banan-os/userspace/libraries/LibC/arch/i686/string.S

88 lines
1.4 KiB
ArmAsm

.global memchr
memchr:
xchgl 4(%esp), %edi
movl 8(%esp), %eax
movl 12(%esp), %ecx
movl $1, %edx
cmpl $1, %ecx # clear ZF if count is zero
repne scasb
cmovel %edi, %edx
leal -1(%edx), %eax
movl 4(%esp), %edi
ret
.global memcmp
memcmp:
xchgl 4(%esp), %edi
xchgl 8(%esp), %esi
movl 12(%esp), %ecx
testl %ecx, %ecx # set ZF if count is zero
repe cmpsb
jne .memcmp_not_equal
xorl %eax, %eax
jmp .memcmp_done
.memcmp_not_equal:
movzbl -1(%edi), %eax
movzbl -1(%esi), %ecx
subl %ecx, %eax
.memcmp_done:
movl 4(%esp), %edi
movl 8(%esp), %esi
ret
.global memcpy
memcpy:
xchgl 4(%esp), %edi
xchgl 8(%esp), %esi
movl 12(%esp), %ecx
movl %edi, %edx
rep movsb
movl 4(%esp), %edi
movl 8(%esp), %esi
movl %edx, %eax
ret
.global memmove
memmove:
xchgl 4(%esp), %edi
xchgl 8(%esp), %esi
movl 12(%esp), %ecx
movl %edi, %edx
cmpl %edi, %esi
jb .memmove_slow
rep movsb
.memmove_done:
movl 4(%esp), %edi
movl 8(%esp), %esi
movl %edx, %eax
ret
.memmove_slow:
leal -1(%edi, %ecx), %edi
leal -1(%esi, %ecx), %esi
std
rep movsb
cld
jmp .memmove_done
.global memset
memset:
xchgl 4(%esp), %edi
movl 8(%esp), %eax
movl 12(%esp), %ecx
movl %edi, %edx
rep stosb
movl 4(%esp), %edi
movl %edx, %eax
ret
.global strlen
strlen:
xchgl 4(%esp), %edi
xorb %al, %al
movl $-1, %ecx
repne scasb
movl 4(%esp), %edi
movl $-2, %eax
subl %ecx, %eax
ret