\input texinfo @c -*-texinfo-*- @c %**start of header @setfilename libquadmath.info @settitle GCC libquadmath @c %**end of header @copying Copyright @copyright{} 2010-2020 Free Software Foundation, Inc. @quotation 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 License.'' (a) The FSF's Back-Cover Text is: ``You have the freedom to copy 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 Foundation 51 Franklin Street, Fifth Floor Boston, 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 1 Published 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-Precision Math 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}: 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{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 the next 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-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 @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 be reported via @value{BUGURL}. @c --------------------------------------------------------------------- @c Index @c --------------------------------------------------------------------- @c @node Index @c @unnumbered Index @c @c @printindex cp @bye