mirror of
https://github.com/cc65/cc65.git
synced 2024-12-26 08:32:00 +00:00
114 lines
2.0 KiB
ArmAsm
114 lines
2.0 KiB
ArmAsm
|
;
|
||
|
|
; void* memcpy (void* dest, const void* src, size_t n);
|
||
|
|
; void* memmove (void* dest, const void* src, size_t n);
|
||
|
|
;
|
||
|
|
; Ullrich von Bassewitz, 10.12.1998
|
||
|
|
;
|
||
|
|
|
||
|
|
.export _memcpy, _memmove
|
||
|
|
.import popax
|
||
|
|
.importzp ptr1, ptr2, ptr3, tmp1, tmp2
|
||
|
|
|
||
|
|
; ----------------------------------------------------------------------
|
||
|
|
_memcpy:
|
||
|
|
jsr getparms ; Get the parameters from stack
|
||
|
|
|
||
|
|
; Copy upwards
|
||
|
|
|
||
|
|
copyup: ldy #0 ; set up to move 256
|
||
|
|
ldx tmp2 ; hi byte of n
|
||
|
|
beq @L2
|
||
|
|
|
||
|
|
@L1: lda (ptr1),y ; get a byte
|
||
|
|
sta (ptr2),y ; store it
|
||
|
|
iny
|
||
|
|
bne @L1
|
||
|
|
inc ptr1+1 ; bump ptrs
|
||
|
|
inc ptr2+1
|
||
|
|
dex
|
||
|
|
bne @L1 ; do another block
|
||
|
|
|
||
|
|
@L2: ldx tmp1 ; get low byte of n
|
||
|
|
beq done ; jump if done
|
||
|
|
|
||
|
|
@L3: lda (ptr1),y ; get a byte
|
||
|
|
sta (ptr2),y ; store it
|
||
|
|
iny
|
||
|
|
dex
|
||
|
|
bne @L3
|
||
|
|
|
||
|
|
done: lda ptr3
|
||
|
|
ldx ptr3+1 ; get function result (dest)
|
||
|
|
rts
|
||
|
|
|
||
|
|
|
||
|
|
; ----------------------------------------------------------------------
|
||
|
|
_memmove:
|
||
|
|
jsr getparms ; Get the parameters from stack
|
||
|
|
|
||
|
|
cpx ptr1+1 ; dest > src?
|
||
|
|
bne @L1
|
||
|
|
cmp ptr1
|
||
|
|
@L1: beq done ; Both pointers are equal - nothing to copy
|
||
|
|
bcc copyup ; Copy upwards
|
||
|
|
|
||
|
|
; Copy downwards
|
||
|
|
|
||
|
|
clc
|
||
|
|
lda ptr1+1
|
||
|
|
adc tmp2
|
||
|
|
sta ptr1+1
|
||
|
|
|
||
|
|
clc
|
||
|
|
lda ptr2+1
|
||
|
|
adc tmp2
|
||
|
|
sta ptr2+1
|
||
|
|
|
||
|
|
; Copy the incomplete page
|
||
|
|
|
||
|
|
ldy tmp1 ; Get low byte of count
|
||
|
|
beq @L3
|
||
|
|
|
||
|
|
@L2: dey
|
||
|
|
lda (ptr1),y
|
||
|
|
sta (ptr2),y
|
||
|
|
tya ; Test Y
|
||
|
|
bne @L2 ; Jump if not zero
|
||
|
|
|
||
|
|
; Copy complete pages
|
||
|
|
|
||
|
|
@L3: ldx tmp2 ; Get hi byte of count
|
||
|
|
beq done
|
||
|
|
|
||
|
|
@L4: dec ptr1+1
|
||
|
|
dec ptr2+1
|
||
|
|
@L5: dey
|
||
|
|
lda (ptr1),y
|
||
|
|
sta (ptr2),y
|
||
|
|
tya
|
||
|
|
bne @L5
|
||
|
|
dex
|
||
|
|
bne @L4
|
||
|
|
|
||
|
|
; Done
|
||
|
|
|
||
|
|
beq done
|
||
|
|
|
||
|
|
; ----------------------------------------------------------------------
|
||
|
|
; Get the parameters from stack
|
||
|
|
|
||
|
|
getparms:
|
||
|
|
sta tmp1 ; Save n
|
||
|
|
stx tmp2
|
||
|
|
jsr popax ; src
|
||
|
|
sta ptr1
|
||
|
|
stx ptr1+1
|
||
|
|
jsr popax ; dest
|
||
|
|
sta ptr2
|
||
|
|
stx ptr2+1 ; save work copy
|
||
|
|
sta ptr3
|
||
|
|
stx ptr3+1 ; save function result
|
||
|
|
rts
|
||
|
|
|
||
|
|
|