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#include "macros.inc"
#define dest_hi r25
#define dest_lo r24
#define src_hi r23
#define src_lo r22
#define len_hi r21
#define len_lo r20
; void *memmove(void *dest, const void *src, size_t len)
.extern _U(memcpy)
.text
.global _U(memmove)
.type _U(memmove), @function
_U(memmove):
; if src < dest, we have to copy in reverse order
; otherwise memcpy will do the right thing
cp src_lo, dest_lo
cpc src_hi, dest_hi
brcc .memmove_fwd
LOAD_Z(src_lo, src_hi)
LOAD_X(dest_lo, dest_hi)
add ZL, len_lo
adc ZH, len_hi
add XL, len_lo
adc XH, len_hi
rjmp .memmove_start
.memmove_loop:
ld __tmp_reg__, -Z
st -X, __tmp_reg__
.memmove_start:
subi len_lo, lo8(1)
sbci len_hi, hi8(1)
brcc .memmove_loop
; return dest (unchanged)
ret
.memmove_fwd:
XJMP _U(memcpy)
.memmove_end:
.size _U(memmove), .memmove_end - _U(memmove)
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