diff options
Diffstat (limited to 'lib/hweight.c')
-rw-r--r-- | lib/hweight.c | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/lib/hweight.c b/lib/hweight.c index 389424ecb129..3c79d50814cf 100644 --- a/lib/hweight.c +++ b/lib/hweight.c | |||
@@ -9,37 +9,45 @@ | |||
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 | ||
15 | w -= (w >> 1) & 0x55555555; | ||
16 | w = (w & 0x33333333) + ((w >> 2) & 0x33333333); | ||
17 | w = (w + (w >> 4)) & 0x0f0f0f0f; | ||
18 | return (w * 0x01010101) >> 24; | ||
19 | #else | ||
14 | unsigned int res = w - ((w >> 1) & 0x55555555); | 20 | unsigned int res = w - ((w >> 1) & 0x55555555); |
15 | res = (res & 0x33333333) + ((res >> 2) & 0x33333333); | 21 | res = (res & 0x33333333) + ((res >> 2) & 0x33333333); |
16 | res = (res + (res >> 4)) & 0x0F0F0F0F; | 22 | res = (res + (res >> 4)) & 0x0F0F0F0F; |
17 | res = res + (res >> 8); | 23 | res = res + (res >> 8); |
18 | return (res + (res >> 16)) & 0x000000FF; | 24 | return (res + (res >> 16)) & 0x000000FF; |
25 | #endif | ||
19 | } | 26 | } |
20 | EXPORT_SYMBOL(hweight32); | 27 | EXPORT_SYMBOL(__sw_hweight32); |
21 | 28 | ||
22 | unsigned int hweight16(unsigned int w) | 29 | unsigned int __sw_hweight16(unsigned int w) |
23 | { | 30 | { |
24 | unsigned int res = w - ((w >> 1) & 0x5555); | 31 | unsigned int res = w - ((w >> 1) & 0x5555); |
25 | res = (res & 0x3333) + ((res >> 2) & 0x3333); | 32 | res = (res & 0x3333) + ((res >> 2) & 0x3333); |
26 | res = (res + (res >> 4)) & 0x0F0F; | 33 | res = (res + (res >> 4)) & 0x0F0F; |
27 | return (res + (res >> 8)) & 0x00FF; | 34 | return (res + (res >> 8)) & 0x00FF; |
28 | } | 35 | } |
29 | EXPORT_SYMBOL(hweight16); | 36 | EXPORT_SYMBOL(__sw_hweight16); |
30 | 37 | ||
31 | unsigned int hweight8(unsigned int w) | 38 | unsigned int __sw_hweight8(unsigned int w) |
32 | { | 39 | { |
33 | unsigned int res = w - ((w >> 1) & 0x55); | 40 | unsigned int res = w - ((w >> 1) & 0x55); |
34 | res = (res & 0x33) + ((res >> 2) & 0x33); | 41 | res = (res & 0x33) + ((res >> 2) & 0x33); |
35 | return (res + (res >> 4)) & 0x0F; | 42 | return (res + (res >> 4)) & 0x0F; |
36 | } | 43 | } |
37 | EXPORT_SYMBOL(hweight8); | 44 | EXPORT_SYMBOL(__sw_hweight8); |
38 | 45 | ||
39 | unsigned long hweight64(__u64 w) | 46 | unsigned long __sw_hweight64(__u64 w) |
40 | { | 47 | { |
41 | #if BITS_PER_LONG == 32 | 48 | #if BITS_PER_LONG == 32 |
42 | return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w); | 49 | return __sw_hweight32((unsigned int)(w >> 32)) + |
50 | __sw_hweight32((unsigned int)w); | ||
43 | #elif BITS_PER_LONG == 64 | 51 | #elif BITS_PER_LONG == 64 |
44 | #ifdef ARCH_HAS_FAST_MULTIPLIER | 52 | #ifdef ARCH_HAS_FAST_MULTIPLIER |
45 | w -= (w >> 1) & 0x5555555555555555ul; | 53 | w -= (w >> 1) & 0x5555555555555555ul; |
@@ -56,4 +64,4 @@ unsigned long hweight64(__u64 w) | |||
56 | #endif | 64 | #endif |
57 | #endif | 65 | #endif |
58 | } | 66 | } |
59 | EXPORT_SYMBOL(hweight64); | 67 | EXPORT_SYMBOL(__sw_hweight64); |