26 |
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
27 |
POSSIBILITY OF SUCH DAMAGE. */ |
POSSIBILITY OF SUCH DAMAGE. */ |
28 |
|
|
29 |
|
/* $Id$ */ |
30 |
|
|
31 |
/* |
/* |
32 |
strrev.S |
strrev.S |
33 |
Reverse a string |
Reverse a string |
58 |
.type _U(strrev), @function |
.type _U(strrev), @function |
59 |
|
|
60 |
_U(strrev): |
_U(strrev): |
61 |
LOAD_X(str_lo, str_hi) ; X is start of string |
X_movw XL, str_lo ; X is start of string |
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LOAD_Z(str_lo, str_hi) ; Z becomes end of string |
X_movw ZL, str_lo ; Z becomes end of string |
63 |
.strrev_eos: |
.L_strrev_eos: |
64 |
LD __tmp_reg__, Z+ |
LD __tmp_reg__, Z+ |
65 |
TST __tmp_reg__ |
TST __tmp_reg__ |
66 |
BRNE .strrev_eos |
BRNE .L_strrev_eos |
67 |
SBIW ZL, 2 ; now Z points at end of string |
SBIW ZL, 2 ; now Z points at end of string |
68 |
.strrev_loop: |
.L_strrev_loop: |
69 |
CP XL, ZL |
CP XL, ZL |
70 |
CPC XH, ZH ; if X >= Z we are done |
CPC XH, ZH ; if X >= Z we are done |
71 |
BRSH .strrev_done |
BRSH .L_strrev_done |
72 |
LD ltemp, X ; get left character |
LD ltemp, X ; get left character |
73 |
LD rtemp, Z ; get right character |
LD rtemp, Z ; get right character |
74 |
ST Z, ltemp |
ST Z, ltemp |
75 |
SBIW ZL, 1 |
SBIW ZL, 1 |
76 |
ST X+, rtemp ; swap chars |
ST X+, rtemp ; swap chars |
77 |
RJMP .strrev_loop ; next pair |
RJMP .L_strrev_loop ; next pair |
78 |
.strrev_done: |
.L_strrev_done: |
79 |
RET |
RET |
80 |
.strrev_end: |
.L_strrev_end: |
81 |
.size _U(strrev), .strrev_end - _U(strrev) |
.size _U(strrev), .L_strrev_end - _U(strrev) |
82 |
|
|
83 |
#endif /* not DOXYGEN */ |
#endif /* not DOXYGEN */ |