1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2004 David Schultz <das (at) 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 __FBSDID("$FreeBSD: head/lib/msun/src/s_nearbyint.c 326219 2017-11-26 02:00:33Z pfg $"); 31 32 #include <fenv.h> 33 #include <math.h> 34 35 /* 36 * We save and restore the floating-point environment to avoid raising 37 * an inexact exception. We can get away with using fesetenv() 38 * instead of feclearexcept()/feupdateenv() to restore the environment 39 * because the only exception defined for rint() is overflow, and 40 * rounding can't overflow as long as emax >= p. 41 * 42 * The volatile keyword is needed below because clang incorrectly assumes 43 * that rint won't raise any floating-point exceptions. Declaring ret volatile 44 * is sufficient to trick the compiler into doing the right thing. 45 */ 46 #define DECL(type, fn, rint) \ 47 type \ 48 fn(type x) \ 49 { \ 50 volatile type ret; \ 51 fenv_t env; \ 52 \ 53 fegetenv(&env); \ 54 ret = rint(x); \ 55 fesetenv(&env); \ 56 return (ret); \ 57 } 58 59 DECL(double, nearbyint, rint) 60 DECL(float, nearbyintf, rintf) 61 DECL(long double, nearbyintl, rintl) 62
