From: David Howells Fix FRV fls() to handle bit 31 being set correctly (it should return 32 not 0). Signed-off-by: David Howells Signed-off-by: Andrew Morton --- include/asm-frv/bitops.h | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff -puN include/asm-frv/bitops.h~frv-fix-fls-to-handle-bit-31-being-set-correctly include/asm-frv/bitops.h --- a/include/asm-frv/bitops.h~frv-fix-fls-to-handle-bit-31-being-set-correctly +++ a/include/asm-frv/bitops.h @@ -161,16 +161,29 @@ static inline int __test_bit(int nr, con #include #include -/* - * fls: find last bit set. +/** + * fls - find last bit set + * @x: the word to search + * + * This is defined the same way as ffs: + * - return 32..1 to indicate bit 31..0 most significant bit set + * - return 0 to indicate no bits set */ #define fls(x) \ ({ \ int bit; \ \ - asm("scan %1,gr0,%0" : "=r"(bit) : "r"(x)); \ + asm(" subcc %1,gr0,gr0,icc0 \n" \ + " ckne icc0,cc4 \n" \ + " cscan.p %1,gr0,%0 ,cc4,#1 \n" \ + " csub %0,%0,%0 ,cc4,#0 \n" \ + " csub %2,%0,%0 ,cc4,#1 \n" \ + : "=&r"(bit) \ + : "r"(x), "r"(32) \ + : "icc0", "cc4" \ + ); \ \ - bit ? 33 - bit : bit; \ + bit; \ }) #include _