33 lines
778 B
C
33 lines
778 B
C
/* ~(#)fmod.c 2.1.1.1 */
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/* ~(#)fmod.c 1.8 */
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/*LINTLIBRARY*/
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/*
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* fmod(x, y) returns the remainder of x on division by y,
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* with the same sign as x,
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* except that if |y| << |x|, it returns 0.
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*/
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#include <math.h>
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double
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fmod(x, y)
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register double x, y;
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{
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double d; /* can't be in register because of modf() below */
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/*
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* The next lines determine if |y| is negligible compared to |x|,
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* without dividing, and without adding values of the same sign.
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*/
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if( y==0.0 ) return( x ); /* fmod(x,0.0)==x */
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d = _ABS(x);
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if (d - _ABS(y) == d)
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return (0.0);
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#if !defined(pdp11) && !defined(u3b5) /* pdp11 and u3b5 "cc" cant handle
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cast of a double to a void */
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(void)
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#endif
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modf(x/y, &d); /* now it's safe to divide without overflow */
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return (x - d * y);
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}
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