PSUM2 3CW "16 April 2007" "mathcw-1.00"

Table of contents


NAME

psum2f, psum2, psum2l, psum2w, psum2q, psum2ll, psum2df, psum2d, psum2dl, psum2dll - pair-precision sum and error estimate

SYNOPSIS

cc [ flags ] -I/usr/local/include file(s) -L/usr/local/lib -lmcw [ ... ]

#include <mathcw.h>
#include <paircw.h>

extern void psum2f (float_pair result, float x, float y);

extern void psum2 (double_pair result, double x, double y);

extern void psum2l (long_double_pair result, long double x, long double y);

extern void psum2w (__float80_pair result, __float80 x, __float80 y);

extern void psum2q (__float128_pair result, __float128 x, __float128 y);

extern void psum2ll (long_long_double_pair result, long_long_double x, long_long_double y);

extern void psum2df (decimal_float_pair result, decimal_float x, decimal_float y);

extern void psum2d (decimal_double_pair result, decimal_double x, decimal_double y);

extern void psum2dl (decimal_long_double_pair result, decimal_long_double x, decimal_long_double y);

extern void psum2dll (decimal_long_long_double_pair result, decimal_long_long_double x,
                      decimal_long_long_double y);

NB: Functions with prototypes containing underscores in type names may be available only with certain extended compilers.


DESCRIPTION

Compute the scalar sum x + y in pair-precision arithmetic, such that the high part is an accurate estimate of the sum, and the low part, an estimate of the error.

If the magnitude of y is zero, or smaller than that of x by at least a factor of the machine epsilon, it is faster to use pset(3CW).

This function provides a type cast from ordinary scalar floating-point arithmetic to pair-precision arithmetic.


RETURN VALUES

None. The function result is stored in the first argument, result.

ERRORS

None.

SEE ALSO

pabs(3CW), pacos(3CW), pacosh(3CW), padd(3CW), pasin(3CW), pasinh(3CW), patan(3CW), patan2(3CW), patanh(3CW), pcbrt(3CW), pcmp(3CW), pcon(3CW), pcopy(3CW), pcopysign(3CW), pcos(3CW), pcosh(3CW), pcotan(3CW), pdiv(3CW), pdot(3CW), peps(3CW), peval(3CW), pexp(3CW), pexp10(3CW), pexp16(3CW), pexp2(3CW), pexp8(3CW), pexpm1(3CW), pfdim(3CW), pfmax(3CW), pfmin(3CW), pfrexp(3CW), pfrexph(3CW), phigh(3CW), phypot(3CW), pierf(3CW), pierfc(3CW), pilogb(3CW), pin(3CW), pinfty(3CW), pipow(3CW), pisinf(3CW), pisnan(3CW), pisqnan(3CW), pissnan(3CW), pldexp(3CW), pldexph(3CW), plog(3CW), plog101p(3CW), plog1p(3CW), plow(3CW), pmul(3CW), pmul2(3CW), pneg(3CW), pout(3CW), pprosum(3CW), pqnan(3CW), pscalbln(3CW), pscalbn(3CW), pset(3CW), psignbit(3CW), psin(3CW), psinh(3CW), psnan(3CW), psplit(3CW), psqrt(3CW), psub(3CW), psum(3CW), ptan(3CW), ptanh(3CW).