projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| 63551311 UD |
1 | /* s_rintl.c -- long double version of s_rint.c. |
| 2 | * Conversion to long double by Ulrich Drepper, | |
| 3 | * Cygnus Support, drepper@cygnus.com. | |
| 4 | */ | |
| 5 | /* Adapted for use as nearbyint by Ulrich Drepper <drepper@cygnus.com>. */ | |
| 6 | ||
| 7 | /* | |
| 8 | * ==================================================== | |
| 9 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. | |
| 10 | * | |
| 11 | * Developed at SunPro, a Sun Microsystems, Inc. business. | |
| 12 | * Permission to use, copy, modify, and distribute this | |
| 13 | * software is freely granted, provided that this notice | |
| 14 | * is preserved. | |
| 15 | * ==================================================== | |
| 16 | */ | |
| 17 | ||
| 63551311 UD |
18 | /* |
| 19 | * rintl(x) | |
| 20 | * Return x rounded to integral value according to the prevailing | |
| 21 | * rounding mode. | |
| 22 | * Method: | |
| 23 | * Using floating addition. | |
| 24 | * Exception: | |
| 25 | * Inexact flag raised if x not equal to rintl(x). | |
| 26 | */ | |
| 27 | ||
| 28 | #include <fenv.h> | |
| 29 | #include "math.h" | |
| 30 | #include "math_private.h" | |
| 31 | ||
| 32 | #ifdef __STDC__ | |
| 33 | static const long double | |
| 34 | #else | |
| 35 | static long double | |
| 36 | #endif | |
| 37 | TWO63[2]={ | |
| 38 | 9.223372036854775808000000e+18, /* 0x403E, 0x00000000, 0x00000000 */ | |
| 39 | -9.223372036854775808000000e+18 /* 0xC03E, 0x00000000, 0x00000000 */ | |
| 40 | }; | |
| 41 | ||
| 42 | #ifdef __STDC__ | |
| b4012b75 | 43 | long double __nearbyintl(long double x) |
| 63551311 | 44 | #else |
| b4012b75 | 45 | long double __nearbyintl(x) |
| 63551311 UD |
46 | long double x; |
| 47 | #endif | |
| 48 | { | |
| 49 | fenv_t env; | |
| 50 | int32_t se,j0,sx; | |
| 51 | u_int32_t i,i0,i1; | |
| 52 | long double w,t; | |
| 53 | GET_LDOUBLE_WORDS(se,i0,i1,x); | |
| 54 | sx = (se>>15)&1; | |
| 55 | j0 = (se&0x7fff)-0x3fff; | |
| 56 | if(j0<31) { | |
| 57 | if(j0<0) { | |
| 58 | if(((se&0x7fff)|i0|i1)==0) return x; | |
| 59 | i1 |= i0; | |
| 60 | i0 &= 0xe0000000; | |
| 61 | i0 |= (i1|-i1)&0x80000000; | |
| 62 | SET_LDOUBLE_MSW(x,i0); | |
| 63 | feholdexcept (&env); | |
| 64 | w = TWO63[sx]+x; | |
| 65 | t = w-TWO63[sx]; | |
| 66 | fesetenv (&env); | |
| 67 | GET_LDOUBLE_EXP(i0,t); | |
| 68 | SET_LDOUBLE_EXP(t,(i0&0x7fff)|(sx<<15)); | |
| 69 | return t; | |
| 70 | } else { | |
| 71 | i = (0x7fffffff)>>j0; | |
| 72 | if(((i0&i)|i1)==0) return x; /* x is integral */ | |
| 73 | i>>=1; | |
| 74 | if(((i0&i)|i1)!=0) { | |
| 75 | if(j0==31) i1 = 0x40000000; else | |
| 76 | i0 = (i0&(~i))|((0x20000000)>>j0); | |
| 77 | /* Shouldn't this be | |
| 78 | if (j0 >= 30) i1 = 0x80000000 >> (j0 - 30); | |
| 79 | i0 = (i0&(~i))|((0x20000000)>>j0); | |
| 80 | If yes, this should be correct in s_rint and | |
| 81 | s_rintf, too. -- drepper@cygnus.com */ | |
| 82 | } | |
| 83 | } | |
| 84 | } else if (j0>62) { | |
| 85 | if(j0==0x4000) return x+x; /* inf or NaN */ | |
| 86 | else return x; /* x is integral */ | |
| 87 | } else { | |
| 88 | i = ((u_int32_t)(0xffffffff))>>(j0-31); | |
| 89 | if((i1&i)==0) return x; /* x is integral */ | |
| 90 | i>>=1; | |
| 91 | if((i1&i)!=0) i1 = (i1&(~i))|((0x40000000)>>(j0-31)); | |
| 92 | } | |
| 93 | SET_LDOUBLE_WORDS(x,se,i0,i1); | |
| 94 | feholdexcept (&env); | |
| 95 | w = TWO63[sx]+x; | |
| 96 | t = w-TWO63[sx]; | |
| 97 | fesetenv (&env); | |
| 98 | return t; | |
| 99 | } | |
| b4012b75 | 100 | weak_alias (__nearbyintl, nearbyintl) |