libvpx: Pull from upstream

source/libvpx/vp8/common/arm/neon/dc_only_idct_add_neon.c

+/*
+ *  Copyright (c) 2014 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.
+ */
+
+#include <arm_neon.h>
+
+void vp8_dc_only_idct_add_neon(
+        int16_t input_dc,
+        unsigned char *pred_ptr,
+        int pred_stride,
+        unsigned char *dst_ptr,
+        int dst_stride) {
+    int i;
+    uint16_t a1 = ((input_dc + 4) >> 3);
+    uint32x2_t d2u32 = vdup_n_u32(0);
+    uint8x8_t d2u8;
+    uint16x8_t q1u16;
+    uint16x8_t qAdd;
+
+    qAdd = vdupq_n_u16(a1);
+
+    for (i = 0; i < 2; i++) {
+        d2u32 = vld1_lane_u32((const uint32_t *)pred_ptr, d2u32, 0);
+        pred_ptr += pred_stride;
+        d2u32 = vld1_lane_u32((const uint32_t *)pred_ptr, d2u32, 1);
+        pred_ptr += pred_stride;
+
+        q1u16 = vaddw_u8(qAdd, vreinterpret_u8_u32(d2u32));
+        d2u8 = vqmovun_s16(vreinterpretq_s16_u16(q1u16));
+
+        vst1_lane_u32((uint32_t *)dst_ptr, vreinterpret_u32_u8(d2u8), 0);
+        dst_ptr += dst_stride;
+        vst1_lane_u32((uint32_t *)dst_ptr, vreinterpret_u32_u8(d2u8), 1);
+        dst_ptr += dst_stride;
+    }
+}