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  * 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.
  11  *
  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
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  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.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  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_ */