Subversion Repositories planix.SVN

        TEXT    memset(SB),$0

/*
 * performance:
 *      (tba)
 */

MOVW    R7, 0(FP)
        MOVW    n+8(FP), R9             /* R9 is count */
        MOVW    p+0(FP), R10            /* R10 is pointer */
        MOVW    c+4(FP), R11            /* R11 is char */
        ADD     R9,R10, R12             /* R12 is end pointer */

/*
 * if not at least 4 chars,
 * dont even mess around.
 * 3 chars to guarantee any
 * rounding up to a word
 * boundary and 4 characters
 * to get at least maybe one
 * full word store.
 */
        SUBCC   $4,R9, R0
        BL      out

/*
 * turn R11 into a word of characters
 */
        AND     $0xff, R11
        SLL     $8,R11, R7
        OR      R7, R11
        SLL     $16,R11, R7
        OR      R7, R11

/*
 * store one byte at a time until pointer
 * is alligned on a word boundary
 */
l1:
        ANDCC   $3,R10, R0
        BE      l2
        MOVB    R11, 0(R10)
        ADD     $1, R10
        JMP     l1

/*
 * turn R9 into end pointer-15
 * store 16 at a time while theres room
 */
l2:
        ADD     $-15,R12, R9
        SUBCC   R10,R9, R0
        BLEU    l4
l3:
        MOVW    R11, 0(R10)
        MOVW    R11, 4(R10)
        ADD     $16, R10
        SUBCC   R10,R9, R0
        MOVW    R11, -8(R10)
        MOVW    R11, -4(R10)
        BGU     l3

/*
 * turn R9 into end pointer-3
 * store 4 at a time while theres room
 */
l4:
        ADD     $-3,R12, R9
l5:
        SUBCC   R10,R9, R0
        BLEU    out
        MOVW    R11, 0(R10)
        ADD     $4, R10
        JMP     l5

/*
 * last loop, store byte at a time
 */
out:
        SUBCC   R10,R12, R0
        BLEU    ret
        MOVB    R11, 0(R10)
        ADD     $1, R10
        JMP     out

ret:
        MOVW    s1+0(FP), R7
        RETURN