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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
f5967101 | 2 | #include <linux/linkage.h> |
784d5699 | 3 | #include <asm/export.h> |
f5967101 BP |
4 | |
5 | #include <asm/asm.h> | |
6 | ||
7 | /* | |
8 | * unsigned int __sw_hweight32(unsigned int w) | |
9 | * %rdi: w | |
10 | */ | |
11 | ENTRY(__sw_hweight32) | |
12 | ||
13 | #ifdef CONFIG_X86_64 | |
14 | movl %edi, %eax # w | |
15 | #endif | |
16 | __ASM_SIZE(push,) %__ASM_REG(dx) | |
17 | movl %eax, %edx # w -> t | |
18 | shrl %edx # t >>= 1 | |
19 | andl $0x55555555, %edx # t &= 0x55555555 | |
20 | subl %edx, %eax # w -= t | |
21 | ||
22 | movl %eax, %edx # w -> t | |
23 | shrl $2, %eax # w_tmp >>= 2 | |
24 | andl $0x33333333, %edx # t &= 0x33333333 | |
25 | andl $0x33333333, %eax # w_tmp &= 0x33333333 | |
26 | addl %edx, %eax # w = w_tmp + t | |
27 | ||
28 | movl %eax, %edx # w -> t | |
29 | shrl $4, %edx # t >>= 4 | |
30 | addl %edx, %eax # w_tmp += t | |
31 | andl $0x0f0f0f0f, %eax # w_tmp &= 0x0f0f0f0f | |
32 | imull $0x01010101, %eax, %eax # w_tmp *= 0x01010101 | |
33 | shrl $24, %eax # w = w_tmp >> 24 | |
34 | __ASM_SIZE(pop,) %__ASM_REG(dx) | |
35 | ret | |
36 | ENDPROC(__sw_hweight32) | |
784d5699 | 37 | EXPORT_SYMBOL(__sw_hweight32) |
f5967101 BP |
38 | |
39 | ENTRY(__sw_hweight64) | |
40 | #ifdef CONFIG_X86_64 | |
65ea11ec | 41 | pushq %rdi |
f5967101 BP |
42 | pushq %rdx |
43 | ||
44 | movq %rdi, %rdx # w -> t | |
45 | movabsq $0x5555555555555555, %rax | |
46 | shrq %rdx # t >>= 1 | |
47 | andq %rdx, %rax # t &= 0x5555555555555555 | |
48 | movabsq $0x3333333333333333, %rdx | |
49 | subq %rax, %rdi # w -= t | |
50 | ||
51 | movq %rdi, %rax # w -> t | |
52 | shrq $2, %rdi # w_tmp >>= 2 | |
53 | andq %rdx, %rax # t &= 0x3333333333333333 | |
54 | andq %rdi, %rdx # w_tmp &= 0x3333333333333333 | |
55 | addq %rdx, %rax # w = w_tmp + t | |
56 | ||
57 | movq %rax, %rdx # w -> t | |
58 | shrq $4, %rdx # t >>= 4 | |
59 | addq %rdx, %rax # w_tmp += t | |
60 | movabsq $0x0f0f0f0f0f0f0f0f, %rdx | |
61 | andq %rdx, %rax # w_tmp &= 0x0f0f0f0f0f0f0f0f | |
62 | movabsq $0x0101010101010101, %rdx | |
63 | imulq %rdx, %rax # w_tmp *= 0x0101010101010101 | |
64 | shrq $56, %rax # w = w_tmp >> 56 | |
65 | ||
66 | popq %rdx | |
65ea11ec | 67 | popq %rdi |
f5967101 BP |
68 | ret |
69 | #else /* CONFIG_X86_32 */ | |
70 | /* We're getting an u64 arg in (%eax,%edx): unsigned long hweight64(__u64 w) */ | |
71 | pushl %ecx | |
72 | ||
73 | call __sw_hweight32 | |
74 | movl %eax, %ecx # stash away result | |
75 | movl %edx, %eax # second part of input | |
76 | call __sw_hweight32 | |
77 | addl %ecx, %eax # result | |
78 | ||
79 | popl %ecx | |
80 | ret | |
81 | #endif | |
82 | ENDPROC(__sw_hweight64) | |
784d5699 | 83 | EXPORT_SYMBOL(__sw_hweight64) |