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author | Ulrich Drepper <drepper@redhat.com> | 1999-07-14 00:54:57 +0000 |
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committer | Ulrich Drepper <drepper@redhat.com> | 1999-07-14 00:54:57 +0000 |
commit | abfbdde177c3a7155070dda1b2cdc8292054cc26 (patch) | |
tree | e021306b596381fbf8311d2b7eb294e918ff17c8 /sysdeps/generic/s_nextafter.c | |
parent | 86421aa57ecfd70963ae66848bd6a6dd3b8e0fe6 (diff) | |
download | glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.tar.gz glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.tar.xz glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.zip |
Update.
Diffstat (limited to 'sysdeps/generic/s_nextafter.c')
-rw-r--r-- | sysdeps/generic/s_nextafter.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/sysdeps/generic/s_nextafter.c b/sysdeps/generic/s_nextafter.c new file mode 100644 index 0000000000..8b81e563d9 --- /dev/null +++ b/sysdeps/generic/s_nextafter.c @@ -0,0 +1,86 @@ +/* @(#)s_nextafter.c 5.1 93/09/24 */ +/* + * ==================================================== + * 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: s_nextafter.c,v 1.8 1995/05/10 20:47:58 jtc Exp $"; +#endif + +/* IEEE functions + * nextafter(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__ + double __nextafter(double x, double y) +#else + double __nextafter(x,y) + double x,y; +#endif +{ + int32_t hx,hy,ix,iy; + u_int32_t lx,ly; + + EXTRACT_WORDS(hx,lx,x); + EXTRACT_WORDS(hy,ly,y); + ix = hx&0x7fffffff; /* |x| */ + iy = hy&0x7fffffff; /* |y| */ + + if(((ix>=0x7ff00000)&&((ix-0x7ff00000)|lx)!=0) || /* x is nan */ + ((iy>=0x7ff00000)&&((iy-0x7ff00000)|ly)!=0)) /* y is nan */ + return x+y; + if(x==y) return y; /* x=y, return y */ + if((ix|lx)==0) { /* x == 0 */ + INSERT_WORDS(x,hy&0x80000000,1); /* return +-minsubnormal */ + y = x*x; + if(y==x) return y; else return x; /* raise underflow flag */ + } + if(hx>=0) { /* x > 0 */ + if(hx>hy||((hx==hy)&&(lx>ly))) { /* x > y, x -= ulp */ + if(lx==0) hx -= 1; + lx -= 1; + } else { /* x < y, x += ulp */ + lx += 1; + if(lx==0) hx += 1; + } + } else { /* x < 0 */ + if(hy>=0||hx>hy||((hx==hy)&&(lx>ly))){/* x < y, x -= ulp */ + if(lx==0) hx -= 1; + lx -= 1; + } else { /* x > y, x += ulp */ + lx += 1; + if(lx==0) hx += 1; + } + } + hy = hx&0x7ff00000; + if(hy>=0x7ff00000) return x+x; /* overflow */ + if(hy<0x00100000) { /* underflow */ + y = x*x; + if(y!=x) { /* raise underflow flag */ + INSERT_WORDS(y,hx,lx); + return y; + } + } + INSERT_WORDS(x,hx,lx); + return x; +} +weak_alias (__nextafter, nextafter) +#ifdef NO_LONG_DOUBLE +strong_alias (__nextafter, __nextafterl) +weak_alias (__nextafter, nextafterl) +strong_alias (__nextafter, __nexttoward) +weak_alias (__nextafter, nexttoward) +#endif |