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author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-18 12:17:01 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-18 12:17:01 -0400 |
commit | cb41838bbc4403f7270a94b93a9a0d9fc9c2e7ea (patch) | |
tree | 0f359975ccad4ac72e86b8edf1924c076e74bd89 /lib | |
parent | 98f01720cbe3e2eb719682777049b6514e9db556 (diff) | |
parent | c59bd5688299cddb71183e156e7a3c1409b90df2 (diff) |
Merge branch 'core-hweight-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-hweight-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, hweight: Use a 32-bit popcnt for __arch_hweight32()
arch, hweight: Fix compilation errors
x86: Add optimized popcnt variants
bitops: Optimize hweight() by making use of compile-time evaluation
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Makefile | 3 | ||||
-rw-r--r-- | lib/hweight.c | 19 |
2 files changed, 13 insertions, 9 deletions
diff --git a/lib/Makefile b/lib/Makefile index af759f39d4ae..9e6d3c29d73a 100644 --- a/lib/Makefile +++ b/lib/Makefile | |||
@@ -39,7 +39,10 @@ lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o | |||
39 | lib-$(CONFIG_GENERIC_FIND_FIRST_BIT) += find_next_bit.o | 39 | lib-$(CONFIG_GENERIC_FIND_FIRST_BIT) += find_next_bit.o |
40 | lib-$(CONFIG_GENERIC_FIND_NEXT_BIT) += find_next_bit.o | 40 | lib-$(CONFIG_GENERIC_FIND_NEXT_BIT) += find_next_bit.o |
41 | obj-$(CONFIG_GENERIC_FIND_LAST_BIT) += find_last_bit.o | 41 | obj-$(CONFIG_GENERIC_FIND_LAST_BIT) += find_last_bit.o |
42 | |||
43 | CFLAGS_hweight.o = $(subst $(quote),,$(CONFIG_ARCH_HWEIGHT_CFLAGS)) | ||
42 | obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o | 44 | obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o |
45 | |||
43 | obj-$(CONFIG_LOCK_KERNEL) += kernel_lock.o | 46 | obj-$(CONFIG_LOCK_KERNEL) += kernel_lock.o |
44 | obj-$(CONFIG_BTREE) += btree.o | 47 | obj-$(CONFIG_BTREE) += btree.o |
45 | obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o | 48 | obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o |
diff --git a/lib/hweight.c b/lib/hweight.c index 63ee4eb1228d..3c79d50814cf 100644 --- a/lib/hweight.c +++ b/lib/hweight.c | |||
@@ -9,7 +9,7 @@ | |||
9 | * The Hamming Weight of a number is the total number of bits set in it. | 9 | * The Hamming Weight of a number is the total number of bits set in it. |
10 | */ | 10 | */ |
11 | 11 | ||
12 | unsigned int hweight32(unsigned int w) | 12 | unsigned int __sw_hweight32(unsigned int w) |
13 | { | 13 | { |
14 | #ifdef ARCH_HAS_FAST_MULTIPLIER | 14 | #ifdef ARCH_HAS_FAST_MULTIPLIER |
15 | w -= (w >> 1) & 0x55555555; | 15 | w -= (w >> 1) & 0x55555555; |
@@ -24,29 +24,30 @@ unsigned int hweight32(unsigned int w) | |||
24 | return (res + (res >> 16)) & 0x000000FF; | 24 | return (res + (res >> 16)) & 0x000000FF; |
25 | #endif | 25 | #endif |
26 | } | 26 | } |
27 | EXPORT_SYMBOL(hweight32); | 27 | EXPORT_SYMBOL(__sw_hweight32); |
28 | 28 | ||
29 | unsigned int hweight16(unsigned int w) | 29 | unsigned int __sw_hweight16(unsigned int w) |
30 | { | 30 | { |
31 | unsigned int res = w - ((w >> 1) & 0x5555); | 31 | unsigned int res = w - ((w >> 1) & 0x5555); |
32 | res = (res & 0x3333) + ((res >> 2) & 0x3333); | 32 | res = (res & 0x3333) + ((res >> 2) & 0x3333); |
33 | res = (res + (res >> 4)) & 0x0F0F; | 33 | res = (res + (res >> 4)) & 0x0F0F; |
34 | return (res + (res >> 8)) & 0x00FF; | 34 | return (res + (res >> 8)) & 0x00FF; |
35 | } | 35 | } |
36 | EXPORT_SYMBOL(hweight16); | 36 | EXPORT_SYMBOL(__sw_hweight16); |
37 | 37 | ||
38 | unsigned int hweight8(unsigned int w) | 38 | unsigned int __sw_hweight8(unsigned int w) |
39 | { | 39 | { |
40 | unsigned int res = w - ((w >> 1) & 0x55); | 40 | unsigned int res = w - ((w >> 1) & 0x55); |
41 | res = (res & 0x33) + ((res >> 2) & 0x33); | 41 | res = (res & 0x33) + ((res >> 2) & 0x33); |
42 | return (res + (res >> 4)) & 0x0F; | 42 | return (res + (res >> 4)) & 0x0F; |
43 | } | 43 | } |
44 | EXPORT_SYMBOL(hweight8); | 44 | EXPORT_SYMBOL(__sw_hweight8); |
45 | 45 | ||
46 | unsigned long hweight64(__u64 w) | 46 | unsigned long __sw_hweight64(__u64 w) |
47 | { | 47 | { |
48 | #if BITS_PER_LONG == 32 | 48 | #if BITS_PER_LONG == 32 |
49 | return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w); | 49 | return __sw_hweight32((unsigned int)(w >> 32)) + |
50 | __sw_hweight32((unsigned int)w); | ||
50 | #elif BITS_PER_LONG == 64 | 51 | #elif BITS_PER_LONG == 64 |
51 | #ifdef ARCH_HAS_FAST_MULTIPLIER | 52 | #ifdef ARCH_HAS_FAST_MULTIPLIER |
52 | w -= (w >> 1) & 0x5555555555555555ul; | 53 | w -= (w >> 1) & 0x5555555555555555ul; |
@@ -63,4 +64,4 @@ unsigned long hweight64(__u64 w) | |||
63 | #endif | 64 | #endif |
64 | #endif | 65 | #endif |
65 | } | 66 | } |
66 | EXPORT_SYMBOL(hweight64); | 67 | EXPORT_SYMBOL(__sw_hweight64); |