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1 | #include <linux/linkage.h> |
2 | ||
3 | #include <asm/asm.h> | |
4 | ||
5 | /* | |
6 | * unsigned int __sw_hweight32(unsigned int w) | |
7 | * %rdi: w | |
8 | */ | |
9 | ENTRY(__sw_hweight32) | |
10 | ||
11 | #ifdef CONFIG_X86_64 | |
12 | movl %edi, %eax # w | |
13 | #endif | |
14 | __ASM_SIZE(push,) %__ASM_REG(dx) | |
15 | movl %eax, %edx # w -> t | |
16 | shrl %edx # t >>= 1 | |
17 | andl $0x55555555, %edx # t &= 0x55555555 | |
18 | subl %edx, %eax # w -= t | |
19 | ||
20 | movl %eax, %edx # w -> t | |
21 | shrl $2, %eax # w_tmp >>= 2 | |
22 | andl $0x33333333, %edx # t &= 0x33333333 | |
23 | andl $0x33333333, %eax # w_tmp &= 0x33333333 | |
24 | addl %edx, %eax # w = w_tmp + t | |
25 | ||
26 | movl %eax, %edx # w -> t | |
27 | shrl $4, %edx # t >>= 4 | |
28 | addl %edx, %eax # w_tmp += t | |
29 | andl $0x0f0f0f0f, %eax # w_tmp &= 0x0f0f0f0f | |
30 | imull $0x01010101, %eax, %eax # w_tmp *= 0x01010101 | |
31 | shrl $24, %eax # w = w_tmp >> 24 | |
32 | __ASM_SIZE(pop,) %__ASM_REG(dx) | |
33 | ret | |
34 | ENDPROC(__sw_hweight32) | |
35 | ||
36 | ENTRY(__sw_hweight64) | |
37 | #ifdef CONFIG_X86_64 | |
65ea11ec | 38 | pushq %rdi |
f5967101 BP |
39 | pushq %rdx |
40 | ||
41 | movq %rdi, %rdx # w -> t | |
42 | movabsq $0x5555555555555555, %rax | |
43 | shrq %rdx # t >>= 1 | |
44 | andq %rdx, %rax # t &= 0x5555555555555555 | |
45 | movabsq $0x3333333333333333, %rdx | |
46 | subq %rax, %rdi # w -= t | |
47 | ||
48 | movq %rdi, %rax # w -> t | |
49 | shrq $2, %rdi # w_tmp >>= 2 | |
50 | andq %rdx, %rax # t &= 0x3333333333333333 | |
51 | andq %rdi, %rdx # w_tmp &= 0x3333333333333333 | |
52 | addq %rdx, %rax # w = w_tmp + t | |
53 | ||
54 | movq %rax, %rdx # w -> t | |
55 | shrq $4, %rdx # t >>= 4 | |
56 | addq %rdx, %rax # w_tmp += t | |
57 | movabsq $0x0f0f0f0f0f0f0f0f, %rdx | |
58 | andq %rdx, %rax # w_tmp &= 0x0f0f0f0f0f0f0f0f | |
59 | movabsq $0x0101010101010101, %rdx | |
60 | imulq %rdx, %rax # w_tmp *= 0x0101010101010101 | |
61 | shrq $56, %rax # w = w_tmp >> 56 | |
62 | ||
63 | popq %rdx | |
65ea11ec | 64 | popq %rdi |
f5967101 BP |
65 | ret |
66 | #else /* CONFIG_X86_32 */ | |
67 | /* We're getting an u64 arg in (%eax,%edx): unsigned long hweight64(__u64 w) */ | |
68 | pushl %ecx | |
69 | ||
70 | call __sw_hweight32 | |
71 | movl %eax, %ecx # stash away result | |
72 | movl %edx, %eax # second part of input | |
73 | call __sw_hweight32 | |
74 | addl %ecx, %eax # result | |
75 | ||
76 | popl %ecx | |
77 | ret | |
78 | #endif | |
79 | ENDPROC(__sw_hweight64) |