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\input texinfo @c -*-texinfo-*-
@c %**start of header
@settitle GCC libquadmath
@c %**end of header
Copyright @copyright{} 2010-2013 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 1.2 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 as in (a) below. A copy of the
license is included in the section entitled ``GNU Free Documentation
(a) The FSF's Back-Cover Text is: ``You have the freedom to
copy and modify this GNU manual.
@end quotation
@end copying
@dircategory GNU Libraries
* libquadmath: (libquadmath). GCC Quad-Precision Math Library
@end direntry
This manual documents the GCC Quad-Precision Math Library API.
Published by the Free Software Foundation
51 Franklin Street, Fifth Floor
Boston, MA 02110-1301 USA
@end ifinfo
@setchapternewpage odd
@title The GCC Quad-Precision Math Library
@vskip 0pt plus 1filll
@comment For the @value{version-GCC} Version*
@sp 1
Published by the Free Software Foundation @*
51 Franklin Street, Fifth Floor@*
Boston, MA 02110-1301, USA@*
@sp 1
@end titlepage
@node Top
@top Introduction
@cindex Introduction
This manual documents the usage of libquadmath, the GCC Quad-Precision
Math Library Application Programming Interface (API).
@comment When you add a new menu item, please keep the right hand
@comment aligned to the same column. Do not use tabs. This provides
@comment better formatting.
* Typedef and constants:: Defined data types and constants
* Math Library Routines:: The Libquadmath math runtime application
programming interface.
* I/O Library Routines:: The Libquadmath I/O runtime application
programming interface.
* GNU Free Documentation License::
How you can copy and share this manual.
* Reporting Bugs:: How to report bugs in GCC Libquadmath.
@c * Index:: Index of this documentation.
@end menu
@c ---------------------------------------------------------------------
@c Defined macros
@c ---------------------------------------------------------------------
@node Typedef and constants
@chapter Typedef and constants
The following data type has been defined via @code{typedef}.
@table @asis
@item @code{__complex128}: @code{__float128}-based complex number
@end table
The following macros are defined, which give the numeric limits of the
@code{__float128} data type.
@table @asis
@item @code{FLT128_MAX}: largest finite number
@item @code{FLT128_MIN}: smallest positive number with full precision
@item @code{FLT128_EPSILON}: difference between 1 and the next larger
representable number
@item @code{FLT128_DENORM_MIN}: smallest positive denormalized number
@item @code{FLT128_MANT_DIG}: number of digits in the mantissa (bit precision)
@item @code{FLT128_MIN_EXP}: maximal negative exponent
@item @code{FLT128_MAX_EXP}: maximal positive exponent
@item @code{FLT128_DIG}: number of decimal digits in the mantissa
@item @code{FLT128_MIN_10_EXP}: maximal negative decimal exponent
@item @code{FLT128_MAX_10_EXP}: maximal positive decimal exponent
@end table
The following mathematical constants of type @code{__float128} are defined.
@table @asis
@item @code{M_Eq}: the constant e (Euler's number)
@item @code{M_LOG2Eq}: binary logarithm of 2
@item @code{M_LOG10Eq}: common, decimal logarithm of 2
@item @code{M_LN2q}: natural logarithm of 2
@item @code{M_LN10q}: natural logarithm of 10
@item @code{M_PIq}: pi
@item @code{M_PI_2q}: pi divided by two
@item @code{M_PI_4q}: pi divided by four
@item @code{M_1_PIq}: one over pi
@item @code{M_2_PIq}: one over two pi
@item @code{M_2_SQRTPIq}: two over square root of pi
@item @code{M_SQRT2q}: square root of 2
@item @code{M_SQRT1_2q}: one over square root of 2
@end table
@c ---------------------------------------------------------------------
@c Math routines
@c ---------------------------------------------------------------------
@node Math Library Routines
@chapter Math Library Routines
The following mathematical functions are available:
@table @asis
@item @code{acosq}: arc cosine function
@item @code{acoshq}: inverse hyperbolic cosine function
@item @code{asinq}: arc sine function
@item @code{asinhq}: inverse hyperbolic sine function
@item @code{atanq}: arc tangent function
@item @code{atanhq}: inverse hyperbolic tangent function
@item @code{atan2q}: arc tangent function
@item @code{cbrtq}: cube root function
@item @code{ceilq}: ceiling value function
@item @code{copysignq}: copy sign of a number
@item @code{coshq}: hyperbolic cosine function
@item @code{cosq}: cosine function
@item @code{erfq}: error function
@item @code{erfcq}: complementary error function
@item @code{expq}: exponential function
@item @code{expm1q}: exponential minus 1 function
@need 800
@item @code{fabsq}: absolute value function
@item @code{fdimq}: positive difference function
@item @code{finiteq}: check finiteness of value
@item @code{floorq}: floor value function
@item @code{fmaq}: fused multiply and add
@item @code{fmaxq}: determine maximum of two values
@item @code{fminq}: determine minimum of two values
@item @code{fmodq}: remainder value function
@item @code{frexpq}: extract mantissa and exponent
@item @code{hypotq}: Eucledian distance function
@item @code{ilogbq}: get exponent of the value
@item @code{isinfq}: check for infinity
@item @code{isnanq}: check for not a number
@item @code{j0q}: Bessel function of the first kind, first order
@item @code{j1q}: Bessel function of the first kind, second order
@item @code{jnq}: Bessel function of the first kind, @var{n}-th order
@item @code{ldexpq}: load exponent of the value
@item @code{lgammaq}: logarithmic gamma function
@item @code{llrintq}: round to nearest integer value
@item @code{llroundq}: round to nearest integer value away from zero
@item @code{logq}: natural logarithm function
@item @code{log10q}: base 10 logarithm function
@item @code{log1pq}: compute natural logarithm of the value plus one
@item @code{log2q}: base 2 logarithm function
@need 800
@item @code{lrintq}: round to nearest integer value
@item @code{lroundq}: round to nearest integer value away from zero
@item @code{modfq}: decompose the floating-point number
@item @code{nanq}: return quiet NaN
@item @code{nearbyintq}: round to nearest integer
@item @code{nextafterq}: next representable floating-point number
@item @code{powq}: power function
@item @code{remainderq}: remainder function
@item @code{remquoq}: remainder and part of quotient
@item @code{rintq}: round-to-nearest integral value
@item @code{roundq}: round-to-nearest integral value, return @code{__float128}
@item @code{scalblnq}: compute exponent using @code{FLT_RADIX}
@item @code{scalbnq}: compute exponent using @code{FLT_RADIX}
@item @code{signbitq}: return sign bit
@item @code{sincosq}: calculate sine and cosine simulataneously
@item @code{sinhq}: hyperbolic sine function
@item @code{sinq}: sine function
@item @code{sqrtq}: square root function
@item @code{tanq}: tangent function
@item @code{tanhq}: hyperbolic tangent function
@need 800
@item @code{tgammaq}: true gamma function
@item @code{truncq}: round to integer, towards zero
@item @code{y0q}: Bessel function of the second kind, first order
@item @code{y1q}: Bessel function of the second kind, second order
@item @code{ynq}: Bessel function of the second kind, @var{n}-th order
@item @code{cabsq} complex absolute value function
@item @code{cargq}: calculate the argument
@item @code{cimagq} imaginary part of complex number
@item @code{crealq}: real part of complex number
@item @code{cacoshq}: complex arc hyperbolic cosine function
@item @code{cacosq}: complex arc cosine function
@item @code{casinhq}: complex arc hyperbolic sine function
@item @code{casinq}: complex arc sine function
@item @code{catanhq}: complex arc hyperbolic tangent function
@item @code{catanq}: complex arc tangent function
@item @code{ccosq} complex cosine function:
@item @code{ccoshq}: complex hyperbolic cosine function
@item @code{cexpq}: complex exponential function
@need 800
@item @code{cexpiq}: computes the exponential function of ``i'' times a
real value
@item @code{clogq}: complex natural logarithm
@item @code{clog10q}: complex base 10 logarithm
@item @code{conjq}: complex conjugate function
@item @code{cpowq}: complex power function
@item @code{cprojq}: project into Riemann Sphere
@item @code{csinq}: complex sine function
@item @code{csinhq}: complex hyperbolic sine function
@item @code{csqrtq}: complex square root
@item @code{ctanq}: complex tangent function
@item @code{ctanhq}: complex hyperbolic tangent function
@end table
@c ---------------------------------------------------------------------
@c I/O routines
@c ---------------------------------------------------------------------
@node I/O Library Routines
@chapter I/O Library Routines
* @code{strtoflt128}: strtoflt128, Convert from string
* @code{quadmath_snprintf}: quadmath_snprintf, Convert to string
@end menu
@node strtoflt128
@section @code{strtoflt128} --- Convert from string
The function @code{strtoflt128} converts a string into a
@code{__float128} number.
@table @asis
@item Syntax
@code{__float128 strtoflt128 (const char *s, char **sp)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .70
@item @var{s} @tab input string
@item @var{sp} @tab the address of the next character in the string
@end multitable
The argument @var{sp} contains, if not @code{NULL}, the address of the
next character following the parts of the string, which have been read.
@item Example
#include <quadmath.h>
int main ()
__float128 r;
r = strtoflt128 ("1.2345678", NULL);
return 0;
@end smallexample
@end table
@node quadmath_snprintf
@section @code{quadmath_snprintf} --- Convert to string
The function @code{quadmath_snprintf} converts a @code{__float128} floating-point
number into a string. It is a specialized alternative to @code{snprintf}, where
the format string is restricted to a single conversion specifier with @code{Q}
modifier and conversion specifier @code{e}, @code{E}, @code{f}, @code{F}, @code{g},
@code{G}, @code{a} or @code{A}, with no extra characters before or after the
conversion specifier. The @code{%m$} or @code{*m$} style must not be used in
the format.
@table @asis
@item Syntax
@code{int quadmath_snprintf (char *s, size_t size, const char *format, ...)}
@item @emph{Arguments}:
@multitable @columnfractions .15 .70
@item @var{s} @tab output string
@item @var{size} @tab byte size of the string, including tailing NUL
@item @var{format} @tab conversion specifier string
@end multitable
@item Note
On some targets when supported by the C library hooks are installed
for @code{printf} family of functions, so that @code{printf ("%Qe", 1.2Q);}
etc.@: works too.
@item Example
#include <quadmath.h>
#include <stdlib.h>
#include <stdio.h>
int main ()
__float128 r;
int prec = 20;
int width = 46;
char buf[128];
r = 2.0q;
r = sqrtq (r);
int n = quadmath_snprintf (buf, sizeof buf, "%+-#*.20Qe", width, r);
if ((size_t) n < sizeof buf)
printf ("%s\n", buf);
/* Prints: +1.41421356237309504880e+00 */
quadmath_snprintf (buf, sizeof buf, "%Qa", r);
if ((size_t) n < sizeof buf)
printf ("%s\n", buf);
/* Prints: 0x1.6a09e667f3bcc908b2fb1366ea96p+0 */
n = quadmath_snprintf (NULL, 0, "%+-#46.*Qe", prec, r);
if (n > -1)
char *str = malloc (n + 1);
if (str)
quadmath_snprintf (str, n + 1, "%+-#46.*Qe", prec, r);
printf ("%s\n", str);
/* Prints: +1.41421356237309504880e+00 */
free (str);
return 0;
@end smallexample
@end table
@c ---------------------------------------------------------------------
@c GNU Free Documentation License
@c ---------------------------------------------------------------------
@include fdl.texi
@c ---------------------------------------------------------------------
@c Reporting Bugs
@c ---------------------------------------------------------------------
@include libquadmath-vers.texi
@node Reporting Bugs
@chapter Reporting Bugs
Bugs in the GCC Quad-Precision Math Library implementation should be
reported via @value{BUGURL}.
@c ---------------------------------------------------------------------
@c Index
@c ---------------------------------------------------------------------
@c @node Index
@c @unnumbered Index
@c @printindex cp