diff options
| author | Taru Karttunen <taruti@taruti.net> | 2011-03-30 15:46:40 +0300 |
|---|---|---|
| committer | Taru Karttunen <taruti@taruti.net> | 2011-03-30 15:46:40 +0300 |
| commit | e5888a1ffdae813d7575f5fb02275c6bb07e5199 (patch) | |
| tree | d8d51eac403f07814b9e936eed0c9a79195e2450 /sys/src/ape/lib/ap/arm/strchr.s | |
Import sources from 2011-03-30 iso image
Diffstat (limited to 'sys/src/ape/lib/ap/arm/strchr.s')
| -rwxr-xr-x | sys/src/ape/lib/ap/arm/strchr.s | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/sys/src/ape/lib/ap/arm/strchr.s b/sys/src/ape/lib/ap/arm/strchr.s new file mode 100755 index 000000000..349b5a49f --- /dev/null +++ b/sys/src/ape/lib/ap/arm/strchr.s @@ -0,0 +1,56 @@ +TEXT strchr(SB), $-4 + MOVBU c+4(FP), R1 + CMP $0, R1 + BEQ _null + +_strchr: /* not looking for a null, byte at a time */ + MOVBU.P 1(R0), R2 + CMP R1, R2 + BEQ _sub1 + + CMP $0, R2 + BNE _strchr + +_return0: /* character not found in string, return 0 */ + MOVW $0, R0 + RET + +_null: /* looking for null, align */ + AND.S $3, R0, R2 + BEQ _aligned + + MOVBU.P 1(R0), R4 + CMP $0, R4 + BEQ _sub1 + B _null + +_aligned: + MOVW $0xFF, R3 /* mask */ + +_loop: + MOVW.P 4(R0), R4 /* 4 at a time */ + TST R4, R3 /* AND.S R2, R3, Rx */ + TST.NE R4>>8, R3 + TST.NE R4>>16, R3 + TST.NE R4>>24, R3 + BNE _loop + + TST R4, R3 /* its somewhere, find it and correct */ + BEQ _sub4 + TST R4>>8, R3 + BEQ _sub3 + TST R4>>16, R3 + BEQ _sub2 + +_sub1: /* compensate for pointer increment */ + SUB $1, R0 + RET +_sub2: + SUB $2, R0 + RET +_sub3: + SUB $3, R0 + RET +_sub4: + SUB $4, R0 + RET |