GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libm/src/s_nextafter.c Lines: 22 35 62.9 %
Date: 2017-11-13 Branches: 18 44 40.9 %

Line Branch Exec Source
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/* @(#)s_nextafter.c 5.1 93/09/24 */
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/*
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 * ====================================================
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 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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 *
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 * Developed at SunPro, a Sun Microsystems, Inc. business.
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 * Permission to use, copy, modify, and distribute this
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 * software is freely granted, provided that this notice
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 * is preserved.
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 * ====================================================
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 */
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/* IEEE functions
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 *	nextafter(x,y)
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 *	return the next machine floating-point number of x in the
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 *	direction toward y.
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 *   Special cases:
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 */
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#include <float.h>
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#include <math.h>
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#include "math_private.h"
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double
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nextafter(double x, double y)
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{
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	int32_t hx,hy,ix,iy;
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	u_int32_t lx,ly;
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	EXTRACT_WORDS(hx,lx,x);
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	EXTRACT_WORDS(hy,ly,y);
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	ix = hx&0x7fffffff;		/* |x| */
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	iy = hy&0x7fffffff;		/* |y| */
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	if(((ix>=0x7ff00000)&&((ix-0x7ff00000)|lx)!=0) ||   /* x is nan */
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	   ((iy>=0x7ff00000)&&((iy-0x7ff00000)|ly)!=0))     /* y is nan */
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	   return x+y;
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	if(x==y) return y;		/* x=y, return y */
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	if((ix|lx)==0) {			/* x == 0 */
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	    INSERT_WORDS(x,hy&0x80000000,1);	/* return +-minsubnormal */
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	    y = x*x;
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	    if(y==x) return y; else return x;	/* raise underflow flag */
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	}
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	if(hx>=0) {				/* x > 0 */
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	    if(hx>hy||((hx==hy)&&(lx>ly))) {	/* x > y, x -= ulp */
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		if(lx==0) hx -= 1;
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		lx -= 1;
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	    } else {				/* x < y, x += ulp */
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		lx += 1;
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		if(lx==0) hx += 1;
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	    }
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	} else {				/* x < 0 */
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	    if(hy>=0||hx>hy||((hx==hy)&&(lx>ly))){/* x < y, x -= ulp */
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		if(lx==0) hx -= 1;
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		lx -= 1;
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	    } else {				/* x > y, x += ulp */
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		lx += 1;
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		if(lx==0) hx += 1;
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	    }
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	}
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	hy = hx&0x7ff00000;
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	if(hy>=0x7ff00000) return x+x;	/* overflow  */
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	if(hy<0x00100000) {		/* underflow */
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	    y = x*x;
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	    if(y!=x) {		/* raise underflow flag */
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	        INSERT_WORDS(y,hx,lx);
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		return y;
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	    }
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	}
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	INSERT_WORDS(x,hx,lx);
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	return x;
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}
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DEF_STD(nextafter);
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LDBL_MAYBE_CLONE(nextafter);
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#if	LDBL_MANT_DIG == DBL_MANT_DIG
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MAKE_UNUSED_CLONE(nexttoward, nextafter);
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MAKE_UNUSED_CLONE(nexttowardl, nextafter);
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#endif	/* LDBL_MANT_DIG == DBL_MANT_DIG */