arch_hweight.h

 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
15static __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
27static inline unsigned int __arch_hweight16(unsigned int w)
28{
29	return __arch_hweight32(w & 0xffff);
30}
31
32static inline unsigned int __arch_hweight8(unsigned int w)
33{
34	return __arch_hweight32(w & 0xff);
35}
36
37#ifdef CONFIG_X86_32
38static inline unsigned long __arch_hweight64(__u64 w)
39{
40	return  __arch_hweight32((u32)w) +
41		__arch_hweight32((u32)(w >> 32));
42}
43#else
44static __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