fpu.h revision 117865 
1/*-
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * William Jolitz.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 *	from: @(#)npx.h	5.3 (Berkeley) 1/18/91
37 * $FreeBSD: head/sys/amd64/include/fpu.h 117865 2003-07-22 06:50:34Z peter $
38 */
39
40/*
41 * 287/387 NPX Coprocessor Data Structures and Constants
42 * W. Jolitz 1/90
43 */
44
45#ifndef _MACHINE_NPX_H_
46#define	_MACHINE_NPX_H_
47
48/* Contents of each x87 floating point accumulator */
49struct fpacc87 {
50	u_char	fp_bytes[10];
51};
52
53/* Contents of each SSE extended accumulator */
54struct  xmmacc {
55	u_char	xmm_bytes[16];
56};
57
58struct  envxmm {
59	u_int16_t	en_cw;		/* control word (16bits) */
60	u_int16_t	en_sw;		/* status word (16bits) */
61	u_int8_t	en_tw;		/* tag word (8bits) */
62	u_int8_t	en_zero;
63	u_int16_t	en_opcode;	/* opcode last executed (11 bits ) */
64	u_int64_t	en_rip;		/* floating point instruction pointer */
65	u_int64_t	en_rdp;		/* floating operand pointer */
66	u_int32_t	en_mxcsr;	/* SSE sontorol/status register */
67	u_int32_t	en_mxcsr_mask;	/* valid bits in mxcsr */
68};
69
70struct  savefpu {
71	struct	envxmm	sv_env;
72	struct {
73		struct fpacc87	fp_acc;
74		u_char		fp_pad[6];      /* padding */
75	} sv_fp[8];
76	struct xmmacc	sv_xmm[16];
77	u_char sv_pad[96];
78} __aligned(16);
79
80/*
81 * The hardware default control word for i387's and later coprocessors is
82 * 0x37F, giving:
83 *
84 *	round to nearest
85 *	64-bit precision
86 *	all exceptions masked.
87 *
88 * FreeBSD/i386 uses 53 bit precision for things like fadd/fsub/fsqrt etc
89 * because of the difference between memory and fpu register stack arguments.
90 * If its using an intermediate fpu register, it has 80/64 bits to work
91 * with.  If it uses memory, it has 64/53 bits to work with.  However,
92 * gcc is aware of this and goes to a fair bit of trouble to make the
93 * best use of it.
94 *
95 * This is mostly academic for AMD64, because the ABI prefers the use
96 * SSE2 based math.  For FreeBSD/amd64, we go with the default settings.
97 */
98#define	__INITIAL_NPXCW__	0x037F
99#define	__INITIAL_MXCSR__	0x1F80
100#define	__INITIAL_MXCSR_MASK__	0xFFBF
101
102#ifdef _KERNEL
103int	npxdna(void);
104void	npxdrop(void);
105void	npxexit(struct thread *td);
106int	npxformat(void);
107int	npxgetregs(struct thread *td, struct savefpu *addr);
108void	npxinit(u_short control);
109void	npxsave(struct savefpu *addr);
110void	npxsetregs(struct thread *td, struct savefpu *addr);
111int	npxtrap(void);
112#endif
113
114#endif /* !_MACHINE_NPX_H_ */
115