMP reserved prefix (experimental). - Mini-gmp support: replaced --enable-mini-gmp configure option by --with-mini-gmp (still experimental, read doc/mini-gmp). - A GCC bug on Sparc (present at least in old GCC 4.5.3 and 5.5.0 versions), which made several tests fail when TLS was enabled, is now avoided in the tests. The MPFR library itself was not affected and normal code using the MPFR library should not be affected either. Users and distributions that disabled TLS just because of the test failures can safely re-enable it. Changes from versions 3.1.* to version 4.0.0: - The "dinde aux marrons" release. - MPFR now depends on GMP 5.0+ instead of 4.1+. - API change: Applications that call GMP's mp_set_memory_functions function to change the allocators must first call the new function mpfr_mp_memory_cleanup in all threads where MPFR is potentially used; this new function is currently equivalent to mpfr_free_cache. The reason is that the way memory allocation is done by MPFR has changed (again), so that the current GMP allocators are used (since for some applications, the old allocators may become invalid). Note: Freeing the caches like this might have a performance impact on some particular applications; if this is an issue, this could be handled for a future MPFR version. - Mini-gmp support via the --enable-mini-gmp configure option (experimental). - The minimum precision MPFR_PREC_MIN is now 1, with rounding defined as in the errata of IEEE 754-2008 and in the following IEEE 754 revision (ties rounded away from zero). - Shared caches for multithreaded applications. New function mpfr_free_cache2. - Partial support of MPFR_RNDF (faithful rounding). - New functions: mpfr_fpif_export and mpfr_fpif_import to export and import numbers in a floating-point interchange format, independent both on the number of bits per word and on the endianness. - New function mpfr_fmodquo to return the low bits of the quotient corresponding to mpfr_fmod. - New functions mpfr_flags_clear, mpfr_flags_set, mpfr_flags_test, mpfr_flags_save and mpfr_flags_restore to operate on groups of flags. - New functions mpfr_set_float128 and mpfr_get_float128 to convert from/to the __float128 type (requires --enable-float128 and compiler support). - New functions mpfr_buildopt_float128_p and mpfr_buildopt_sharedcache_p. - New functions mpfr_rint_roundeven and mpfr_roundeven, completing the other similar round-to-integer functions for rounding to nearest with the even-rounding rule. - New macro mpfr_round_nearest_away to add partial emulation of the rounding to nearest-away (as defined in IEEE 754-2008). - New functions mpfr_nrandom and mpfr_erandom to generate random numbers following normal and exponential distributions respectively. - New functions mpfr_fmma and mpfr_fmms to compute a*b+c*d and a*b-c*d. - New function mpfr_rootn_ui, similar to mpfr_root, but agreeing with the rootn function of the IEEE 754-2008 standard. - New functions mpfr_log_ui to compute the logarithm of an integer, mpfr_gamma_inc for the incomplete Gamma function. - New function mpfr_beta for the Beta function (incomplete, experimental). - New function mpfr_get_q to convert a floating-point number into rational. - The mpfr_dump function is now described in the manual; its output format has slightly changed. - The mpfr_eint function now returns the value of the E1/eint1 function for negative argument. - The behavior of the mpfr_set_exp function changed, as it could easily yield undefined behavior in some cases (this modifies both the API and the ABI). - In function mpfr_urandom, the next random state no longer depends on the current exponent range and the rounding mode. The exceptions due to the rounding of the random number are now correctly generated, following the uniform distribution. - Functions mpfr_grandom and mpfr_root are deprecated and will be removed in a future release. - Complete rewrite of function mpfr_sum, which now works in all cases (the old one could take all the memory and/or crash with inputs of different magnitudes in case of huge cancellation or table maker's dilemma). The sign of an exact zero result is now specified, and the return value is now the usual ternary value. Note that the position of "const" in the mpfr_sum prototype has been fixed (the manual was correct); user code should not be affected. - Old, deprecated macros mpfr_add_one_ulp and mpfr_sub_one_ulp removed. The mpfr_next* functions should be used instead. - Internally, improved caching: a minimum of 10% increase of the precision is guaranteed to avoid too many recomputations. - Added internal small-precision mpz_t pool, which aims to avoid the overhead of memory allocation, in particular. New function mpfr_free_pool. - Added configure option --enable-assert=none to avoid checking any assertion. - The --enable-decimal-float configure option no longer requires --with-gmp-build, and support for decimal floats is now automatically detected by default (similarly for support for __float128). - Updated tuning parameters. - Better support for Automake 1.13+ (now used to generate the tarball). - Dropped K&R C compatibility. - Improved MPFR manual. - New MPFRbench program (see the tools/bench directory). - Major speedup in mpfr_add, mpfr_sub, mpfr_mul, mpfr_div and mpfr_sqrt when all operands have the same precision and this precision is less than twice the number of bits per word, e.g., less than 128 on a 64-bit computer. - Speedup by a factor of almost 2 in the double <--> mpfr conversions (mpfr_set_d and mpfr_get_d). - Speedup in mpfr_log1p and mpfr_atanh for small arguments. - Speedup in the mpfr_const_euler function (contributed by Fredrik Johansson), in the computation of Bernoulli numbers (used in mpfr_gamma, mpfr_li2, mpfr_digamma, mpfr_lngamma and mpfr_lgamma), in mpfr_div, in mpfr_fma and mpfr_fms. - Test coverage: 96.3% lines of code. - Bug fixes. In particular: a speed improvement when the --enable-assert or --enable-assert=full configure option is used with GCC; mpfr_get_str now sets the NaN flag on NaN input and the inexact flag when the conversion is inexact. For a full list, see https://www.mpfr.org/mpfr-3.1.6/#fixed and the same section for any previous 3.1.x version (follow the links in the "Changes..." sections). - Microsoft Windows: Added support for thread-safe DLL (shared library). Tested with MinGW, ICC and MSVC. - Limited pkg-config support. - Autotools: Under Linux, make sure that the old dtags (when supported) are used if LD_LIBRARY_PATH is defined; otherwise "make check" would check an installed, compatible MPFR library found in LD_LIBRARY_PATH instead of the one that has been built with "make". - New: optional "make check-gmp-symbols", mainly for binary distributions, to check that MPFR does not use GMP internal symbols (experimental). Changes from versions 3.0.* to version 3.1.0: - The "canard à l'orange" release. - The MPFR source has been reorganized. - Dropped ansi2knr support. - TLS support is now detected automatically. If TLS is supported, MPFR is built as thread safe by default. To disable TLS explicitly, configure MPFR with --disable-thread-safe. - New --enable-gmp-internals configure option to use GMP's undocumented functions (not from the public API). Note that library versioning is not guaranteed to work if this option is used. - The mpfr_urandom and mpfr_urandomb functions now return identical values on processors with different word size (assuming the same random seed, and since the GMP random generator does not depend itself on the word size, cf https://gmplib.org/list-archives/gmp-devel/2010-September/001642.html). - The mpfr_add_one_ulp and mpfr_sub_one_ulp macros (which are obsolete and no more documented) will be removed in a future release. - Speed improvement for the mpfr_sqr and mpfr_div functions using Mulders' algorithm. As a consequence, other functions using those routines are also faster. - Much faster formatted output (mpfr_printf, etc.) with %Rg and similar. - The --with-gmp-build configure option can now be used when the GMP source directory and the GMP build directory are different (without having to copy header files manually as before). - New functions mpfr_buildopt_gmpinternals_p, mpfr_buildopt_tune_case, mpfr_frexp, mpfr_grandom and mpfr_z_sub. - New divide-by-zero exception (flag) and associated functions. - The mpfr.h header can be included several times, while still supporting optional functions (see Section "Headers and Libraries" in the manual). - Updated tuning parameters. - Improved MPFR manual. - MPFR tests: libtool no longer generates wrapper scripts with "make check" (so that running the tests under valgrind or gdb is easier). - Internal change: the logging mechanism has been improved. - Test coverage: 95.2% lines of code. - Bug fixes, in particular a huge inefficiency in mpfr_exp (when the target precision is less than MPFR_EXP_THRESHOLD) on hard-to-round cases, which can take several minutes. Note: The mpfr_subnormalize implementation up to MPFR 3.0.0 did not change the flags. In particular, it did not follow the generic rule concerning the inexact flag (and no special behavior was specified). The case of the underflow flag was more a lack of specification. Changes from versions 2.4.* to version 3.0.0: - The "boudin aux pommes" release. - MPFR 3.0.0 is binary incompatible with previous versions but (almost) API compatible. More precisely the obsolete functions mpfr_random and mpfr_random2 have been removed, the meaning of the return type of the function mpfr_get_f has changed, and the return type of the function mpfr_get_z is now int instead of void. In practice, this should not break any existing code. - MPFR is now distributed under the GNU Lesser General Public License version 3 or later (LGPL v3+). - Rounding modes GMP_RNDx are now MPFR_RNDx (GMP_RNDx kept for compatibility). - A new rounding mode (MPFR_RNDA) is available to round away from zero. - The rounding mode type is now mpfr_rnd_t (as in previous versions, both mpfr_rnd_t and mp_rnd_t are accepted, but mp_rnd_t may be removed in the future). - The precision type is now mpfr_prec_t (as in previous versions, both mpfr_prec_t and mp_prec_t are accepted, but mp_prec_t may be removed in the future) and it is now signed (it was unsigned in MPFR 2.*, but this was not documented). In practice, this change should not affect existing code that assumed nothing on the precision type. - MPFR now has its own exponent type mpfr_exp_t, which is currently the same as GMP's mp_exp_t. - Functions mpfr_random and mpfr_random2 have been removed. - mpfr_get_f and mpfr_get_z now return a ternary value. - mpfr_strtofr now accepts bases from 37 to 62. - mpfr_custom_get_mantissa was renamed to mpfr_custom_get_significand (mpfr_custom_get_mantissa is still available via a #define). - Functions mpfr_get_si, mpfr_get_ui, mpfr_get_sj, mpfr_get_uj, mpfr_get_z and mpfr_get_z_2exp no longer have cases with undefined behavior; in these cases, the behavior is now specified, and in particular, the erange flag is set. - New functions mpfr_buildopt_tls_p and mpfr_buildopt_decimal_p giving information about options used at MPFR build time. - New function mpfr_regular_p. - New function mpfr_set_zero. - New function mpfr_digamma. - New function mpfr_ai (incomplete, experimental). - New functions mpfr_set_flt and mpfr_get_flt to convert from/to the float type. - New function mpfr_urandom. - New function mpfr_set_z_2exp (companion to mpfr_get_z_2exp, which was renamed from mpfr_get_z_exp in previous versions). - New function mpfr_min_prec. - Speed improvement for large precisions in the trigonometric functions (mpfr_sin, mpfr_cos, mpfr_tan, mpfr_sin_cos): speedup of about 2.5 for 10^5 digits, of about 5 for 10^6 digits. - Speed improvement for large precisions of the inverse trigonometric functions (arcsin, arccos, arctan): about 2 for 10^3 digits, up to 2.7 for 10^6 digits. - Some documentation files are installed in $docdir. - The detection of a GMP build directory (more precisely, the internal header files of GMP) was previously done separately from the use of the --with-gmp-build configure option. This was not consistent with the documentation and with other parts of the configure script. So, as of MPFR 3.0.0, the internal header files of GMP are now used if and only if the --with-gmp-build configure option is given. - The configure script recognizes some extra "long double" formats (double big endian, double little endian, double-double big endian). - MPFR manual: added "API Compatibility" section. - Test coverage: 97.1% lines of code. - Bug fixes. Changes from versions 2.3.* to version 2.4.0: - The "andouillette sauce moutarde" release. - MPFR is now a GNU package. - Changes in the behavior of mpfr_strtofr and in its documentation concerning particular cases where the code and the documentation did not match; this change is also present in MPFR 2.3.1. - Behavior of mpfr_check_range changed: if the value is an inexact infinity, the overflow flag is set (in case it was lost); this change is also present in MPFR 2.3.2. - Function mpfr_init_gmp_rand (only defined when building MPFR without the --with-gmp-build configure option) is no longer defined at all. This function was private and not documented, and was used only in the MPFR test suite. User code that calls it is regarded as broken and may fail as a consequence. Running the old test suite against MPFR 2.4.0 may also fail. - New functions: * between a MPFR number and a double: mpfr_add_d, mpfr_sub_d, mpfr_d_sub, mpfr_mul_d, mpfr_div_d, mpfr_d_div, * formatted input/output: mpfr_printf, mpfr_fprintf, mpfr_vprintf, mpfr_vfprintf, mpfr_sprintf, mpfr_snprintf, mpfr_vsprintf, mpfr_vsnprintf, mpfr_asprintf, mpfr_vasprintf. * mpfr_sinh_cosh, mpfr_li2, mpfr_modf, mpfr_fmod, mpfr_rec_sqrt. - Configure test for TLS support. - Get default $CC and $CFLAGS from gmp.h (__GMP_CC / __GMP_CFLAGS, which are available as of GMP 4.2.3). - Documented the fact that mpfr_random and mpfr_random2 will be suppressed in the next release, and that the specification of mpfr_eq may change in the next release (for compatibility with the mpf layer of GMP). - Test coverage: 96.7% lines of code. - Bug fixes. Changes from versions 2.2.* to version 2.3.0: - The mpfr.info file is now installed in the share subdirectory (as required by the Filesystem Hierarchy Standard); see output of "./configure --help". - The shared library is now enabled by default. If the MPFR build fails on your platform, try the --disable-shared configure option to disable the shared library. - Thread-safe support with Microsoft Visual compiler. - New functions mpfr_j0, mpfr_j1, mpfr_jn, mpfr_y0, mpfr_y1, mpfr_yn, mpfr_lgamma, mpfr_remainder, mpfr_remquo, mpfr_fms, mpfr_signbit, mpfr_setsign, mpfr_copysign, mpfr_get_patches. - Functions mpfr_sin, mpfr_cos and mpfr_sin_cos improved (argument reduction). - More detailed MPFR manual. - Improved tests (make check). - Bug fixes. Changes from versions 2.1.* to version 2.2.0: - Bug fixes. - new functions mpfr_set_overflow, mpfr_set_underflow, mpfr_set_inexflag, mpfr_set_erangeflag, mpfr_set_nanflag, mpfr_erfc, mpfr_atan2, mpfr_pow_z, mpfr_subnormalize, mpfr_const_catalan, mpfr_sec, mpfr_csc, mpfr_cot, mpfr_root, mpfr_eint, mpfr_get_f, mpfr_sech, mpfr_csch, mpfr_coth, mpfr_lngamma. - new macro: MPFR_VERSION_STRING - Remove the exported MPFR variables from mpfr.h to mpfr-impl.h. (They were undocumented, so programs which respect the API still work). - Grep CC and CFLAGS from GMP Makefile if possible. - Math functions are faster (both average and worst cases). - Better support for long double. - Shared library of MPFR. - Binary compatible with previous versions if you do not use undocumented features. - Thread safe (if built with --enable-thread-safe). - Logging facility. - Change in the semantics of mpfr_out_str/mpfr_get_str when n_digits=0. - Better locale support. Changes from version 2.1.0 to version 2.1.1: - Better way to detect the GMP library. - Bug fixes. Changes from version 2.0.3 to version 2.1.0: - Bug fixes. - new functions mpfr_strtofr, mpfr_set_uj, mpfr_set_sj, mpfr_set_ui_2exp, mpfr_set_si_2exp, mpfr_set_sj_2exp, mpfr_set_uj_2exp, mpfr_get_uj, mpfr_get_sj, mpfr_get_z, mpfr_free_str, mpfr_si_sub, mpfr_sub_si, mpfr_mul_si, mpfr_si_div, mpfr_div_si, mpfr_sqr, mpfr_cmp_z, mpfr_cmp_q, mpfr_zero_p, mpfr_free_cache, mpfr_sum, mpfr_get_version, mpfr_get_default_rounding_mode, mpfr_get_emin_min, mpfr_get_emin_max, mpfr_get_emax_min, mpfr_get_emax_max, mpfr_inits, mpfr_inits2, mpfr_clears, mpfr_fits_intmax_p, mpfr_fits_uintmax_p, mpfr_clear_erangeflag, mpfr_erangeflag_p, mpfr_rint_round, mpfr_rint_trunc, mpfr_rint_ceil, mpfr_rint_floor. - new macros MPFR_DECL_INIT, MPFR_VERSION, MPFR_VERSION_NUM, MPFR_VERSION_MAJOR, MPFR_VERSION_MINOR, MPFR_VERSION_PATCHLEVEL. - improved documentation. - improved configure. - improved portability (library and test suite). - It handles correctly non IEEE-754 double. - GMP internal files are not needed to install MPFR. - It is faster with low-precision floating point. - New global flag: ERANGE_FLAG. - Binary incompatible with previous versions, but API compatible. - mpfr_set_str doesn't allow anymore "@NAN@garbagechar" and "@INF@garbagechar", allows base 0 (detection of the base), prefix (0x, 0b), leading whitespace. Changes from version 2.0.2 to version 2.0.3: - Bug fixes. - Support GMP as a shared library (not fully tested). Changes from version 2.0.1 to version 2.0.2: - many bug fixes and other improvements. - new functions mpfr_prec_round (replaces mpfr_round_prec), mpfr_get_exp, mpfr_set_exp, mpfr_get_ld, mpfr_set_ld, mpfr_get_d_2exp, mpfr_get_si, mpfr_get_ui, mpfr_nextabove, mpfr_nextbelow, mpfr_nexttoward, mpfr_frac, mpfr_fits_*, mpfr_cmp_d, mpfr_cmpabs, mpfr_erf, mpfr_gamma, mpfr_zeta, mpfr_greater_p, mpfr_greaterequal_p, mpfr_less_p, mpfr_lessequal_p, mpfr_lessgreater_p, mpfr_equal_p, mpfr_unordered_p. - removed functions: mpfr_print_binary, mpfr_round_prec (replaced by mpfr_prec_round), mpfr_set_str_raw, mpfr_set_machine_rnd_mode. - function mpfr_isinteger renamed mpfr_integer_p. - return type of some functions changed from void to int, for consistency. - return type of mpfr_set_prec changed from int to void. - new values for exponent range. - rename internal variables. Changes from version 2001 to version 2.0.1: - new mathematical functions: acos, acosh, asin, asinh, atan, atanh, cosh, base-2 exponential and logarithm, base-10 logarithm, expm1, factorial, pow, pow_si, pow_ui, sinh, tan, tanh, ui_pow, ui_pow_ui - other new functions: mpfr_const_euler, mpfr_dim, mpfr_fma, mpfr_hypot, mpfr_min, mpfr_max, mpfr_rint, mpfr_set_inf, mpfr_set_nan - new operations with MPZ or MPQ: mpfr_{add,sub,mul,div}_[zq] - new predicates: mpfr_inf_p, mpfr_nan_p, mpfr_number_p, mpfr_isinteger, - add mechanism to set/check exponent range (overflow, underflow), partially implemented in the mpfr functions. - efficiency: mpfr_div is now faster when the divisor has a few limbs - rounding: now mpfr_pow implements exact rounding, and most functions return a ternary value indicating the position of the returned value wrt the exact one (thus the return value is now 'int' instead of 'void') - complete rewrite of the configuration files - mpfr_get_d, mpfr_{add,sub}_one_ulp now get a rounding mode as 2nd argument - some function names did change: mpz_set_fr is now mpfr_get_z_exp, mpfr_print_raw is now mpfr_print_binary. Changes from version 1.0 to version 2001: - the default installation does not provide any more access to machine rounding mode, and as a consequence does not compare MPFR results with precision=53 to machine results. Add option -DTEST if you want to have access to machine rounding mode, and to check MPFR results against. - the MPFR files do not need any more - the header file was split into for exported functions and for internal functions. The user should not use functions or macros from , since those may change in further releases. - was modified in order to make easy a C++ interface - MPFR now deals with infinities (+infinity and -infinity) and NaN - the missing function mpfr_swap is now available - mpfr_zeta was removed (was incomplete) - mpfr_init and mpfr_init2 now initialize the corresponding variable to 0 (like in other initialization functions from GNU MP) - in case memory allocation fails, an error message is output - several bugs of version 1.0 were fixed Changes from version 0.4 to version 1.0: - Version 1.0 now uses a standard configure/make installation. - Version 1.0 implements all functions that are available in the MPF class from GMP 3.1 (except mpf_swap) and a header file mpf2mpfr.h is included in the distribution for easy change from MPF to MPFR. - Version 1.0 implements new elementary functions: mpfr_sincos - Some functions and macros have been renamed: mpfr_log2 is now mpfr_const_log2, mpfr_pi is now mpfr_const_pi, SIGN is now MPFR_SIGN. - Version 1.0 uses faster algorithms for mpfr_exp, mpfr_const_pi, mpfr_const_log2. Compare the timings from version 1.0 and version 0.4. - Version 1.0 corrects some bugs of version 0.4. - The precision of MPFR variables is now named mpfr_prec, which makes it easier to change it, to say unsigned long long. Same for the rounding mode which is called mp_rnd_t. You'll find other news concerning the GNU MPFR library on the web page .