223 lines
2.8 KiB
Plaintext
223 lines
2.8 KiB
Plaintext
; 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 strnlen(char *, int)
|
|
;
|
|
strnlen:
|
|
mov rcx, ax1
|
|
scasb ax0, zero
|
|
|
|
sub rax, ax1, rcx
|
|
ret
|
|
|
|
;
|
|
; int strlen(char *)
|
|
;
|
|
strlen:
|
|
mov rcx, STRLEN_MAX
|
|
mov rdx, rcx
|
|
scasb ax0, zero
|
|
|
|
sub rax, rdx, rcx
|
|
ret
|
|
|
|
;
|
|
; void strcpy(char *, const char *)
|
|
;
|
|
strcpy:
|
|
.l:
|
|
mov rcx, b[ax1]
|
|
mov b[ax0], rcx
|
|
|
|
jrcxz .r
|
|
|
|
inc ax0, 1
|
|
inc ax1, 1
|
|
|
|
jmp .l
|
|
|
|
.r:
|
|
ret
|
|
|
|
;
|
|
; void strncpy(char *, const char *, int)
|
|
;
|
|
strncpy:
|
|
mov rcx, ax2
|
|
jrcxz .r
|
|
|
|
.l:
|
|
mov b[ax0], b[ax1]
|
|
|
|
inc ax0, 1
|
|
inc ax1, 1
|
|
|
|
loop .l
|
|
|
|
.r:
|
|
ret
|
|
|
|
;
|
|
; void strnzcpy(char *, const char *, int)
|
|
;
|
|
strnzcpy:
|
|
mov rcx, ax2
|
|
jrcxz .r
|
|
|
|
.l:
|
|
mov rax, b[ax1]
|
|
mov b[ax0], rax
|
|
|
|
jraxz .r
|
|
|
|
inc ax0, 1
|
|
inc ax1, 1
|
|
|
|
loop .l
|
|
|
|
.z:
|
|
nul b[ax0]
|
|
|
|
.r:
|
|
ret
|
|
|
|
;
|
|
; 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:
|
|
nul rsi
|
|
.l:
|
|
movzx rax, b[ax0+rsi]
|
|
movzx rdx, b[ax1+rsi]
|
|
|
|
bne rax, rdx, .r
|
|
|
|
; both zero?
|
|
add rcx, rax, rdx
|
|
jrcxz .r
|
|
|
|
inc rsi, 1
|
|
jmp .l
|
|
|
|
.r:
|
|
dec rax, rdx
|
|
ret
|
|
|
|
;
|
|
; int strncmp(const char *str1, const char *str2, int maxn)
|
|
;
|
|
strncmp:
|
|
mov rcx, ax2
|
|
jrcxz .r
|
|
|
|
.l:
|
|
movzx rax, b[ax0]
|
|
movzx rdx, b[ax1]
|
|
|
|
bne rax, rdx, .r
|
|
|
|
inc ax0, 1
|
|
inc ax1, 1
|
|
loop .l
|
|
|
|
.r:
|
|
dec rax, rdx
|
|
ret
|
|
|
|
;
|
|
; char *strchrnul(const char *str, int ch)
|
|
;
|
|
strchrnul:
|
|
mov rcx, STRLEN_MAX
|
|
scasb ax0, ax1
|
|
|
|
mov rax, ax0
|
|
ret
|
|
|
|
;
|
|
; char *strchr(const char *str, int ch)
|
|
;
|
|
strchr:
|
|
mov rcx, STRLEN_MAX
|
|
scasb ax0, ax1
|
|
|
|
bnz b[ax0], .r
|
|
nul rax
|
|
ret
|
|
|
|
.r:
|
|
mov rax, ax0
|
|
ret
|
|
|
|
;
|
|
; void strrev(char *buf, const char *str)
|
|
;
|
|
; buf and src must NOT overlap
|
|
;
|
|
strrev:
|
|
bzr b[ax1], .z
|
|
|
|
; save str's location
|
|
mov rsi, ax1
|
|
|
|
; go to str's end, just before
|
|
; the null terminator
|
|
mov rcx, STRLEN_MAX
|
|
scasb ax1, zero
|
|
dec ax1, 1
|
|
|
|
.l:
|
|
; copy, going backward though str
|
|
; and forward through buf
|
|
mov b[ax0], b[ax1]
|
|
|
|
beq ax1, rsi, .r
|
|
|
|
inc ax0, 1
|
|
dec ax1, 1
|
|
jmp .l
|
|
|
|
.r:
|
|
nul b[ax0+1]
|
|
ret
|
|
|
|
.z:
|
|
nul b[ax0]
|
|
ret
|
|
|
|
;
|
|
; void strrev2(char *str)
|
|
;
|
|
; Inverses str
|
|
;
|
|
strrev2:
|
|
bzr b[ax0], .r
|
|
|
|
mov ax1, ax0
|
|
|
|
; go to str's end, just before
|
|
; the null terminator
|
|
mov rcx, STRLEN_MAX
|
|
scasb ax1, zero
|
|
dec ax1, 1
|
|
|
|
; increase ax0 while decreasing ax1, performing exchanges
|
|
.l:
|
|
blteu ax1, ax0, .r
|
|
|
|
xchg b[ax0], b[ax1]
|
|
|
|
inc ax0, 1
|
|
dec ax1, 1
|
|
jmp .l
|
|
|
|
.r:
|
|
ret
|
|
|