1*0a6a1f1dSLionel Sambuc /* $NetBSD: fpsetsticky.c,v 1.1 2014/09/03 19:34:25 matt Exp $ */
2*0a6a1f1dSLionel Sambuc
3*0a6a1f1dSLionel Sambuc /*
4*0a6a1f1dSLionel Sambuc * Copyright (c) 1999 The NetBSD Foundation, Inc.
5*0a6a1f1dSLionel Sambuc * All rights reserved.
6*0a6a1f1dSLionel Sambuc *
7*0a6a1f1dSLionel Sambuc * This code is derived from software contributed to The NetBSD Foundation
8*0a6a1f1dSLionel Sambuc * by Dan Winship.
9*0a6a1f1dSLionel Sambuc *
10*0a6a1f1dSLionel Sambuc * Redistribution and use in source and binary forms, with or without
11*0a6a1f1dSLionel Sambuc * modification, are permitted provided that the following conditions
12*0a6a1f1dSLionel Sambuc * are met:
13*0a6a1f1dSLionel Sambuc * 1. Redistributions of source code must retain the above copyright
14*0a6a1f1dSLionel Sambuc * notice, this list of conditions and the following disclaimer.
15*0a6a1f1dSLionel Sambuc * 2. Redistributions in binary form must reproduce the above copyright
16*0a6a1f1dSLionel Sambuc * notice, this list of conditions and the following disclaimer in the
17*0a6a1f1dSLionel Sambuc * documentation and/or other materials provided with the distribution.
18*0a6a1f1dSLionel Sambuc *
19*0a6a1f1dSLionel Sambuc * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20*0a6a1f1dSLionel Sambuc * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21*0a6a1f1dSLionel Sambuc * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22*0a6a1f1dSLionel Sambuc * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23*0a6a1f1dSLionel Sambuc * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24*0a6a1f1dSLionel Sambuc * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25*0a6a1f1dSLionel Sambuc * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26*0a6a1f1dSLionel Sambuc * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27*0a6a1f1dSLionel Sambuc * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28*0a6a1f1dSLionel Sambuc * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29*0a6a1f1dSLionel Sambuc * POSSIBILITY OF SUCH DAMAGE.
30*0a6a1f1dSLionel Sambuc */
31*0a6a1f1dSLionel Sambuc
32*0a6a1f1dSLionel Sambuc #include <sys/cdefs.h>
33*0a6a1f1dSLionel Sambuc #if defined(LIBC_SCCS) && !defined(lint)
34*0a6a1f1dSLionel Sambuc __RCSID("$NetBSD: fpsetsticky.c,v 1.1 2014/09/03 19:34:25 matt Exp $");
35*0a6a1f1dSLionel Sambuc #endif /* LIBC_SCCS and not lint */
36*0a6a1f1dSLionel Sambuc
37*0a6a1f1dSLionel Sambuc #include "namespace.h"
38*0a6a1f1dSLionel Sambuc
39*0a6a1f1dSLionel Sambuc #include <sys/types.h>
40*0a6a1f1dSLionel Sambuc #include <ieeefp.h>
41*0a6a1f1dSLionel Sambuc #include <powerpc/fpu.h>
42*0a6a1f1dSLionel Sambuc
43*0a6a1f1dSLionel Sambuc #define STICKYBITS (FPSCR_XX|FPSCR_ZX|FPSCR_UX|FPSCR_OX|FPSCR_VX)
44*0a6a1f1dSLionel Sambuc #define INVBITS (FPSCR_VXCVI|FPSCR_VXSQRT|FPSCR_VXSOFT|FPSCR_VXVC|\
45*0a6a1f1dSLionel Sambuc FPSCR_VXIMZ|FPSCR_VXZDZ|FPSCR_VXIDI|FPSCR_VXISI|\
46*0a6a1f1dSLionel Sambuc FPSCR_VXSNAN)
47*0a6a1f1dSLionel Sambuc #define STICKYSHFT 25
48*0a6a1f1dSLionel Sambuc
49*0a6a1f1dSLionel Sambuc #ifdef __weak_alias
__weak_alias(fpsetsticky,_fpsetsticky)50*0a6a1f1dSLionel Sambuc __weak_alias(fpsetsticky,_fpsetsticky)
51*0a6a1f1dSLionel Sambuc #endif
52*0a6a1f1dSLionel Sambuc
53*0a6a1f1dSLionel Sambuc fp_except
54*0a6a1f1dSLionel Sambuc fpsetsticky(fp_except mask)
55*0a6a1f1dSLionel Sambuc {
56*0a6a1f1dSLionel Sambuc union {
57*0a6a1f1dSLionel Sambuc double u_d;
58*0a6a1f1dSLionel Sambuc uint64_t u_fpscr;
59*0a6a1f1dSLionel Sambuc } ud;
60*0a6a1f1dSLionel Sambuc fp_except old;
61*0a6a1f1dSLionel Sambuc
62*0a6a1f1dSLionel Sambuc __asm volatile("mffs %0" : "=f"(ud.u_d));
63*0a6a1f1dSLionel Sambuc old = ((uint32_t)ud.u_fpscr & STICKYBITS) >> STICKYSHFT;
64*0a6a1f1dSLionel Sambuc /*
65*0a6a1f1dSLionel Sambuc * FPSCR_VX (aka FP_X_INV) is not a sticky bit but a summary of the
66*0a6a1f1dSLionel Sambuc * all the FPSCR_VX* sticky bits. So when FP_X_INV is cleared then
67*0a6a1f1dSLionel Sambuc * clear all of those bits, likewise when it's set, set them all.
68*0a6a1f1dSLionel Sambuc */
69*0a6a1f1dSLionel Sambuc if ((mask & FP_X_INV) == 0)
70*0a6a1f1dSLionel Sambuc ud.u_fpscr &= ~INVBITS;
71*0a6a1f1dSLionel Sambuc else
72*0a6a1f1dSLionel Sambuc ud.u_fpscr |= INVBITS;
73*0a6a1f1dSLionel Sambuc ud.u_fpscr &= ~STICKYBITS;
74*0a6a1f1dSLionel Sambuc ud.u_fpscr |= ((uint32_t)mask << STICKYSHFT) & STICKYBITS;
75*0a6a1f1dSLionel Sambuc /*
76*0a6a1f1dSLionel Sambuc * Make FPSCR_FX reflect the presence of a set sticky bit (or not).
77*0a6a1f1dSLionel Sambuc */
78*0a6a1f1dSLionel Sambuc if (ud.u_fpscr & (STICKYBITS|INVBITS))
79*0a6a1f1dSLionel Sambuc ud.u_fpscr |= FPSCR_FX;
80*0a6a1f1dSLionel Sambuc else
81*0a6a1f1dSLionel Sambuc ud.u_fpscr &= ~FPSCR_FX;
82*0a6a1f1dSLionel Sambuc /*
83*0a6a1f1dSLionel Sambuc * Write back the fpscr.
84*0a6a1f1dSLionel Sambuc */
85*0a6a1f1dSLionel Sambuc __asm volatile("mtfsf 0xff,%0" :: "f"(ud.u_d));
86*0a6a1f1dSLionel Sambuc return (old);
87*0a6a1f1dSLionel Sambuc }
88