1 /* $NetBSD: fpsetround.c,v 1.6 2002/01/13 21:45:40 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 1995 Christopher G. Demetriou 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 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed for the 18 * NetBSD Project. See http://www.netbsd.org/ for 19 * information about NetBSD. 20 * 4. The name of the author may not be used to endorse or promote products 21 * derived from this software without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 * 34 * <<Id: LICENSE,v 1.2 2000/06/14 15:57:33 cgd Exp>> 35 */ 36 37 #include <sys/cdefs.h> 38 39 #include "namespace.h" 40 41 #include <sys/types.h> 42 #include <ieeefp.h> 43 44 #ifdef __weak_alias 45 __weak_alias(fpsetround,_fpsetround) 46 #endif 47 48 fp_rnd 49 fpsetround(rnd_dir) 50 fp_rnd rnd_dir; 51 { 52 double fpcrval; 53 u_int64_t old, new; 54 55 __asm__("excb"); 56 __asm__("mf_fpcr %0" : "=f" (fpcrval)); 57 old = *(u_int64_t *)&fpcrval; 58 59 new = old & ~(long)0x0c00000000000000; 60 new = (long)rnd_dir << 58; 61 *(u_int64_t *)&fpcrval = new; 62 63 __asm__("mt_fpcr %0" : : "f" (fpcrval)); 64 __asm__("excb"); 65 66 return ((old >> 58) & 0x3); 67 } 68