1#include <linux/linkage.h> 2#include <asm/export.h> 3 4#include <asm/asm.h> 5 6/* 7 * unsigned int __sw_hweight32(unsigned int w) 8 * %rdi: w 9 */ 10ENTRY(__sw_hweight32) 11 12#ifdef CONFIG_X86_64 13 movl %edi, %eax # w 14#endif 15 __ASM_SIZE(push,) %__ASM_REG(dx) 16 movl %eax, %edx # w -> t 17 shrl %edx # t >>= 1 18 andl $0x55555555, %edx # t &= 0x55555555 19 subl %edx, %eax # w -= t 20 21 movl %eax, %edx # w -> t 22 shrl $2, %eax # w_tmp >>= 2 23 andl $0x33333333, %edx # t &= 0x33333333 24 andl $0x33333333, %eax # w_tmp &= 0x33333333 25 addl %edx, %eax # w = w_tmp + t 26 27 movl %eax, %edx # w -> t 28 shrl $4, %edx # t >>= 4 29 addl %edx, %eax # w_tmp += t 30 andl $0x0f0f0f0f, %eax # w_tmp &= 0x0f0f0f0f 31 imull $0x01010101, %eax, %eax # w_tmp *= 0x01010101 32 shrl $24, %eax # w = w_tmp >> 24 33 __ASM_SIZE(pop,) %__ASM_REG(dx) 34 ret 35ENDPROC(__sw_hweight32) 36EXPORT_SYMBOL(__sw_hweight32) 37 38ENTRY(__sw_hweight64) 39#ifdef CONFIG_X86_64 40 pushq %rdi 41 pushq %rdx 42 43 movq %rdi, %rdx # w -> t 44 movabsq $0x5555555555555555, %rax 45 shrq %rdx # t >>= 1 46 andq %rdx, %rax # t &= 0x5555555555555555 47 movabsq $0x3333333333333333, %rdx 48 subq %rax, %rdi # w -= t 49 50 movq %rdi, %rax # w -> t 51 shrq $2, %rdi # w_tmp >>= 2 52 andq %rdx, %rax # t &= 0x3333333333333333 53 andq %rdi, %rdx # w_tmp &= 0x3333333333333333 54 addq %rdx, %rax # w = w_tmp + t 55 56 movq %rax, %rdx # w -> t 57 shrq $4, %rdx # t >>= 4 58 addq %rdx, %rax # w_tmp += t 59 movabsq $0x0f0f0f0f0f0f0f0f, %rdx 60 andq %rdx, %rax # w_tmp &= 0x0f0f0f0f0f0f0f0f 61 movabsq $0x0101010101010101, %rdx 62 imulq %rdx, %rax # w_tmp *= 0x0101010101010101 63 shrq $56, %rax # w = w_tmp >> 56 64 65 popq %rdx 66 popq %rdi 67 ret 68#else /* CONFIG_X86_32 */ 69 /* We're getting an u64 arg in (%eax,%edx): unsigned long hweight64(__u64 w) */ 70 pushl %ecx 71 72 call __sw_hweight32 73 movl %eax, %ecx # stash away result 74 movl %edx, %eax # second part of input 75 call __sw_hweight32 76 addl %ecx, %eax # result 77 78 popl %ecx 79 ret 80#endif 81ENDPROC(__sw_hweight64) 82EXPORT_SYMBOL(__sw_hweight64) 83