[thirdparty/glibc.git] / sysdeps / i386 / fpu / s_nextafterl.c

/* s_nextafterl.c -- long double version of s_nextafter.c.
 * Special version for i387.
 * Conversion to long double by Ulrich Drepper,
 * Cygnus Support, drepper@cygnus.com.
 */

/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */

#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: $";
#endif

/* IEEE functions
 *	nextafterl(x,y)
 *	return the next machine floating-point number of x in the
 *	direction toward y.
 *   Special cases:
 */

#include "math.h"
#include <math_private.h>

#ifdef __STDC__
	long double __nextafterl(long double x, long double y)
#else
	long double __nextafterl(x,y)
	long double x,y;
#endif
{
	u_int32_t hx,hy,ix,iy;
	u_int32_t lx,ly;
	int32_t esx,esy;

	GET_LDOUBLE_WORDS(esx,hx,lx,x);
	GET_LDOUBLE_WORDS(esy,hy,ly,y);
	ix = esx&0x7fff;		/* |x| */
	iy = esy&0x7fff;		/* |y| */

	/* Intel's extended format has the normally implicit 1 explicit
	   present.  Sigh!  */
	if(((ix==0x7fff)&&(((hx&0x7fffffff)|lx)!=0)) ||   /* x is nan */
	   ((iy==0x7fff)&&(((hy&0x7fffffff)|ly)!=0)))     /* y is nan */
	   return x+y;
	if(x==y) return y;		/* x=y, return y */
	if((ix|hx|lx)==0) {			/* x == 0 */
	    long double u;
	    SET_LDOUBLE_WORDS(x,esy&0x8000,0,1);/* return +-minsubnormal */
	    u = math_opt_barrier (x);
	    u = u * u;
	    math_force_eval (u);		/* raise underflow flag */
	    return x;
	}
	if(esx>=0) {			/* x > 0 */
	    if(esx>esy||((esx==esy) && (hx>hy||((hx==hy)&&(lx>ly))))) {
	      /* x > y, x -= ulp */
		if(lx==0) {
		    if (hx <= 0x80000000) {
		      if (esx == 0) {
			--hx;
		      } else {
			esx -= 1;
			hx = hx - 1;
			if (esx > 0)
			  hx |= 0x80000000;
		      }
		    } else
		      hx -= 1;
		}
		lx -= 1;
	    } else {				/* x < y, x += ulp */
		lx += 1;
		if(lx==0) {
		    hx += 1;
		    if (hx==0 || (esx == 0 && hx == 0x80000000)) {
			esx += 1;
			hx |= 0x80000000;
		    }
		}
	    }
	} else {				/* x < 0 */
	    if(esy>=0||(esx>esy||((esx==esy)&&(hx>hy||((hx==hy)&&(lx>ly)))))){
	      /* x < y, x -= ulp */
		if(lx==0) {
		    if (hx <= 0x80000000) {
			esx -= 1;
			hx = hx - 1;
			if ((esx&0x7fff) > 0)
			  hx |= 0x80000000;
		    } else
		      hx -= 1;
		}
		lx -= 1;
	    } else {				/* x > y, x += ulp */
		lx += 1;
		if(lx==0) {
		    hx += 1;
		    if (hx==0 || (esx == 0xffff8000 && hx == 0x80000000)) {
			esx += 1;
			hx |= 0x80000000;
		    }
		}
	    }
	}
	esy = esx&0x7fff;
	if(esy==0x7fff) return x+x;	/* overflow  */
	if(esy==0) {
	    long double u = x*x;		/* underflow */
	    math_force_eval (u);		/* raise underflow flag */
	}
	SET_LDOUBLE_WORDS(x,esx,hx,lx);
	return x;
}
weak_alias (__nextafterl, nextafterl)
strong_alias (__nextafterl, __nexttowardl)
weak_alias (__nextafterl, nexttowardl)
Commit	Line	Data
76060ec0 RM	1	/* s_nextafterl.c -- long double version of s_nextafter.c.
	2	* Special version for i387.
	3	* Conversion to long double by Ulrich Drepper,
	4	* Cygnus Support, drepper@cygnus.com.
	5	*/
	6
	7	/*
	8	* ====================================================
	9	* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
	10	*
	11	* Developed at SunPro, a Sun Microsystems, Inc. business.
	12	* Permission to use, copy, modify, and distribute this
	13	* software is freely granted, provided that this notice
	14	* is preserved.
	15	* ====================================================
	16	*/
	17
	18	#if defined(LIBM_SCCS) && !defined(lint)
	19	static char rcsid[] = "$NetBSD: $";
	20	#endif
	21
	22	/* IEEE functions
	23	* nextafterl(x,y)
	24	* return the next machine floating-point number of x in the
	25	* direction toward y.
	26	* Special cases:
	27	*/
	28
	29	#include "math.h"
0ecb606c	30	#include <math_private.h>
76060ec0 RM	31
	32	#ifdef __STDC__
	33	long double __nextafterl(long double x, long double y)
	34	#else
	35	long double __nextafterl(x,y)
	36	long double x,y;
	37	#endif
	38	{
cc46d0cf UD	39	u_int32_t hx,hy,ix,iy;
	40	u_int32_t lx,ly;
	41	int32_t esx,esy;
76060ec0 RM	42
	43	GET_LDOUBLE_WORDS(esx,hx,lx,x);
	44	GET_LDOUBLE_WORDS(esy,hy,ly,y);
	45	ix = esx&0x7fff; /* \|x\| */
	46	iy = esy&0x7fff; /* \|y\| */
	47
636ccfc8 UD	48	/* Intel's extended format has the normally implicit 1 explicit
636ccfc8 UD	49	present. Sigh! */
37695e8f AJ	50	if(((ix==0x7fff)&&(((hx&0x7fffffff)\|lx)!=0)) \|\| /* x is nan */
37695e8f AJ	51	((iy==0x7fff)&&(((hy&0x7fffffff)\|ly)!=0))) /* y is nan */
76060ec0	52	return x+y;
bc9f6000	53	if(x==y) return y; /* x=y, return y */
76060ec0	54	if((ix\|hx\|lx)==0) { /* x == 0 */
0ecb606c	55	long double u;
e3bb40e6	56	SET_LDOUBLE_WORDS(x,esy&0x8000,0,1);/* return +-minsubnormal */
0ecb606c JJ	57	u = math_opt_barrier (x);
	58	u = u * u;
	59	math_force_eval (u); /* raise underflow flag */
	60	return x;
76060ec0	61	}
ddc3ed9d	62	if(esx>=0) { /* x > 0 */
e3bb40e6	63	if(esx>esy\|\|((esx==esy) && (hx>hy\|\|((hx==hy)&&(lx>ly))))) {
76060ec0 RM	64	/* x > y, x -= ulp */
76060ec0 RM	65	if(lx==0) {
f8da88b0	66	if (hx <= 0x80000000) {
a439bb2f UD	67	if (esx == 0) {
	68	--hx;
	69	} else {
f8da88b0 UD	70	esx -= 1;
	71	hx = hx - 1;
	72	if (esx > 0)
	73	hx \|= 0x80000000;
	74	}
	75	} else
	76	hx -= 1;
76060ec0 RM	77	}
	78	lx -= 1;
	79	} else { /* x < y, x += ulp */
	80	lx += 1;
	81	if(lx==0) {
	82	hx += 1;
e3bb40e6	83	if (hx==0 \|\| (esx == 0 && hx == 0x80000000)) {
76060ec0	84	esx += 1;
e3bb40e6 UD	85	hx \|= 0x80000000;
e3bb40e6 UD	86	}
76060ec0 RM	87	}
	88	}
	89	} else { /* x < 0 */
e3bb40e6	90	if(esy>=0\|\|(esx>esy\|\|((esx==esy)&&(hx>hy\|\|((hx==hy)&&(lx>ly)))))){
76060ec0 RM	91	/* x < y, x -= ulp */
76060ec0 RM	92	if(lx==0) {
f8da88b0	93	if (hx <= 0x80000000) {
f8da88b0 UD	94	esx -= 1;
f8da88b0 UD	95	hx = hx - 1;
cc46d0cf	96	if ((esx&0x7fff) > 0)
f8da88b0	97	hx \|= 0x80000000;
f8da88b0 UD	98	} else
f8da88b0 UD	99	hx -= 1;
76060ec0 RM	100	}
	101	lx -= 1;
	102	} else { /* x > y, x += ulp */
	103	lx += 1;
	104	if(lx==0) {
	105	hx += 1;
e3bb40e6 UD	106	if (hx==0 \|\| (esx == 0xffff8000 && hx == 0x80000000)) {
	107	esx += 1;
	108	hx \|= 0x80000000;
	109	}
76060ec0 RM	110	}
	111	}
	112	}
	113	esy = esx&0x7fff;
	114	if(esy==0x7fff) return x+x; /* overflow */
0ecb606c JJ	115	if(esy==0) {
	116	long double u = xx; / underflow */
	117	math_force_eval (u); /* raise underflow flag */
76060ec0 RM	118	}
	119	SET_LDOUBLE_WORDS(x,esx,hx,lx);
	120	return x;
	121	}
	122	weak_alias (__nextafterl, nextafterl)
f30e0cd3 UD	123	strong_alias (__nextafterl, __nexttowardl)
f30e0cd3 UD	124	weak_alias (__nextafterl, nexttowardl)