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FMA(3)                     Linux Programmer's Manual                    FMA(3)

NAME
       fma, fmaf, fmal - floating-point multiply and add
SYNOPSIS
       #include <math.h>
       double fma(double x, double y, double z);
       float fmaf(float x, float y, float z);
       long double fmal(long double x, long double y, long double z);
       Link with -lm.
   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
       fma(), fmaf(), fmal():
           _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
           _POSIX_C_SOURCE >= 200112L;
           or cc -std=c99
DESCRIPTION
       The fma() function computes x * y + z.  The result is  rounded  as  one
       ternary operation according to the current rounding mode (see fenv(3)).
RETURN VALUE
       These  functions  return the value of x * y + z, rounded as one ternary
       operation.
       If x or y is a NaN, a NaN is returned.
       If x times y is an exact infinity, and z is an infinity with the  oppo-
       site sign, a domain error occurs, and a NaN is returned.
       If  one of x or y is an infinity, the other is 0, and z is not a NaN, a
       domain error occurs, and a NaN is returned.
       If one of x or y is an infinity, and the other is 0, and z is a NaN,  a
       domain error occurs, and a NaN is returned.
       If  x times y is not an infinity times zero (or vice versa), and z is a
       NaN, a NaN is returned.
       If the result overflows, a range error occurs, and an infinity with the
       correct sign is returned.
       If  the  result  underflows,  a  range  error occurs, and a signed 0 is
       returned.
ERRORS
       See math_error(7) for information on how to determine whether an  error
       has occurred when calling these functions.
       The following errors can occur:
       Domain error: x * y + z, or x * y is invalid and z is not a NaN
              An invalid floating-point exception (FE_INVALID) is raised.
       Range error: result overflow
              An overflow floating-point exception (FE_OVERFLOW) is raised.
       Range error: result underflow
              An underflow floating-point exception (FE_UNDERFLOW) is raised.
       These functions do not set errno.
VERSIONS
       These functions first appeared in glibc in version 2.1.
CONFORMING TO
       C99, POSIX.1-2001.
SEE ALSO
       remainder(3), remquo(3)
COLOPHON
       This  page  is  part of release 3.53 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

                                  2010-09-20                            FMA(3)