libvpx: Pull from upstream

source/libvpx/vp9/common/arm/neon/vp9_dc_only_idct_add_neon.asm

-;
-;  Copyright (c) 2013 The WebM project authors. All Rights Reserved.
-;
-;  Use of this source code is governed by a BSD-style license and patent
-;  grant that can be found in the LICENSE file in the root of the source
-;  tree. All contributing project authors may be found in the AUTHORS
-;  file in the root of the source tree.
-;
-
-
-    EXPORT  |vp9_dc_only_idct_add_neon|
-    ARM
-    REQUIRE8
-    PRESERVE8
-
-    AREA ||.text||, CODE, READONLY, ALIGN=2
-
-;void vp9_dc_only_idct_add_neon(int input_dc, uint8_t *pred_ptr,
-;                            uint8_t *dst_ptr, int pitch, int stride)
-;
-; r0  int input_dc
-; r1  uint8_t *pred_ptr
-; r2  uint8_t *dst_ptr
-; r3  int pitch
-; sp  int stride
-
-|vp9_dc_only_idct_add_neon| PROC
-
-    ; generate cospi_16_64 = 11585
-    mov              r12, #0x2d00
-    add              r12, #0x41
-
-    ; dct_const_round_shift(input_dc * cospi_16_64)
-    mul              r0, r0, r12               ; input_dc * cospi_16_64
-    add              r0, r0, #0x2000           ; +(1 << ((DCT_CONST_BITS) - 1))
-    asr              r0, r0, #14               ; >> DCT_CONST_BITS
-
-    ; dct_const_round_shift(out * cospi_16_64)
-    mul              r0, r0, r12               ; out * cospi_16_64
-    add              r0, r0, #0x2000           ; +(1 << ((DCT_CONST_BITS) - 1))
-    asr              r0, r0, #14               ; >> DCT_CONST_BITS
-
-    ; ROUND_POWER_OF_TWO(out, 4)
-    add              r0, r0, #8                ; + (1 <<((4) - 1))
-    asr              r0, r0, #4                ; >> 4
-
-    vdup.16         q0, r0;                   ; duplicate a1
-    ldr              r12, [sp]                 ; load stride
-
-    vld1.32         {d2[0]}, [r1], r3
-    vld1.32         {d2[1]}, [r1], r3
-    vld1.32         {d4[0]}, [r1], r3
-    vld1.32         {d4[1]}, [r1]
-
-    vaddw.u8        q1, q0, d2                ; a1 + pred_ptr[c]
-    vaddw.u8        q2, q0, d4
-
-    vqmovun.s16     d2, q1                    ; clip_pixel
-    vqmovun.s16     d4, q2
-
-    vst1.32         {d2[0]}, [r2], r12
-    vst1.32         {d2[1]}, [r2], r12
-    vst1.32         {d4[0]}, [r2], r12
-    vst1.32         {d4[1]}, [r2]
-
-    bx               lr
-    ENDP             ; |vp9_dc_only_idct_add_neon|
-
-    END