\input texinfo @c -*-texinfo-*- @c %**start of header@setfilename libquadmath.info@settitle GCC libquadmath@c %**end of header @copyingCopyright @copyright{} 2010-2026 Free Software Foundation, Inc. @quotationPermission is granted to copy, distribute and/or modify this documentunder the terms of the GNU Free Documentation License, Version 1.2 orany later version published by the Free Software Foundation; with noInvariant Sections, with the Front-Cover Texts being ``A GNU Manual,''and with the Back-Cover Texts as in (a) below.  A copy of thelicense is included in the section entitled ``GNU Free DocumentationLicense.'' (a) The FSF's Back-Cover Text is: ``You have the freedom tocopy and modify this GNU manual.@end quotation@end copying @ifinfo@dircategory GNU Libraries@direntry* libquadmath: (libquadmath).                  GCC Quad-Precision Math Library@end direntry This manual documents the GCC Quad-Precision Math Library API. Published by the Free Software Foundation51 Franklin Street, Fifth FloorBoston, MA 02110-1301 USA @insertcopying@end ifinfo  @setchapternewpage odd @titlepage@title The GCC Quad-Precision Math Library@page@vskip 0pt plus 1filll@comment For the @value{version-GCC} Version*@sp 1Published by the Free Software Foundation @*51 Franklin Street, Fifth Floor@*Boston, MA 02110-1301, USA@*@sp 1@insertcopying@end titlepage @summarycontents@contents@page  @node Top@top Introduction@cindex Introduction This manual documents the usage of libquadmath, the GCC Quad-PrecisionMath Library Application Programming Interface (API).  @comment@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.@comment@menu* 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}: base 2 logarithm of e@item @code{M_LOG10Eq}: decimal (base 10) logarithm of e@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 divided by pi@item @code{M_2_PIq}: two divided by pi@item @code{M_2_SQRTPIq}: two divided by square root of pi@item @code{M_SQRT2q}: square root of 2@item @code{M_SQRT1_2q}: one divided by 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{exp2q}: base 2 exponential 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{issignalingq}: check for signaling 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{logbq}: get exponent of the value@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 simultaneously@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 @menu* @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 thenext character following the parts of the string, which have been read. @item Example@smallexample#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-pointnumber into a string.  It is a specialized alternative to @code{snprintf}, wherethe 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 theconversion specifier.  The @code{%m$} or @code{*m$} style must not be used inthe 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 trailing NUL@item @var{format} @tab conversion specifier string@end multitable @item NoteOn some targets when supported by the C library hooks are installedfor @code{printf} family of functions, so that @code{printf ("%Qe", 1.2Q);}etc.@: works too. @item Example@smallexample#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 --------------------------------------------------------------------- @c For BUGURL@include libquadmath-vers.texi @node Reporting Bugs@chapter Reporting Bugs Bugs in the GCC Quad-Precision Math Library implementation should bereported via @value{BUGURL}.  @c ---------------------------------------------------------------------@c Index@c --------------------------------------------------------------------- @c @node Index@c @unnumbered Index@c @c @printindex cp @bye