| /* |
| SDL - Simple DirectMedia Layer |
| Copyright (C) 1997-2004 Sam Lantinga |
| |
| This library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Library General Public |
| License as published by the Free Software Foundation; either |
| version 2 of the License, or (at your option) any later version. |
| |
| This library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Library General Public License for more details. |
| |
| You should have received a copy of the GNU Library General Public |
| License along with this library; if not, write to the Free |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| |
| Sam Lantinga |
| slouken@libsdl.org |
| */ |
| |
| #ifdef SAVE_RCSID |
| static char rcsid = |
| "@(#) $Id: SDL_endian.h,v 1.11 2004/11/27 23:11:20 pmandin Exp $"; |
| #endif |
| |
| /* Functions for reading and writing endian-specific values */ |
| |
| #ifndef _SDL_endian_h |
| #define _SDL_endian_h |
| |
| /* These functions read and write data of the specified endianness, |
| dynamically translating to the host machine endianness. |
| |
| e.g.: If you want to read a 16 bit value on big-endian machine from |
| an open file containing little endian values, you would use: |
| value = SDL_ReadLE16(rp); |
| Note that the read/write functions use SDL_RWops pointers |
| instead of FILE pointers. This allows you to read and write |
| endian values from large chunks of memory as well as files |
| and other data sources. |
| */ |
| |
| #include <stdio.h> |
| |
| #include "SDL_types.h" |
| #include "SDL_rwops.h" |
| #include "SDL_byteorder.h" |
| |
| #include "begin_code.h" |
| /* Set up for C function definitions, even when using C++ */ |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| /* Use inline functions for compilers that support them, and static |
| functions for those that do not. Because these functions become |
| static for compilers that do not support inline functions, this |
| header should only be included in files that actually use them. |
| */ |
| #if defined(__GNUC__) && defined(__i386__) |
| static __inline__ Uint16 SDL_Swap16(Uint16 x) |
| { |
| __asm__("xchgb %b0,%h0" : "=q" (x) : "0" (x)); |
| return x; |
| } |
| #elif defined(__GNUC__) && defined(__x86_64__) |
| static __inline__ Uint16 SDL_Swap16(Uint16 x) |
| { |
| __asm__("xchgb %b0,%h0" : "=q" (x) : "0" (x)); |
| return x; |
| } |
| #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__)) |
| static __inline__ Uint16 SDL_Swap16(Uint16 x) |
| { |
| Uint16 result; |
| |
| __asm__("rlwimi %0,%2,8,16,23" : "=&r" (result) : "0" (x >> 8), "r" (x)); |
| return result; |
| } |
| #elif defined(__GNUC__) && defined(__M68000__) |
| static __inline__ Uint16 SDL_Swap16(Uint16 x) |
| { |
| __asm__("rorw #8,%0" : "=d" (x) : "0" (x) : "cc"); |
| return x; |
| } |
| #else |
| static __inline__ Uint16 SDL_Swap16(Uint16 x) { |
| return((x<<8)|(x>>8)); |
| } |
| #endif |
| |
| #if defined(__GNUC__) && defined(__i386__) |
| static __inline__ Uint32 SDL_Swap32(Uint32 x) |
| { |
| __asm__("bswap %0" : "=r" (x) : "0" (x)); |
| return x; |
| } |
| #elif defined(__GNUC__) && defined(__x86_64__) |
| static __inline__ Uint32 SDL_Swap32(Uint32 x) |
| { |
| __asm__("bswapl %0" : "=r" (x) : "0" (x)); |
| return x; |
| } |
| #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__)) |
| static __inline__ Uint32 SDL_Swap32(Uint32 x) |
| { |
| Uint32 result; |
| |
| __asm__("rlwimi %0,%2,24,16,23" : "=&r" (result) : "0" (x>>24), "r" (x)); |
| __asm__("rlwimi %0,%2,8,8,15" : "=&r" (result) : "0" (result), "r" (x)); |
| __asm__("rlwimi %0,%2,24,0,7" : "=&r" (result) : "0" (result), "r" (x)); |
| return result; |
| } |
| #elif defined(__GNUC__) && defined(__M68000__) |
| static __inline__ Uint32 SDL_Swap32(Uint32 x) |
| { |
| __asm__("rorw #8,%0\n\tswap %0\n\tror #8,%0" : "=d" (x) : "0" (x) : "cc"); |
| return x; |
| } |
| #else |
| static __inline__ Uint32 SDL_Swap32(Uint32 x) { |
| return((x<<24)|((x<<8)&0x00FF0000)|((x>>8)&0x0000FF00)|(x>>24)); |
| } |
| #endif |
| |
| #ifdef SDL_HAS_64BIT_TYPE |
| #if defined(__GNUC__) && defined(__i386__) |
| static __inline__ Uint64 SDL_Swap64(Uint64 x) |
| { |
| union { |
| struct { Uint32 a,b; } s; |
| Uint64 u; |
| } v; |
| v.u = x; |
| __asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1" |
| : "=r" (v.s.a), "=r" (v.s.b) |
| : "0" (v.s.a), "1" (v.s.b)); |
| return v.u; |
| } |
| #elif defined(__GNUC__) && defined(__x86_64__) |
| static __inline__ Uint64 SDL_Swap64(Uint64 x) |
| { |
| __asm__("bswapq %0" : "=r" (x) : "0" (x)); |
| return x; |
| } |
| #else |
| static __inline__ Uint64 SDL_Swap64(Uint64 x) |
| { |
| Uint32 hi, lo; |
| |
| /* Separate into high and low 32-bit values and swap them */ |
| lo = (Uint32)(x&0xFFFFFFFF); |
| x >>= 32; |
| hi = (Uint32)(x&0xFFFFFFFF); |
| x = SDL_Swap32(lo); |
| x <<= 32; |
| x |= SDL_Swap32(hi); |
| return(x); |
| } |
| #endif |
| #else |
| /* This is mainly to keep compilers from complaining in SDL code. |
| If there is no real 64-bit datatype, then compilers will complain about |
| the fake 64-bit datatype that SDL provides when it compiles user code. |
| */ |
| #define SDL_Swap64(X) (X) |
| #endif /* SDL_HAS_64BIT_TYPE */ |
| |
| |
| /* Byteswap item from the specified endianness to the native endianness */ |
| #if SDL_BYTEORDER == SDL_LIL_ENDIAN |
| #define SDL_SwapLE16(X) (X) |
| #define SDL_SwapLE32(X) (X) |
| #define SDL_SwapLE64(X) (X) |
| #define SDL_SwapBE16(X) SDL_Swap16(X) |
| #define SDL_SwapBE32(X) SDL_Swap32(X) |
| #define SDL_SwapBE64(X) SDL_Swap64(X) |
| #else |
| #define SDL_SwapLE16(X) SDL_Swap16(X) |
| #define SDL_SwapLE32(X) SDL_Swap32(X) |
| #define SDL_SwapLE64(X) SDL_Swap64(X) |
| #define SDL_SwapBE16(X) (X) |
| #define SDL_SwapBE32(X) (X) |
| #define SDL_SwapBE64(X) (X) |
| #endif |
| |
| /* Read an item of the specified endianness and return in native format */ |
| extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops *src); |
| extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops *src); |
| extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops *src); |
| extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops *src); |
| extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops *src); |
| extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops *src); |
| |
| /* Write an item of native format to the specified endianness */ |
| extern DECLSPEC int SDLCALL SDL_WriteLE16(SDL_RWops *dst, Uint16 value); |
| extern DECLSPEC int SDLCALL SDL_WriteBE16(SDL_RWops *dst, Uint16 value); |
| extern DECLSPEC int SDLCALL SDL_WriteLE32(SDL_RWops *dst, Uint32 value); |
| extern DECLSPEC int SDLCALL SDL_WriteBE32(SDL_RWops *dst, Uint32 value); |
| extern DECLSPEC int SDLCALL SDL_WriteLE64(SDL_RWops *dst, Uint64 value); |
| extern DECLSPEC int SDLCALL SDL_WriteBE64(SDL_RWops *dst, Uint64 value); |
| |
| |
| /* Ends C function definitions when using C++ */ |
| #ifdef __cplusplus |
| } |
| #endif |
| #include "close_code.h" |
| |
| #endif /* _SDL_endian_h */ |
