1 /*- 2 * Copyright (c) 2015 The NetBSD Foundation, Inc. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to The NetBSD Foundation 6 * by Matt Thomas of 3am Software Foundry. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 * POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 32 __RCSID("$NetBSD: fpsetround.c,v 1.4 2024/10/29 20:04:30 riastradh Exp $"); 33 34 #include <sys/param.h> 35 #include <sys/bitops.h> 36 37 #include "namespace.h" 38 39 #include <ieeefp.h> 40 41 #include <aarch64/armreg.h> 42 43 __weak_alias(fpsetround,_fpsetround) 44 45 fp_rnd_t 46 fpsetround(fp_rnd_t rnd) 47 { 48 const uint32_t old_fpcr = reg_fpcr_read(); 49 const uint32_t new_fpcr = (old_fpcr & ~FPCR_RMODE) 50 | __SHIFTIN(rnd, FPCR_RMODE); 51 reg_fpcr_write(new_fpcr); 52 return __SHIFTOUT(old_fpcr, FPCR_RMODE); 53 } 54