ref: 458f4fedd2d32ca5b7185df44656c4ccba2bae8d
dir: /vp8/common/arm/armv6/copymem8x4_v6.asm/
;
;  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
;
;  Use of this source code is governed by a BSD-style license
;  that can be found in the LICENSE file in the root of the source
;  tree. An additional intellectual property rights grant can be found
;  in the file PATENTS.  All contributing project authors may
;  be found in the AUTHORS file in the root of the source tree.
;
    EXPORT  |vp8_copy_mem8x4_v6|
    ; ARM
    ; REQUIRE8
    ; PRESERVE8
    AREA    Block, CODE, READONLY ; name this block of code
;void vp8_copy_mem8x4_v6( unsigned char *src, int src_stride, unsigned char *dst, int dst_stride)
;-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
|vp8_copy_mem8x4_v6| PROC
    ;push   {r4-r5}
    stmdb  sp!, {r4-r5}
    ;preload
    pld     [r0]
    pld     [r0, r1]
    pld     [r0, r1, lsl #1]
    ands    r4, r0, #7
    beq     copy_mem8x4_fast
    ands    r4, r0, #3
    beq     copy_mem8x4_4
    ;copy 1 byte each time
    ldrb    r4, [r0]
    ldrb    r5, [r0, #1]
    mov     r12, #4
copy_mem8x4_1_loop
    strb    r4, [r2]
    strb    r5, [r2, #1]
    ldrb    r4, [r0, #2]
    ldrb    r5, [r0, #3]
    subs    r12, r12, #1
    strb    r4, [r2, #2]
    strb    r5, [r2, #3]
    ldrb    r4, [r0, #4]
    ldrb    r5, [r0, #5]
    strb    r4, [r2, #4]
    strb    r5, [r2, #5]
    ldrb    r4, [r0, #6]
    ldrb    r5, [r0, #7]
    add     r0, r0, r1
    strb    r4, [r2, #6]
    strb    r5, [r2, #7]
    add     r2, r2, r3
    ldrneb  r4, [r0]
    ldrneb  r5, [r0, #1]
    bne     copy_mem8x4_1_loop
    ldmia       sp!, {r4 - r5}
    ;pop        {r4-r5}
    mov     pc, lr
;copy 4 bytes each time
copy_mem8x4_4
    ldr     r4, [r0]
    ldr     r5, [r0, #4]
    mov     r12, #4
copy_mem8x4_4_loop
    subs    r12, r12, #1
    add     r0, r0, r1
    str     r4, [r2]
    str     r5, [r2, #4]
    add     r2, r2, r3
    ldrne   r4, [r0]
    ldrne   r5, [r0, #4]
    bne     copy_mem8x4_4_loop
    ldmia  sp!, {r4-r5}
    ;pop        {r4-r5}
    mov     pc, lr
;copy 8 bytes each time
copy_mem8x4_fast
    ;sub        r1, r1, #8
    ;sub        r3, r3, #8
    mov     r12, #4
copy_mem8x4_fast_loop
    ldmia   r0, {r4-r5}
    ;ldm        r0, {r4-r5}
    add     r0, r0, r1
    subs    r12, r12, #1
    stmia   r2, {r4-r5}
    ;stm        r2, {r4-r5}
    add     r2, r2, r3
    bne     copy_mem8x4_fast_loop
    ldmia  sp!, {r4-r5}
    ;pop        {r4-r5}
    mov     pc, lr
    ENDP  ; |vp8_copy_mem8x4_v6|
    END