libvpx: Pull from upstream

source/libvpx/vp8/common/arm/armv6/vp8_sad16x16_armv6.asm

-;
-;  Copyright (c) 2011 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_sad16x16_armv6|
-
-    ARM
-    REQUIRE8
-    PRESERVE8
-
-    AREA ||.text||, CODE, READONLY, ALIGN=2
-
-; r0    const unsigned char *src_ptr
-; r1    int  src_stride
-; r2    const unsigned char *ref_ptr
-; r3    int  ref_stride
-; stack max_sad (not used)
-|vp8_sad16x16_armv6| PROC
-    stmfd   sp!, {r4-r12, lr}
-
-    pld     [r0, r1, lsl #0]
-    pld     [r2, r3, lsl #0]
-    pld     [r0, r1, lsl #1]
-    pld     [r2, r3, lsl #1]
-
-    mov     r4, #0              ; sad = 0;
-    mov     r5, #8              ; loop count
-
-loop
-    ; 1st row
-    ldr     r6, [r0, #0x0]      ; load 4 src pixels (1A)
-    ldr     r8, [r2, #0x0]      ; load 4 ref pixels (1A)
-    ldr     r7, [r0, #0x4]      ; load 4 src pixels (1A)
-    ldr     r9, [r2, #0x4]      ; load 4 ref pixels (1A)
-    ldr     r10, [r0, #0x8]     ; load 4 src pixels (1B)
-    ldr     r11, [r0, #0xC]     ; load 4 src pixels (1B)
-
-    usada8  r4, r8, r6, r4      ; calculate sad for 4 pixels
-    usad8   r8, r7, r9          ; calculate sad for 4 pixels
-
-    ldr     r12, [r2, #0x8]     ; load 4 ref pixels (1B)
-    ldr     lr, [r2, #0xC]      ; load 4 ref pixels (1B)
-
-    add     r0, r0, r1          ; set src pointer to next row
-    add     r2, r2, r3          ; set dst pointer to next row
-
-    pld     [r0, r1, lsl #1]
-    pld     [r2, r3, lsl #1]
-
-    usada8  r4, r10, r12, r4    ; calculate sad for 4 pixels
-    usada8  r8, r11, lr, r8     ; calculate sad for 4 pixels
-
-    ldr     r6, [r0, #0x0]      ; load 4 src pixels (2A)
-    ldr     r7, [r0, #0x4]      ; load 4 src pixels (2A)
-    add     r4, r4, r8          ; add partial sad values
-
-    ; 2nd row
-    ldr     r8, [r2, #0x0]      ; load 4 ref pixels (2A)
-    ldr     r9, [r2, #0x4]      ; load 4 ref pixels (2A)
-    ldr     r10, [r0, #0x8]     ; load 4 src pixels (2B)
-    ldr     r11, [r0, #0xC]     ; load 4 src pixels (2B)
-
-    usada8  r4, r6, r8, r4      ; calculate sad for 4 pixels
-    usad8   r8, r7, r9          ; calculate sad for 4 pixels
-
-    ldr     r12, [r2, #0x8]     ; load 4 ref pixels (2B)
-    ldr     lr, [r2, #0xC]      ; load 4 ref pixels (2B)
-
-    add     r0, r0, r1          ; set src pointer to next row
-    add     r2, r2, r3          ; set dst pointer to next row
-
-    usada8  r4, r10, r12, r4    ; calculate sad for 4 pixels
-    usada8  r8, r11, lr, r8     ; calculate sad for 4 pixels
-
-    pld     [r0, r1, lsl #1]
-    pld     [r2, r3, lsl #1]
-
-    subs    r5, r5, #1          ; decrement loop counter
-    add     r4, r4, r8          ; add partial sad values
-
-    bne     loop
-
-    mov     r0, r4              ; return sad
-    ldmfd   sp!, {r4-r12, pc}
-
-    ENDP
-
-    END
-