From 37da2899f40661e3e9631e497da8dc59b971cbd0 Mon Sep 17 00:00:00 2001 From: "Charles.Forsyth" Date: Fri, 22 Dec 2006 17:07:39 +0000 Subject: 20060303a --- libmath/fdlibm/s_ceil.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 libmath/fdlibm/s_ceil.c (limited to 'libmath/fdlibm/s_ceil.c') diff --git a/libmath/fdlibm/s_ceil.c b/libmath/fdlibm/s_ceil.c new file mode 100644 index 00000000..7bb2a00c --- /dev/null +++ b/libmath/fdlibm/s_ceil.c @@ -0,0 +1,70 @@ +/* derived from /netlib/fdlibm */ + +/* @(#)s_ceil.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. + * ==================================================== + */ + +/* + * ceil(x) + * Return x rounded toward -inf to integral value + * Method: + * Bit twiddling. + * Exception: + * Inexact flag raised if x not equal to ceil(x). + */ + +#include "fdlibm.h" + +static const double Huge = 1.0e300; + + double ceil(double x) +{ + int i0,i1,j0; + unsigned i,j; + i0 = __HI(x); + i1 = __LO(x); + j0 = ((i0>>20)&0x7ff)-0x3ff; + if(j0<20) { + if(j0<0) { /* raise inexact if x != 0 */ + if(Huge+x>0.0) {/* return 0*sign(x) if |x|<1 */ + if(i0<0) {i0=0x80000000;i1=0;} + else if((i0|i1)!=0) { i0=0x3ff00000;i1=0;} + } + } else { + i = (0x000fffff)>>j0; + if(((i0&i)|i1)==0) return x; /* x is integral */ + if(Huge+x>0.0) { /* raise inexact flag */ + if(i0>0) i0 += (0x00100000)>>j0; + i0 &= (~i); i1=0; + } + } + } else if (j0>51) { + if(j0==0x400) return x+x; /* inf or NaN */ + else return x; /* x is integral */ + } else { + i = ((unsigned)(0xffffffff))>>(j0-20); + if((i1&i)==0) return x; /* x is integral */ + if(Huge+x>0.0) { /* raise inexact flag */ + if(i0>0) { + if(j0==20) i0+=1; + else { + j = i1 + (1<<(52-j0)); + if(j