Subversion Repositories openrisc_2011-10-31

/*

FUNCTION

<<fma>>, <<fmaf>>--floating multiply add

INDEX

        fma

INDEX

        fmaf

ANSI_SYNOPSIS

        #include <math.h>

        double fma(double <[x]>, double <[y]>, double <[z]>);

        float fmaf(float <[x]>, float <[y]>, float <[z]>);

DESCRIPTION

The <<fma>> functions compute (<[x]> * <[y]>) + <[z]>, rounded as one ternary

operation:  they compute the value (as if) to infinite precision and round once

to the result format, according to the rounding mode characterized by the value

of FLT_ROUNDS.  That is, they are supposed to do this:  see below.

RETURNS

The <<fma>> functions return (<[x]> * <[y]>) + <[z]>, rounded as one ternary

operation.

BUGS

This implementation does not provide the function that it should, purely

returning "(<[x]> * <[y]>) + <[z]>;" with no attempt at all to provide the

simulated infinite precision intermediates which are required.  DO NOT USE THEM.

If double has enough more precision than float, then <<fmaf>> should provide

the expected numeric results, as it does use double for the calculation.  But

since this is not the case for all platforms, this manual cannot determine

if it is so for your case.

PORTABILITY

ANSI C, POSIX.

*/

#include "fdlibm.h"

#ifndef _DOUBLE_IS_32BITS

#ifdef __STDC__

        double fma(double x, double y, double z)

#else

        double fma(x,y)

        double x;

        double y;

        double z;

#endif

{

  /* Implementation defined. */

  return (x * y) + z;

}

#endif /* _DOUBLE_IS_32BITS */