libvpx: Pull from upstream

source/libvpx/vp8/common/ppc/copy_altivec.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.
-;
-
-
-    .globl copy_mem16x16_ppc
-
-;# r3 unsigned char *src
-;# r4 int src_stride
-;# r5 unsigned char *dst
-;# r6 int dst_stride
-
-;# Make the assumption that input will not be aligned,
-;#  but the output will be.  So two reads and a perm
-;#  for the input, but only one store for the output.
-copy_mem16x16_ppc:
-    mfspr   r11, 256            ;# get old VRSAVE
-    oris    r12, r11, 0xe000
-    mtspr   256, r12            ;# set VRSAVE
-
-    li      r10, 16
-    mtctr   r10
-
-cp_16x16_loop:
-    lvsl    v0,  0, r3          ;# permutate value for alignment
-
-    lvx     v1,   0, r3
-    lvx     v2, r10, r3
-
-    vperm   v1, v1, v2, v0
-
-    stvx    v1,  0, r5
-
-    add     r3, r3, r4          ;# increment source pointer
-    add     r5, r5, r6          ;# increment destination pointer
-
-    bdnz    cp_16x16_loop
-
-    mtspr   256, r11            ;# reset old VRSAVE
-
-    blr