Subversion Repositories planix.SVN

        TEXT    memset(SB),$0
#define BDNZ    BC      16,0,
        MOVW R3, p+0(FP)                /* R3 is pointer */

/*
 * performance:
 *      about 100mbytes/sec (8k blocks) on a 603/105 without L2 cache
 *      drops to 40mbytes/sec (10k blocks) and 28mbytes/sec with 32k blocks
 */

        MOVW    n+8(FP), R4             /* R4 is count */
        CMP     R4, $0
        BLE     ret
        MOVW    c+4(FP), R5             /* R5 is char */

/*
 * create 16 copies of c in R5 .. R8
 */
        RLWNM   $0, R5, $0xff, R5
        RLWMI   $8, R5, $0xff00, R5
        RLWMI   $16, R5, $0xffff0000, R5
        MOVW    R5, R6
        MOVW    R5, R7
        MOVW    R5, R8

/*
 * let STSW do the work for 16 characters or less; aligned and unaligned
 */
        CMP     R4, $16
        BLE     out

/*
 * store enough bytes to align pointer
 */
        ANDCC   $7,R3, R9
        BEQ     l2
        SUBC    R9, $8, R9
        MOVW    R9, XER
        STSW    R5, (R3)
        ADD     R9, R3
        SUB     R9, R4

/*
 * store 16 at a time while there's room
 * STSW was used here originally, but it's `completion serialised'
 */
l2:
        SRAWCC  $4, R4, R9
        BLE     out
        MOVW    R9, CTR
l3:
        MOVW    R5, 0(R3)
        ADD     $8, R3, R10
        MOVW    R6, 4(R3)
        MOVW    R7, 0(R10)
        ADD     $8, R10, R3
        MOVW    R8, 4(R10)
        BDNZ    l3
        RLWNMCC $0, R4, $15, R4 /* residue */
        BEQ     ret

/*
 * store up to 16 bytes from R5 .. R8; aligned and unaligned
 */

out:
        MOVW    R4, XER
        STSW    R5, (R3)

ret:
        MOVW    0(FP), R3
        RETURN
        END