libvpx: Pull from upstream

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

Index: source/libvpx/vp8/common/arm/neon/dequant_idct_neon.c
===================================================================
--- source/libvpx/vp8/common/arm/neon/dequant_idct_neon.c	(revision 0)
+++ source/libvpx/vp8/common/arm/neon/dequant_idct_neon.c	(revision 0)
@@ -0,0 +1,142 @@
+/*
+ *  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>
+
+static const int16_t cospi8sqrt2minus1 = 20091;
+static const int16_t sinpi8sqrt2       = 35468;
+
+void vp8_dequant_idct_add_neon(
+        int16_t *input,
+        int16_t *dq,
+        unsigned char *dst,
+        int stride) {
+    unsigned char *dst0;
+    int32x2_t d14, d15;
+    int16x4_t d2, d3, d4, d5, d10, d11, d12, d13;
+    int16x8_t q1, q2, q3, q4, q5, q6;
+    int16x8_t qEmpty = vdupq_n_s16(0);
+    int32x2x2_t d2tmp0, d2tmp1;
+    int16x4x2_t d2tmp2, d2tmp3;
+
+    d14 = d15 = vdup_n_s32(0);
+
+    // load input
+    q3 = vld1q_s16(input);
+    vst1q_s16(input, qEmpty);
+    input += 8;
+    q4 = vld1q_s16(input);
+    vst1q_s16(input, qEmpty);
+
+    // load dq
+    q5 = vld1q_s16(dq);
+    dq += 8;
+    q6 = vld1q_s16(dq);
+
+    // load src from dst
+    dst0 = dst;
+    d14 = vld1_lane_s32((const int32_t *)dst0, d14, 0);
+    dst0 += stride;
+    d14 = vld1_lane_s32((const int32_t *)dst0, d14, 1);
+    dst0 += stride;
+    d15 = vld1_lane_s32((const int32_t *)dst0, d15, 0);
+    dst0 += stride;
+    d15 = vld1_lane_s32((const int32_t *)dst0, d15, 1);
+
+    q1 = vreinterpretq_s16_u16(vmulq_u16(vreinterpretq_u16_s16(q3),
+                                         vreinterpretq_u16_s16(q5)));
+    q2 = vreinterpretq_s16_u16(vmulq_u16(vreinterpretq_u16_s16(q4),
+                                         vreinterpretq_u16_s16(q6)));
+
+    d12 = vqadd_s16(vget_low_s16(q1), vget_low_s16(q2));
+    d13 = vqsub_s16(vget_low_s16(q1), vget_low_s16(q2));
+
+    q2 = vcombine_s16(vget_high_s16(q1), vget_high_s16(q2));
+
+    q3 = vqdmulhq_n_s16(q2, sinpi8sqrt2);
+    q4 = vqdmulhq_n_s16(q2, cospi8sqrt2minus1);
+
+    q3 = vshrq_n_s16(q3, 1);
+    q4 = vshrq_n_s16(q4, 1);
+
+    q3 = vqaddq_s16(q3, q2);
+    q4 = vqaddq_s16(q4, q2);
+
+    d10 = vqsub_s16(vget_low_s16(q3), vget_high_s16(q4));
+    d11 = vqadd_s16(vget_high_s16(q3), vget_low_s16(q4));
+
+    d2 = vqadd_s16(d12, d11);
+    d3 = vqadd_s16(d13, d10);
+    d4 = vqsub_s16(d13, d10);
+    d5 = vqsub_s16(d12, d11);
+
+    d2tmp0 = vtrn_s32(vreinterpret_s32_s16(d2), vreinterpret_s32_s16(d4));
+    d2tmp1 = vtrn_s32(vreinterpret_s32_s16(d3), vreinterpret_s32_s16(d5));
+    d2tmp2 = vtrn_s16(vreinterpret_s16_s32(d2tmp0.val[0]),
+                      vreinterpret_s16_s32(d2tmp1.val[0]));
+    d2tmp3 = vtrn_s16(vreinterpret_s16_s32(d2tmp0.val[1]),
+                      vreinterpret_s16_s32(d2tmp1.val[1]));
+
+    // loop 2
+    q2 = vcombine_s16(d2tmp2.val[1], d2tmp3.val[1]);
+
+    q3 = vqdmulhq_n_s16(q2, sinpi8sqrt2);
+    q4 = vqdmulhq_n_s16(q2, cospi8sqrt2minus1);
+
+    d12 = vqadd_s16(d2tmp2.val[0], d2tmp3.val[0]);
+    d13 = vqsub_s16(d2tmp2.val[0], d2tmp3.val[0]);
+
+    q3 = vshrq_n_s16(q3, 1);
+    q4 = vshrq_n_s16(q4, 1);
+
+    q3 = vqaddq_s16(q3, q2);
+    q4 = vqaddq_s16(q4, q2);
+
+    d10 = vqsub_s16(vget_low_s16(q3), vget_high_s16(q4));
+    d11 = vqadd_s16(vget_high_s16(q3), vget_low_s16(q4));
+
+    d2 = vqadd_s16(d12, d11);
+    d3 = vqadd_s16(d13, d10);
+    d4 = vqsub_s16(d13, d10);
+    d5 = vqsub_s16(d12, d11);
+
+    d2 = vrshr_n_s16(d2, 3);
+    d3 = vrshr_n_s16(d3, 3);
+    d4 = vrshr_n_s16(d4, 3);
+    d5 = vrshr_n_s16(d5, 3);
+
+    d2tmp0 = vtrn_s32(vreinterpret_s32_s16(d2), vreinterpret_s32_s16(d4));
+    d2tmp1 = vtrn_s32(vreinterpret_s32_s16(d3), vreinterpret_s32_s16(d5));
+    d2tmp2 = vtrn_s16(vreinterpret_s16_s32(d2tmp0.val[0]),
+                      vreinterpret_s16_s32(d2tmp1.val[0]));
+    d2tmp3 = vtrn_s16(vreinterpret_s16_s32(d2tmp0.val[1]),
+                      vreinterpret_s16_s32(d2tmp1.val[1]));
+
+    q1 = vcombine_s16(d2tmp2.val[0], d2tmp2.val[1]);
+    q2 = vcombine_s16(d2tmp3.val[0], d2tmp3.val[1]);
+
+    q1 = vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(q1),
+                                        vreinterpret_u8_s32(d14)));
+    q2 = vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(q2),
+                                        vreinterpret_u8_s32(d15)));
+
+    d14 = vreinterpret_s32_u8(vqmovun_s16(q1));
+    d15 = vreinterpret_s32_u8(vqmovun_s16(q2));
+
+    dst0 = dst;
+    vst1_lane_s32((int32_t *)dst0, d14, 0);
+    dst0 += stride;
+    vst1_lane_s32((int32_t *)dst0, d14, 1);
+    dst0 += stride;
+    vst1_lane_s32((int32_t *)dst0, d15, 0);
+    dst0 += stride;
+    vst1_lane_s32((int32_t *)dst0, d15, 1);
+    return;
+}