mirror of
https://github.com/cc65/cc65.git
synced 2024-10-31 04:04:49 +00:00
57 lines
1018 B
ArmAsm
57 lines
1018 B
ArmAsm
|
;
|
||
|
|
; Ullrich von Bassewitz, 11.06.1998
|
||
|
|
;
|
||
|
|
; size_t strspn (const char* s1, const char* s2);
|
||
|
|
;
|
||
|
|
|
||
|
|
.export _strspn
|
||
|
|
.import popax
|
||
|
|
.importzp ptr1, ptr2, tmp1, tmp2, tmp3
|
||
|
|
|
||
|
|
_strspn:
|
||
|
|
sta ptr2 ; Save s2
|
||
|
|
stx ptr2+1
|
||
|
|
jsr popax ; get s1
|
||
|
|
sta ptr1
|
||
|
|
stx ptr1+1
|
||
|
|
ldx #0 ; low counter byte
|
||
|
|
stx tmp1 ; high counter byte
|
||
|
|
ldy #$00
|
||
|
|
|
||
|
|
L1: lda (ptr1),y ; get next char from s1
|
||
|
|
beq L6 ; jump if done
|
||
|
|
sta tmp2 ; save char
|
||
|
|
iny
|
||
|
|
bne L2
|
||
|
|
inc ptr1+1
|
||
|
|
L2: sty tmp3 ; save index into s1
|
||
|
|
|
||
|
|
ldy #0 ; get index into s2
|
||
|
|
L3: lda (ptr2),y ;
|
||
|
|
beq L6 ; jump if done
|
||
|
|
cmp tmp2
|
||
|
|
beq L4
|
||
|
|
iny
|
||
|
|
bne L3
|
||
|
|
|
||
|
|
; The character was found in s2. Increment the counter and start over
|
||
|
|
|
||
|
|
L4: ldy tmp3 ; reload index
|
||
|
|
inx
|
||
|
|
bne L1
|
||
|
|
inc tmp1
|
||
|
|
bne L1
|
||
|
|
|
||
|
|
; The character was not found, or we reached the end of s1. Return count of
|
||
|
|
; characters
|
||
|
|
|
||
|
|
L6: txa ; get low counter byte
|
||
|
|
ldx tmp1 ; get high counter byte
|
||
|
|
rts
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|