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/libc/arm/strcpy.s | |
Import sources from 2011-03-30 iso image
Diffstat (limited to 'sys/src/libc/arm/strcpy.s')
| -rwxr-xr-x | sys/src/libc/arm/strcpy.s | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/sys/src/libc/arm/strcpy.s b/sys/src/libc/arm/strcpy.s new file mode 100755 index 000000000..3e69fdc7d --- /dev/null +++ b/sys/src/libc/arm/strcpy.s @@ -0,0 +1,46 @@ +TEXT strcpy(SB), $-4 + MOVW R0, to+0(FP) /* need to save for return value */ + MOVW from+4(FP), R1 + MOVW $0xFF, R2 /* mask */ + +salign: /* align source on 4 */ + AND.S $3, R1, R3 + BEQ dalign + MOVBU.P 1(R1), R3 /* implicit write back */ + TST R3, R2 + MOVBU.P R3, 1(R0) /* implicit write back */ + BNE salign + B return + +dalign: /* is destination now aligned? */ + AND.S $3, R0, R3 + BNE uloop + +aloop: + MOVW.P 4(R1), R4 /* read 4, write 4 */ + TST R4, R2 /* AND.S R3, R2, Rx */ + TST.NE R4>>8, R2 + TST.NE R4>>16, R2 + TST.NE R4>>24, R2 + BEQ tail + MOVW.P R4, 4(R0) + B aloop + +uloop: + MOVW.P 4(R1), R4 /* read 4, write 1,1,1,1 */ + +tail: + AND.S R4, R2, R3 + MOVBU.NE.P R3, 1(R0) + AND.NE.S R4>>8, R2, R3 + MOVBU.NE.P R3, 1(R0) + AND.NE.S R4>>16, R2, R3 + MOVBU.NE.P R3, 1(R0) + AND.NE.S R4>>24, R2, R3 + MOVBU.P R3, 1(R0) + BNE uloop + B return + +return: + MOVW to+0(FP), R0 + RET |