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#include "macros.inc"
#define dest_hi r25
#define dest_lo r24
; #define val_hi r23
#define val_lo r22
#define len_hi r21
#define len_lo r20
; void *memset(void *dest, int val, size_t len)
.text
.global _U(memset)
.type _U(memset), @function
_U(memset):
LOAD_X(dest_lo, dest_hi)
#if OPTIMIZE_SPEED
; 11 words, (12 + len * 4 - (len & 1)) cycles
sbrs len_lo, 0
rjmp .memset_start
rjmp .memset_odd
.memset_loop:
st X+, val_lo
.memset_odd:
st X+, val_lo
.memset_start:
subi len_lo, lo8(2)
sbci len_hi, hi8(2)
#else
; 8 words, (11 + len * 6) cycles
rjmp .memset_start
.memset_loop:
st X+, val_lo
.memset_start:
subi len_lo, lo8(1)
sbci len_hi, hi8(1)
#endif
brcc .memset_loop
; return dest (unchanged)
ret
.memset_end:
.size _U(memset), .memset_end - _U(memset)
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