Subversion Repositories or1k

/*

 *  linux/arch/arm/lib/memset.S

 *

 *  Copyright (C) 1995-2000 Russell King

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 *

 *  ASM optimised string functions

 */

#include 

#include 

        .text

        .align  5

        .word   0

1:      subs    r2, r2, #4              @ 1 do we have enough

        blt     5f                      @ 1 bytes to align with?

        cmp     r3, #2                  @ 1

        strltb  r1, [r0], #1            @ 1

        strleb  r1, [r0], #1            @ 1

        strb    r1, [r0], #1            @ 1

        add     r2, r2, r3              @ 1 (r2 = r2 - (4 - r3))

/*

 * The pointer is now aligned and the length is adjusted.  Try doing the

 * memzero again.

 */

ENTRY(memset)

        ands    r3, r0, #3              @ 1 unaligned?

        bne     1b                      @ 1

/*

 * we know that the pointer in r0 is aligned to a word boundary.

 */

        orr     r1, r1, r1, lsl #8

        orr     r1, r1, r1, lsl #16

        mov     r3, r1

        cmp     r2, #16

        blt     4f

/*

 * We need an extra register for this loop - save the return address and

 * use the LR

 */

        str     lr, [sp, #-4]!

        mov     ip, r1

        mov     lr, r1

2:      subs    r2, r2, #64

        stmgeia r0!, {r1, r3, ip, lr}   @ 64 bytes at a time.

        stmgeia r0!, {r1, r3, ip, lr}

        stmgeia r0!, {r1, r3, ip, lr}

        stmgeia r0!, {r1, r3, ip, lr}

        bgt     2b

        LOADREGS(eqfd, sp!, {pc})       @ Now <64 bytes to go.

/*

 * No need to correct the count; we're only testing bits from now on

 */

        tst     r2, #32

        stmneia r0!, {r1, r3, ip, lr}

        stmneia r0!, {r1, r3, ip, lr}

        tst     r2, #16

        stmneia r0!, {r1, r3, ip, lr}

        ldr     lr, [sp], #4

4:      tst     r2, #8

        stmneia r0!, {r1, r3}

        tst     r2, #4

        strne   r1, [r0], #4

/*

 * When we get here, we've got less than 4 bytes to zero.  We

 * may have an unaligned pointer as well.

 */

5:      tst     r2, #2

        strneb  r1, [r0], #1

        strneb  r1, [r0], #1

        tst     r2, #1

        strneb  r1, [r0], #1

        RETINSTR(mov,pc,lr)