12116Sjkh/* s_nextafterf.c -- float version of s_nextafter.c.
22116Sjkh * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
32116Sjkh */
42116Sjkh
52116Sjkh/*
62116Sjkh * ====================================================
72116Sjkh * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
82116Sjkh *
92116Sjkh * Developed at SunPro, a Sun Microsystems, Inc. business.
102116Sjkh * Permission to use, copy, modify, and distribute this
118870Srgrimes * software is freely granted, provided that this notice
122116Sjkh * is preserved.
132116Sjkh * ====================================================
142116Sjkh */
152116Sjkh
16176451Sdas#include <sys/cdefs.h>
17176451Sdas__FBSDID("$FreeBSD$");
182116Sjkh
192116Sjkh#include "math.h"
202116Sjkh#include "math_private.h"
212116Sjkh
2297413Salfredfloat
2397413Salfrednextafterf(float x, float y)
242116Sjkh{
25143216Sdas	volatile float t;
262116Sjkh	int32_t hx,hy,ix,iy;
272116Sjkh
282116Sjkh	GET_FLOAT_WORD(hx,x);
292116Sjkh	GET_FLOAT_WORD(hy,y);
302116Sjkh	ix = hx&0x7fffffff;		/* |x| */
312116Sjkh	iy = hy&0x7fffffff;		/* |y| */
322116Sjkh
338870Srgrimes	if((ix>0x7f800000) ||   /* x is nan */
348870Srgrimes	   (iy>0x7f800000))     /* y is nan */
358870Srgrimes	   return x+y;
36140685Sdas	if(x==y) return y;		/* x=y, return y */
372116Sjkh	if(ix==0) {				/* x == 0 */
382116Sjkh	    SET_FLOAT_WORD(x,(hy&0x80000000)|1);/* return +-minsubnormal */
39143216Sdas	    t = x*x;
40143216Sdas	    if(t==x) return t; else return x;	/* raise underflow flag */
418870Srgrimes	}
422116Sjkh	if(hx>=0) {				/* x > 0 */
432116Sjkh	    if(hx>hy) {				/* x > y, x -= ulp */
442116Sjkh		hx -= 1;
452116Sjkh	    } else {				/* x < y, x += ulp */
462116Sjkh		hx += 1;
472116Sjkh	    }
482116Sjkh	} else {				/* x < 0 */
492116Sjkh	    if(hy>=0||hx>hy){			/* x < y, x -= ulp */
502116Sjkh		hx -= 1;
512116Sjkh	    } else {				/* x > y, x += ulp */
522116Sjkh		hx += 1;
532116Sjkh	    }
542116Sjkh	}
552116Sjkh	hy = hx&0x7f800000;
562116Sjkh	if(hy>=0x7f800000) return x+x;	/* overflow  */
572116Sjkh	if(hy<0x00800000) {		/* underflow */
58143216Sdas	    t = x*x;
59143216Sdas	    if(t!=x) {		/* raise underflow flag */
602116Sjkh	        SET_FLOAT_WORD(y,hx);
612116Sjkh		return y;
622116Sjkh	    }
632116Sjkh	}
642116Sjkh	SET_FLOAT_WORD(x,hx);
652116Sjkh	return x;
662116Sjkh}
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