fpu.h revision 187867 
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 * 4. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 *	from: @(#)npx.h	5.3 (Berkeley) 1/18/91
33 * $FreeBSD: head/sys/amd64/include/fpu.h 187867 2009-01-28 20:35:16Z jhb $
34 */
35
36/*
37 * Floating Point Data Structures and Constants
38 * W. Jolitz 1/90
39 */
40
41#ifndef _MACHINE_FPU_H_
42#define	_MACHINE_FPU_H_
43
44/* Contents of each x87 floating point accumulator */
45struct fpacc87 {
46	u_char	fp_bytes[10];
47};
48
49/* Contents of each SSE extended accumulator */
50struct  xmmacc {
51	u_char	xmm_bytes[16];
52};
53
54struct  envxmm {
55	u_int16_t	en_cw;		/* control word (16bits) */
56	u_int16_t	en_sw;		/* status word (16bits) */
57	u_int8_t	en_tw;		/* tag word (8bits) */
58	u_int8_t	en_zero;
59	u_int16_t	en_opcode;	/* opcode last executed (11 bits ) */
60	u_int64_t	en_rip;		/* floating point instruction pointer */
61	u_int64_t	en_rdp;		/* floating operand pointer */
62	u_int32_t	en_mxcsr;	/* SSE sontorol/status register */
63	u_int32_t	en_mxcsr_mask;	/* valid bits in mxcsr */
64};
65
66struct  savefpu {
67	struct	envxmm	sv_env;
68	struct {
69		struct fpacc87	fp_acc;
70		u_char		fp_pad[6];      /* padding */
71	} sv_fp[8];
72	struct xmmacc	sv_xmm[16];
73	u_char sv_pad[96];
74} __aligned(16);
75
76/*
77 * The hardware default control word for i387's and later coprocessors is
78 * 0x37F, giving:
79 *
80 *	round to nearest
81 *	64-bit precision
82 *	all exceptions masked.
83 *
84 * FreeBSD/i386 uses 53 bit precision for things like fadd/fsub/fsqrt etc
85 * because of the difference between memory and fpu register stack arguments.
86 * If its using an intermediate fpu register, it has 80/64 bits to work
87 * with.  If it uses memory, it has 64/53 bits to work with.  However,
88 * gcc is aware of this and goes to a fair bit of trouble to make the
89 * best use of it.
90 *
91 * This is mostly academic for AMD64, because the ABI prefers the use
92 * SSE2 based math.  For FreeBSD/amd64, we go with the default settings.
93 */
94#define	__INITIAL_FPUCW__	0x037F
95#define	__INITIAL_FPUCW_I386__	0x127F
96#define	__INITIAL_MXCSR__	0x1F80
97#define	__INITIAL_MXCSR_MASK__	0xFFBF
98
99#ifdef _KERNEL
100int	fpudna(void);
101void	fpudrop(void);
102void	fpuexit(struct thread *td);
103int	fpuformat(void);
104int	fpugetregs(struct thread *td, struct savefpu *addr);
105void	fpuinit(void);
106void	fpusetregs(struct thread *td, struct savefpu *addr);
107int	fputrap(void);
108#endif
109
110#endif /* !_MACHINE_FPU_H_ */
111