fpsetsticky.c revision 1.11 1 1.11 matt /* $NetBSD: fpsetsticky.c,v 1.11 2011/07/10 21:18:47 matt Exp $ */
2 1.1 danw
3 1.1 danw /*
4 1.1 danw * Copyright (c) 1999 The NetBSD Foundation, Inc.
5 1.1 danw * All rights reserved.
6 1.1 danw *
7 1.1 danw * This code is derived from software contributed to The NetBSD Foundation
8 1.1 danw * by Dan Winship.
9 1.1 danw *
10 1.1 danw * Redistribution and use in source and binary forms, with or without
11 1.1 danw * modification, are permitted provided that the following conditions
12 1.1 danw * are met:
13 1.1 danw * 1. Redistributions of source code must retain the above copyright
14 1.1 danw * notice, this list of conditions and the following disclaimer.
15 1.1 danw * 2. Redistributions in binary form must reproduce the above copyright
16 1.1 danw * notice, this list of conditions and the following disclaimer in the
17 1.1 danw * documentation and/or other materials provided with the distribution.
18 1.1 danw *
19 1.1 danw * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 1.1 danw * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 1.1 danw * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 1.1 danw * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 1.1 danw * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 1.1 danw * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 1.1 danw * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 1.1 danw * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 1.1 danw * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 1.1 danw * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 1.1 danw * POSSIBILITY OF SUCH DAMAGE.
30 1.1 danw */
31 1.1 danw
32 1.3 thorpej #include <sys/cdefs.h>
33 1.7 lukem #if defined(LIBC_SCCS) && !defined(lint)
34 1.11 matt __RCSID("$NetBSD: fpsetsticky.c,v 1.11 2011/07/10 21:18:47 matt Exp $");
35 1.7 lukem #endif /* LIBC_SCCS and not lint */
36 1.3 thorpej
37 1.3 thorpej #include "namespace.h"
38 1.3 thorpej
39 1.1 danw #include <sys/types.h>
40 1.1 danw #include <ieeefp.h>
41 1.4 matt #include <powerpc/fpu.h>
42 1.4 matt
43 1.4 matt #define STICKYBITS (FPSCR_XX|FPSCR_ZX|FPSCR_UX|FPSCR_OX|FPSCR_VX)
44 1.5 matt #define INVBITS (FPSCR_VXCVI|FPSCR_VXSQRT|FPSCR_VXSOFT|FPSCR_VXVC|\
45 1.5 matt FPSCR_VXIMZ|FPSCR_VXZDZ|FPSCR_VXIDI|FPSCR_VXISI|\
46 1.5 matt FPSCR_VXSNAN)
47 1.4 matt #define STICKYSHFT 25
48 1.3 thorpej
49 1.3 thorpej #ifdef __weak_alias
50 1.3 thorpej __weak_alias(fpsetsticky,_fpsetsticky)
51 1.3 thorpej #endif
52 1.1 danw
53 1.1 danw fp_except
54 1.4 matt fpsetsticky(fp_except mask)
55 1.1 danw {
56 1.11 matt union {
57 1.11 matt double u_d;
58 1.11 matt uint64_t u_fpscr;
59 1.11 matt } ud;
60 1.4 matt fp_except old;
61 1.1 danw
62 1.11 matt __asm volatile("mffs %0" : "=f"(ud.u_d));
63 1.11 matt old = ((uint32_t)ud.u_fpscr & STICKYBITS) >> STICKYSHFT;
64 1.5 matt /*
65 1.6 matt * FPSCR_VX (aka FP_X_INV) is not a sticky bit but a summary of the
66 1.6 matt * all the FPSCR_VX* sticky bits. So when FP_X_INV is cleared then
67 1.5 matt * clear all of those bits, likewise when it's set, set them all.
68 1.5 matt */
69 1.5 matt if ((mask & FP_X_INV) == 0)
70 1.11 matt ud.u_fpscr &= ~INVBITS;
71 1.5 matt else
72 1.11 matt ud.u_fpscr |= INVBITS;
73 1.11 matt ud.u_fpscr &= ~STICKYBITS;
74 1.11 matt ud.u_fpscr |= ((uint32_t)mask << STICKYSHFT) & STICKYBITS;
75 1.6 matt /*
76 1.6 matt * Make FPSCR_FX reflect the presence of a set sticky bit (or not).
77 1.6 matt */
78 1.11 matt if (ud.u_fpscr & (STICKYBITS|INVBITS))
79 1.11 matt ud.u_fpscr |= FPSCR_FX;
80 1.6 matt else
81 1.11 matt ud.u_fpscr &= ~FPSCR_FX;
82 1.6 matt /*
83 1.6 matt * Write back the fpscr.
84 1.6 matt */
85 1.11 matt __asm volatile("mtfsf 0xff,%0" :: "f"(ud.u_d));
86 1.1 danw return (old);
87 1.1 danw }
88