Copyright 2000-2017 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
http://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 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 http://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 <math.h> any more
- the header file <mpfr.h> was split into <mpfr.h> for exported functions
  and <mpfr-impl.h> for internal functions. The user should not use functions
  or macros from <mpfr-impl.h>, since those may change in further releases.
- <mpfr.h> 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 <http://www.mpfr.org/>.
