diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-alpha/byteorder.h |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/asm-alpha/byteorder.h')
-rw-r--r-- | include/asm-alpha/byteorder.h | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/include/asm-alpha/byteorder.h b/include/asm-alpha/byteorder.h new file mode 100644 index 000000000000..7af2b8d25486 --- /dev/null +++ b/include/asm-alpha/byteorder.h @@ -0,0 +1,47 @@ +#ifndef _ALPHA_BYTEORDER_H +#define _ALPHA_BYTEORDER_H + +#include <asm/types.h> +#include <linux/compiler.h> +#include <asm/compiler.h> + +#ifdef __GNUC__ + +static __inline __attribute_const__ __u32 __arch__swab32(__u32 x) +{ + /* + * Unfortunately, we can't use the 6 instruction sequence + * on ev6 since the latency of the UNPKBW is 3, which is + * pretty hard to hide. Just in case a future implementation + * has a lower latency, here's the sequence (also by Mike Burrows) + * + * UNPKBW a0, v0 v0: 00AA00BB00CC00DD + * SLL v0, 24, a0 a0: BB00CC00DD000000 + * BIS v0, a0, a0 a0: BBAACCBBDDCC00DD + * EXTWL a0, 6, v0 v0: 000000000000BBAA + * ZAP a0, 0xf3, a0 a0: 00000000DDCC0000 + * ADDL a0, v0, v0 v0: ssssssssDDCCBBAA + */ + + __u64 t0, t1, t2, t3; + + t0 = __kernel_inslh(x, 7); /* t0 : 0000000000AABBCC */ + t1 = __kernel_inswl(x, 3); /* t1 : 000000CCDD000000 */ + t1 |= t0; /* t1 : 000000CCDDAABBCC */ + t2 = t1 >> 16; /* t2 : 0000000000CCDDAA */ + t0 = t1 & 0xFF00FF00; /* t0 : 00000000DD00BB00 */ + t3 = t2 & 0x00FF00FF; /* t3 : 0000000000CC00AA */ + t1 = t0 + t3; /* t1 : ssssssssDDCCBBAA */ + + return t1; +} + +#define __arch__swab32 __arch__swab32 + +#endif /* __GNUC__ */ + +#define __BYTEORDER_HAS_U64__ + +#include <linux/byteorder/little_endian.h> + +#endif /* _ALPHA_BYTEORDER_H */ |