Subversion Repositories planix.SVN

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