EXTERNAL_HEADERS/architecture/i386/reg_help.h

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