diff options
Diffstat (limited to 'sysdeps/libm-ieee754/s_rintl.c')
| -rw-r--r-- | sysdeps/libm-ieee754/s_rintl.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_rintl.c b/sysdeps/libm-ieee754/s_rintl.c new file mode 100644 index 0000000000..c9f12b162a --- /dev/null +++ b/sysdeps/libm-ieee754/s_rintl.c @@ -0,0 +1,96 @@ +/* s_rintl.c -- long double version of s_rint.c. + * 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 + +/* + * rintl(x) + * Return x rounded to integral value according to the prevailing + * rounding mode. + * Method: + * Using floating addition. + * Exception: + * Inexact flag raised if x not equal to rintl(x). + */ + +#include "math.h" +#include "math_private.h" + +#ifdef __STDC__ +static const long double +#else +static long double +#endif +TWO64[2]={ + 1.844674407370955161600000e+19, /* 0x403F, 0x00000000, 0x00000000 */ + -1.844674407370955161600000e+19, /* 0xC03F, 0x00000000, 0x00000000 */ +}; + +#ifdef __STDC__ + long double __rintl(long double x) +#else + long double __rintl(x) + long double x; +#endif +{ + int32_t se,j0,sx; + u_int32_t i,i0,i1; + long double w,t; + GET_LDOUBLE_WORDS(se,i0,i1,x); + sx = (se>>15)&1; + j0 = (se&0x7fff)-0x3fff; + if(j0<32) { + if(j0<0) { + if(((se&0x7fff)|i0|i1)==0) return x; + i1 |= i0; + i0 &= 0xe0000000; + i0 |= (i1|-i1)&0x80000000; + SET_LDOUBLE_MSW(x,i0); + w = TWO64[sx]+x; + t = w-TWO64[sx]; + GET_LDOUBLE_EXP(i0,t); + SET_LDOUBLE_EXP(t,(i0&0x7fff)|(sx<<15)); + return t; + } else { + i = (0xffffffff)>>j0; + if(((i0&i)|i1)==0) return x; /* x is integral */ + i>>=1; + if(((i0&i)|i1)!=0) { + if(j0==31) i1 = 0x40000000; else + i0 = (i0&(~i))|((0x20000000)>>j0); + /* Shouldn't this be + if (j0 >= 30) i1 = 0x80000000 >> (j0 - 30); + i0 = (i0&(~i))|((0x20000000)>>j0); + If yes, this should be correct in s_rint and + s_rintf, too. -- drepper@cygnus.com */ + } + } + } else if (j0>63) { + if(j0==0x4000) return x+x; /* inf or NaN */ + else return x; /* x is integral */ + } else { + i = ((u_int32_t)(0xffffffff))>>(j0-32); + if((i1&i)==0) return x; /* x is integral */ + i>>=1; + if((i1&i)!=0) i1 = (i1&(~i))|((0x40000000)>>(j0-32)); + } + SET_LDOUBLE_WORDS(x,se,i0,i1); + w = TWO64[sx]+x; + return w-TWO64[sx]; +} +weak_alias (__rintl, rintl) |