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 <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 0 insertions, 64 deletions

diff --git a/include/asm-x86/bitops_32.h b/include/asm-x86/bitops_32.h
index 7c9ed75..3ed64b2 100644
--- a/include/asm-x86/bitops_32.h
+++ b/include/asm-x86/bitops_32.h
@@ -40,20 +40,6 @@ static inline int find_first_zero_bit(const unsigned long *addr, unsigned size)
 }
 
 /**
- * __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
  * @size: The maximum size to search
@@ -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 <asm-generic/bitops/sched.h>
 
-/**
- * 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 <asm-generic/bitops/hweight.h>
 
 #endif /* __KERNEL__ */