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
62