kvisc/ka/crt/str/strcmp.k

; 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:
    mov rcx, STRLEN_MAX
    cmpzsb.rep.z ax0, ax1

    mov rax, b[ax0-1]
    mov rcx, b[ax1-1]
    sub rax, rax, rcx

    ret

;
; int strncmp(const char *str1, const char *str2, int maxn)
;
strncmp:
    mov rcx, ax2
    mov.cxz rax, zero
    ret.cxz

    cmpzsb.rep.z ax0, ax1

    mov rax, b[ax0-1]
    mov rcx, b[ax1-1]
    sub rax, rax, rcx

    ret