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alpha: introduce asm/swab.h
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Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Harvey Harrison authored and Linus Torvalds committed Jan 7, 2009
1 parent c6f09f0 commit dd8b72c
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Showing 3 changed files with 44 additions and 41 deletions.
1 change: 1 addition & 0 deletions arch/alpha/include/asm/Kbuild
Original file line number Diff line number Diff line change
Expand Up @@ -9,3 +9,4 @@ unifdef-y += console.h
unifdef-y += fpu.h
unifdef-y += sysinfo.h
unifdef-y += compiler.h
unifdef-y += swab.h
42 changes: 1 addition & 41 deletions arch/alpha/include/asm/byteorder.h
Original file line number Diff line number Diff line change
@@ -1,47 +1,7 @@
#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 <asm/swab.h>
#include <linux/byteorder/little_endian.h>

#endif /* _ALPHA_BYTEORDER_H */
42 changes: 42 additions & 0 deletions arch/alpha/include/asm/swab.h
Original file line number Diff line number Diff line change
@@ -0,0 +1,42 @@
#ifndef _ALPHA_SWAB_H
#define _ALPHA_SWAB_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__ */

#endif /* _ALPHA_SWAB_H */

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