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[PATCH] FRV: Implement fls64()

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

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
David Howells 2006-09-25 23:32:08 -07:00 committed by Linus Torvalds
parent 92fc707208
commit a8ad27d03f
1 changed files with 41 additions and 1 deletions
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42
include/asm-frv/bitops.h
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@ -186,7 +186,47 @@ static inline int __test_bit(int nr, const volatile void * addr)
bit; \ 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/sched.h>
#include <asm-generic/bitops/hweight.h> #include <asm-generic/bitops/hweight.h>