src/Port.h

   1 // -*- C++ -*-
   2 // VisualBoyAdvance - Nintendo Gameboy/GameboyAdvance (TM) emulator.
   3 // Copyright (C) 1999-2003 Forgotten
   4 // Copyright (C) 2004 Forgotten and the VBA development team
   5
   6 // This program is free software; you can redistribute it and/or modify
   7 // it under the terms of the GNU General Public License as published by
   8 // the Free Software Foundation; either version 2, or(at your option)
   9 // any later version.
  10 //
  11 // This program is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15 //
  16 // You should have received a copy of the GNU General Public License
  17 // along with this program; if not, write to the Free Software Foundation,
  18 // Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19
  20 #ifndef VBA_PORT_H
  21 #define VBA_PORT_H
  22
  23 // swaps a 16-bit value
  24 static inline u16 swap16(u16 v)
  25 {
  26   return (v<<8)|(v>>8);
  27 }
  28
  29 // swaps a 32-bit value
  30 static inline u32 swap32(u32 v)
  31 {
  32   return (v<<24)|((v<<8)&0xff0000)|((v>>8)&0xff00)|(v>>24);
  33 }
  34
  35 #ifdef WORDS_BIGENDIAN
  36 #if defined(__GNUC__) && defined(__ppc__)
  37
  38 #define READ16LE(base) \
  39   ({ unsigned short lhbrxResult;       \
  40      __asm__ ("lhbrx %0, 0, %1" : "=r" (lhbrxResult) : "r" (base) : "memory"); \
  41       lhbrxResult; })
  42
  43 #define READ32LE(base) \
  44   ({ unsigned long lwbrxResult; \
  45      __asm__ ("lwbrx %0, 0, %1" : "=r" (lwbrxResult) : "r" (base) : "memory"); \
  46       lwbrxResult; })
  47
  48 #define WRITE16LE(base, value) \
  49   __asm__ ("sthbrx %0, 0, %1" : : "r" (value), "r" (base) : "memory")
  50
  51 #define WRITE32LE(base, value) \
  52   __asm__ ("stwbrx %0, 0, %1" : : "r" (value), "r" (base) : "memory")
  53
  54 #else
  55 #define READ16LE(x) \
  56   swap16(*((u16 *)(x)))
  57 #define READ32LE(x) \
  58   swap32(*((u32 *)(x)))
  59 #define WRITE16LE(x,v) \
  60   *((u16 *)x) = swap16((v))
  61 #define WRITE32LE(x,v) \
  62   *((u32 *)x) = swap32((v))
  63 #endif
  64 #else
  65 #define READ16LE(x) \
  66   *((u16 *)x)
  67 #define READ32LE(x) \
  68   *((u32 *)x)
  69 #define WRITE16LE(x,v) \
  70   *((u16 *)x) = (v)
  71 #define WRITE32LE(x,v) \
  72   *((u32 *)x) = (v)
  73 #endif
  74
  75 #endif