| /* SPDX-License-Identifier: GPL-2.0 */ |
| #include <linux/linkage.h> |
| #include <asm/export.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) |
| |
| SYM_FUNC_START(__sw_hweight64) |
| #ifdef CONFIG_X86_64 |
| 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 |
| #else /* CONFIG_X86_32 */ |
| /* We're getting an u64 arg in (%eax,%edx): unsigned long hweight64(__u64 w) */ |
| pushl %ecx |
| |
| call __sw_hweight32 |
| movl %eax, %ecx # stash away result |
| movl %edx, %eax # second part of input |
| call __sw_hweight32 |
| addl %ecx, %eax # result |
| |
| popl %ecx |
| ret |
| #endif |
| SYM_FUNC_END(__sw_hweight64) |
| EXPORT_SYMBOL(__sw_hweight64) |
