Commit 7b80a23c authored by Heiko Carstens's avatar Heiko Carstens Committed by Alexander Gordeev
Browse files

s390/bitops: Switch to generic fls(), fls64(), etc. 



Switch to generic fls(), fls64(), etc. which are implemented with
__builtin_ctzl(), __builtin_clzl().
Those builtins are available for all supported compilers.

Kernel image size is reduced by ~10kb (gcc 15.1.0 + defconfig).

Acked-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
parent 5671ce2a

arch/s390/include/asm/bitops.h

+5 −51
Original line number Diff line number Diff line
@@ -180,17 +180,6 @@ static __always_inline __attribute_const__ unsigned long __flogr(unsigned long w 
	}

}



/**

 * __ffs - find first bit in word.

 * @word: The word to search

 *

 * Undefined if no bit exists, so code should check against 0 first.

 */

static __always_inline __flatten unsigned long __ffs(unsigned long word)

{

	return __flogr(-word & word) ^ (BITS_PER_LONG - 1);

}



/**

 * ffs - find first bit set

 * @word: the word to search
@@ -205,48 +194,13 @@ static __always_inline __flatten int ffs(int word) 
	return BITS_PER_LONG - __flogr(-val & val);

}



/**

 * __fls - find last (most-significant) set bit in a long word

 * @word: the word to search

 *

 * Undefined if no set bit exists, so code should check against 0 first.

 */

static __always_inline __flatten unsigned long __fls(unsigned long word)

{

	return __flogr(word) ^ (BITS_PER_LONG - 1);

}



/**

 * fls64 - find last set bit in a 64-bit word

 * @word: the word to search

 *

 * This is defined in a similar way as the libc and compiler builtin

 * ffsll, but returns the position of the most significant set bit.

 *

 * fls64(value) returns 0 if value is 0 or the position of the last

 * set bit if value is nonzero. The last (most significant) bit is

 * at position 64.

 */

static __always_inline __flatten int fls64(unsigned long word)

{

	return BITS_PER_LONG - __flogr(word);

}



/**

 * fls - find last (most-significant) bit set

 * @word: the word to search

 *

 * This is defined the same way as ffs.

 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.

 */

static __always_inline __flatten int fls(unsigned int word)

{

	return fls64(word);

}



#include <asm-generic/bitops/builtin-__ffs.h>

#include <asm-generic/bitops/ffz.h>

#include <asm-generic/bitops/builtin-__fls.h>

#include <asm-generic/bitops/builtin-fls.h>

#include <asm-generic/bitops/fls64.h>

#include <asm/arch_hweight.h>

#include <asm-generic/bitops/const_hweight.h>

#include <asm-generic/bitops/ffz.h>

#include <asm-generic/bitops/sched.h>

#include <asm-generic/bitops/le.h>

#include <asm-generic/bitops/ext2-atomic-setbit.h>