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/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/export.h>
#include <linux/linkage.h>
#include <asm/asm.h>
/*
* unsigned int __sw_hweight32(unsigned int w)
* %rdi: w
*/
SYM_FUNC_START(__sw_hweight32)
#ifdef CONFIG_X86_64
movl %edi, %eax # w
#endif
__ASM_SIZE(push,) %__ASM_REG(dx)
movl %eax, %edx # w -> t
shrl %edx # t >>= 1
andl $0x55555555, %edx # t &= 0x55555555
subl %edx, %eax # w -= t
movl %eax, %edx # w -> t
shrl $2, %eax # w_tmp >>= 2
andl $0x33333333, %edx # t &= 0x33333333
andl $0x33333333, %eax # w_tmp &= 0x33333333
addl %edx, %eax # w = w_tmp + t
movl %eax, %edx # w -> t
shrl $4, %edx # t >>= 4
addl %edx, %eax # w_tmp += t
andl $0x0f0f0f0f, %eax # w_tmp &= 0x0f0f0f0f
imull $0x01010101, %eax, %eax # w_tmp *= 0x01010101
shrl $24, %eax # w = w_tmp >> 24
__ASM_SIZE(pop,) %__ASM_REG(dx)
RET
SYM_FUNC_END(__sw_hweight32)
EXPORT_SYMBOL(__sw_hweight32)
/*
* No 32-bit variant, because it's implemented as an inline wrapper
* on top of __arch_hweight32():
*/
#ifdef CONFIG_X86_64
SYM_FUNC_START(__sw_hweight64)
pushq %rdi
pushq %rdx
movq %rdi, %rdx # w -> t
movabsq $0x5555555555555555, %rax
shrq %rdx # t >>= 1
andq %rdx, %rax # t &= 0x5555555555555555
movabsq $0x3333333333333333, %rdx
subq %rax, %rdi # w -= t
movq %rdi, %rax # w -> t
shrq $2, %rdi # w_tmp >>= 2
andq %rdx, %rax # t &= 0x3333333333333333
andq %rdi, %rdx # w_tmp &= 0x3333333333333333
addq %rdx, %rax # w = w_tmp + t
movq %rax, %rdx # w -> t
shrq $4, %rdx # t >>= 4
addq %rdx, %rax # w_tmp += t
movabsq $0x0f0f0f0f0f0f0f0f, %rdx
andq %rdx, %rax # w_tmp &= 0x0f0f0f0f0f0f0f0f
movabsq $0x0101010101010101, %rdx
imulq %rdx, %rax # w_tmp *= 0x0101010101010101
shrq $56, %rax # w = w_tmp >> 56
popq %rdx
popq %rdi
RET
SYM_FUNC_END(__sw_hweight64)
EXPORT_SYMBOL(__sw_hweight64)
#endif
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