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-rw-r--r--lib/hweight.c29
1 files changed, 14 insertions, 15 deletions
diff --git a/lib/hweight.c b/lib/hweight.c
index 721a4b8b4fb8..438257671708 100644
--- a/lib/hweight.c
+++ b/lib/hweight.c
@@ -10,28 +10,28 @@
10 10
11unsigned int hweight32(unsigned int w) 11unsigned int hweight32(unsigned int w)
12{ 12{
13 unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555); 13 unsigned int res = w - ((w >> 1) & 0x55555555);
14 res = (res & 0x33333333) + ((res >> 2) & 0x33333333); 14 res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
15 res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F); 15 res = (res + (res >> 4)) & 0x0F0F0F0F;
16 res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF); 16 res = res + (res >> 8);
17 return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF); 17 return (res + (res >> 16)) & 0x000000FF;
18} 18}
19EXPORT_SYMBOL(hweight32); 19EXPORT_SYMBOL(hweight32);
20 20
21unsigned int hweight16(unsigned int w) 21unsigned int hweight16(unsigned int w)
22{ 22{
23 unsigned int res = (w & 0x5555) + ((w >> 1) & 0x5555); 23 unsigned int res = w - ((w >> 1) & 0x5555);
24 res = (res & 0x3333) + ((res >> 2) & 0x3333); 24 res = (res & 0x3333) + ((res >> 2) & 0x3333);
25 res = (res & 0x0F0F) + ((res >> 4) & 0x0F0F); 25 res = (res + (res >> 4)) & 0x0F0F;
26 return (res & 0x00FF) + ((res >> 8) & 0x00FF); 26 return (res + (res >> 8)) & 0x00FF;
27} 27}
28EXPORT_SYMBOL(hweight16); 28EXPORT_SYMBOL(hweight16);
29 29
30unsigned int hweight8(unsigned int w) 30unsigned int hweight8(unsigned int w)
31{ 31{
32 unsigned int res = (w & 0x55) + ((w >> 1) & 0x55); 32 unsigned int res = w - ((w >> 1) & 0x55);
33 res = (res & 0x33) + ((res >> 2) & 0x33); 33 res = (res & 0x33) + ((res >> 2) & 0x33);
34 return (res & 0x0F) + ((res >> 4) & 0x0F); 34 return (res + (res >> 4)) & 0x0F;
35} 35}
36EXPORT_SYMBOL(hweight8); 36EXPORT_SYMBOL(hweight8);
37 37
@@ -40,13 +40,12 @@ unsigned long hweight64(__u64 w)
40#if BITS_PER_LONG == 32 40#if BITS_PER_LONG == 32
41 return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w); 41 return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w);
42#elif BITS_PER_LONG == 64 42#elif BITS_PER_LONG == 64
43 u64 res; 43 __u64 res = w - ((w >> 1) & 0x5555555555555555ul);
44 res = (w & 0x5555555555555555ul) + ((w >> 1) & 0x5555555555555555ul);
45 res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul); 44 res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul);
46 res = (res & 0x0F0F0F0F0F0F0F0Ful) + ((res >> 4) & 0x0F0F0F0F0F0F0F0Ful); 45 res = (res + (res >> 4)) & 0x0F0F0F0F0F0F0F0Ful;
47 res = (res & 0x00FF00FF00FF00FFul) + ((res >> 8) & 0x00FF00FF00FF00FFul); 46 res = res + (res >> 8);
48 res = (res & 0x0000FFFF0000FFFFul) + ((res >> 16) & 0x0000FFFF0000FFFFul); 47 res = res + (res >> 16);
49 return (res & 0x00000000FFFFFFFFul) + ((res >> 32) & 0x00000000FFFFFFFFul); 48 return (res + (res >> 32)) & 0x00000000000000FFul;
50#else 49#else
51#error BITS_PER_LONG not defined 50#error BITS_PER_LONG not defined
52#endif 51#endif