diff options
Diffstat (limited to 'third_party/js-1.7/fdlibm/s_nextafter.c')
| -rw-r--r-- | third_party/js-1.7/fdlibm/s_nextafter.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/third_party/js-1.7/fdlibm/s_nextafter.c b/third_party/js-1.7/fdlibm/s_nextafter.c new file mode 100644 index 0000000..f71c5c8 --- /dev/null +++ b/third_party/js-1.7/fdlibm/s_nextafter.c @@ -0,0 +1,124 @@ +/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- + * + * ***** BEGIN LICENSE BLOCK ***** + * Version: MPL 1.1/GPL 2.0/LGPL 2.1 + * + * The contents of this file are subject to the Mozilla Public License Version + * 1.1 (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * http://www.mozilla.org/MPL/ + * + * Software distributed under the License is distributed on an "AS IS" basis, + * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License + * for the specific language governing rights and limitations under the + * License. + * + * The Original Code is Mozilla Communicator client code, released + * March 31, 1998. + * + * The Initial Developer of the Original Code is + * Sun Microsystems, Inc. + * Portions created by the Initial Developer are Copyright (C) 1998 + * the Initial Developer. All Rights Reserved. + * + * Contributor(s): + * + * Alternatively, the contents of this file may be used under the terms of + * either of the GNU General Public License Version 2 or later (the "GPL"), + * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), + * in which case the provisions of the GPL or the LGPL are applicable instead + * of those above. If you wish to allow use of your version of this file only + * under the terms of either the GPL or the LGPL, and not to allow others to + * use your version of this file under the terms of the MPL, indicate your + * decision by deleting the provisions above and replace them with the notice + * and other provisions required by the GPL or the LGPL. If you do not delete + * the provisions above, a recipient may use your version of this file under + * the terms of any one of the MPL, the GPL or the LGPL. + * + * ***** END LICENSE BLOCK ***** */ + +/* @(#)s_nextafter.c 1.3 95/01/18 */ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunSoft, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +/* IEEE functions + * nextafter(x,y) + * return the next machine floating-point number of x in the + * direction toward y. + * Special cases: + */ + +#include "fdlibm.h" + +#ifdef __STDC__ + double fd_nextafter(double x, double y) +#else + double fd_nextafter(x,y) + double x,y; +#endif +{ + int hx,hy,ix,iy; + unsigned lx,ly; + fd_twoints ux, uy; + + ux.d = x; uy.d = y; + hx = __HI(ux); /* high word of x */ + lx = __LO(ux); /* low word of x */ + hy = __HI(uy); /* high word of y */ + ly = __LO(uy); /* low word of 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 x; /* x=y, return x */ + if((ix|lx)==0) { /* x == 0 */ + ux.d = x; + __HI(ux) = hy&0x80000000; /* return +-minsubnormal */ + __LO(ux) = 1; + x = ux.d; + 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 */ + uy.d = y; + __HI(uy) = hx; __LO(uy) = lx; + y = uy.d; + return y; + } + } + ux.d = x; + __HI(ux) = hx; __LO(ux) = lx; + x = ux.d; + return x; +} |