Loading...
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 (ALTERNATIVE("call __sw_hweight32", "popcntl %1, %0", X86_FEATURE_POPCNT)
20 : "="REG_OUT (res)
21 : REG_IN (w));
22
23 return res;
24}
25
26static inline unsigned int __arch_hweight16(unsigned int w)
27{
28 return __arch_hweight32(w & 0xffff);
29}
30
31static inline unsigned int __arch_hweight8(unsigned int w)
32{
33 return __arch_hweight32(w & 0xff);
34}
35
36#ifdef CONFIG_X86_32
37static inline unsigned long __arch_hweight64(__u64 w)
38{
39 return __arch_hweight32((u32)w) +
40 __arch_hweight32((u32)(w >> 32));
41}
42#else
43static __always_inline unsigned long __arch_hweight64(__u64 w)
44{
45 unsigned long res;
46
47 asm (ALTERNATIVE("call __sw_hweight64", "popcntq %1, %0", X86_FEATURE_POPCNT)
48 : "="REG_OUT (res)
49 : REG_IN (w));
50
51 return res;
52}
53#endif /* CONFIG_X86_32 */
54
55#endif
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 <arch/x86/Kconfig> for the respective
22 * compiler switches.
23 */
24static inline unsigned int __arch_hweight32(unsigned int w)
25{
26 unsigned int res = 0;
27
28 asm (ALTERNATIVE("call __sw_hweight32", POPCNT32, X86_FEATURE_POPCNT)
29 : "="REG_OUT (res)
30 : REG_IN (w));
31
32 return res;
33}
34
35static inline unsigned int __arch_hweight16(unsigned int w)
36{
37 return __arch_hweight32(w & 0xffff);
38}
39
40static inline unsigned int __arch_hweight8(unsigned int w)
41{
42 return __arch_hweight32(w & 0xff);
43}
44
45static 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