EXTERNAL_HEADERS/architecture/i386/reg_help.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /* Copyright (c) 1991 NeXT Computer, Inc.  All rights reserved.
  26  *
  27  *      File:   architecture/i386/reg_help.h
  28  *      Author: Mike DeMoney, NeXT Computer, Inc.
  29  *      Modified for i386 by: Bruce Martin, NeXT Computer, Inc.
  30  *
  31  *      This header file defines cpp macros useful for defining
  32  *      machine register and doing machine-level operations.
  33  *
  34  * HISTORY
  35  * 10-Mar-92  Bruce Martin (bmartin@next.com)
  36  *      Adapted to i386
  37  * 23-Jan-91  Mike DeMoney (mike@next.com)
  38  *      Created.
  39  */
  40
  41 #ifndef _ARCH_I386_REG_HELP_H_
  42 #define _ARCH_I386_REG_HELP_H_
  43
  44 /* Bitfield definition aid */
  45 #define BITS_WIDTH(msb, lsb)    ((msb)-(lsb)+1)
  46 #define BIT_WIDTH(pos)          (1)     /* mostly to record the position */
  47
  48 /* Mask creation */
  49 #define MKMASK(width, offset)   (((unsigned)-1)>>(32-(width))<<(offset))
  50 #define BITSMASK(msb, lsb)      MKMASK(BITS_WIDTH(msb, lsb), lsb & 0x1f)
  51 #define BITMASK(pos)            MKMASK(BIT_WIDTH(pos), pos & 0x1f)
  52
  53 /* Register addresses */
  54 #if     __ASSEMBLER__
  55 # define        REG_ADDR(type, addr)    (addr)
  56 #else   /* __ASSEMBLER__ */
  57 # define        REG_ADDR(type, addr)    (*(volatile type *)(addr))
  58 #endif  /* __ASSEMBLER__ */
  59
  60 /* Cast a register to be an unsigned */
  61 #define CONTENTS(foo)   (*(unsigned *) &(foo))
  62
  63 /* Stack pointer must always be a multiple of 4 */
  64 #define STACK_INCR      4
  65 #define ROUND_FRAME(x)  ((((unsigned)(x)) + STACK_INCR - 1) & ~(STACK_INCR-1))
  66
  67 /* STRINGIFY -- perform all possible substitutions, then stringify */
  68 #define __STR(x)        #x              /* just a helper macro */
  69 #define STRINGIFY(x)    __STR(x)
  70
  71 /*
  72  * REG_PAIR_DEF -- define a register pair
  73  * Register pairs are appropriately aligned to allow access via
  74  * ld.d and st.d.
  75  *
  76  * Usage:
  77  *      struct foo {
  78  *              REG_PAIR_DEF(
  79  *                      bar_t *,        barp,
  80  *                      afu_t,          afu
  81  *              );
  82  *      };
  83  *
  84  * Access to individual entries of the pair is via the REG_PAIR
  85  * macro (below).
  86  */
  87 #define REG_PAIR_DEF(type0, name0, type1, name1)                \
  88         struct {                                                \
  89                 type0   name0 __attribute__(( aligned(8) ));    \
  90                 type1   name1;                                  \
  91         } name0##_##name1
  92
  93 /*
  94  * REG_PAIR -- Macro to define names for accessing individual registers
  95  * of register pairs.
  96  *
  97  * Usage:
  98  *      arg0 is first element of pair
  99  *      arg1 is second element of pair
 100  *      arg2 is desired element of pair
 101  * eg:
 102  *      #define foo_barp        REG_PAIR(barp, afu, afu)
 103  */
 104 #define REG_PAIR(name0, name1, the_name)                        \
 105         name0##_##name1.the_name
 106
 107 #endif  /* _ARCH_I386_REG_HELP_H_ */