| 1 | /* s_nearbyintl.c -- long double version of s_nearbyint.c. |
| 2 | * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz. |
| 3 | */ |
| 4 | |
| 5 | /* |
| 6 | * ==================================================== |
| 7 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
| 8 | * |
| 9 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
| 10 | * Permission to use, copy, modify, and distribute this |
| 11 | * software is freely granted, provided that this notice |
| 12 | * is preserved. |
| 13 | * ==================================================== |
| 14 | */ |
| 15 | |
| 16 | /* |
| 17 | * nearbyintl(x) |
| 18 | * Return x rounded to integral value according to the prevailing |
| 19 | * rounding mode. |
| 20 | * Method: |
| 21 | * Using floating addition. |
| 22 | * Exception: |
| 23 | * Inexact flag raised if x not equal to rintl(x). |
| 24 | */ |
| 25 | |
| 26 | #include <fenv.h> |
| 27 | #include <math.h> |
| 28 | #include <math-barriers.h> |
| 29 | #include <math_private.h> |
| 30 | #include <libm-alias-ldouble.h> |
| 31 | |
| 32 | static const _Float128 |
| 33 | TWO112[2]={ |
| 34 | L(5.19229685853482762853049632922009600E+33), /* 0x406F000000000000, 0 */ |
| 35 | L(-5.19229685853482762853049632922009600E+33) /* 0xC06F000000000000, 0 */ |
| 36 | }; |
| 37 | |
| 38 | _Float128 __nearbyintl(_Float128 x) |
| 39 | { |
| 40 | fenv_t env; |
| 41 | int64_t i0,j0,sx; |
| 42 | uint64_t i1 __attribute__ ((unused)); |
| 43 | _Float128 w,t; |
| 44 | GET_LDOUBLE_WORDS64(i0,i1,x); |
| 45 | sx = (((uint64_t)i0)>>63); |
| 46 | j0 = ((i0>>48)&0x7fff)-0x3fff; |
| 47 | if(j0<112) { |
| 48 | if(j0<0) { |
| 49 | feholdexcept (&env); |
| 50 | w = TWO112[sx] + math_opt_barrier (x); |
| 51 | t = w-TWO112[sx]; |
| 52 | math_force_eval (t); |
| 53 | fesetenv (&env); |
| 54 | GET_LDOUBLE_MSW64(i0,t); |
| 55 | SET_LDOUBLE_MSW64(t,(i0&0x7fffffffffffffffLL)|(sx<<63)); |
| 56 | return t; |
| 57 | } |
| 58 | } else { |
| 59 | if(j0==0x4000) return x+x; /* inf or NaN */ |
| 60 | else return x; /* x is integral */ |
| 61 | } |
| 62 | feholdexcept (&env); |
| 63 | w = TWO112[sx] + math_opt_barrier (x); |
| 64 | t = w-TWO112[sx]; |
| 65 | math_force_eval (t); |
| 66 | fesetenv (&env); |
| 67 | return t; |
| 68 | } |
| 69 | libm_alias_ldouble (__nearbyint, nearbyint) |
| 70 | |