xref: /linux/arch/x86/include/asm/arch_hweight.h (revision e78f70bad29c5ae1e1076698b690b15794e9b81e)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_HWEIGHT_H
3 #define _ASM_X86_HWEIGHT_H
4 
5 #include <asm/cpufeatures.h>
6 
7 #ifdef CONFIG_64BIT
8 #define REG_IN "D"
9 #define REG_OUT "a"
10 #else
11 #define REG_IN "a"
12 #define REG_OUT "a"
13 #endif
14 
15 static __always_inline unsigned int __arch_hweight32(unsigned int w)
16 {
17 	unsigned int res;
18 
19 	asm_inline (ALTERNATIVE("call __sw_hweight32",
20 				"popcntl %[val], %[cnt]", X86_FEATURE_POPCNT)
21 			 : [cnt] "=" REG_OUT (res), ASM_CALL_CONSTRAINT
22 			 : [val] REG_IN (w));
23 
24 	return res;
25 }
26 
27 static inline unsigned int __arch_hweight16(unsigned int w)
28 {
29 	return __arch_hweight32(w & 0xffff);
30 }
31 
32 static inline unsigned int __arch_hweight8(unsigned int w)
33 {
34 	return __arch_hweight32(w & 0xff);
35 }
36 
37 #ifdef CONFIG_X86_32
38 static inline unsigned long __arch_hweight64(__u64 w)
39 {
40 	return  __arch_hweight32((u32)w) +
41 		__arch_hweight32((u32)(w >> 32));
42 }
43 #else
44 static __always_inline unsigned long __arch_hweight64(__u64 w)
45 {
46 	unsigned long res;
47 
48 	asm_inline (ALTERNATIVE("call __sw_hweight64",
49 				"popcntq %[val], %[cnt]", X86_FEATURE_POPCNT)
50 			 : [cnt] "=" REG_OUT (res), ASM_CALL_CONSTRAINT
51 			 : [val] REG_IN (w));
52 
53 	return res;
54 }
55 #endif /* CONFIG_X86_32 */
56 
57 #endif
58