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authorFabrice Bellard <fabrice@bellard.org>2002-05-25 22:36:01 +0000
committerFabrice Bellard <fabrice@bellard.org>2002-05-25 22:36:01 +0000
commitb17c92d10e8b5d6b6846444db08bfd4f89c74af8 (patch)
tree41949107ab5068bd5305ec82195cb84af04d5217 /libavcodec/bswap.h
parent19720f15fd30a0f81c56989e1faf4ff6058793f3 (diff)
downloadffmpeg-b17c92d10e8b5d6b6846444db08bfd4f89c74af8.tar.gz
moved in libavcodec
Originally committed as revision 594 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/bswap.h')
-rw-r--r--libavcodec/bswap.h86
1 files changed, 86 insertions, 0 deletions
diff --git a/libavcodec/bswap.h b/libavcodec/bswap.h
new file mode 100644
index 0000000000..af80e507f6
--- /dev/null
+++ b/libavcodec/bswap.h
@@ -0,0 +1,86 @@
+#ifndef __BSWAP_H__
+#define __BSWAP_H__
+
+#ifdef HAVE_BYTESWAP_H
+#include <byteswap.h>
+#else
+
+#ifdef ARCH_X86
+inline static unsigned short ByteSwap16(unsigned short x)
+{
+ __asm("xchgb %b0,%h0" :
+ "=q" (x) :
+ "0" (x));
+ return x;
+}
+#define bswap_16(x) ByteSwap16(x)
+
+inline static unsigned int ByteSwap32(unsigned int x)
+{
+#if __CPU__ > 386
+ __asm("bswap %0":
+ "=r" (x) :
+#else
+ __asm("xchgb %b0,%h0\n"
+ " rorl $16,%0\n"
+ " xchgb %b0,%h0":
+ "=q" (x) :
+#endif
+ "0" (x));
+ return x;
+}
+#define bswap_32(x) ByteSwap32(x)
+
+inline static unsigned long long int ByteSwap64(unsigned long long int x)
+{
+ register union { __extension__ unsigned long long int __ll;
+ unsigned long int __l[2]; } __x;
+ asm("xchgl %0,%1":
+ "=r"(__x.__l[0]),"=r"(__x.__l[1]):
+ "0"(bswap_32((unsigned long)x)),"1"(bswap_32((unsigned long)(x>>32))));
+ return __x.__ll;
+}
+#define bswap_64(x) ByteSwap64(x)
+
+#else
+
+#define bswap_16(x) (((x) & 0x00ff) << 8 | ((x) & 0xff00) >> 8)
+
+
+// code from bits/byteswap.h (C) 1997, 1998 Free Software Foundation, Inc.
+#define bswap_32(x) \
+ ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >> 8) | \
+ (((x) & 0x0000ff00) << 8) | (((x) & 0x000000ff) << 24))
+
+#define bswap_64(x) \
+ (__extension__ \
+ ({ union { __extension__ unsigned long long int __ll; \
+ unsigned long int __l[2]; } __w, __r; \
+ __w.__ll = (x); \
+ __r.__l[0] = bswap_32 (__w.__l[1]); \
+ __r.__l[1] = bswap_32 (__w.__l[0]); \
+ __r.__ll; }))
+#endif /* !ARCH_X86 */
+
+#endif /* !HAVE_BYTESWAP_H */
+
+// be2me ... BigEndian to MachineEndian
+// le2me ... LittleEndian to MachineEndian
+
+#ifdef WORDS_BIGENDIAN
+#define be2me_16(x) (x)
+#define be2me_32(x) (x)
+#define be2me_64(x) (x)
+#define le2me_16(x) bswap_16(x)
+#define le2me_32(x) bswap_32(x)
+#define le2me_64(x) bswap_64(x)
+#else
+#define be2me_16(x) bswap_16(x)
+#define be2me_32(x) bswap_32(x)
+#define be2me_64(x) bswap_64(x)
+#define le2me_16(x) (x)
+#define le2me_32(x) (x)
+#define le2me_64(x) (x)
+#endif
+
+#endif /* __BSWAP_H__ */