Subversion Repositories planix.SVN

        TEXT    memcmp(SB), $0
#define BDNZ    BC      16,0,
        MOVW R3, s1+0(FP)               /* R3 is pointer1 */

/*
 * performance:
 *      67mb/sec aligned; 16mb/sec unaligned
 */

        MOVW    n+8(FP), R4             /* R4 is count */
        MOVW    s2+4(FP), R5            /* R5 is pointer2 */

/*
 * let LSW do the work for 4 characters or less; aligned and unaligned
 */
        CMP     R4, $0
        BLE     eq
        CMP     R4, $4
        BLE     out

        XOR     R3, R5, R9
        ANDCC   $3, R9
        BNE     l4      /* pointers misaligned; use LSW loop */

/*
 * do enough bytes to align pointers
 */
        ANDCC   $3,R3, R9
        BEQ     l2
        SUBC    R9, $4, R9
        MOVW    R9, XER
        LSW     (R3), R10
        ADD     R9, R3
        LSW     (R5), R14
        ADD     R9, R5
        SUB     R9, R4
        CMPU    R10, R14
        BNE     ne

/*
 * compare 16 at a time
 */
l2:
        SRAWCC  $4, R4, R9
        BLE     l4
        MOVW    R9, CTR
        SUB     $4, R3
        SUB     $4, R5
l3:
        MOVWU   4(R3), R10
        MOVWU   4(R5), R12
        MOVWU   4(R3), R11
        MOVWU   4(R5), R13
        CMPU    R10, R12
        BNE     ne
        MOVWU   4(R3), R10
        MOVWU   4(R5), R12
        CMPU    R11, R13
        BNE     ne
        MOVWU   4(R3), R11
        MOVWU   4(R5), R13
        CMPU    R10, R12
        BNE     ne
        CMPU    R11, R13
        BNE     ne
        BDNZ    l3
        ADD     $4, R3
        ADD     $4, R5
        RLWNMCC $0, R4, $15, R4 /* residue */
        BEQ     eq

/*
 * do remaining words with LSW; also does unaligned case
 */
l4:
        SRAWCC  $2, R4, R9
        BLE     out
        MOVW    R9, CTR
l5:
        LSW     (R3), $4, R10
        ADD     $4, R3
        LSW     (R5), $4, R11
        ADD     $4, R5
        CMPU    R10, R11
        BNE     ne
        BDNZ    l5
        RLWNMCC $0, R4, $3, R4  /* residue */
        BEQ     eq

/*
 * do remaining bytes with final LSW
 */
out:
        MOVW    R4, XER
        LSW     (R3), R10
        LSW     (R5), R11
        CMPU    R10, R11
        BNE     ne

eq:
        MOVW    $0, R3
        RETURN

ne:
        MOVW    $1, R3
        BGE     ret
        MOVW    $-1,R3
ret:
        RETURN
        END