Commit a8ad27d0 authored by David Howells's avatar David Howells Committed by Linus Torvalds
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[PATCH] FRV: Implement fls64() 



Implement fls64() for FRV without recource to conditional jumps.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 92fc7072

include/asm-frv/bitops.h

+41 −1
Original line number Diff line number Diff line
@@ -186,7 +186,47 @@ static inline int __test_bit(int nr, const volatile void * addr) 
	bit;						\

})



#include <asm-generic/bitops/fls64.h>

/**

 * fls64 - find last bit set in a 64-bit value

 * @n: the value to search

 *

 * This is defined the same way as ffs:

 * - return 64..1 to indicate bit 63..0 most significant bit set

 * - return 0 to indicate no bits set

 */

static inline __attribute__((const))

int fls64(u64 n)

{

	union {

		u64 ll;

		struct { u32 h, l; };

	} _;

	int bit, x, y;



	_.ll = n;



	asm("	subcc.p		%3,gr0,gr0,icc0		\n"

	    "	subcc		%4,gr0,gr0,icc1		\n"

	    "	ckne		icc0,cc4		\n"

	    "	ckne		icc1,cc5		\n"

	    "	norcr		cc4,cc5,cc6		\n"

	    "	csub.p		%0,%0,%0	,cc6,1	\n"

	    "	orcr		cc5,cc4,cc4		\n"

	    "	andcr		cc4,cc5,cc4		\n"

	    "	cscan.p		%3,gr0,%0	,cc4,0	\n"

	    "   setlos		#64,%1			\n"

	    "	cscan.p		%4,gr0,%0	,cc4,1	\n"

	    "   setlos		#32,%2			\n"

	    "	csub.p		%1,%0,%0	,cc4,0	\n"

	    "	csub		%2,%0,%0	,cc4,1	\n"

	    : "=&r"(bit), "=r"(x), "=r"(y)

	    : "0r"(_.h), "r"(_.l)

	    : "icc0", "icc1", "cc4", "cc5", "cc6"

	    );

	return bit;



}



#include <asm-generic/bitops/sched.h>

#include <asm-generic/bitops/hweight.h>