1 /* $NetBSD: s_nearbyint.c,v 1.6 2024/10/30 16:57:16 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 2004 David Schultz <das@FreeBSD.ORG> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 #if 0 31 __FBSDID("$FreeBSD: src/lib/msun/src/s_nearbyint.c,v 1.2 2008/01/14 02:12:06 das Exp $"); 32 #else 33 __RCSID("$NetBSD: s_nearbyint.c,v 1.6 2024/10/30 16:57:16 riastradh Exp $"); 34 #endif 35 36 #include "namespace.h" 37 38 #include <machine/ieee.h> 39 #include <fenv.h> 40 #include <math.h> 41 42 /* 43 * We save and restore the floating-point environment to avoid raising 44 * an inexact exception. We can get away with using fesetenv() 45 * instead of feclearexcept()/feupdateenv() to restore the environment 46 * because the only exception defined for rint() is overflow, and 47 * rounding can't overflow as long as emax >= p. 48 */ 49 #define DECL(type, fn, rintfn) \ 50 type \ 51 fn(type x) \ 52 { \ 53 type ret; \ 54 fenv_t env; \ 55 \ 56 fegetenv(&env); \ 57 ret = rintfn(x); \ 58 fesetenv(&env); \ 59 return (ret); \ 60 } 61 62 DECL(double, nearbyint, rint) 63 DECL(float, nearbyintf, rintf) 64 DECL(long double, nearbyintl, rintl) 65