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, 76 deletions

diff --git a/include/asm-x86/bitops_64.h b/include/asm-x86/bitops_64.h
index 7118ef2cc4e..a5fbe7a02a3 100644
--- a/include/asm-x86/bitops_64.h
+++ b/include/asm-x86/bitops_64.h
@@ -35,71 +35,11 @@ static inline void set_bit_string(unsigned long *bitmap, unsigned long i,
 	}
 }
 
-/**
- * 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__("bsfq %1,%0"
-		:"=r" (word)
-		:"r" (~word));
-	return word;
-}
-
-/**
- * __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__("bsfq %1,%0"
-		:"=r" (word)
-		:"rm" (word));
-	return word;
-}
-
-/*
- * __fls: find last bit set.
- * @word: The word to search
- *
- * Undefined if no zero exists, so code should check against ~0UL first.
- */
-static inline unsigned long __fls(unsigned long word)
-{
-	__asm__("bsrq %1,%0"
-		:"=r" (word)
-		:"rm" (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"
-		"cmovzl %2,%0" 
-		: "=r" (r) : "rm" (x), "r" (-1));
-	return r+1;
-}
-
-/**
  * fls64 - find last bit set in 64 bit word
  * @x: the word to search
  *
@@ -112,22 +52,6 @@ static inline int fls64(__u64 x)
 	return __fls(x) + 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"
-		"cmovzl %2,%0"
-		: "=&r" (r) : "rm" (x), "rm" (-1));
-	return r+1;
-}
-
 #define ARCH_HAS_FAST_MULTIPLIER 1
 
 #include <asm-generic/bitops/hweight.h>