Rev 6082 | Go to most recent revision | Details | Last modification | View Log | RSS feed
Rev | Author | Line No. | Line |
---|---|---|---|
5270 | serge | 1 | #ifndef _ASM_X86_HWEIGHT_H |
2 | #define _ASM_X86_HWEIGHT_H |
||
3 | |||
4 | #ifdef CONFIG_64BIT |
||
5 | /* popcnt %edi, %eax -- redundant REX prefix for alignment */ |
||
6 | #define POPCNT32 ".byte 0xf3,0x40,0x0f,0xb8,0xc7" |
||
7 | /* popcnt %rdi, %rax */ |
||
8 | #define POPCNT64 ".byte 0xf3,0x48,0x0f,0xb8,0xc7" |
||
9 | #define REG_IN "D" |
||
10 | #define REG_OUT "a" |
||
11 | #else |
||
12 | /* popcnt %eax, %eax */ |
||
13 | #define POPCNT32 ".byte 0xf3,0x0f,0xb8,0xc0" |
||
14 | #define REG_IN "a" |
||
15 | #define REG_OUT "a" |
||
16 | #endif |
||
17 | |||
18 | /* |
||
19 | * __sw_hweightXX are called from within the alternatives below |
||
20 | * and callee-clobbered registers need to be taken care of. See |
||
21 | * ARCH_HWEIGHT_CFLAGS in |
||
22 | * compiler switches. |
||
23 | */ |
||
24 | static inline unsigned int __arch_hweight32(unsigned int w) |
||
25 | { |
||
26 | unsigned int res = 0; |
||
27 | |||
28 | asm ("call __sw_hweight32" |
||
29 | : "="REG_OUT (res) |
||
30 | : REG_IN (w)); |
||
31 | |||
32 | return res; |
||
33 | } |
||
34 | |||
35 | static inline unsigned int __arch_hweight16(unsigned int w) |
||
36 | { |
||
37 | return __arch_hweight32(w & 0xffff); |
||
38 | } |
||
39 | |||
40 | static inline unsigned int __arch_hweight8(unsigned int w) |
||
41 | { |
||
42 | return __arch_hweight32(w & 0xff); |
||
43 | } |
||
44 | |||
45 | static inline unsigned long __arch_hweight64(__u64 w) |
||
46 | { |
||
47 | unsigned long res = 0; |
||
48 | |||
49 | #ifdef CONFIG_X86_32 |
||
50 | return __arch_hweight32((u32)w) + |
||
51 | __arch_hweight32((u32)(w >> 32)); |
||
52 | #else |
||
53 | asm (ALTERNATIVE("call __sw_hweight64", POPCNT64, X86_FEATURE_POPCNT) |
||
54 | : "="REG_OUT (res) |
||
55 | : REG_IN (w)); |
||
56 | #endif /* CONFIG_X86_32 */ |
||
57 | |||
58 | return res; |
||
59 | } |
||
60 | |||
61 | #endif |