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| 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/memset.s | |
Import sources from 2011-03-30 iso image
Diffstat (limited to 'sys/src/libc/arm/memset.s')
| -rwxr-xr-x | sys/src/libc/arm/memset.s | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/sys/src/libc/arm/memset.s b/sys/src/libc/arm/memset.s new file mode 100755 index 000000000..7ebbb44c3 --- /dev/null +++ b/sys/src/libc/arm/memset.s @@ -0,0 +1,60 @@ +TO = 1 +TOE = 2 +N = 3 +TMP = 3 /* N and TMP don't overlap */ + +TEXT memset(SB), $0 + MOVW R0, R(TO) + MOVW data+4(FP), R(4) + MOVW n+8(FP), R(N) + + ADD R(N), R(TO), R(TOE) /* to end pointer */ + + CMP $4, R(N) /* need at least 4 bytes to copy */ + BLT _1tail + + AND $0xFF, R(4) + ORR R(4)<<8, R(4) + ORR R(4)<<16, R(4) /* replicate to word */ + +_4align: /* align on 4 */ + AND.S $3, R(TO), R(TMP) + BEQ _4aligned + + MOVBU.P R(4), 1(R(TO)) /* implicit write back */ + B _4align + +_4aligned: + SUB $15, R(TOE), R(TMP) /* do 16-byte chunks if possible */ + CMP R(TMP), R(TO) + BHS _4tail + + MOVW R4, R5 /* replicate */ + MOVW R4, R6 + MOVW R4, R7 + +_f16loop: + CMP R(TMP), R(TO) + BHS _4tail + + MOVM.IA.W [R4-R7], (R(TO)) + B _f16loop + +_4tail: + SUB $3, R(TOE), R(TMP) /* do remaining words if possible */ +_4loop: + CMP R(TMP), R(TO) + BHS _1tail + + MOVW.P R(4), 4(R(TO)) /* implicit write back */ + B _4loop + +_1tail: + CMP R(TO), R(TOE) + BEQ _return + + MOVBU.P R(4), 1(R(TO)) /* implicit write back */ + B _1tail + +_return: + RET |