This manual documents how to install and use the Multiple Precision Floating-Point Reliable Library, version 2.1.1.

Copyright 1991, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with the Front-Cover Texts being “A GNU Manual”, and with the Back-Cover Texts being “You have freedom to copy and modify this GNU Manual, like GNU software”. A copy of the license is included in GNU Free Documentation License.

This library is free; this means that everyone is free to use it and free to redistribute it on a free basis. The library is not in the public domain; it is copyrighted and there are restrictions on its distribution, but these restrictions are designed to permit everything that a good cooperating citizen would want to do. What is not allowed is to try to prevent others from further sharing any version of this library that they might get from you.

Specifically, we want to make sure that you have the right to give away copies of the library, that you receive source code or else can get it if you want it, that you can change this library or use pieces of it in new free programs, and that you know you can do these things.

To make sure that everyone has such rights, we have to forbid you to deprive anyone else of these rights. For example, if you distribute copies of the MPFR library, you must give the recipients all the rights that you have. You must make sure that they, too, receive or can get the source code. And you must tell them their rights.

Also, for our own protection, we must make certain that everyone finds out that there is no warranty for the MPFR library. If it is modified by someone else and passed on, we want their recipients to know that what they have is not what we distributed, so that any problems introduced by others will not reflect on our reputation.

The precise conditions of the license for the MPFR library are found in the Lesser General Public License that accompanies the source code. See the file COPYING.LIB.

MPFR is a portable library written in C for arbitrary precision arithmetic
on floating-point numbers. It is based on the GNU MP library.
It aims to extend the class of floating-point numbers provided by the
GNU MP library by a precise semantics. The main differences
with the `mpf`

class from GNU MP are:

- the
`mpfr`

code is portable, i.e. the result of any operation does not depend (or should not) on the machine word size`mp_bits_per_limb`

(32 or 64 on most machines); - the precision in bits can be set exactly to any valid value for each variable (including very small precision);
`mpfr`

provides the four rounding modes from the IEEE 754-1985 standard.

In particular, with a precision of 53 bits, `mpfr`

should be able
to exactly reproduce all computations with double-precision machine
floating-point
numbers (`double`

type in C), except the default exponent range
is much wider and subnormal numbers are not implemented.

This version of MPFR is released under the GNU Lesser General Public License. It is permitted to link MPFR to non-free programs, as long as when distributing them the MPFR source code and a means to re-link with a modified MPFR library is provided.

Everyone should read MPFR Basics. If you need to install the library yourself, you need to read Installing MPFR, too.

The rest of the manual can be used for later reference, although it is probably a good idea to glance through it.

Here are the steps needed to install the library on Unix systems (more details are provided in the INSTALL file):

- To build MPFR, you first have to install GNU MP (version 4.1 or higher) on your computer. You need a C compiler, preferably GCC, but any reasonable compiler should work. And you need a standard Unix make program, plus some other standard Unix utility programs.
- In the MPFR build directory, type
./configure
This will prepare the build and setup the options according to your system. If you get error messages, you might check that you use the same compiler and compile options as for GNU MP (see the INSTALL file).

- make
This will compile MPFR, and create a library archive file libmpfr.a in the working directory. No dynamic library is provided yet.

- make check
This will make sure MPFR was built correctly. If you get error messages, please report this to mpfr@loria.fr. (See Reporting Bugs, for information on what to include in useful bug reports.)

- make install
This will copy the files mpfr.h and mpf2mpfr.h to the directory /usr/local/include, the file libmpfr.a to the directory /usr/local/lib, and the file mpfr.info to the directory /usr/local/info (or if you passed the --prefix option to configure, using the prefix directory given as argument to --prefix instead of /usr/local).

There are some other useful make targets:

- mpfr.info or info
Create an info version of the manual, in mpfr.info.

- mpfr.dvi or dvi
Create a DVI version of the manual, in mpfr.dvi.

- mpfr.ps
Create a Postscript version of the manual, in mpfr.ps.

- clean
Delete all object files and archive files, but not the configuration files.

- distclean
Delete all files not included in the distribution.

- uninstall
Delete all files copied by make install.

MPFR suffers from all bugs from the GNU MP library, plus many more.

Please report other problems to mpfr@loria.fr. See Reporting Bugs. Some bug fixes are available on the MPFR web page http://www.mpfr.org/.

The latest version of MPFR is available from http://www.mpfr.org/.

If you think you have found a bug in the MPFR library, first have a look on the MPFR web page http://www.mpfr.org/: perhaps this bug is already known, in which case you may find there a workaround for it. Otherwise, please investigate and report it. We have made this library available to you, and it is not to ask too much from you, to ask you to report the bugs that you find.

There are a few things you should think about when you put your bug report together.

You have to send us a test case that makes it possible for us to reproduce the bug. Include instructions on how to run the test case.

You also have to explain what is wrong; if you get a crash, or if the results printed are incorrect and in that case, in what way.

Please include compiler version information in your bug report. This can be extracted using cc -V on some machines, or, if you're using gcc, gcc -v. Also, include the output from uname -a.

If your bug report is good, we will do our best to help you to get a corrected version of the library; if the bug report is poor, we won't do anything about it (aside of chiding you to send better bug reports).

Send your bug report to: mpfr@loria.fr.

If you think something in this manual is unclear, or downright incorrect, or if the language needs to be improved, please send a note to the same address.

All declarations needed to use MPFR are collected in the include file mpfr.h. It is designed to work with both C and C++ compilers. You should include that file in any program using the MPFR library:

#include <mpfr.h>

A floating-point number or float for short, is an arbitrary
precision mantissa with a limited precision exponent. The C data type
for such objects is `mpfr_t`

. A floating-point number can have
three special values: Not-a-Number (NaN) or plus or minus Infinity. NaN
represents an uninitialized object, the result of an invalid operation
(like 0 divided by 0), or a value that cannot be determined (like
+Infinity minus +Infinity). Moreover, like in the IEEE 754-1985 standard,
zero is signed, i.e. there are both +0 and −0; the behavior
is the same as in the IEEE 754-1985 standard and it is generalized to
the other functions supported by MPFR.

The precision is the number of bits used to represent the mantissa
of a floating-point number;
the corresponding C data type is `mp_prec_t`

.
The precision can be any integer between `MPFR_PREC_MIN`

and
`MPFR_PREC_MAX`

. In the current implementation, `MPFR_PREC_MIN`

is equal to 2.

The rounding mode specifies the way to round the result of a
floating-point operation, in case the exact result can not be represented
exactly in the destination mantissa;
the corresponding C data type is `mp_rnd_t`

.

A limb means the part of a multi-precision number that fits in a single
word. (We chose this word because a limb of the human body is analogous to a
digit, only larger, and containing several digits.) Normally a limb contains
32 or 64 bits. The C data type for a limb is `mp_limb_t`

.

There is only one class of functions in the MPFR library:

- Functions for floating-point arithmetic, with names beginning with
`mpfr_`

. The associated type is`mpfr_t`

.

As a general rule, all MPFR functions expect output arguments before input arguments. This notation is based on an analogy with the assignment operator.

MPFR allows you to use the same variable for both input and output in the same
expression. For example, the main function for floating-point multiplication,
`mpfr_mul`

, can be used like this: `mpfr_mul (x, x, x, rnd_mode)`

.
This
computes the square of `x` with rounding mode `rnd_mode`

and puts the result back in `x`.

Before you can assign to an MPFR variable, you need to initialize it by calling one of the special initialization functions. When you're done with a variable, you need to clear it out, using one of the functions for that purpose.

A variable should only be initialized once, or at least cleared out between each initialization. After a variable has been initialized, it may be assigned to any number of times.

For efficiency reasons, avoid to initialize and clear out a variable in loops. Instead, initialize it before entering the loop, and clear it out after the loop has exited.

You don't need to be concerned about allocating additional space for MPFR variables, since any variable has a mantissa of fixed size. Hence unless you change its precision, or clear and reinitialize it, a floating-point variable will have the same allocated space during all its life.

The following four rounding modes are supported:

`GMP_RNDN`

: round to nearest`GMP_RNDZ`

: round towards zero`GMP_RNDU`

: round towards plus infinity`GMP_RNDD`

: round towards minus infinity

The round to nearest mode works as in the IEEE 754-1985 standard: in case the number to be rounded lies exactly in the middle of two representable numbers, it is rounded to the one with the least significant bit set to zero. For example, the number 5/2, which is represented by (10.1) in binary, is rounded to (10.0)=2 with a precision of two bits, and not to (11.0)=3. This rule avoids the drift phenomenon mentioned by Knuth in volume 2 of The Art of Computer Programming (Section 4.2.2).

Most MPFR functions take as first argument the destination variable, as
second and following arguments the input variables, as last argument a
rounding mode, and have a return value of type `int`

, called the
ternary value. The value stored in the destination variable is
exactly rounded, i.e. MPFR behaves as if it computed the result with
an infinite precision, then rounded it to the precision of this variable.
The input variables are regarded as exact (in particular, their precision
does not affect the result).

Unless documented otherwise, functions returning an `int`

return
a ternary value.
If the ternary value is zero, it means that the value stored in the
destination variable is the exact result of the corresponding mathematical
function. If the ternary value is positive (resp. negative), it means
the value stored in the destination variable is greater (resp. lower)
than the exact result. For example with the `GMP_RNDU`

rounding mode,
the ternary value is usually positive, except when the result is exact, in
which case it is zero. In the case of an infinite result, it is considered
as inexact when it was obtained by overflow, and exact otherwise. A NaN
result (Not-a-Number) always corresponds to an exact return value.
The opposite of a returned ternary value is guaranteed to be representable
in an `int`

.

The floating-point functions expect arguments of type `mpfr_t`

.

The MPFR floating-point functions have an interface that is similar to the
GNU MP
integer functions. The function prefix for floating-point operations is
`mpfr_`

.

There is one significant characteristic of floating-point numbers that has motivated a difference between this function class and other GNU MP function classes: the inherent inexactness of floating-point arithmetic. The user has to specify the precision for each variable. A computation that assigns a variable will take place with the precision of the assigned variable; the cost of that computation should not depend from the precision of variables used as input (on average).

The semantics of a calculation in MPFR is specified as follows: Compute the requested operation exactly (with “infinite accuracy”), and round the result to the precision of the destination variable, with the given rounding mode. The MPFR floating-point functions are intended to be a smooth extension of the IEEE 754-1985 arithmetic. The results obtained on one computer should not differ from the results obtained on a computer with a different word size.

MPFR does not keep track of the accuracy of a computation. This is left to the user or to a higher layer. As a consequence, if two variables are used to store only a few significant bits, and their product is stored in a variable with large precision, then MPFR will still compute the result with full precision.

An `mpfr_t`

object must be initialized before storing the first value in
it. The functions `mpfr_init`

and `mpfr_init2`

are used for that
purpose.

— Function: void **mpfr_init2** (`mpfr_t x, mp_prec_t prec`)

Initialize

x, set its precision to beexactlyprecbits and its value to NaN. (Warning: the corresponding`mpf`

functions initialize to zero instead.)Normally, a variable should be initialized once only or at least be cleared, using

`mpfr_clear`

, between initializations. To change the precision of a variable which has already been initialized, use`mpfr_set_prec`

. The precisionprecmust be an integer between`MPFR_PREC_MIN`

and`MPFR_PREC_MAX`

(otherwise the behavior is undefined).

— Function: void **mpfr_clear** (`mpfr_t x`)

Free the space occupied by

x. Make sure to call this function for all`mpfr_t`

variables when you are done with them.

— Function: void **mpfr_init** (`mpfr_t x`)

Initialize

xand set its value to NaN.Normally, a variable should be initialized once only or at least be cleared, using

`mpfr_clear`

, between initializations. The precision ofxis the default precision, which can be changed by a call to`mpfr_set_default_prec`

.

— Function: void **mpfr_set_default_prec** (`mp_prec_t prec`)

Set the default precision to be

exactlyprecbits. The precision of a variable means the number of bits used to store its mantissa. All subsequent calls to`mpfr_init`

will use this precision, but previously initialized variables are unaffected. This default precision is set to 53 bits initially. The precision can be any integer between`MPFR_PREC_MIN`

and`MPFR_PREC_MAX`

.

Here is an example on how to initialize floating-point variables:

{ mpfr_t x, y; mpfr_init (x); /* use default precision */ mpfr_init2 (y, 256); /* precisionexactly256 bits */ ... /* When the program is about to exit, do ... */ mpfr_clear (x); mpfr_clear (y); }

The following functions are useful for changing the precision during a calculation. A typical use would be for adjusting the precision gradually in iterative algorithms like Newton-Raphson, making the computation precision closely match the actual accurate part of the numbers.

— Function: void **mpfr_set_prec** (`mpfr_t x, mp_prec_t prec`)

Reset the precision of

xto beexactlyprecbits, and set its value to NaN. The previous value stored inxis lost. It is equivalent to a call to`mpfr_clear(x)`

followed by a call to`mpfr_init2(x, prec)`

, but more efficient as no allocation is done in case the current allocated space for the mantissa ofxis enough. The precisionpreccan be any integer between`MPFR_PREC_MIN`

and`MPFR_PREC_MAX`

.In case you want to keep the previous value stored in

x, use`mpfr_prec_round`

instead.

— Function: mp_prec_t **mpfr_get_prec** (`mpfr_t x`)

Return the precision actually used for assignments of

x, i.e. the number of bits used to store its mantissa.

Next: Combined Initialization and Assignment Functions, Previous: Initialization Functions, Up: MPFR Interface

These functions assign new values to already initialized floats
(see Initialization Functions). When using any functions using
`intmax_t`

, you must include `<stdint.h>`

or `<inttypes.h>`

before mpfr.h, to allow mpfr.h to define prototypes for
these functions.

— Function: int **mpfr_set** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_set_ui** (`mpfr_t rop, unsigned long int op, mp_rnd_t rnd`)

— Function: int**mpfr_set_si** (`mpfr_t rop, long int op, mp_rnd_t rnd`)

— Function: int**mpfr_set_uj** (`mpfr_t rop, uintmax_t op, mp_rnd_t rnd`)

— Function: int**mpfr_set_sj** (`mpfr_t rop, intmax_t op, mp_rnd_t rnd`)

— Function: int**mpfr_set_d** (`mpfr_t rop, double op, mp_rnd_t rnd`)

— Function: int**mpfr_set_ld** (`mpfr_t rop, long double op, mp_rnd_t rnd`)

— Function: int**mpfr_set_z** (`mpfr_t rop, mpz_t op, mp_rnd_t rnd`)

— Function: int**mpfr_set_q** (`mpfr_t rop, mpq_t op, mp_rnd_t rnd`)

— Function: int**mpfr_set_f** (`mpfr_t rop, mpf_t op, mp_rnd_t rnd`)

— Function: int

— Function: int

— Function: int

— Function: int

— Function: int

— Function: int

— Function: int

— Function: int

— Function: int

Set the value of

ropfromop, rounded towards the given directionrnd. Note that the input 0 is converted to +0 by`mpfr_set_ui`

,`mpfr_set_si`

,`mpfr_set_sj`

,`mpfr_set_uj`

,`mpfr_set_z`

,`mpfr_set_q`

and`mpfr_set_f`

, regardless of the rounding mode. If the system doesn't support the IEEE-754 standard,`mpfr_set_d`

and`mpfr_set_ld`

might not preserve the signed zeros.

— Function: int **mpfr_set_ui_2exp** (`mpfr_t rop, unsigned long int op, mp_exp_t e, mp_rnd_t rnd`)

— Function: int**mpfr_set_si_2exp** (`mpfr_t rop, long int op, mp_exp_t e, mp_rnd_t rnd`)

— Function: int**mpfr_set_uj_2exp** (`mpfr_t rop, uintmax_t op, intmax_t e, mp_rnd_t rnd`)

— Function: int**mpfr_set_sj_2exp** (`mpfr_t rop, intmax_t op, intmax_t e, mp_rnd_t rnd`)

— Function: int

— Function: int

— Function: int

Set the value of

ropfromopmultiplied by two to the powere, rounded towards the given directionrnd. Note that the input 0 is converted to +0.

— Function: int **mpfr_set_str** (`mpfr_t rop, const char *s, int base, mp_rnd_t rnd`)

Set

ropto the value of the whole stringsin basebase, rounded in the directionrnd. See the documentation of`mpfr_strtofr`

for a detailed description of the valid string formats. This function returns 0 if the entire string up to the final null character is a valid number in basebase; otherwise it returns −1, andropmay have changed.

— Function: int **mpfr_strtofr** (`mpfr_t rop, const char *nptr, char **endptr, int base, mp_rnd_t rnd`)

Read a floating point number from a string

nptrin basebase, rounded in the directionrnd. If successful, the result is stored inropand`*`

endptrpoints to the character just after those parsed. Ifstrdoesn't start with a valid number thenropis set to zero and the value ofnptris stored in the location referenced byendptr.Parsing follows the standard C

`strtod`

function. This means optional leading whitespace, an optional`+`

or`-`

, mantissa digits, and an optional exponent consisting of an`e`

or`E`

(ifbase<= 10) or`@`

, an optional sign, and digits. A hex mantissa can be given with a leading`0x`

or`0X`

, in which case`p`

or`P`

may introduce an optional binary exponent. A binary mantissa can be given with a leading`0b`

or`0B`

, in which case`e`

,`E`

,`p`

,`P`

or`@`

may introduce the binary exponent.In addition

`infinity`

,`inf`

(ifbase<= 10) or`@inf@`

with an optional sign, or`nan`

,`nan(n-char-sequence)`

(ifbase<= 10),`@nan@`

or`@nan@(n-char-sequence)`

all non case significant, can be given. A`n-char-sequence`

is a string containing only digits (0, 1, 2, ..., 9) and non-digits (_, a, b, ..., z, A, B, ..., Z).There must be at least one digit in the mantissa for the number to be valid. If an exponent has no digits it's ignored and parsing stops after the mantissa. If an

`0x`

,`0X`

,`0b`

or`0B`

is not followed by hexadecimal/binary digits, parsing stops after the first`0`

: the subject sequence is defined as the longest initial subsequence of the input string, starting with the first non-white-space character, that is of the expected form. The subject sequence contains no characters if the input string is not of the expected form.Note that in the hex format the exponent

`P`

represents a power of 2, whereas`@`

represents a power of the base (i.e. 16).If the argument

baseis different from 0, it must be in the range 2 to 36. Case is ignored; upper-case and lower-case letters have the same valueIf

`base`

is 0, then it tries to identify the used base: if the mantissa begins with the`0x`

prefix, it assumes thatbaseis 16. If it begins with`0b`

, it assumes thatbaseis 2. Otherwise, it assumes it is 10.It returns a usual ternary value. If

endptris not a null pointer, a pointer to the character after the last character used in the conversion is stored in the location referenced byendptr.

— Function: void **mpfr_set_inf** (`mpfr_t x, int sign`)

— Function: void**mpfr_set_nan** (`mpfr_t x`)

— Function: void

Set the variable

xto infinity or NaN (Not-a-Number) respectively. In`mpfr_set_inf`

,xis set to plus infinity iffsignis nonnegative.

— Function: void **mpfr_swap** (`mpfr_t x, mpfr_t y`)

Swap the values

xandyefficiently. Warning: the precisions are exchanged too; in case the precisions are different,`mpfr_swap`

is thus not equivalent to three`mpfr_set`

calls using a third auxiliary variable.

— Macro: int **mpfr_init_set** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Macro: int**mpfr_init_set_ui** (`mpfr_t rop, unsigned long int op, mp_rnd_t rnd`)

— Macro: int**mpfr_init_set_si** (`mpfr_t rop, signed long int op, mp_rnd_t rnd`)

— Macro: int**mpfr_init_set_d** (`mpfr_t rop, double op, mp_rnd_t rnd`)

— Macro: int**mpfr_init_set_ld** (`mpfr_t rop, long double op, mp_rnd_t rnd`)

— Macro: int**mpfr_init_set_z** (`mpfr_t rop, mpz_t op, mp_rnd_t rnd`)

— Macro: int**mpfr_init_set_q** (`mpfr_t rop, mpq_t op, mp_rnd_t rnd`)

— Macro: int**mpfr_init_set_f** (`mpfr_t rop, mpf_t op, mp_rnd_t rnd`)

— Macro: int

— Macro: int

— Macro: int

— Macro: int

— Macro: int

— Macro: int

— Macro: int

Initialize

ropand set its value fromop, rounded in the directionrnd. The precision ofropwill be taken from the active default precision, as set by`mpfr_set_default_prec`

.

— Function: int **mpfr_init_set_str** (`mpfr_t x, const char *s, int base, mp_rnd_t rnd`)

Initialize

xand set its value from the stringsin basebase, rounded in the directionrnd. See`mpfr_set_str`

.

Next: Basic Arithmetic Functions, Previous: Combined Initialization and Assignment Functions, Up: MPFR Interface

— Function: double **mpfr_get_d** (`mpfr_t op, mp_rnd_t rnd`)

— Function: long double**mpfr_get_ld** (`mpfr_t op, mp_rnd_t rnd`)

— Function: long double

Convert

opto a`double`

(respectively`long double`

), using the rounding modernd. If the system doesn't support IEEE 754 standard, this function might not preserve the signed zeros.

— Function: double **mpfr_get_d_2exp** (`long *exp, mpfr_t op, mp_rnd_t rnd`)

Return

dand setexpsuch that 0.5<=abs(d)<1 anddtimes 2 raised toexpequalsoprounded to double precision, using the given rounding mode.

— Function: long **mpfr_get_si** (`mpfr_t op, mp_rnd_t rnd`)

— Function: unsigned long**mpfr_get_ui** (`mpfr_t op, mp_rnd_t rnd`)

— Function: intmax_t**mpfr_get_sj** (`mpfr_t op, mp_rnd_t rnd`)

— Function: uintmax_t**mpfr_get_uj** (`mpfr_t op, mp_rnd_t rnd`)

— Function: unsigned long

— Function: intmax_t

— Function: uintmax_t

Convert

opto a`long`

, an`unsigned long`

, an`intmax_t`

or an`uintmax_t`

(respectively) after rounding it with respect tornd. Ifopis NaN, the result is undefined. Ifopis too big for the return type, it returns the maximum or the minimum of the corresponding C type, depending on the direction of the overflow. The flag erange is set too. See also`mpfr_fits_slong_p`

,`mpfr_fits_ulong_p`

,`mpfr_fits_intmax_p`

and`mpfr_fits_uintmax_p`

.

— Function: mp_exp_t **mpfr_get_z_exp** (`mpz_t rop, mpfr_t op`)

Put the scaled mantissa of

op(regarded as an integer, with the precision ofop) intorop, and return the exponentexp(which may be outside the current exponent range) such thatopexactly equalsropmultiplied by two exponentexp. If the exponent is not representable in the`mp_exp_t`

type, the behavior is undefined.

— Function: void **mpfr_get_z** (`mpz_t rop, mpfr_t op, mp_rnd_t rnd`)

Convert

opto a`mpz_t`

, after rounding it with respect tornd. Ifopis NaN or Inf, the result is undefined.

— Function: char * **mpfr_get_str** (`char *str, mp_exp_t *expptr, int base, size_t n, mpfr_t op, mp_rnd_t rnd`)

Convert

opto a string of digits in basebase, with rounding in the directionrnd. The base may vary from 2 to 36.The generated string is a fraction, with an implicit radix point immediately to the left of the first digit. For example, the number -3.1416 would be returned as "-31416" in the string and 1 written at

expptr. Ifrndis to nearest, andopis exactly in the middle of two possible outputs, the one with an even last digit is chosen (for an odd base, this may not correspond to an even mantissa).If

nis zero, the number of digits of the mantissa is determined automatically from the precision ofopand the value ofbase. Warning: this functionality may disappear or change in future versions. Otherwise generate exactlynsignificant digits, which must be at least 2.If

stris a null pointer, space for the mantissa is allocated using the current allocation function, and a pointer to the string is returned. To free the returned string, you must use`mpfr_free_str`

.If

stris not a null pointer, it should point to a block of storage large enough for the mantissa, i.e., at least`max(`

n`+ 2, 7)`

. The extra two bytes are for a possible minus sign, and for the terminating null character.If

nis 0, note that the space requirements forstrin this case will be impossible for the user to predetermine. Therefore, one needs to pass a null pointer for the string argument whenevernis 0.If the input number is an ordinary number, the exponent is written through the pointer

expptr(the current minimal exponent for 0).A pointer to the string is returned, unless there is an error, in which case a null pointer is returned.

— Function: void **mpfr_free_str** (`char *str`)

Free a string allocated by

`mpfr_get_str`

using the current unallocation function (preliminary interface). The block is assumed to be`strlen(`

str`)+1`

bytes. For more information about how it is done: see Custom Allocation (GNU MP).

— Function: int **mpfr_fits_ulong_p** (`mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_fits_slong_p** (`mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_fits_uint_p** (`mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_fits_sint_p** (`mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_fits_ushort_p** (`mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_fits_sshort_p** (`mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_fits_intmax_p** (`mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_fits_uintmax_p** (`mpfr_t op, mp_rnd_t rnd`)

— Function: int

— Function: int

— Function: int

— Function: int

— Function: int

— Function: int

— Function: int

Return non-zero if

opwould fit in the respective C data type, when rounded to an integer in the directionrnd.

— Function: int **mpfr_add** (`mpfr_t rop, mpfr_t op1, mpfr_t op2, mp_rnd_t rnd`)

— Function: int**mpfr_add_ui** (`mpfr_t rop, mpfr_t op1, unsigned long int op2, mp_rnd_t rnd`)

— Function: int**mpfr_add_si** (`mpfr_t rop, mpfr_t op1, long int op2, mp_rnd_t rnd`)

— Function: int**mpfr_add_z** (`mpfr_t rop, mpfr_t op1, mpz_t op2, mp_rnd_t rnd`)

— Function: int**mpfr_add_q** (`mpfr_t rop, mpfr_t op1, mpq_t op2, mp_rnd_t rnd`)

— Function: int

— Function: int

— Function: int

— Function: int

Set

roptoop1+op2rounded in the directionrnd. For types having no signed zero, it is considered unsigned (i.e. (+0) + 0 = (+0) and (-0) + 0 = (-0)).

— Function: int **mpfr_sub** (`mpfr_t rop, mpfr_t op1, mpfr_t op2, mp_rnd_t rnd`)

— Function: int**mpfr_ui_sub** (`mpfr_t rop, unsigned long int op1, mpfr_t op2, mp_rnd_t rnd`)

— Function: int**mpfr_sub_ui** (`mpfr_t rop, mpfr_t op1, unsigned long int op2, mp_rnd_t rnd`)

— Function: int**mpfr_si_sub** (`mpfr_t rop, long int op1, mpfr_t op2, mp_rnd_t rnd`)

— Function: int**mpfr_sub_si** (`mpfr_t rop, mpfr_t op1, long int op2, mp_rnd_t rnd`)

— Function: int**mpfr_sub_z** (`mpfr_t rop, mpfr_t op1, mpz_t op2, mp_rnd_t rnd`)

— Function: int**mpfr_sub_q** (`mpfr_t rop, mpfr_t op1, mpq_t op2, mp_rnd_t rnd`)

— Function: int

— Function: int

— Function: int

— Function: int

— Function: int

— Function: int

Set

roptoop1-op2rounded in the directionrnd. For types having no signed zero, it is considered unsigned (i.e. (+0) - 0 = (+0), (-0) - 0 = (-0), 0 - (+0) = (-0) and 0 - (-0) = (+0)).

— Function: int **mpfr_mul** (`mpfr_t rop, mpfr_t op1, mpfr_t op2, mp_rnd_t rnd`)

— Function: int**mpfr_mul_ui** (`mpfr_t rop, mpfr_t op1, unsigned long int op2, mp_rnd_t rnd`)

— Function: int**mpfr_mul_si** (`mpfr_t rop, mpfr_t op1, long int op2, mp_rnd_t rnd`)

— Function: int**mpfr_mul_z** (`mpfr_t rop, mpfr_t op1, mpz_t op2, mp_rnd_t rnd`)

— Function: int**mpfr_mul_q** (`mpfr_t rop, mpfr_t op1, mpq_t op2, mp_rnd_t rnd`)

— Function: int

— Function: int

— Function: int

— Function: int

Set

roptoop1timesop2rounded in the directionrnd. When a result is zero, its sign is the product of the signs of the operands (for types having no signed zero, it is considered positive).

— Function: int **mpfr_sqr** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

Set

ropto the square ofoprounded in the directionrnd.

— Function: int **mpfr_div** (`mpfr_t rop, mpfr_t op1, mpfr_t op2, mp_rnd_t rnd`)

— Function: int**mpfr_ui_div** (`mpfr_t rop, unsigned long int op1, mpfr_t op2, mp_rnd_t rnd`)

— Function: int**mpfr_div_ui** (`mpfr_t rop, mpfr_t op1, unsigned long int op2, mp_rnd_t rnd`)

— Function: int**mpfr_si_div** (`mpfr_t rop, long int op1, mpfr_t op2, mp_rnd_t rnd`)

— Function: int**mpfr_div_si** (`mpfr_t rop, mpfr_t op1, long int op2, mp_rnd_t rnd`)

— Function: int**mpfr_div_z** (`mpfr_t rop, mpfr_t op1, mpz_t op2, mp_rnd_t rnd`)

— Function: int**mpfr_div_q** (`mpfr_t rop, mpfr_t op1, mpq_t op2, mp_rnd_t rnd`)

— Function: int

— Function: int

— Function: int

— Function: int

— Function: int

— Function: int

Set

roptoop1/op2rounded in the directionrnd. When a result is zero, its sign is the product of the signs of the operands (for types having no signed zero, it is considered positive).

— Function: int **mpfr_sqrt** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_sqrt_ui** (`mpfr_t rop, unsigned long int op, mp_rnd_t rnd`)

— Function: int

Set

ropto the square root ofoprounded in the directionrnd. Return −0 ifropis −0 (to be consistent with the IEEE 754-1985 standard). Setropto NaN ifopis negative.

— Function: int **mpfr_cbrt** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

Set

ropto the cubic root (defined over the real numbers) ofoprounded in the directionrnd.

— Function: int **mpfr_pow** (`mpfr_t rop, mpfr_t op1, mpfr_t op2, mp_rnd_t rnd`)

— Function: int**mpfr_pow_ui** (`mpfr_t rop, mpfr_t op1, unsigned long int op2, mp_rnd_t rnd`)

— Function: int**mpfr_pow_si** (`mpfr_t rop, mpfr_t op1, long int op2, mp_rnd_t rnd`)

— Function: int**mpfr_ui_pow_ui** (`mpfr_t rop, unsigned long int op1, unsigned long int op2, mp_rnd_t rnd`)

— Function: int**mpfr_ui_pow** (`mpfr_t rop, unsigned long int op1, mpfr_t op2, mp_rnd_t rnd`)

— Function: int

— Function: int

— Function: int

— Function: int

Set

roptoop1raised toop2, rounded in the directionrnd. Special values are currently handled as described in the ISO C99 standard for the`pow`

function (note this may change in future versions):

`pow(±0,`

y`)`

returns plus or minus infinity forya negative odd integer.`pow(±0,`

y`)`

returns plus infinity forynegative and not an odd integer.`pow(±0,`

y`)`

returns plus or minus zero forya positive odd integer.`pow(±0,`

y`)`

returns plus zero forypositive and not an odd integer.`pow(-1, ±inf)`

returns 1.`pow(+1,`

y`)`

returns 1 for anyy, even a NaN.`pow(`

x`,`

y`)`

returns NaN for finite negativexand finite non-integery.`pow(`

x`, -inf)`

returns plus infinity for 0 < abs(x) < 1, and plus zero for abs(x) > 1.`pow(`

x`, +inf)`

returns plus zero for 0 < abs(x) < 1, and plus infinity for abs(x) > 1.`pow(-inf,`

y`)`

returns minus zero forya negative odd integer.`pow(-inf,`

y`)`

returns plus zero forynegative and not an odd integer.`pow(-inf,`

y`)`

returns minus infinity forya positive odd integer.`pow(-inf,`

y`)`

returns plus infinity forypositive and not an odd integer.`pow(+inf,`

y`)`

returns plus zero forynegative, and plus infinity forypositive.

— Function: int **mpfr_neg** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

Set

ropto -oprounded in the directionrnd. Just changes the sign ifropandopare the same variable.

— Function: int **mpfr_abs** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

Set

ropto the absolute value ofop, rounded in the directionrnd. Just changes the sign ifropandopare the same variable.

— Function: int **mpfr_mul_2ui** (`mpfr_t rop, mpfr_t op1, unsigned long int op2, mp_rnd_t rnd`)

— Function: int**mpfr_mul_2si** (`mpfr_t rop, mpfr_t op1, long int op2, mp_rnd_t rnd`)

— Function: int

Set

roptoop1times 2 raised toop2rounded in the directionrnd. Just increases the exponent byop2whenropandop1are identical.

— Function: int **mpfr_div_2ui** (`mpfr_t rop, mpfr_t op1, unsigned long int op2, mp_rnd_t rnd`)

— Function: int**mpfr_div_2si** (`mpfr_t rop, mpfr_t op1, long int op2, mp_rnd_t rnd`)

— Function: int

Set

roptoop1divided by 2 raised toop2rounded in the directionrnd. Just decreases the exponent byop2whenropandop1are identical.

— Function: int **mpfr_cmp** (`mpfr_t op1, mpfr_t op2`)

— Function: int**mpfr_cmp_ui** (`mpfr_t op1, unsigned long int op2`)

— Function: int**mpfr_cmp_si** (`mpfr_t op1, signed long int op2`)

— Function: int**mpfr_cmp_d** (`mpfr_t op1, double op2`)

— Function: int**mpfr_cmp_ld** (`mpfr_t op1, long double op2`)

— Function: int**mpfr_cmp_z** (`mpfr_t op1, mpz_t op2`)

— Function: int**mpfr_cmp_q** (`mpfr_t op1, mpq_t op2`)

— Function: int**mpfr_cmp_f** (`mpfr_t op1, mpf_t op2`)

— Function: int

— Function: int

— Function: int

— Function: int

— Function: int

— Function: int

— Function: int

Compare

op1andop2. Return a positive value ifop1>op2, zero ifop1=op2, and a negative value ifop1<op2. Bothop1andop2are considered to their full own precision, which may differ. If one of the operands is NaN (Not-a-Number), return zero and set the erange flag.

— Function: int **mpfr_cmp_ui_2exp** (`mpfr_t op1, unsigned long int op2, mp_exp_t e`)

— Function: int**mpfr_cmp_si_2exp** (`mpfr_t op1, long int op2, mp_exp_t e`)

— Function: int

Compare

op1andop2multiplied by two to the powere. Similar as above.

— Function: int **mpfr_cmpabs** (`mpfr_t op1, mpfr_t op2`)

Compare |

op1| and |op2|. Return a positive value if |op1| > |op2|, zero if |op1| = |op2|, and a negative value if |op1| < |op2|. If one of the operands is NaN (Not-a-Number), return zero and set the erange flag.

— Function: int **mpfr_nan_p** (`mpfr_t op`)

— Function: int**mpfr_inf_p** (`mpfr_t op`)

— Function: int**mpfr_number_p** (`mpfr_t op`)

— Function: int**mpfr_zero_p** (`mpfr_t op`)

— Function: int

— Function: int

— Function: int

Return non-zero if

opis respectively Not-a-Number (NaN), an infinity, an ordinary number (i.e. neither Not-a-Number nor an infinity) or zero. Return zero otherwise.

— Macro: int **mpfr_sgn** (`mpfr_t op`)

Return a positive value if

op> 0, zero ifop= 0, and a negative value ifop< 0. Its result is undefined whenopis NaN (Not-a-Number).

— Function: int **mpfr_greater_p** (`mpfr_t op1, mpfr_t op2`)

Return non-zero if

op1>op2, zero otherwise.

— Function: int **mpfr_greaterequal_p** (`mpfr_t op1, mpfr_t op2`)

Return non-zero if

op1>=op2, zero otherwise.

— Function: int **mpfr_lessequal_p** (`mpfr_t op1, mpfr_t op2`)

Return non-zero if

op1<=op2, zero otherwise.

— Function: int **mpfr_lessgreater_p** (`mpfr_t op1, mpfr_t op2`)

Return non-zero if

op1<op2orop1>op2(i.e. neitherop1, norop2is NaN, andop1<>op2), zero otherwise (i.e.op1and/orop2are NaN, orop1=op2).

— Function: int **mpfr_equal_p** (`mpfr_t op1, mpfr_t op2`)

Return non-zero if

op1=op2, zero otherwise (i.e.op1and/orop2are NaN, orop1<>op2).

— Function: int **mpfr_unordered_p** (`mpfr_t op1, mpfr_t op2`)

Return non-zero if

op1orop2is a NaN (i.e. they cannot be compared), zero otherwise.

All those functions, except explicitly stated, return zero for an exact return value, a positive value for a return value larger than the exact result, and a negative value otherwise.

— Function: int **mpfr_log** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_log2** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_log10** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int

— Function: int

Set

ropto the natural logarithm ofop, log2(op) or log10(op), respectively, rounded in the directionrnd.

— Function: int **mpfr_exp** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_exp2** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_exp10** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int

— Function: int

Set

ropto the exponential ofop, to 2 power ofopor to 10 power ofop, respectively, rounded in the directionrnd.

— Function: int **mpfr_cos** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_sin** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_tan** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int

— Function: int

Set

ropto the cosine ofop, sine ofop, tangent ofop, rounded in the directionrnd.

— Function: int **mpfr_sin_cos** (`mpfr_t sop, mpfr_t cop, mpfr_t op, mp_rnd_t rnd`)

Set simultaneously

sopto the sine ofopandcopto the cosine ofop, rounded in the directionrndwith the corresponding precisions ofsopandcop. Return 0 iff both results are exact.

— Function: int **mpfr_acos** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_asin** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_atan** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int

— Function: int

Set

ropto the arc-cosine, arc-sine or arc-tangent ofop, rounded in the directionrnd.

— Function: int **mpfr_cosh** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_sinh** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_tanh** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int

— Function: int

Set

ropto the hyperbolic cosine, sine or tangent ofop, rounded in the directionrnd.

— Function: int **mpfr_acosh** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_asinh** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_atanh** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int

— Function: int

Set

ropto the inverse hyperbolic cosine, sine or tangent ofop, rounded in the directionrnd.

— Function: int **mpfr_fac_ui** (`mpfr_t rop, unsigned long int op, mp_rnd_t rnd`)

Set

ropto the factorial of the`unsigned long int`

op, rounded in the directionrnd.

— Function: int **mpfr_log1p** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

Set

ropto the logarithm of one plusop, rounded in the directionrnd.

— Function: int **mpfr_expm1** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

Set

ropto the exponential ofopminus one, rounded in the directionrnd.

— Function: int **mpfr_gamma** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

Set

ropto the value of the Gamma function onop, rounded in the directionrnd.

— Function: int **mpfr_zeta** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

Set

ropto the value of the Riemann Zeta function onop, rounded in the directionrnd.

— Function: int **mpfr_erf** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

Set

ropto the value of the error function onop, rounded in the directionrnd.

— Function: int **mpfr_fma** (`mpfr_t rop, mpfr_t op1, mpfr_t op2, mpfr_t op3, mp_rnd_t rnd`)

Set

roptoop1timesop2+op3, rounded in the directionrnd.

— Function: int **mpfr_agm** (`mpfr_t rop, mpfr_t op1, mpfr_t op2, mp_rnd_t rnd`)

Set

ropto the arithmetic-geometric mean ofop1andop2, rounded in the directionrnd. The arithmetic-geometric mean is the common limit of the sequences u[n] and v[n], where u[0]=op1, v[0]=op2, u[n+1] is the arithmetic mean of u[n] and v[n], and v[n+1] is the geometric mean of u[n] and v[n]. If any operand is negative, the return value is NaN.

— Function: int **mpfr_const_log2** (`mpfr_t rop, mp_rnd_t rnd`)

— Function: int**mpfr_const_pi** (`mpfr_t rop, mp_rnd_t rnd`)

— Function: int**mpfr_const_euler** (`mpfr_t rop, mp_rnd_t rnd`)

— Function: int

— Function: int

Set

ropto the logarithm of 2, the value of Pi, the value of Euler's constant 0.577..., respectively, rounded in the directionrnd. These functions cache the computed values to avoid other calculations if a lower or equal precision is requested. To free these caches, use`mpfr_free_cache`

.

— Function: void **mpfr_free_cache** (`void`)

Free the cache used by the functions computing constants if needed (currently

`mpfr_const_log2`

,`mpfr_const_pi`

and`mpfr_const_euler`

).

— Function: int **mpfr_sum** (`mpfr_t rop, const mpfr_t* const tab`[]`, unsigned long n, mp_rnd_t rnd`)

Set

retto the sum of all elements oftabwhose size isn, rounded in the directionrnd. Warning,tabis a table of pointers to mpfr_t, not a table of mpfr_t (preliminary interface).

This section describes functions that perform input from an input/output
stream, and functions that output to an input/output stream.
Passing a null pointer for a `stream` argument to any of
these functions will make them read from `stdin`

and write to
`stdout`

, respectively.

When using any of these functions, you must include the `<stdio.h>`

standard header before mpfr.h, to allow mpfr.h to define
prototypes for these functions.

— Function: size_t **mpfr_out_str** (`FILE *stream, int base, size_t n, mpfr_t op, mp_rnd_t rnd`)

Output

opon streamstream, as a string of digits in basebase, rounded in the directionrnd. The base may vary from 2 to 36. Printnsignificant digits exactly, or ifnis 0, the maximum number of digits accurately representable byop(this feature may disappear).In addition to the significant digits, a decimal point at the right of the first digit and a trailing exponent in base 10, in the form eNNN, are printed. If

baseis greater than 10, @ will be used instead of e as exponent delimiter.Return the number of bytes written, or if an error occurred, return 0.

— Function: size_t **mpfr_inp_str** (`mpfr_t rop, FILE *stream, int base, mp_rnd_t rnd`)

Input a string in base

basefrom streamstream, rounded in the directionrnd, and put the read float inrop.This function reads a word (defined as a sequence of characters between whitespace) and parses it using

`mpfr_set_str`

(it may change). See the documentation of`mpfr_strtofr`

for a detailed description of the valid string formats.Return the number of bytes read, or if an error occurred, return 0.

— Function: int **mpfr_rint** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_ceil** (`mpfr_t rop, mpfr_t op`)

— Function: int**mpfr_floor** (`mpfr_t rop, mpfr_t op`)

— Function: int**mpfr_round** (`mpfr_t rop, mpfr_t op`)

— Function: int**mpfr_trunc** (`mpfr_t rop, mpfr_t op`)

— Function: int

— Function: int

— Function: int

— Function: int

Set

roptooprounded to an integer.`mpfr_rint`

rounds to the nearest representable integer in the given rounding mode,`mpfr_ceil`

rounds to the next higher or equal representable integer,`mpfr_floor`

to the next lower or equal representable integer,`mpfr_round`

to the nearest representable integer, rounding halfway cases away from zero, and`mpfr_trunc`

to the next representable integer towards zero.The returned value is zero when the result is exact, positive when it is greater than the original value of

op, and negative when it is smaller. More precisely, the returned value is 0 whenopis an integer representable inrop, 1 or −1 whenopis an integer that is not representable inrop, 2 or −2 whenopis not an integer.Note that

`mpfr_round`

is different from`mpfr_rint`

called with the rounding to the nearest mode (where halfway cases are rounded to an even integer or mantissa). Note also that no double rounding is performed; for instance, 4.5 (100.1 in binary) is rounded by`mpfr_round`

to 4 (100 in binary) in 2-bit precision, though`round(4.5)`

is equal to 5 and 5 (101 in binary) is rounded to 6 (110 in binary) in 2-bit precision.

— Function: int **mpfr_rint_ceil** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_rint_floor** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_rint_round** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int**mpfr_rint_trunc** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

— Function: int

— Function: int

— Function: int

Set

roptooprounded to an integer.`mpfr_rint_ceil`

rounds to the next higher or equal integer,`mpfr_rint_floor`

to the next lower or equal integer,`mpfr_rint_round`

to the nearest integer, rounding halfway cases away from zero, and`mpfr_rint_trunc`

to the next integer towards zero. If the result is not representable, it is rounded in the directionrnd. The returned value is the ternary value associated with the considered round-to-integer function (regarded in the same way as any other mathematical function).

— Function: int **mpfr_frac** (`mpfr_t rop, mpfr_t op, mp_rnd_t rnd`)

Set

ropto the fractional part ofop, having the same sign asop, rounded in the directionrnd(unlike in`mpfr_rint`

,rndaffects only how the exact fractional part is rounded, not how the fractional part is generated).

— Function: void **mpfr_nexttoward** (`mpfr_t x, mpfr_t y`)

If

xoryis NaN, setxto NaN. Otherwise, ifxis different fromy, replacexby the next floating-point number (with the precision ofxand the current exponent range) in the direction ofy, if there is one (the infinite values are seen as the smallest and largest floating-point numbers). If the result is zero, it keeps the same sign. No underflow or overflow is generated.

— Function: int **mpfr_min** (`mpfr_t rop, mpfr_t op1, mpfr_t op2, mp_rnd_t rnd`)

Set

ropto the minimum ofop1andop2. Ifop1andop2are both NaN, thenropis set to NaN. Ifop1orop2is NaN, thenropis set to the numeric value. Ifop1andop2are zeros of different signs, thenropis set to −0.

— Function: int **mpfr_max** (`mpfr_t rop, mpfr_t op1, mpfr_t op2, mp_rnd_t rnd`)

Set

ropto the maximum ofop1andop2. Ifop1andop2are both NaN, thenropis set to NaN. Ifop1orop2is NaN, thenropis set to the numeric value. Ifop1andop2are zeros of different signs, thenropis set to +0.

— Function: int **mpfr_urandomb** (`mpfr_t rop, gmp_randstate_t state`)

Generate a uniformly distributed random float in the interval 0 <=

rop< 1. Return 0, unless the exponent is not in the current exponent range, in which caseropis set to NaN and a non-zero value is returned.

— Function: void **mpfr_random** (`mpfr_t rop`)

Generate a uniformly distributed random float in the interval 0 <=

rop< 1. This function is deprecated;`mpfr_urandomb`

should be used instead.

— Function: void **mpfr_random2** (`mpfr_t rop, mp_size_t size, mp_exp_t exp`)

Generate a random float of at most

sizelimbs, with long strings of zeros and ones in the binary representation. The exponent of the number is in the interval −exptoexp. This function is useful for testing functions and algorithms, since this kind of random numbers have proven to be more likely to trigger corner-case bugs. Negative random numbers are generated whensizeis negative. Put +0 inropwhen size if zero.

— Function: mp_exp_t **mpfr_get_exp** (`mpfr_t x`)

Get the exponent of

x, assuming thatxis a non-zero ordinary number. The return value for Nan, Infinity or Zero is undefined.

— Function: int **mpfr_set_exp** (`mpfr_t x, mp_exp_t e`)

Set the exponent of

xifeis in the current exponent range, and return 0 (even ifxis not a non-zero ordinary number); otherwise, return a non-zero value.

— Function: const char * **mpfr_get_version** (`void`)

Return the MPFR version, as a null-terminated string.

— Macro: **MPFR_VERSION**

— Macro:**MPFR_VERSION_MAJOR**

— Macro:**MPFR_VERSION_MINOR**

— Macro:**MPFR_VERSION_PATCHLEVEL**

— Macro:

— Macro:

— Macro:

`MPFR_VERSION`

is the version of MPFR as a preprocessing constant.`MPFR_VERSION_MAJOR`

,`MPFR_VERSION_MINOR`

and`MPFR_VERSION_PATCHLEVEL`

are respectively the major, minor and patch level of MPFR version, as preprocessing constants.

— Macro: long **MPFR_VERSION_NUM** (`major, minor, patchlevel`)

Create an integer in the same format as used by

`MPFR_VERSION`

from the givenmajor,minorandpatchlevel. Here is an example of how to check the MPFR version at compile time:#if (!defined(MPFR_VERSION) || (MPFR_VERSION<MPFR_VERSION_NUM(2,1,0))) # error "Wrong MPFR version." #endif

— Function: void **mpfr_set_default_rounding_mode** (`mp_rnd_t rnd`)

Set the default rounding mode to

rnd. The default rounding mode is to nearest initially.

— Function: int **mpfr_prec_round** (`mpfr_t x, mp_prec_t prec, mp_rnd_t rnd`)

Round

xaccording torndwith precisionprec, which must be an integer between`MPFR_PREC_MIN`

and`MPFR_PREC_MAX`

(otherwise the behavior is undefined). Ifprecis greater or equal to the precision ofx, then new space is allocated for the mantissa, and it is filled with zeros. Otherwise, the mantissa is rounded to precisionprecwith the given direction. In both cases, the precision ofxis changed toprec.

— Function: int **mpfr_round_prec** (`mpfr_t x, mp_rnd_t rnd, mp_prec_t prec`)

[This function is obsolete. Please use

`mpfr_prec_round`

instead.]

— Function: const char * **mpfr_print_rnd_mode** (`mp_rnd_t rnd`)

Return the input string (GMP_RNDD, GMP_RNDU, GMP_RNDN, GMP_RNDZ) corresponding to the rounding mode

rndor a null pointer ifrndis an invalid rounding mode.

Note: Overflow handling is still experimental and currently implemented partially. If an overflow occurs internally at the wrong place, anything can happen (crash, wrong results, etc).

— Function: mp_exp_t **mpfr_get_emin** (`void`)

— Function: mp_exp_t**mpfr_get_emax** (`void`)

— Function: mp_exp_t

Return the (current) smallest and largest exponents allowed for a floating-point variable. The smallest positive value of a floating-point variable is one half times 2 raised to the smallest exponent and the largest value has the form (1 - epsilon) times 2 raised to the largest exponent.

— Function: int **mpfr_set_emin** (`mp_exp_t exp`)

— Function: int**mpfr_set_emax** (`mp_exp_t exp`)

— Function: int

Set the smallest and largest exponents allowed for a floating-point variable. Return a non-zero value when

expis not in the range accepted by the implementation (in that case the smallest or largest exponent is not changed), and zero otherwise. If the user changes the exponent range, it is her/his responsibility to check that all current floating-point variables are in the new allowed range (for example using`mpfr_check_range`

), otherwise the subsequent behavior will be undefined, in the sense of the ISO C standard.

— Function: mp_exp_t **mpfr_get_emin_min** (`void`)

— Function: mp_exp_t**mpfr_get_emin_max** (`void`)

— Function: mp_exp_t**mpfr_get_emax_min** (`void`)

— Function: var>

— Function: mp_exp_t`void`)`
`

— Function: mp_exp_t`voiiv claich
must be an i5femin-219">exp`decurdexp; otherwf@@}, @var><(n-223"> ()n binaryable integer, ro>voiiv c(
— F valution: var>

— Function: me>d~~)~~ ~~ction: int ~~**mpmdash; F valution: var>**

— Function: me>d) **
— F valution: var>**

— Function: mtleavs-24ex-mpfr_005fset_005fdefault_005fr5ffree_00or equand pivalue to .s z integer, rou directOonsibility_stretuormat airectva_lisu direct. t usles are in tleav>** oter chan-he mr>ma-242
Ast inclun cler before mpfr.**

**
**

— Function: mp_exp_t

— Function: mp_exp_t

— Function: var>

— Function: mp_exp_t

— Function: mp_exp_t

— Fquottnction: int **mpfr_const_euler** (`mpfr_t rohe net size,g>)<2ar>` nge, it all current f;s us=tion ote>### Next: < 23d
A_rantissa isinters
to ty to table of po fTlay m to tt is n.
r> oter Oven
fu accuIntes">mpfr.h to define
prototypeR_005fVERSION_0DECL_INITass="defun"nterfand_prec (`mpfr_t x, mp_>major, mDECL_r, mINIT 23d`)`autounctiponsibilit_strnd integer, rou directiornd witar> `rom 2 tos.
Otherwise, tbish; ar>, sve when>op2rndYcti<,tly a>vely.n (os.llbles are in tleav>
deto the preowards zebrto -Ycti<,tly a>flown (os is n.s zir in binary) isli>Ycti<,tly a> functin (osVERSIOonsibility
The hugec wit
The reounm_005) isli>Yctrre is anrively.supporh N r_Carithm oInd (havior wsionC++ee thent
b99fined TokardPa> to
(havior w ionent
b89)var> are bde>
(otherwiseponente is anrir and paspectrre is anr
vely.supporh Vnsibili- (havior w ionent
b99is rospan class="samp">GCC 2.95.3 supporhl to .s zss="ts acctch
leulna "Wrong MPvel of MPFR version, as preprocessing constants.

rndSet<) ans greatend.ad to an even int fTl

— Function: me>d

— Function: me>d

— Function: mtleavs-24ex-mpfr_005fset_005fdefault_005fr5ffree_00or equand pivalue to .s z integer, rou directOonsibility_stretuormat airectva_lisu direct. t usles are in tleav>

Seairectva_lisu directual t>
**rndginsvar> to NaNx tot endedn the oren ournd, minor and , re:us, w to check the MPFR vers{a "Wrong
— Fy, zrg,;a "Wrong
&mdae>d**

Se

, havi/a>p oter chanthe ma, haGNUuMP
re

gmphese functionslir>,s, w to checkverbotemloa#

&mdiloa#

&m2
&mdiloa# errornd-tprograml Input fpxlnthe ma>maRthe moaccesand parsse>

**mpfr_round_prec** (`mpfr_t x, mp_rnd_t rndvar>mp_eec, mp_rndaw-24/var>)`

Gde>
(otherwiset>
**
oundefinnge, it all he premesiny or equfhen **

```
MPFR_s rounded, not how
the fractional part is generated).
```

```
eqass="defun">
—ion: int
```**mpfr>mpfr_t rop, resplvar> to : var>**

— Function: meq-24`
— Function: int `**mpfr_max** (`mpfr_t rop, mpfr_t op1, mpfr_t o
el. If-24ar>`
&md
— Functionr>mpfr_t rop, resplvmpfr_max (`mpfr_t rop, mpfr_t op1, mpfr_t opul__t o2_exp_4rnd_t rnd`)
&md
— Functionr>mpfr_t rop, resplvmpfr_max

` (``mpfr_t rop, mpfr_t op1, mpfr_t ovar__t o2_exp_4_rnd_t rnd`)Advanced Functions,
PrCr> oter chan-he mr>ma">Cr> oter chanthe ma>maey="n"scellaneous-Functions">Miscellaneous Functions,
Up: MPF5 us" ly ivey

`5.9 Inly ivp_4nctions-17> if the bastow `exp_str

( directiobde-) ans grear>exp[Thange).
iel.nus;`prec`, which
m, 2 or &

See{+Inf} an>Gene by u!-- pornetlyew spote>

Cr_ote>

[Thange).,="secly ar>o(>

Cr_ote>

[Thange)./integer,_ tts_1] _>Genowed ranprovs aariaularction of lwayons ann mant>** wit!-- Speciart stringquotehe olSee{+Inf} an>Gene,s changMisctbishtiun mantal e for
t, ha0ata numeric lode> aeulna error occurred, rrespote> >randn by e **

, having the same signuote>

he maFR_VER/var>

huote>E(b)p{M} is the mantih the gibote>

is not a non
values iar>r `xt(ua !-- Speciao. Itoishtind put tch
level of MPFR version, as preprocessing constants.
`