1/*
2 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/* Copyright (c) 1991 NeXT Computer, Inc. All rights reserved.
29 *
30 * File: architecture/i386/reg_help.h
31 * Author: Mike DeMoney, NeXT Computer, Inc.
32 * Modified for i386 by: Bruce Martin, NeXT Computer, Inc.
33 *
34 * This header file defines cpp macros useful for defining
35 * machine register and doing machine-level operations.
36 *
37 * HISTORY
38 * 10-Mar-92 Bruce Martin (bmartin@next.com)
39 * Adapted to i386
40 * 23-Jan-91 Mike DeMoney (mike@next.com)
41 * Created.
42 */
43
44#ifndef _ARCH_I386_REG_HELP_H_
45#define _ARCH_I386_REG_HELP_H_
46
47/* Bitfield definition aid */
48#define BITS_WIDTH(msb, lsb) ((msb)-(lsb)+1)
49#define BIT_WIDTH(pos) (1) /* mostly to record the position */
50
51/* Mask creation */
52#define MKMASK(width, offset) (((unsigned)-1)>>(32-(width))<<(offset))
53#define BITSMASK(msb, lsb) MKMASK(BITS_WIDTH(msb, lsb), lsb & 0x1f)
54#define BITMASK(pos) MKMASK(BIT_WIDTH(pos), pos & 0x1f)
55
56/* Register addresses */
57#if __ASSEMBLER__
58# define REG_ADDR(type, addr) (addr)
59#else /* __ASSEMBLER__ */
60# define REG_ADDR(type, addr) (*(volatile type *)(addr))
61#endif /* __ASSEMBLER__ */
62
63/* Cast a register to be an unsigned */
64#define CONTENTS(foo) (*(unsigned *) &(foo))
65
66/* Stack pointer must always be a multiple of 4 */
67#define STACK_INCR 4
68#define ROUND_FRAME(x) ((((unsigned)(x)) + STACK_INCR - 1) & ~(STACK_INCR-1))
69
70/* STRINGIFY -- perform all possible substitutions, then stringify */
71#define __STR(x) #x /* just a helper macro */
72#define STRINGIFY(x) __STR(x)
73
74/*
75 * REG_PAIR_DEF -- define a register pair
76 * Register pairs are appropriately aligned to allow access via
77 * ld.d and st.d.
78 *
79 * Usage:
80 * struct foo {
81 * REG_PAIR_DEF(
82 * bar_t *, barp,
83 * afu_t, afu
84 * );
85 * };
86 *
87 * Access to individual entries of the pair is via the REG_PAIR
88 * macro (below).
89 */
90#define REG_PAIR_DEF(type0, name0, type1, name1) \
91 struct { \
92 type0 name0 __attribute__(( aligned(8) )); \
93 type1 name1; \
94 } name0##_##name1
95
96/*
97 * REG_PAIR -- Macro to define names for accessing individual registers
98 * of register pairs.
99 *
100 * Usage:
101 * arg0 is first element of pair
102 * arg1 is second element of pair
103 * arg2 is desired element of pair
104 * eg:
105 * #define foo_barp REG_PAIR(barp, afu, afu)
106 */
107#define REG_PAIR(name0, name1, the_name) \
108 name0##_##name1.the_name
109
110#endif /* _ARCH_I386_REG_HELP_H_ */
111