1*e415d488SLionel Sambuc /* $NetBSD: fpsetround.c,v 1.10 2011/07/10 21:18:47 matt Exp $ */
22fe8fb19SBen Gras
32fe8fb19SBen Gras /*
42fe8fb19SBen Gras * Copyright (c) 1999 The NetBSD Foundation, Inc.
52fe8fb19SBen Gras * All rights reserved.
62fe8fb19SBen Gras *
72fe8fb19SBen Gras * This code is derived from software contributed to The NetBSD Foundation
82fe8fb19SBen Gras * by Dan Winship.
92fe8fb19SBen Gras *
102fe8fb19SBen Gras * Redistribution and use in source and binary forms, with or without
112fe8fb19SBen Gras * modification, are permitted provided that the following conditions
122fe8fb19SBen Gras * are met:
132fe8fb19SBen Gras * 1. Redistributions of source code must retain the above copyright
142fe8fb19SBen Gras * notice, this list of conditions and the following disclaimer.
152fe8fb19SBen Gras * 2. Redistributions in binary form must reproduce the above copyright
162fe8fb19SBen Gras * notice, this list of conditions and the following disclaimer in the
172fe8fb19SBen Gras * documentation and/or other materials provided with the distribution.
182fe8fb19SBen Gras *
192fe8fb19SBen Gras * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
202fe8fb19SBen Gras * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
212fe8fb19SBen Gras * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
222fe8fb19SBen Gras * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
232fe8fb19SBen Gras * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
242fe8fb19SBen Gras * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
252fe8fb19SBen Gras * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
262fe8fb19SBen Gras * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
272fe8fb19SBen Gras * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
282fe8fb19SBen Gras * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
292fe8fb19SBen Gras * POSSIBILITY OF SUCH DAMAGE.
302fe8fb19SBen Gras */
312fe8fb19SBen Gras
322fe8fb19SBen Gras #include <sys/cdefs.h>
332fe8fb19SBen Gras #if defined(LIBC_SCCS) && !defined(lint)
34*e415d488SLionel Sambuc __RCSID("$NetBSD: fpsetround.c,v 1.10 2011/07/10 21:18:47 matt Exp $");
352fe8fb19SBen Gras #endif /* LIBC_SCCS and not lint */
362fe8fb19SBen Gras
372fe8fb19SBen Gras #include "namespace.h"
382fe8fb19SBen Gras
392fe8fb19SBen Gras #include <sys/types.h>
402fe8fb19SBen Gras #include <ieeefp.h>
412fe8fb19SBen Gras #include <powerpc/fpu.h>
422fe8fb19SBen Gras
432fe8fb19SBen Gras #ifdef __weak_alias
__weak_alias(fpsetround,_fpsetround)442fe8fb19SBen Gras __weak_alias(fpsetround,_fpsetround)
452fe8fb19SBen Gras #endif
462fe8fb19SBen Gras
472fe8fb19SBen Gras #define ROUNDBITS FPSCR_RN
482fe8fb19SBen Gras
492fe8fb19SBen Gras fp_rnd
502fe8fb19SBen Gras fpsetround(fp_rnd rnd_dir)
512fe8fb19SBen Gras {
52*e415d488SLionel Sambuc union {
53*e415d488SLionel Sambuc double u_d;
54*e415d488SLionel Sambuc uint64_t u_fpscr;
55*e415d488SLionel Sambuc } ud;
562fe8fb19SBen Gras fp_rnd old;
572fe8fb19SBen Gras
58*e415d488SLionel Sambuc __asm volatile("mffs %0" : "=f"(ud.u_d));
59*e415d488SLionel Sambuc old = (uint32_t)ud.u_fpscr & ROUNDBITS;
60*e415d488SLionel Sambuc ud.u_fpscr &= ~ROUNDBITS;
61*e415d488SLionel Sambuc ud.u_fpscr |= rnd_dir & ROUNDBITS;
62*e415d488SLionel Sambuc __asm volatile("mtfsf 0xff,%0" :: "f"(ud.u_d));
632fe8fb19SBen Gras return (old);
642fe8fb19SBen Gras }
65