EXTERNAL_HEADERS/architecture/i386/reg_help.h

   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_ */