1 /* $NetBSD: fpsetmask.c,v 1.11 2017/02/27 06:54:00 chs Exp $ */
2
3 /*
4 * Copyright (c) 1999 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Dan Winship.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 __RCSID("$NetBSD: fpsetmask.c,v 1.11 2017/02/27 06:54:00 chs Exp $");
35 #endif /* LIBC_SCCS and not lint */
36
37 #include "namespace.h"
38
39 #include <sys/types.h>
40 #include <ieeefp.h>
41 #include <powerpc/fpu.h>
42 #include <powerpc/psl.h>
43
44 #ifdef __weak_alias
__weak_alias(fpsetmask,_fpsetmask)45 __weak_alias(fpsetmask,_fpsetmask)
46 #endif
47
48 #define MASKBITS (FPSCR_XE|FPSCR_ZE|FPSCR_UE|FPSCR_OE|FPSCR_VE)
49 #define MASKSHFT 3
50
51 static __inline uint32_t
52 mfmsr(void)
53 {
54 uint32_t msr;
55
56 __asm volatile ("mfmsr %0" : "=r"(msr));
57 return msr;
58 }
59
60 static __inline void
mtmsr(uint32_t msr)61 mtmsr(uint32_t msr)
62 {
63
64 __asm volatile ("mtmsr %0" : : "r"(msr));
65 }
66
67 #include <stdio.h>
68
69 fp_except
fpsetmask(fp_except mask)70 fpsetmask(fp_except mask)
71 {
72 union {
73 double u_d;
74 uint64_t u_fpscr;
75 } ud;
76 fp_except old, new;
77 uint32_t msr;
78
79 __asm volatile("mffs %0" : "=f"(ud.u_d));
80 old = ((uint32_t)ud.u_fpscr & MASKBITS) >> MASKSHFT;
81 ud.u_fpscr &= ~MASKBITS;
82 new = ((uint32_t)mask << MASKSHFT) & MASKBITS;
83 ud.u_fpscr |= new;
84 __asm volatile("mtfsf 0xff,%0" :: "f"(ud.u_d));
85
86 msr = mfmsr();
87 msr = (msr & ~(PSL_FE0 | PSL_FE1)) |
88 (new ? PSL_FE_PREC : PSL_FE_DIS);
89 mtmsr(msr);
90
91 return (old);
92 }
93