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1/*
2 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3 *
6601e61a 4 * @APPLE_LICENSE_HEADER_START@
1c79356b 5 *
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6 * The contents of this file constitute Original Code as defined in and
7 * are subject to the Apple Public Source License Version 1.1 (the
8 * "License"). You may not use this file except in compliance with the
9 * License. Please obtain a copy of the License at
10 * http://www.apple.com/publicsource and read it before using this file.
8f6c56a5 11 *
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12 * This Original Code and all software distributed under the License are
13 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
8f6c56a5
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14 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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16 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
17 * License for the specific language governing rights and limitations
18 * under the License.
8f6c56a5 19 *
6601e61a 20 * @APPLE_LICENSE_HEADER_END@
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21 */
22/* Copyright (c) 1991 NeXT Computer, Inc. All rights reserved.
23 *
24 * File: architecture/i386/reg_help.h
25 * Author: Mike DeMoney, NeXT Computer, Inc.
26 * Modified for i386 by: Bruce Martin, NeXT Computer, Inc.
27 *
28 * This header file defines cpp macros useful for defining
29 * machine register and doing machine-level operations.
30 *
31 * HISTORY
32 * 10-Mar-92 Bruce Martin (bmartin@next.com)
33 * Adapted to i386
34 * 23-Jan-91 Mike DeMoney (mike@next.com)
35 * Created.
36 */
37
38#ifndef _ARCH_I386_REG_HELP_H_
39#define _ARCH_I386_REG_HELP_H_
40
41/* Bitfield definition aid */
42#define BITS_WIDTH(msb, lsb) ((msb)-(lsb)+1)
43#define BIT_WIDTH(pos) (1) /* mostly to record the position */
44
45/* Mask creation */
46#define MKMASK(width, offset) (((unsigned)-1)>>(32-(width))<<(offset))
47#define BITSMASK(msb, lsb) MKMASK(BITS_WIDTH(msb, lsb), lsb & 0x1f)
48#define BITMASK(pos) MKMASK(BIT_WIDTH(pos), pos & 0x1f)
49
50/* Register addresses */
51#if __ASSEMBLER__
52# define REG_ADDR(type, addr) (addr)
53#else /* __ASSEMBLER__ */
54# define REG_ADDR(type, addr) (*(volatile type *)(addr))
55#endif /* __ASSEMBLER__ */
56
57/* Cast a register to be an unsigned */
58#define CONTENTS(foo) (*(unsigned *) &(foo))
59
60/* Stack pointer must always be a multiple of 4 */
61#define STACK_INCR 4
62#define ROUND_FRAME(x) ((((unsigned)(x)) + STACK_INCR - 1) & ~(STACK_INCR-1))
63
64/* STRINGIFY -- perform all possible substitutions, then stringify */
65#define __STR(x) #x /* just a helper macro */
66#define STRINGIFY(x) __STR(x)
67
68/*
69 * REG_PAIR_DEF -- define a register pair
70 * Register pairs are appropriately aligned to allow access via
71 * ld.d and st.d.
72 *
73 * Usage:
74 * struct foo {
75 * REG_PAIR_DEF(
76 * bar_t *, barp,
77 * afu_t, afu
78 * );
79 * };
80 *
81 * Access to individual entries of the pair is via the REG_PAIR
82 * macro (below).
83 */
84#define REG_PAIR_DEF(type0, name0, type1, name1) \
85 struct { \
86 type0 name0 __attribute__(( aligned(8) )); \
87 type1 name1; \
88 } name0##_##name1
89
90/*
91 * REG_PAIR -- Macro to define names for accessing individual registers
92 * of register pairs.
93 *
94 * Usage:
95 * arg0 is first element of pair
96 * arg1 is second element of pair
97 * arg2 is desired element of pair
98 * eg:
99 * #define foo_barp REG_PAIR(barp, afu, afu)
100 */
101#define REG_PAIR(name0, name1, the_name) \
102 name0##_##name1.the_name
103
104#endif /* _ARCH_I386_REG_HELP_H_ */