From 12d9c8420b9daa1da3d9e090640fb24bcd0deba2 Mon Sep 17 00:00:00 2001 From: Alexander van Heukelum Date: Sat, 15 Mar 2008 13:04:42 +0100 Subject: x86: merge the simple bitops and move them to bitops.h Some of those can be written in such a way that the same inline assembly can be used to generate both 32 bit and 64 bit code. For ffs and fls, x86_64 unconditionally used the cmov instruction and i386 unconditionally used a conditional branch over a mov instruction. In the current patch I chose to select the version based on the availability of the cmov instruction instead. A small detail here is that x86_64 did not previously set CONFIG_X86_CMOV=y. Improved comments for ffs, ffz, fls and variations. Signed-off-by: Alexander van Heukelum Signed-off-by: Ingo Molnar --- include/asm-x86/bitops_32.h | 64 --------------------------------------------- 1 file changed, 64 deletions(-) (limited to 'include/asm-x86/bitops_32.h') diff --git a/include/asm-x86/bitops_32.h b/include/asm-x86/bitops_32.h index 7c9ed759afb..3ed64b21b76 100644 --- a/include/asm-x86/bitops_32.h +++ b/include/asm-x86/bitops_32.h @@ -39,20 +39,6 @@ static inline int find_first_zero_bit(const unsigned long *addr, unsigned size) return res; } -/** - * __ffs - find first bit in word. - * @word: The word to search - * - * Undefined if no bit exists, so code should check against 0 first. - */ -static inline unsigned long __ffs(unsigned long word) -{ - __asm__("bsfl %1,%0" - :"=r" (word) - :"rm" (word)); - return word; -} - /** * find_first_bit - find the first set bit in a memory region * @addr: The address to start the search at @@ -74,60 +60,10 @@ static inline unsigned find_first_bit(const unsigned long *addr, unsigned size) return x; } -/** - * ffz - find first zero in word. - * @word: The word to search - * - * Undefined if no zero exists, so code should check against ~0UL first. - */ -static inline unsigned long ffz(unsigned long word) -{ - __asm__("bsfl %1,%0" - :"=r" (word) - :"r" (~word)); - return word; -} - #ifdef __KERNEL__ #include -/** - * ffs - find first bit set - * @x: the word to search - * - * This is defined the same way as - * the libc and compiler builtin ffs routines, therefore - * differs in spirit from the above ffz() (man ffs). - */ -static inline int ffs(int x) -{ - int r; - - __asm__("bsfl %1,%0\n\t" - "jnz 1f\n\t" - "movl $-1,%0\n" - "1:" : "=r" (r) : "rm" (x)); - return r+1; -} - -/** - * fls - find last bit set - * @x: the word to search - * - * This is defined the same way as ffs(). - */ -static inline int fls(int x) -{ - int r; - - __asm__("bsrl %1,%0\n\t" - "jnz 1f\n\t" - "movl $-1,%0\n" - "1:" : "=r" (r) : "rm" (x)); - return r+1; -} - #include #endif /* __KERNEL__ */ -- cgit v1.2.3