kvisc/ka/crt/str/strcmp.k

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; The OS/K Team licenses this file to you under the MIT license.
; See the LICENSE file in the project root for more information.
;
; int strcmp(const char *str1, const char *str2)
;
; Returns:
; 0 if the contents of both strings are equal
; >0 if the first character that does not match has a greater value in str1 than in str2
; <0 if the first character that does not match has a lower value in str1 than in str2
;
strcmp:
.l:
movzx rax, b[ax0]
movzx rdx, b[ax1]
cmp rax, rdx
jmp.nz .r
; both zero?
add rbx, rax, rdx
jmp.bxz .r
add ax0, ax0, 1
add ax1, ax1, 1
jmp .l
.r:
sub rax, rax, rdx
ret
;
; int strncmp(const char *str1, const char *str2, int maxn)
;
strncmp:
mov rcx, ax2
jmp.cxz .r
.l:
mov rax, b[ax0]
mov rdx, b[ax1]
cmp rax, rdx
jmp.nz .r
add ax0, ax0, 1
add ax1, ax1, 1
loop .l
.r:
sub rax, rax, rdx
ret