/* SPDX-License-Identifier: GPL-2.0 */
/*
 * "memset" implementation for SH4
 *
 * Copyright (C) 1999  Niibe Yutaka
 * Copyright (c) 2009  STMicroelectronics Limited
 * Author: Stuart Menefy <stuart.menefy:st.com>
 */

/*
 *            void *memset(void *s, int c, size_t n);
 */

#include <linux/linkage.h>

ENTRY(memset)
        mov     #12,r0
        add     r6,r4
        cmp/gt  r6,r0
        bt/s    40f             ! if it's too small, set a byte at once
         mov    r4,r0
        and     #3,r0
        cmp/eq  #0,r0
        bt/s    2f              ! It's aligned
         sub    r0,r6
1:
        dt      r0
        bf/s    1b
         mov.b  r5,@-r4
2:                              ! make VVVV
        extu.b  r5,r5
        swap.b  r5,r0           !   V0
        or      r0,r5           !   VV
        swap.w  r5,r0           ! VV00
        or      r0,r5           ! VVVV

        ! Check if enough bytes need to be copied to be worth the big loop
        mov     #0x40, r0       ! (MT)
        cmp/gt  r6,r0           ! (MT)  64 > len => slow loop

        bt/s    22f
         mov    r6,r0

        ! align the dst to the cache block size if necessary
        mov     r4, r3
        mov     #~(0x1f), r1

        and     r3, r1
        cmp/eq  r3, r1

        bt/s    11f             ! dst is already aligned
         sub    r1, r3          ! r3-r1 -> r3
        shlr2   r3              ! number of loops

10:     mov.l   r5,@-r4
        dt      r3
        bf/s    10b
         add    #-4, r6

11:     ! dst is 32byte aligned
        mov     r6,r2
        mov     #-5,r0
        shld    r0,r2           ! number of loops

        add     #-32, r4
        mov     r5, r0
12:
        movca.l r0,@r4
        mov.l   r5,@(4, r4)
        mov.l   r5,@(8, r4)
        mov.l   r5,@(12,r4)
        mov.l   r5,@(16,r4)
        mov.l   r5,@(20,r4)
        add     #-0x20, r6
        mov.l   r5,@(24,r4)
        dt      r2
        mov.l   r5,@(28,r4)
        bf/s    12b
         add    #-32, r4

        add     #32, r4
        mov     #8, r0
        cmp/ge  r0, r6
        bf      40f

        mov     r6,r0
22:
        shlr2   r0
        shlr    r0              ! r0 = r6 >> 3
3:
        dt      r0
        mov.l   r5,@-r4         ! set 8-byte at once
        bf/s    3b
         mov.l  r5,@-r4
        !
        mov     #7,r0
        and     r0,r6

        ! fill bytes (length may be zero)
40:     tst     r6,r6
        bt      5f
4:
        dt      r6
        bf/s    4b
         mov.b  r5,@-r4
5:
        rts
         mov    r4,r0