Add libwebp 0.6.0 to the tree

1 files changed, 1639 insertions, 0 deletions

diff --git a/media/libwebp/dsp/dec_neon.c b/media/libwebp/dsp/dec_neon.c
new file mode 100644
index 000000000..34796cf4a
--- /dev/null
+++ b/media/libwebp/dsp/dec_neon.c
@@ -0,0 +1,1639 @@
+// Copyright 2012 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING 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.
+// -----------------------------------------------------------------------------
+//
+// ARM NEON version of dsp functions and loop filtering.
+//
+// Authors: Somnath Banerjee (somnath@google.com)
+//          Johann Koenig (johannkoenig@google.com)
+
+#include "./dsp.h"
+
+#if defined(WEBP_USE_NEON)
+
+#include "./neon.h"
+#include "../dec/vp8i_dec.h"
+
+//------------------------------------------------------------------------------
+// NxM Loading functions
+
+// Load/Store vertical edge
+#define LOAD8x4(c1, c2, c3, c4, b1, b2, stride)                                \
+  "vld4.8 {" #c1 "[0]," #c2 "[0]," #c3 "[0]," #c4 "[0]}," #b1 "," #stride "\n" \
+  "vld4.8 {" #c1 "[1]," #c2 "[1]," #c3 "[1]," #c4 "[1]}," #b2 "," #stride "\n" \
+  "vld4.8 {" #c1 "[2]," #c2 "[2]," #c3 "[2]," #c4 "[2]}," #b1 "," #stride "\n" \
+  "vld4.8 {" #c1 "[3]," #c2 "[3]," #c3 "[3]," #c4 "[3]}," #b2 "," #stride "\n" \
+  "vld4.8 {" #c1 "[4]," #c2 "[4]," #c3 "[4]," #c4 "[4]}," #b1 "," #stride "\n" \
+  "vld4.8 {" #c1 "[5]," #c2 "[5]," #c3 "[5]," #c4 "[5]}," #b2 "," #stride "\n" \
+  "vld4.8 {" #c1 "[6]," #c2 "[6]," #c3 "[6]," #c4 "[6]}," #b1 "," #stride "\n" \
+  "vld4.8 {" #c1 "[7]," #c2 "[7]," #c3 "[7]," #c4 "[7]}," #b2 "," #stride "\n"
+
+#define STORE8x2(c1, c2, p, stride)                                            \
+  "vst2.8   {" #c1 "[0], " #c2 "[0]}," #p "," #stride " \n"                    \
+  "vst2.8   {" #c1 "[1], " #c2 "[1]}," #p "," #stride " \n"                    \
+  "vst2.8   {" #c1 "[2], " #c2 "[2]}," #p "," #stride " \n"                    \
+  "vst2.8   {" #c1 "[3], " #c2 "[3]}," #p "," #stride " \n"                    \
+  "vst2.8   {" #c1 "[4], " #c2 "[4]}," #p "," #stride " \n"                    \
+  "vst2.8   {" #c1 "[5], " #c2 "[5]}," #p "," #stride " \n"                    \
+  "vst2.8   {" #c1 "[6], " #c2 "[6]}," #p "," #stride " \n"                    \
+  "vst2.8   {" #c1 "[7], " #c2 "[7]}," #p "," #stride " \n"
+
+#if !defined(WORK_AROUND_GCC)
+
+// This intrinsics version makes gcc-4.6.3 crash during Load4x??() compilation
+// (register alloc, probably). The variants somewhat mitigate the problem, but
+// not quite. HFilter16i() remains problematic.
+static WEBP_INLINE uint8x8x4_t Load4x8(const uint8_t* const src, int stride) {
+  const uint8x8_t zero = vdup_n_u8(0);
+  uint8x8x4_t out;
+  INIT_VECTOR4(out, zero, zero, zero, zero);
+  out = vld4_lane_u8(src + 0 * stride, out, 0);
+  out = vld4_lane_u8(src + 1 * stride, out, 1);
+  out = vld4_lane_u8(src + 2 * stride, out, 2);
+  out = vld4_lane_u8(src + 3 * stride, out, 3);
+  out = vld4_lane_u8(src + 4 * stride, out, 4);
+  out = vld4_lane_u8(src + 5 * stride, out, 5);
+  out = vld4_lane_u8(src + 6 * stride, out, 6);
+  out = vld4_lane_u8(src + 7 * stride, out, 7);
+  return out;
+}
+
+static WEBP_INLINE void Load4x16(const uint8_t* const src, int stride,
+                                 uint8x16_t* const p1, uint8x16_t* const p0,
+                                 uint8x16_t* const q0, uint8x16_t* const q1) {
+  // row0 = p1[0..7]|p0[0..7]|q0[0..7]|q1[0..7]
+  // row8 = p1[8..15]|p0[8..15]|q0[8..15]|q1[8..15]
+  const uint8x8x4_t row0 = Load4x8(src - 2 + 0 * stride, stride);
+  const uint8x8x4_t row8 = Load4x8(src - 2 + 8 * stride, stride);
+  *p1 = vcombine_u8(row0.val[0], row8.val[0]);
+  *p0 = vcombine_u8(row0.val[1], row8.val[1]);
+  *q0 = vcombine_u8(row0.val[2], row8.val[2]);
+  *q1 = vcombine_u8(row0.val[3], row8.val[3]);
+}
+
+#else  // WORK_AROUND_GCC
+
+#define LOADQ_LANE_32b(VALUE, LANE) do {                             \
+  (VALUE) = vld1q_lane_u32((const uint32_t*)src, (VALUE), (LANE));   \
+  src += stride;                                                     \
+} while (0)
+
+static WEBP_INLINE void Load4x16(const uint8_t* src, int stride,
+                                 uint8x16_t* const p1, uint8x16_t* const p0,
+                                 uint8x16_t* const q0, uint8x16_t* const q1) {
+  const uint32x4_t zero = vdupq_n_u32(0);
+  uint32x4x4_t in;
+  INIT_VECTOR4(in, zero, zero, zero, zero);
+  src -= 2;
+  LOADQ_LANE_32b(in.val[0], 0);
+  LOADQ_LANE_32b(in.val[1], 0);
+  LOADQ_LANE_32b(in.val[2], 0);
+  LOADQ_LANE_32b(in.val[3], 0);
+  LOADQ_LANE_32b(in.val[0], 1);
+  LOADQ_LANE_32b(in.val[1], 1);
+  LOADQ_LANE_32b(in.val[2], 1);
+  LOADQ_LANE_32b(in.val[3], 1);
+  LOADQ_LANE_32b(in.val[0], 2);
+  LOADQ_LANE_32b(in.val[1], 2);
+  LOADQ_LANE_32b(in.val[2], 2);
+  LOADQ_LANE_32b(in.val[3], 2);
+  LOADQ_LANE_32b(in.val[0], 3);
+  LOADQ_LANE_32b(in.val[1], 3);
+  LOADQ_LANE_32b(in.val[2], 3);
+  LOADQ_LANE_32b(in.val[3], 3);
+  // Transpose four 4x4 parts:
+  {
+    const uint8x16x2_t row01 = vtrnq_u8(vreinterpretq_u8_u32(in.val[0]),
+                                        vreinterpretq_u8_u32(in.val[1]));
+    const uint8x16x2_t row23 = vtrnq_u8(vreinterpretq_u8_u32(in.val[2]),
+                                        vreinterpretq_u8_u32(in.val[3]));
+    const uint16x8x2_t row02 = vtrnq_u16(vreinterpretq_u16_u8(row01.val[0]),
+                                         vreinterpretq_u16_u8(row23.val[0]));
+    const uint16x8x2_t row13 = vtrnq_u16(vreinterpretq_u16_u8(row01.val[1]),
+                                         vreinterpretq_u16_u8(row23.val[1]));
+    *p1 = vreinterpretq_u8_u16(row02.val[0]);
+    *p0 = vreinterpretq_u8_u16(row13.val[0]);
+    *q0 = vreinterpretq_u8_u16(row02.val[1]);
+    *q1 = vreinterpretq_u8_u16(row13.val[1]);
+  }
+}
+#undef LOADQ_LANE_32b
+
+#endif  // !WORK_AROUND_GCC
+
+static WEBP_INLINE void Load8x16(const uint8_t* const src, int stride,
+                                 uint8x16_t* const p3, uint8x16_t* const p2,
+                                 uint8x16_t* const p1, uint8x16_t* const p0,
+                                 uint8x16_t* const q0, uint8x16_t* const q1,
+                                 uint8x16_t* const q2, uint8x16_t* const q3) {
+  Load4x16(src - 2, stride, p3, p2, p1, p0);
+  Load4x16(src + 2, stride, q0, q1, q2, q3);
+}
+
+static WEBP_INLINE void Load16x4(const uint8_t* const src, int stride,
+                                 uint8x16_t* const p1, uint8x16_t* const p0,
+                                 uint8x16_t* const q0, uint8x16_t* const q1) {
+  *p1 = vld1q_u8(src - 2 * stride);
+  *p0 = vld1q_u8(src - 1 * stride);
+  *q0 = vld1q_u8(src + 0 * stride);
+  *q1 = vld1q_u8(src + 1 * stride);
+}
+
+static WEBP_INLINE void Load16x8(const uint8_t* const src, int stride,
+                                 uint8x16_t* const p3, uint8x16_t* const p2,
+                                 uint8x16_t* const p1, uint8x16_t* const p0,
+                                 uint8x16_t* const q0, uint8x16_t* const q1,
+                                 uint8x16_t* const q2, uint8x16_t* const q3) {
+  Load16x4(src - 2  * stride, stride, p3, p2, p1, p0);
+  Load16x4(src + 2  * stride, stride, q0, q1, q2, q3);
+}
+
+static WEBP_INLINE void Load8x8x2(const uint8_t* const u,
+                                  const uint8_t* const v,
+                                  int stride,
+                                  uint8x16_t* const p3, uint8x16_t* const p2,
+                                  uint8x16_t* const p1, uint8x16_t* const p0,
+                                  uint8x16_t* const q0, uint8x16_t* const q1,
+                                  uint8x16_t* const q2, uint8x16_t* const q3) {
+  // We pack the 8x8 u-samples in the lower half of the uint8x16_t destination
+  // and the v-samples on the higher half.
+  *p3 = vcombine_u8(vld1_u8(u - 4 * stride), vld1_u8(v - 4 * stride));
+  *p2 = vcombine_u8(vld1_u8(u - 3 * stride), vld1_u8(v - 3 * stride));
+  *p1 = vcombine_u8(vld1_u8(u - 2 * stride), vld1_u8(v - 2 * stride));
+  *p0 = vcombine_u8(vld1_u8(u - 1 * stride), vld1_u8(v - 1 * stride));
+  *q0 = vcombine_u8(vld1_u8(u + 0 * stride), vld1_u8(v + 0 * stride));
+  *q1 = vcombine_u8(vld1_u8(u + 1 * stride), vld1_u8(v + 1 * stride));
+  *q2 = vcombine_u8(vld1_u8(u + 2 * stride), vld1_u8(v + 2 * stride));
+  *q3 = vcombine_u8(vld1_u8(u + 3 * stride), vld1_u8(v + 3 * stride));
+}
+
+#if !defined(WORK_AROUND_GCC)
+
+#define LOAD_UV_8(ROW) \
+  vcombine_u8(vld1_u8(u - 4 + (ROW) * stride), vld1_u8(v - 4 + (ROW) * stride))
+
+static WEBP_INLINE void Load8x8x2T(const uint8_t* const u,
+                                   const uint8_t* const v,
+                                   int stride,
+                                   uint8x16_t* const p3, uint8x16_t* const p2,
+                                   uint8x16_t* const p1, uint8x16_t* const p0,
+                                   uint8x16_t* const q0, uint8x16_t* const q1,
+                                   uint8x16_t* const q2, uint8x16_t* const q3) {
+  // We pack the 8x8 u-samples in the lower half of the uint8x16_t destination
+  // and the v-samples on the higher half.
+  const uint8x16_t row0 = LOAD_UV_8(0);
+  const uint8x16_t row1 = LOAD_UV_8(1);
+  const uint8x16_t row2 = LOAD_UV_8(2);
+  const uint8x16_t row3 = LOAD_UV_8(3);
+  const uint8x16_t row4 = LOAD_UV_8(4);
+  const uint8x16_t row5 = LOAD_UV_8(5);
+  const uint8x16_t row6 = LOAD_UV_8(6);
+  const uint8x16_t row7 = LOAD_UV_8(7);
+  // Perform two side-by-side 8x8 transposes
+  // u00 u01 u02 u03 u04 u05 u06 u07 | v00 v01 v02 v03 v04 v05 v06 v07
+  // u10 u11 u12 u13 u14 u15 u16 u17 | v10 v11 v12 ...
+  // u20 u21 u22 u23 u24 u25 u26 u27 | v20 v21 ...
+  // u30 u31 u32 u33 u34 u35 u36 u37 | ...
+  // u40 u41 u42 u43 u44 u45 u46 u47 | ...
+  // u50 u51 u52 u53 u54 u55 u56 u57 | ...
+  // u60 u61 u62 u63 u64 u65 u66 u67 | v60 ...
+  // u70 u71 u72 u73 u74 u75 u76 u77 | v70 v71 v72 ...
+  const uint8x16x2_t row01 = vtrnq_u8(row0, row1);  // u00 u10 u02 u12 ...
+                                                    // u01 u11 u03 u13 ...
+  const uint8x16x2_t row23 = vtrnq_u8(row2, row3);  // u20 u30 u22 u32 ...
+                                                    // u21 u31 u23 u33 ...
+  const uint8x16x2_t row45 = vtrnq_u8(row4, row5);  // ...
+  const uint8x16x2_t row67 = vtrnq_u8(row6, row7);  // ...
+  const uint16x8x2_t row02 = vtrnq_u16(vreinterpretq_u16_u8(row01.val[0]),
+                                       vreinterpretq_u16_u8(row23.val[0]));
+  const uint16x8x2_t row13 = vtrnq_u16(vreinterpretq_u16_u8(row01.val[1]),
+                                       vreinterpretq_u16_u8(row23.val[1]));
+  const uint16x8x2_t row46 = vtrnq_u16(vreinterpretq_u16_u8(row45.val[0]),
+                                       vreinterpretq_u16_u8(row67.val[0]));
+  const uint16x8x2_t row57 = vtrnq_u16(vreinterpretq_u16_u8(row45.val[1]),
+                                       vreinterpretq_u16_u8(row67.val[1]));
+  const uint32x4x2_t row04 = vtrnq_u32(vreinterpretq_u32_u16(row02.val[0]),
+                                       vreinterpretq_u32_u16(row46.val[0]));
+  const uint32x4x2_t row26 = vtrnq_u32(vreinterpretq_u32_u16(row02.val[1]),
+                                       vreinterpretq_u32_u16(row46.val[1]));
+  const uint32x4x2_t row15 = vtrnq_u32(vreinterpretq_u32_u16(row13.val[0]),
+                                       vreinterpretq_u32_u16(row57.val[0]));
+  const uint32x4x2_t row37 = vtrnq_u32(vreinterpretq_u32_u16(row13.val[1]),
+                                       vreinterpretq_u32_u16(row57.val[1]));
+  *p3 = vreinterpretq_u8_u32(row04.val[0]);
+  *p2 = vreinterpretq_u8_u32(row15.val[0]);
+  *p1 = vreinterpretq_u8_u32(row26.val[0]);
+  *p0 = vreinterpretq_u8_u32(row37.val[0]);
+  *q0 = vreinterpretq_u8_u32(row04.val[1]);
+  *q1 = vreinterpretq_u8_u32(row15.val[1]);
+  *q2 = vreinterpretq_u8_u32(row26.val[1]);
+  *q3 = vreinterpretq_u8_u32(row37.val[1]);
+}
+#undef LOAD_UV_8
+
+#endif  // !WORK_AROUND_GCC
+
+static WEBP_INLINE void Store2x8(const uint8x8x2_t v,
+                                 uint8_t* const dst, int stride) {
+  vst2_lane_u8(dst + 0 * stride, v, 0);
+  vst2_lane_u8(dst + 1 * stride, v, 1);
+  vst2_lane_u8(dst + 2 * stride, v, 2);
+  vst2_lane_u8(dst + 3 * stride, v, 3);
+  vst2_lane_u8(dst + 4 * stride, v, 4);
+  vst2_lane_u8(dst + 5 * stride, v, 5);
+  vst2_lane_u8(dst + 6 * stride, v, 6);
+  vst2_lane_u8(dst + 7 * stride, v, 7);
+}
+
+static WEBP_INLINE void Store2x16(const uint8x16_t p0, const uint8x16_t q0,
+                                  uint8_t* const dst, int stride) {
+  uint8x8x2_t lo, hi;
+  lo.val[0] = vget_low_u8(p0);
+  lo.val[1] = vget_low_u8(q0);
+  hi.val[0] = vget_high_u8(p0);
+  hi.val[1] = vget_high_u8(q0);
+  Store2x8(lo, dst - 1 + 0 * stride, stride);
+  Store2x8(hi, dst - 1 + 8 * stride, stride);
+}
+
+#if !defined(WORK_AROUND_GCC)
+static WEBP_INLINE void Store4x8(const uint8x8x4_t v,
+                                 uint8_t* const dst, int stride) {
+  vst4_lane_u8(dst + 0 * stride, v, 0);
+  vst4_lane_u8(dst + 1 * stride, v, 1);
+  vst4_lane_u8(dst + 2 * stride, v, 2);
+  vst4_lane_u8(dst + 3 * stride, v, 3);
+  vst4_lane_u8(dst + 4 * stride, v, 4);
+  vst4_lane_u8(dst + 5 * stride, v, 5);
+  vst4_lane_u8(dst + 6 * stride, v, 6);
+  vst4_lane_u8(dst + 7 * stride, v, 7);
+}
+
+static WEBP_INLINE void Store4x16(const uint8x16_t p1, const uint8x16_t p0,
+                                  const uint8x16_t q0, const uint8x16_t q1,
+                                  uint8_t* const dst, int stride) {
+  uint8x8x4_t lo, hi;
+  INIT_VECTOR4(lo,
+               vget_low_u8(p1), vget_low_u8(p0),
+               vget_low_u8(q0), vget_low_u8(q1));
+  INIT_VECTOR4(hi,
+               vget_high_u8(p1), vget_high_u8(p0),
+               vget_high_u8(q0), vget_high_u8(q1));
+  Store4x8(lo, dst - 2 + 0 * stride, stride);
+  Store4x8(hi, dst - 2 + 8 * stride, stride);
+}
+#endif  // !WORK_AROUND_GCC
+
+static WEBP_INLINE void Store16x2(const uint8x16_t p0, const uint8x16_t q0,
+                                  uint8_t* const dst, int stride) {
+  vst1q_u8(dst - stride, p0);
+  vst1q_u8(dst, q0);
+}
+
+static WEBP_INLINE void Store16x4(const uint8x16_t p1, const uint8x16_t p0,
+                                  const uint8x16_t q0, const uint8x16_t q1,
+                                  uint8_t* const dst, int stride) {
+  Store16x2(p1, p0, dst - stride, stride);
+  Store16x2(q0, q1, dst + stride, stride);
+}
+
+static WEBP_INLINE void Store8x2x2(const uint8x16_t p0, const uint8x16_t q0,
+                                   uint8_t* const u, uint8_t* const v,
+                                   int stride) {
+  // p0 and q0 contain the u+v samples packed in low/high halves.
+  vst1_u8(u - stride, vget_low_u8(p0));
+  vst1_u8(u,          vget_low_u8(q0));
+  vst1_u8(v - stride, vget_high_u8(p0));
+  vst1_u8(v,          vget_high_u8(q0));
+}
+
+static WEBP_INLINE void Store8x4x2(const uint8x16_t p1, const uint8x16_t p0,
+                                   const uint8x16_t q0, const uint8x16_t q1,
+                                   uint8_t* const u, uint8_t* const v,
+                                   int stride) {
+  // The p1...q1 registers contain the u+v samples packed in low/high halves.
+  Store8x2x2(p1, p0, u - stride, v - stride, stride);
+  Store8x2x2(q0, q1, u + stride, v + stride, stride);
+}
+
+#if !defined(WORK_AROUND_GCC)
+
+#define STORE6_LANE(DST, VAL0, VAL1, LANE) do {   \
+  vst3_lane_u8((DST) - 3, (VAL0), (LANE));        \
+  vst3_lane_u8((DST) + 0, (VAL1), (LANE));        \
+  (DST) += stride;                                \
+} while (0)
+
+static WEBP_INLINE void Store6x8x2(const uint8x16_t p2, const uint8x16_t p1,
+                                   const uint8x16_t p0, const uint8x16_t q0,
+                                   const uint8x16_t q1, const uint8x16_t q2,
+                                   uint8_t* u, uint8_t* v,
+                                   int stride) {
+  uint8x8x3_t u0, u1, v0, v1;
+  INIT_VECTOR3(u0, vget_low_u8(p2), vget_low_u8(p1), vget_low_u8(p0));
+  INIT_VECTOR3(u1, vget_low_u8(q0), vget_low_u8(q1), vget_low_u8(q2));
+  INIT_VECTOR3(v0, vget_high_u8(p2), vget_high_u8(p1), vget_high_u8(p0));
+  INIT_VECTOR3(v1, vget_high_u8(q0), vget_high_u8(q1), vget_high_u8(q2));
+  STORE6_LANE(u, u0, u1, 0);
+  STORE6_LANE(u, u0, u1, 1);
+  STORE6_LANE(u, u0, u1, 2);
+  STORE6_LANE(u, u0, u1, 3);
+  STORE6_LANE(u, u0, u1, 4);
+  STORE6_LANE(u, u0, u1, 5);
+  STORE6_LANE(u, u0, u1, 6);
+  STORE6_LANE(u, u0, u1, 7);
+  STORE6_LANE(v, v0, v1, 0);
+  STORE6_LANE(v, v0, v1, 1);
+  STORE6_LANE(v, v0, v1, 2);
+  STORE6_LANE(v, v0, v1, 3);
+  STORE6_LANE(v, v0, v1, 4);
+  STORE6_LANE(v, v0, v1, 5);
+  STORE6_LANE(v, v0, v1, 6);
+  STORE6_LANE(v, v0, v1, 7);
+}
+#undef STORE6_LANE
+
+static WEBP_INLINE void Store4x8x2(const uint8x16_t p1, const uint8x16_t p0,
+                                   const uint8x16_t q0, const uint8x16_t q1,
+                                   uint8_t* const u, uint8_t* const v,
+                                   int stride) {
+  uint8x8x4_t u0, v0;
+  INIT_VECTOR4(u0,
+               vget_low_u8(p1), vget_low_u8(p0),
+               vget_low_u8(q0), vget_low_u8(q1));
+  INIT_VECTOR4(v0,
+               vget_high_u8(p1), vget_high_u8(p0),
+               vget_high_u8(q0), vget_high_u8(q1));
+  vst4_lane_u8(u - 2 + 0 * stride, u0, 0);
+  vst4_lane_u8(u - 2 + 1 * stride, u0, 1);
+  vst4_lane_u8(u - 2 + 2 * stride, u0, 2);
+  vst4_lane_u8(u - 2 + 3 * stride, u0, 3);
+  vst4_lane_u8(u - 2 + 4 * stride, u0, 4);
+  vst4_lane_u8(u - 2 + 5 * stride, u0, 5);
+  vst4_lane_u8(u - 2 + 6 * stride, u0, 6);
+  vst4_lane_u8(u - 2 + 7 * stride, u0, 7);
+  vst4_lane_u8(v - 2 + 0 * stride, v0, 0);
+  vst4_lane_u8(v - 2 + 1 * stride, v0, 1);
+  vst4_lane_u8(v - 2 + 2 * stride, v0, 2);
+  vst4_lane_u8(v - 2 + 3 * stride, v0, 3);
+  vst4_lane_u8(v - 2 + 4 * stride, v0, 4);
+  vst4_lane_u8(v - 2 + 5 * stride, v0, 5);
+  vst4_lane_u8(v - 2 + 6 * stride, v0, 6);
+  vst4_lane_u8(v - 2 + 7 * stride, v0, 7);
+}
+
+#endif  // !WORK_AROUND_GCC
+
+// Zero extend 'v' to an int16x8_t.
+static WEBP_INLINE int16x8_t ConvertU8ToS16(uint8x8_t v) {
+  return vreinterpretq_s16_u16(vmovl_u8(v));
+}
+
+// Performs unsigned 8b saturation on 'dst01' and 'dst23' storing the result
+// to the corresponding rows of 'dst'.
+static WEBP_INLINE void SaturateAndStore4x4(uint8_t* const dst,
+                                            const int16x8_t dst01,
+                                            const int16x8_t dst23) {
+  // Unsigned saturate to 8b.
+  const uint8x8_t dst01_u8 = vqmovun_s16(dst01);
+  const uint8x8_t dst23_u8 = vqmovun_s16(dst23);
+
+  // Store the results.
+  vst1_lane_u32((uint32_t*)(dst + 0 * BPS), vreinterpret_u32_u8(dst01_u8), 0);
+  vst1_lane_u32((uint32_t*)(dst + 1 * BPS), vreinterpret_u32_u8(dst01_u8), 1);
+  vst1_lane_u32((uint32_t*)(dst + 2 * BPS), vreinterpret_u32_u8(dst23_u8), 0);
+  vst1_lane_u32((uint32_t*)(dst + 3 * BPS), vreinterpret_u32_u8(dst23_u8), 1);
+}
+
+static WEBP_INLINE void Add4x4(const int16x8_t row01, const int16x8_t row23,
+                               uint8_t* const dst) {
+  uint32x2_t dst01 = vdup_n_u32(0);
+  uint32x2_t dst23 = vdup_n_u32(0);
+
+  // Load the source pixels.
+  dst01 = vld1_lane_u32((uint32_t*)(dst + 0 * BPS), dst01, 0);
+  dst23 = vld1_lane_u32((uint32_t*)(dst + 2 * BPS), dst23, 0);
+  dst01 = vld1_lane_u32((uint32_t*)(dst + 1 * BPS), dst01, 1);
+  dst23 = vld1_lane_u32((uint32_t*)(dst + 3 * BPS), dst23, 1);
+
+  {
+    // Convert to 16b.
+    const int16x8_t dst01_s16 = ConvertU8ToS16(vreinterpret_u8_u32(dst01));
+    const int16x8_t dst23_s16 = ConvertU8ToS16(vreinterpret_u8_u32(dst23));
+
+    // Descale with rounding.
+    const int16x8_t out01 = vrsraq_n_s16(dst01_s16, row01, 3);
+    const int16x8_t out23 = vrsraq_n_s16(dst23_s16, row23, 3);
+    // Add the inverse transform.
+    SaturateAndStore4x4(dst, out01, out23);
+  }
+}
+
+//-----------------------------------------------------------------------------
+// Simple In-loop filtering (Paragraph 15.2)
+
+static uint8x16_t NeedsFilter(const uint8x16_t p1, const uint8x16_t p0,
+                              const uint8x16_t q0, const uint8x16_t q1,
+                              int thresh) {
+  const uint8x16_t thresh_v = vdupq_n_u8((uint8_t)thresh);
+  const uint8x16_t a_p0_q0 = vabdq_u8(p0, q0);               // abs(p0-q0)
+  const uint8x16_t a_p1_q1 = vabdq_u8(p1, q1);               // abs(p1-q1)
+  const uint8x16_t a_p0_q0_2 = vqaddq_u8(a_p0_q0, a_p0_q0);  // 2 * abs(p0-q0)
+  const uint8x16_t a_p1_q1_2 = vshrq_n_u8(a_p1_q1, 1);       // abs(p1-q1) / 2
+  const uint8x16_t sum = vqaddq_u8(a_p0_q0_2, a_p1_q1_2);
+  const uint8x16_t mask = vcgeq_u8(thresh_v, sum);
+  return mask;
+}
+
+static int8x16_t FlipSign(const uint8x16_t v) {
+  const uint8x16_t sign_bit = vdupq_n_u8(0x80);
+  return vreinterpretq_s8_u8(veorq_u8(v, sign_bit));
+}
+
+static uint8x16_t FlipSignBack(const int8x16_t v) {
+  const int8x16_t sign_bit = vdupq_n_s8(0x80);
+  return vreinterpretq_u8_s8(veorq_s8(v, sign_bit));
+}
+
+static int8x16_t GetBaseDelta(const int8x16_t p1, const int8x16_t p0,
+                              const int8x16_t q0, const int8x16_t q1) {
+  const int8x16_t q0_p0 = vqsubq_s8(q0, p0);      // (q0-p0)
+  const int8x16_t p1_q1 = vqsubq_s8(p1, q1);      // (p1-q1)
+  const int8x16_t s1 = vqaddq_s8(p1_q1, q0_p0);   // (p1-q1) + 1 * (q0 - p0)
+  const int8x16_t s2 = vqaddq_s8(q0_p0, s1);      // (p1-q1) + 2 * (q0 - p0)
+  const int8x16_t s3 = vqaddq_s8(q0_p0, s2);      // (p1-q1) + 3 * (q0 - p0)
+  return s3;
+}
+
+static int8x16_t GetBaseDelta0(const int8x16_t p0, const int8x16_t q0) {
+  const int8x16_t q0_p0 = vqsubq_s8(q0, p0);      // (q0-p0)
+  const int8x16_t s1 = vqaddq_s8(q0_p0, q0_p0);   // 2 * (q0 - p0)
+  const int8x16_t s2 = vqaddq_s8(q0_p0, s1);      // 3 * (q0 - p0)
+  return s2;
+}
+
+//------------------------------------------------------------------------------
+
+static void ApplyFilter2NoFlip(const int8x16_t p0s, const int8x16_t q0s,
+                               const int8x16_t delta,
+                               int8x16_t* const op0, int8x16_t* const oq0) {
+  const int8x16_t kCst3 = vdupq_n_s8(0x03);
+  const int8x16_t kCst4 = vdupq_n_s8(0x04);
+  const int8x16_t delta_p3 = vqaddq_s8(delta, kCst3);
+  const int8x16_t delta_p4 = vqaddq_s8(delta, kCst4);
+  const int8x16_t delta3 = vshrq_n_s8(delta_p3, 3);
+  const int8x16_t delta4 = vshrq_n_s8(delta_p4, 3);
+  *op0 = vqaddq_s8(p0s, delta3);
+  *oq0 = vqsubq_s8(q0s, delta4);
+}
+
+#if defined(WEBP_USE_INTRINSICS)
+
+static void ApplyFilter2(const int8x16_t p0s, const int8x16_t q0s,
+                         const int8x16_t delta,
+                         uint8x16_t* const op0, uint8x16_t* const oq0) {
+  const int8x16_t kCst3 = vdupq_n_s8(0x03);
+  const int8x16_t kCst4 = vdupq_n_s8(0x04);
+  const int8x16_t delta_p3 = vqaddq_s8(delta, kCst3);
+  const int8x16_t delta_p4 = vqaddq_s8(delta, kCst4);
+  const int8x16_t delta3 = vshrq_n_s8(delta_p3, 3);
+  const int8x16_t delta4 = vshrq_n_s8(delta_p4, 3);
+  const int8x16_t sp0 = vqaddq_s8(p0s, delta3);
+  const int8x16_t sq0 = vqsubq_s8(q0s, delta4);
+  *op0 = FlipSignBack(sp0);
+  *oq0 = FlipSignBack(sq0);
+}
+
+static void DoFilter2(const uint8x16_t p1, const uint8x16_t p0,
+                      const uint8x16_t q0, const uint8x16_t q1,
+                      const uint8x16_t mask,
+                      uint8x16_t* const op0, uint8x16_t* const oq0) {
+  const int8x16_t p1s = FlipSign(p1);
+  const int8x16_t p0s = FlipSign(p0);
+  const int8x16_t q0s = FlipSign(q0);
+  const int8x16_t q1s = FlipSign(q1);
+  const int8x16_t delta0 = GetBaseDelta(p1s, p0s, q0s, q1s);
+  const int8x16_t delta1 = vandq_s8(delta0, vreinterpretq_s8_u8(mask));
+  ApplyFilter2(p0s, q0s, delta1, op0, oq0);
+}
+
+static void SimpleVFilter16(uint8_t* p, int stride, int thresh) {
+  uint8x16_t p1, p0, q0, q1, op0, oq0;
+  Load16x4(p, stride, &p1, &p0, &q0, &q1);
+  {
+    const uint8x16_t mask = NeedsFilter(p1, p0, q0, q1, thresh);
+    DoFilter2(p1, p0, q0, q1, mask, &op0, &oq0);
+  }
+  Store16x2(op0, oq0, p, stride);
+}
+
+static void SimpleHFilter16(uint8_t* p, int stride, int thresh) {
+  uint8x16_t p1, p0, q0, q1, oq0, op0;
+  Load4x16(p, stride, &p1, &p0, &q0, &q1);
+  {
+    const uint8x16_t mask = NeedsFilter(p1, p0, q0, q1, thresh);
+    DoFilter2(p1, p0, q0, q1, mask, &op0, &oq0);
+  }
+  Store2x16(op0, oq0, p, stride);
+}
+
+#else
+
+#define QRegs "q0", "q1", "q2", "q3",                                          \
+              "q8", "q9", "q10", "q11", "q12", "q13", "q14", "q15"
+
+#define FLIP_SIGN_BIT2(a, b, s)                                                \
+  "veor     " #a "," #a "," #s "               \n"                             \
+  "veor     " #b "," #b "," #s "               \n"                             \
+
+#define FLIP_SIGN_BIT4(a, b, c, d, s)                                          \
+  FLIP_SIGN_BIT2(a, b, s)                                                      \
+  FLIP_SIGN_BIT2(c, d, s)                                                      \
+
+#define NEEDS_FILTER(p1, p0, q0, q1, thresh, mask)                             \
+  "vabd.u8    q15," #p0 "," #q0 "         \n"  /* abs(p0 - q0) */              \
+  "vabd.u8    q14," #p1 "," #q1 "         \n"  /* abs(p1 - q1) */              \
+  "vqadd.u8   q15, q15, q15               \n"  /* abs(p0 - q0) * 2 */          \
+  "vshr.u8    q14, q14, #1                \n"  /* abs(p1 - q1) / 2 */          \
+  "vqadd.u8   q15, q15, q14     \n"  /* abs(p0 - q0) * 2 + abs(p1 - q1) / 2 */ \
+  "vdup.8     q14, " #thresh "            \n"                                  \
+  "vcge.u8   " #mask ", q14, q15          \n"  /* mask <= thresh */
+
+#define GET_BASE_DELTA(p1, p0, q0, q1, o)                                      \
+  "vqsub.s8   q15," #q0 "," #p0 "         \n"  /* (q0 - p0) */                 \
+  "vqsub.s8  " #o "," #p1 "," #q1 "       \n"  /* (p1 - q1) */                 \
+  "vqadd.s8  " #o "," #o ", q15           \n"  /* (p1 - q1) + 1 * (p0 - q0) */ \
+  "vqadd.s8  " #o "," #o ", q15           \n"  /* (p1 - q1) + 2 * (p0 - q0) */ \
+  "vqadd.s8  " #o "," #o ", q15           \n"  /* (p1 - q1) + 3 * (p0 - q0) */
+
+#define DO_SIMPLE_FILTER(p0, q0, fl)                                           \
+  "vmov.i8    q15, #0x03                  \n"                                  \
+  "vqadd.s8   q15, q15, " #fl "           \n"  /* filter1 = filter + 3 */      \
+  "vshr.s8    q15, q15, #3                \n"  /* filter1 >> 3 */              \
+  "vqadd.s8  " #p0 "," #p0 ", q15         \n"  /* p0 += filter1 */             \
+                                                                               \
+  "vmov.i8    q15, #0x04                  \n"                                  \
+  "vqadd.s8   q15, q15, " #fl "           \n"  /* filter1 = filter + 4 */      \
+  "vshr.s8    q15, q15, #3                \n"  /* filter2 >> 3 */              \
+  "vqsub.s8  " #q0 "," #q0 ", q15         \n"  /* q0 -= filter2 */
+
+// Applies filter on 2 pixels (p0 and q0)
+#define DO_FILTER2(p1, p0, q0, q1, thresh)                                     \
+  NEEDS_FILTER(p1, p0, q0, q1, thresh, q9)     /* filter mask in q9 */         \
+  "vmov.i8    q10, #0x80                  \n"  /* sign bit */                  \
+  FLIP_SIGN_BIT4(p1, p0, q0, q1, q10)          /* convert to signed value */   \
+  GET_BASE_DELTA(p1, p0, q0, q1, q11)          /* get filter level  */         \
+  "vand       q9, q9, q11                 \n"  /* apply filter mask */         \
+  DO_SIMPLE_FILTER(p0, q0, q9)                 /* apply filter */              \
+  FLIP_SIGN_BIT2(p0, q0, q10)
+
+static void SimpleVFilter16(uint8_t* p, int stride, int thresh) {
+  __asm__ volatile (
+    "sub        %[p], %[p], %[stride], lsl #1  \n"  // p -= 2 * stride
+
+    "vld1.u8    {q1}, [%[p]], %[stride]        \n"  // p1
+    "vld1.u8    {q2}, [%[p]], %[stride]        \n"  // p0
+    "vld1.u8    {q3}, [%[p]], %[stride]        \n"  // q0
+    "vld1.u8    {q12}, [%[p]]                  \n"  // q1
+
+    DO_FILTER2(q1, q2, q3, q12, %[thresh])
+
+    "sub        %[p], %[p], %[stride], lsl #1  \n"  // p -= 2 * stride
+
+    "vst1.u8    {q2}, [%[p]], %[stride]        \n"  // store op0
+    "vst1.u8    {q3}, [%[p]]                   \n"  // store oq0
+    : [p] "+r"(p)
+    : [stride] "r"(stride), [thresh] "r"(thresh)
+    : "memory", QRegs
+  );
+}
+
+static void SimpleHFilter16(uint8_t* p, int stride, int thresh) {
+  __asm__ volatile (
+    "sub        r4, %[p], #2                   \n"  // base1 = p - 2
+    "lsl        r6, %[stride], #1              \n"  // r6 = 2 * stride
+    "add        r5, r4, %[stride]              \n"  // base2 = base1 + stride
+
+    LOAD8x4(d2, d3, d4, d5, [r4], [r5], r6)
+    LOAD8x4(d24, d25, d26, d27, [r4], [r5], r6)
+    "vswp       d3, d24                        \n"  // p1:q1 p0:q3
+    "vswp       d5, d26                        \n"  // q0:q2 q1:q4
+    "vswp       q2, q12                        \n"  // p1:q1 p0:q2 q0:q3 q1:q4
+
+    DO_FILTER2(q1, q2, q12, q13, %[thresh])
+
+    "sub        %[p], %[p], #1                 \n"  // p - 1
+
+    "vswp        d5, d24                       \n"
+    STORE8x2(d4, d5, [%[p]], %[stride])
+    STORE8x2(d24, d25, [%[p]], %[stride])
+
+    : [p] "+r"(p)
+    : [stride] "r"(stride), [thresh] "r"(thresh)
+    : "memory", "r4", "r5", "r6", QRegs
+  );
+}
+
+#endif    // WEBP_USE_INTRINSICS
+
+static void SimpleVFilter16i(uint8_t* p, int stride, int thresh) {
+  uint32_t k;
+  for (k = 3; k != 0; --k) {
+    p += 4 * stride;
+    SimpleVFilter16(p, stride, thresh);
+  }
+}
+
+static void SimpleHFilter16i(uint8_t* p, int stride, int thresh) {
+  uint32_t k;
+  for (k = 3; k != 0; --k) {
+    p += 4;
+    SimpleHFilter16(p, stride, thresh);
+  }
+}
+
+//------------------------------------------------------------------------------
+// Complex In-loop filtering (Paragraph 15.3)
+
+static uint8x16_t NeedsHev(const uint8x16_t p1, const uint8x16_t p0,
+                           const uint8x16_t q0, const uint8x16_t q1,
+                           int hev_thresh) {
+  const uint8x16_t hev_thresh_v = vdupq_n_u8((uint8_t)hev_thresh);
+  const uint8x16_t a_p1_p0 = vabdq_u8(p1, p0);  // abs(p1 - p0)
+  const uint8x16_t a_q1_q0 = vabdq_u8(q1, q0);  // abs(q1 - q0)
+  const uint8x16_t a_max = vmaxq_u8(a_p1_p0, a_q1_q0);
+  const uint8x16_t mask = vcgtq_u8(a_max, hev_thresh_v);
+  return mask;
+}
+
+static uint8x16_t NeedsFilter2(const uint8x16_t p3, const uint8x16_t p2,
+                               const uint8x16_t p1, const uint8x16_t p0,
+                               const uint8x16_t q0, const uint8x16_t q1,
+                               const uint8x16_t q2, const uint8x16_t q3,
+                               int ithresh, int thresh) {
+  const uint8x16_t ithresh_v = vdupq_n_u8((uint8_t)ithresh);
+  const uint8x16_t a_p3_p2 = vabdq_u8(p3, p2);  // abs(p3 - p2)
+  const uint8x16_t a_p2_p1 = vabdq_u8(p2, p1);  // abs(p2 - p1)
+  const uint8x16_t a_p1_p0 = vabdq_u8(p1, p0);  // abs(p1 - p0)
+  const uint8x16_t a_q3_q2 = vabdq_u8(q3, q2);  // abs(q3 - q2)
+  const uint8x16_t a_q2_q1 = vabdq_u8(q2, q1);  // abs(q2 - q1)
+  const uint8x16_t a_q1_q0 = vabdq_u8(q1, q0);  // abs(q1 - q0)
+  const uint8x16_t max1 = vmaxq_u8(a_p3_p2, a_p2_p1);
+  const uint8x16_t max2 = vmaxq_u8(a_p1_p0, a_q3_q2);
+  const uint8x16_t max3 = vmaxq_u8(a_q2_q1, a_q1_q0);
+  const uint8x16_t max12 = vmaxq_u8(max1, max2);
+  const uint8x16_t max123 = vmaxq_u8(max12, max3);
+  const uint8x16_t mask2 = vcgeq_u8(ithresh_v, max123);
+  const uint8x16_t mask1 = NeedsFilter(p1, p0, q0, q1, thresh);
+  const uint8x16_t mask = vandq_u8(mask1, mask2);
+  return mask;
+}
+
+//  4-points filter
+
+static void ApplyFilter4(
+    const int8x16_t p1, const int8x16_t p0,
+    const int8x16_t q0, const int8x16_t q1,
+    const int8x16_t delta0,
+    uint8x16_t* const op1, uint8x16_t* const op0,
+    uint8x16_t* const oq0, uint8x16_t* const oq1) {
+  const int8x16_t kCst3 = vdupq_n_s8(0x03);
+  const int8x16_t kCst4 = vdupq_n_s8(0x04);
+  const int8x16_t delta1 = vqaddq_s8(delta0, kCst4);
+  const int8x16_t delta2 = vqaddq_s8(delta0, kCst3);
+  const int8x16_t a1 = vshrq_n_s8(delta1, 3);
+  const int8x16_t a2 = vshrq_n_s8(delta2, 3);
+  const int8x16_t a3 = vrshrq_n_s8(a1, 1);   // a3 = (a1 + 1) >> 1
+  *op0 = FlipSignBack(vqaddq_s8(p0, a2));  // clip(p0 + a2)
+  *oq0 = FlipSignBack(vqsubq_s8(q0, a1));  // clip(q0 - a1)
+  *op1 = FlipSignBack(vqaddq_s8(p1, a3));  // clip(p1 + a3)
+  *oq1 = FlipSignBack(vqsubq_s8(q1, a3));  // clip(q1 - a3)
+}
+
+static void DoFilter4(
+    const uint8x16_t p1, const uint8x16_t p0,
+    const uint8x16_t q0, const uint8x16_t q1,
+    const uint8x16_t mask, const uint8x16_t hev_mask,
+    uint8x16_t* const op1, uint8x16_t* const op0,
+    uint8x16_t* const oq0, uint8x16_t* const oq1) {
+  // This is a fused version of DoFilter2() calling ApplyFilter2 directly
+  const int8x16_t p1s = FlipSign(p1);
+  int8x16_t p0s = FlipSign(p0);
+  int8x16_t q0s = FlipSign(q0);
+  const int8x16_t q1s = FlipSign(q1);
+  const uint8x16_t simple_lf_mask = vandq_u8(mask, hev_mask);
+
+  // do_filter2 part (simple loopfilter on pixels with hev)
+  {
+    const int8x16_t delta = GetBaseDelta(p1s, p0s, q0s, q1s);
+    const int8x16_t simple_lf_delta =
+        vandq_s8(delta, vreinterpretq_s8_u8(simple_lf_mask));
+    ApplyFilter2NoFlip(p0s, q0s, simple_lf_delta, &p0s, &q0s);
+  }
+
+  // do_filter4 part (complex loopfilter on pixels without hev)
+  {
+    const int8x16_t delta0 = GetBaseDelta0(p0s, q0s);
+    // we use: (mask & hev_mask) ^ mask = mask & !hev_mask
+    const uint8x16_t complex_lf_mask = veorq_u8(simple_lf_mask, mask);
+    const int8x16_t complex_lf_delta =
+        vandq_s8(delta0, vreinterpretq_s8_u8(complex_lf_mask));
+    ApplyFilter4(p1s, p0s, q0s, q1s, complex_lf_delta, op1, op0, oq0, oq1);
+  }
+}
+
+//  6-points filter
+
+static void ApplyFilter6(
+    const int8x16_t p2, const int8x16_t p1, const int8x16_t p0,
+    const int8x16_t q0, const int8x16_t q1, const int8x16_t q2,
+    const int8x16_t delta,
+    uint8x16_t* const op2, uint8x16_t* const op1, uint8x16_t* const op0,
+    uint8x16_t* const oq0, uint8x16_t* const oq1, uint8x16_t* const oq2) {
+  // We have to compute: X = (9*a+63) >> 7, Y = (18*a+63)>>7, Z = (27*a+63) >> 7
+  // Turns out, there's a common sub-expression S=9 * a - 1 that can be used
+  // with the special vqrshrn_n_s16 rounding-shift-and-narrow instruction:
+  //   X = (S + 64) >> 7, Y = (S + 32) >> 6, Z = (18 * a + S + 64) >> 7
+  const int8x8_t delta_lo = vget_low_s8(delta);
+  const int8x8_t delta_hi = vget_high_s8(delta);
+  const int8x8_t kCst9 = vdup_n_s8(9);
+  const int16x8_t kCstm1 = vdupq_n_s16(-1);
+  const int8x8_t kCst18 = vdup_n_s8(18);
+  const int16x8_t S_lo = vmlal_s8(kCstm1, kCst9, delta_lo);  // S = 9 * a - 1
+  const int16x8_t S_hi = vmlal_s8(kCstm1, kCst9, delta_hi);
+  const int16x8_t Z_lo = vmlal_s8(S_lo, kCst18, delta_lo);   // S + 18 * a
+  const int16x8_t Z_hi = vmlal_s8(S_hi, kCst18, delta_hi);
+  const int8x8_t a3_lo = vqrshrn_n_s16(S_lo, 7);   // (9 * a + 63) >> 7
+  const int8x8_t a3_hi = vqrshrn_n_s16(S_hi, 7);
+  const int8x8_t a2_lo = vqrshrn_n_s16(S_lo, 6);   // (9 * a + 31) >> 6
+  const int8x8_t a2_hi = vqrshrn_n_s16(S_hi, 6);
+  const int8x8_t a1_lo = vqrshrn_n_s16(Z_lo, 7);   // (27 * a + 63) >> 7
+  const int8x8_t a1_hi = vqrshrn_n_s16(Z_hi, 7);
+  const int8x16_t a1 = vcombine_s8(a1_lo, a1_hi);
+  const int8x16_t a2 = vcombine_s8(a2_lo, a2_hi);
+  const int8x16_t a3 = vcombine_s8(a3_lo, a3_hi);
+
+  *op0 = FlipSignBack(vqaddq_s8(p0, a1));  // clip(p0 + a1)
+  *oq0 = FlipSignBack(vqsubq_s8(q0, a1));  // clip(q0 - q1)
+  *oq1 = FlipSignBack(vqsubq_s8(q1, a2));  // clip(q1 - a2)
+  *op1 = FlipSignBack(vqaddq_s8(p1, a2));  // clip(p1 + a2)
+  *oq2 = FlipSignBack(vqsubq_s8(q2, a3));  // clip(q2 - a3)
+  *op2 = FlipSignBack(vqaddq_s8(p2, a3));  // clip(p2 + a3)
+}
+
+static void DoFilter6(
+    const uint8x16_t p2, const uint8x16_t p1, const uint8x16_t p0,
+    const uint8x16_t q0, const uint8x16_t q1, const uint8x16_t q2,
+    const uint8x16_t mask, const uint8x16_t hev_mask,
+    uint8x16_t* const op2, uint8x16_t* const op1, uint8x16_t* const op0,
+    uint8x16_t* const oq0, uint8x16_t* const oq1, uint8x16_t* const oq2) {
+  // This is a fused version of DoFilter2() calling ApplyFilter2 directly
+  const int8x16_t p2s = FlipSign(p2);
+  const int8x16_t p1s = FlipSign(p1);
+  int8x16_t p0s = FlipSign(p0);
+  int8x16_t q0s = FlipSign(q0);
+  const int8x16_t q1s = FlipSign(q1);
+  const int8x16_t q2s = FlipSign(q2);
+  const uint8x16_t simple_lf_mask = vandq_u8(mask, hev_mask);
+  const int8x16_t delta0 = GetBaseDelta(p1s, p0s, q0s, q1s);
+
+  // do_filter2 part (simple loopfilter on pixels with hev)
+  {
+    const int8x16_t simple_lf_delta =
+        vandq_s8(delta0, vreinterpretq_s8_u8(simple_lf_mask));
+    ApplyFilter2NoFlip(p0s, q0s, simple_lf_delta, &p0s, &q0s);
+  }
+
+  // do_filter6 part (complex loopfilter on pixels without hev)
+  {
+    // we use: (mask & hev_mask) ^ mask = mask & !hev_mask
+    const uint8x16_t complex_lf_mask = veorq_u8(simple_lf_mask, mask);
+    const int8x16_t complex_lf_delta =
+        vandq_s8(delta0, vreinterpretq_s8_u8(complex_lf_mask));
+    ApplyFilter6(p2s, p1s, p0s, q0s, q1s, q2s, complex_lf_delta,
+                 op2, op1, op0, oq0, oq1, oq2);
+  }
+}
+
+// on macroblock edges
+
+static void VFilter16(uint8_t* p, int stride,
+                      int thresh, int ithresh, int hev_thresh) {
+  uint8x16_t p3, p2, p1, p0, q0, q1, q2, q3;
+  Load16x8(p, stride, &p3, &p2, &p1, &p0, &q0, &q1, &q2, &q3);
+  {
+    const uint8x16_t mask = NeedsFilter2(p3, p2, p1, p0, q0, q1, q2, q3,
+                                         ithresh, thresh);
+    const uint8x16_t hev_mask = NeedsHev(p1, p0, q0, q1, hev_thresh);
+    uint8x16_t op2, op1, op0, oq0, oq1, oq2;
+    DoFilter6(p2, p1, p0, q0, q1, q2, mask, hev_mask,
+              &op2, &op1, &op0, &oq0, &oq1, &oq2);
+    Store16x2(op2, op1, p - 2 * stride, stride);
+    Store16x2(op0, oq0, p + 0 * stride, stride);
+    Store16x2(oq1, oq2, p + 2 * stride, stride);
+  }
+}
+
+static void HFilter16(uint8_t* p, int stride,
+                      int thresh, int ithresh, int hev_thresh) {
+  uint8x16_t p3, p2, p1, p0, q0, q1, q2, q3;
+  Load8x16(p, stride, &p3, &p2, &p1, &p0, &q0, &q1, &q2, &q3);
+  {
+    const uint8x16_t mask = NeedsFilter2(p3, p2, p1, p0, q0, q1, q2, q3,
+                                         ithresh, thresh);
+    const uint8x16_t hev_mask = NeedsHev(p1, p0, q0, q1, hev_thresh);
+    uint8x16_t op2, op1, op0, oq0, oq1, oq2;
+    DoFilter6(p2, p1, p0, q0, q1, q2, mask, hev_mask,
+              &op2, &op1, &op0, &oq0, &oq1, &oq2);
+    Store2x16(op2, op1, p - 2, stride);
+    Store2x16(op0, oq0, p + 0, stride);
+    Store2x16(oq1, oq2, p + 2, stride);
+  }
+}
+
+// on three inner edges
+static void VFilter16i(uint8_t* p, int stride,
+                       int thresh, int ithresh, int hev_thresh) {
+  uint32_t k;
+  uint8x16_t p3, p2, p1, p0;
+  Load16x4(p + 2  * stride, stride, &p3, &p2, &p1, &p0);
+  for (k = 3; k != 0; --k) {
+    uint8x16_t q0, q1, q2, q3;
+    p += 4 * stride;
+    Load16x4(p + 2  * stride, stride, &q0, &q1, &q2, &q3);
+    {
+      const uint8x16_t mask =
+          NeedsFilter2(p3, p2, p1, p0, q0, q1, q2, q3, ithresh, thresh);
+      const uint8x16_t hev_mask = NeedsHev(p1, p0, q0, q1, hev_thresh);
+      // p3 and p2 are not just temporary variables here: they will be
+      // re-used for next span. And q2/q3 will become p1/p0 accordingly.
+      DoFilter4(p1, p0, q0, q1, mask, hev_mask, &p1, &p0, &p3, &p2);
+      Store16x4(p1, p0, p3, p2, p, stride);
+      p1 = q2;
+      p0 = q3;
+    }
+  }
+}
+
+#if !defined(WORK_AROUND_GCC)
+static void HFilter16i(uint8_t* p, int stride,
+                       int thresh, int ithresh, int hev_thresh) {
+  uint32_t k;
+  uint8x16_t p3, p2, p1, p0;
+  Load4x16(p + 2, stride, &p3, &p2, &p1, &p0);
+  for (k = 3; k != 0; --k) {
+    uint8x16_t q0, q1, q2, q3;
+    p += 4;
+    Load4x16(p + 2, stride, &q0, &q1, &q2, &q3);
+    {
+      const uint8x16_t mask =
+          NeedsFilter2(p3, p2, p1, p0, q0, q1, q2, q3, ithresh, thresh);
+      const uint8x16_t hev_mask = NeedsHev(p1, p0, q0, q1, hev_thresh);
+      DoFilter4(p1, p0, q0, q1, mask, hev_mask, &p1, &p0, &p3, &p2);
+      Store4x16(p1, p0, p3, p2, p, stride);
+      p1 = q2;
+      p0 = q3;
+    }
+  }
+}
+#endif  // !WORK_AROUND_GCC
+
+// 8-pixels wide variant, for chroma filtering
+static void VFilter8(uint8_t* u, uint8_t* v, int stride,
+                     int thresh, int ithresh, int hev_thresh) {
+  uint8x16_t p3, p2, p1, p0, q0, q1, q2, q3;
+  Load8x8x2(u, v, stride, &p3, &p2, &p1, &p0, &q0, &q1, &q2, &q3);
+  {
+    const uint8x16_t mask = NeedsFilter2(p3, p2, p1, p0, q0, q1, q2, q3,
+                                         ithresh, thresh);
+    const uint8x16_t hev_mask = NeedsHev(p1, p0, q0, q1, hev_thresh);
+    uint8x16_t op2, op1, op0, oq0, oq1, oq2;
+    DoFilter6(p2, p1, p0, q0, q1, q2, mask, hev_mask,
+              &op2, &op1, &op0, &oq0, &oq1, &oq2);
+    Store8x2x2(op2, op1, u - 2 * stride, v - 2 * stride, stride);
+    Store8x2x2(op0, oq0, u + 0 * stride, v + 0 * stride, stride);
+    Store8x2x2(oq1, oq2, u + 2 * stride, v + 2 * stride, stride);
+  }
+}
+static void VFilter8i(uint8_t* u, uint8_t* v, int stride,
+                      int thresh, int ithresh, int hev_thresh) {
+  uint8x16_t p3, p2, p1, p0, q0, q1, q2, q3;
+  u += 4 * stride;
+  v += 4 * stride;
+  Load8x8x2(u, v, stride, &p3, &p2, &p1, &p0, &q0, &q1, &q2, &q3);
+  {
+    const uint8x16_t mask = NeedsFilter2(p3, p2, p1, p0, q0, q1, q2, q3,
+                                         ithresh, thresh);
+    const uint8x16_t hev_mask = NeedsHev(p1, p0, q0, q1, hev_thresh);
+    uint8x16_t op1, op0, oq0, oq1;
+    DoFilter4(p1, p0, q0, q1, mask, hev_mask, &op1, &op0, &oq0, &oq1);
+    Store8x4x2(op1, op0, oq0, oq1, u, v, stride);
+  }
+}
+
+#if !defined(WORK_AROUND_GCC)
+static void HFilter8(uint8_t* u, uint8_t* v, int stride,
+                     int thresh, int ithresh, int hev_thresh) {
+  uint8x16_t p3, p2, p1, p0, q0, q1, q2, q3;
+  Load8x8x2T(u, v, stride, &p3, &p2, &p1, &p0, &q0, &q1, &q2, &q3);
+  {
+    const uint8x16_t mask = NeedsFilter2(p3, p2, p1, p0, q0, q1, q2, q3,
+                                         ithresh, thresh);
+    const uint8x16_t hev_mask = NeedsHev(p1, p0, q0, q1, hev_thresh);
+    uint8x16_t op2, op1, op0, oq0, oq1, oq2;
+    DoFilter6(p2, p1, p0, q0, q1, q2, mask, hev_mask,
+              &op2, &op1, &op0, &oq0, &oq1, &oq2);
+    Store6x8x2(op2, op1, op0, oq0, oq1, oq2, u, v, stride);
+  }
+}
+
+static void HFilter8i(uint8_t* u, uint8_t* v, int stride,
+                      int thresh, int ithresh, int hev_thresh) {
+  uint8x16_t p3, p2, p1, p0, q0, q1, q2, q3;
+  u += 4;
+  v += 4;
+  Load8x8x2T(u, v, stride, &p3, &p2, &p1, &p0, &q0, &q1, &q2, &q3);
+  {
+    const uint8x16_t mask = NeedsFilter2(p3, p2, p1, p0, q0, q1, q2, q3,
+                                         ithresh, thresh);
+    const uint8x16_t hev_mask = NeedsHev(p1, p0, q0, q1, hev_thresh);
+    uint8x16_t op1, op0, oq0, oq1;
+    DoFilter4(p1, p0, q0, q1, mask, hev_mask, &op1, &op0, &oq0, &oq1);
+    Store4x8x2(op1, op0, oq0, oq1, u, v, stride);
+  }
+}
+#endif  // !WORK_AROUND_GCC
+
+//-----------------------------------------------------------------------------
+// Inverse transforms (Paragraph 14.4)
+
+// Technically these are unsigned but vqdmulh is only available in signed.
+// vqdmulh returns high half (effectively >> 16) but also doubles the value,
+// changing the >> 16 to >> 15 and requiring an additional >> 1.
+// We use this to our advantage with kC2. The canonical value is 35468.
+// However, the high bit is set so treating it as signed will give incorrect
+// results. We avoid this by down shifting by 1 here to clear the highest bit.
+// Combined with the doubling effect of vqdmulh we get >> 16.
+// This can not be applied to kC1 because the lowest bit is set. Down shifting
+// the constant would reduce precision.
+
+// libwebp uses a trick to avoid some extra addition that libvpx does.
+// Instead of:
+// temp2 = ip[12] + ((ip[12] * cospi8sqrt2minus1) >> 16);
+// libwebp adds 1 << 16 to cospi8sqrt2minus1 (kC1). However, this causes the
+// same issue with kC1 and vqdmulh that we work around by down shifting kC2
+
+static const int16_t kC1 = 20091;
+static const int16_t kC2 = 17734;  // half of kC2, actually. See comment above.
+
+#if defined(WEBP_USE_INTRINSICS)
+static WEBP_INLINE void Transpose8x2(const int16x8_t in0, const int16x8_t in1,
+                                     int16x8x2_t* const out) {
+  // a0 a1 a2 a3 | b0 b1 b2 b3   => a0 b0 c0 d0 | a1 b1 c1 d1
+  // c0 c1 c2 c3 | d0 d1 d2 d3      a2 b2 c2 d2 | a3 b3 c3 d3
+  const int16x8x2_t tmp0 = vzipq_s16(in0, in1);   // a0 c0 a1 c1 a2 c2 ...
+                                                  // b0 d0 b1 d1 b2 d2 ...
+  *out = vzipq_s16(tmp0.val[0], tmp0.val[1]);
+}
+
+static WEBP_INLINE void TransformPass(int16x8x2_t* const rows) {
+  // {rows} = in0 | in4
+  //          in8 | in12
+  // B1 = in4 | in12
+  const int16x8_t B1 =
+      vcombine_s16(vget_high_s16(rows->val[0]), vget_high_s16(rows->val[1]));
+  // C0 = kC1 * in4 | kC1 * in12
+  // C1 = kC2 * in4 | kC2 * in12
+  const int16x8_t C0 = vsraq_n_s16(B1, vqdmulhq_n_s16(B1, kC1), 1);
+  const int16x8_t C1 = vqdmulhq_n_s16(B1, kC2);
+  const int16x4_t a = vqadd_s16(vget_low_s16(rows->val[0]),
+                                vget_low_s16(rows->val[1]));   // in0 + in8
+  const int16x4_t b = vqsub_s16(vget_low_s16(rows->val[0]),
+                                vget_low_s16(rows->val[1]));   // in0 - in8
+  // c = kC2 * in4 - kC1 * in12
+  // d = kC1 * in4 + kC2 * in12
+  const int16x4_t c = vqsub_s16(vget_low_s16(C1), vget_high_s16(C0));
+  const int16x4_t d = vqadd_s16(vget_low_s16(C0), vget_high_s16(C1));
+  const int16x8_t D0 = vcombine_s16(a, b);      // D0 = a | b
+  const int16x8_t D1 = vcombine_s16(d, c);      // D1 = d | c
+  const int16x8_t E0 = vqaddq_s16(D0, D1);      // a+d | b+c
+  const int16x8_t E_tmp = vqsubq_s16(D0, D1);   // a-d | b-c
+  const int16x8_t E1 = vcombine_s16(vget_high_s16(E_tmp), vget_low_s16(E_tmp));
+  Transpose8x2(E0, E1, rows);
+}
+
+static void TransformOne(const int16_t* in, uint8_t* dst) {
+  int16x8x2_t rows;
+  INIT_VECTOR2(rows, vld1q_s16(in + 0), vld1q_s16(in + 8));
+  TransformPass(&rows);
+  TransformPass(&rows);
+  Add4x4(rows.val[0], rows.val[1], dst);
+}
+
+#else
+
+static void TransformOne(const int16_t* in, uint8_t* dst) {
+  const int kBPS = BPS;
+  // kC1, kC2. Padded because vld1.16 loads 8 bytes
+  const int16_t constants[4] = { kC1, kC2, 0, 0 };
+  /* Adapted from libvpx: vp8/common/arm/neon/shortidct4x4llm_neon.asm */
+  __asm__ volatile (
+    "vld1.16         {q1, q2}, [%[in]]           \n"
+    "vld1.16         {d0}, [%[constants]]        \n"
+
+    /* d2: in[0]
+     * d3: in[8]
+     * d4: in[4]
+     * d5: in[12]
+     */
+    "vswp            d3, d4                      \n"
+
+    /* q8 = {in[4], in[12]} * kC1 * 2 >> 16
+     * q9 = {in[4], in[12]} * kC2 >> 16
+     */
+    "vqdmulh.s16     q8, q2, d0[0]               \n"
+    "vqdmulh.s16     q9, q2, d0[1]               \n"
+
+    /* d22 = a = in[0] + in[8]
+     * d23 = b = in[0] - in[8]
+     */
+    "vqadd.s16       d22, d2, d3                 \n"
+    "vqsub.s16       d23, d2, d3                 \n"
+
+    /* The multiplication should be x * kC1 >> 16
+     * However, with vqdmulh we get x * kC1 * 2 >> 16
+     * (multiply, double, return high half)
+     * We avoided this in kC2 by pre-shifting the constant.
+     * q8 = in[4]/[12] * kC1 >> 16
+     */
+    "vshr.s16        q8, q8, #1                  \n"
+
+    /* Add {in[4], in[12]} back after the multiplication. This is handled by
+     * adding 1 << 16 to kC1 in the libwebp C code.
+     */
+    "vqadd.s16       q8, q2, q8                  \n"
+
+    /* d20 = c = in[4]*kC2 - in[12]*kC1
+     * d21 = d = in[4]*kC1 + in[12]*kC2
+     */
+    "vqsub.s16       d20, d18, d17               \n"
+    "vqadd.s16       d21, d19, d16               \n"
+
+    /* d2 = tmp[0] = a + d
+     * d3 = tmp[1] = b + c
+     * d4 = tmp[2] = b - c
+     * d5 = tmp[3] = a - d
+     */
+    "vqadd.s16       d2, d22, d21                \n"
+    "vqadd.s16       d3, d23, d20                \n"
+    "vqsub.s16       d4, d23, d20                \n"
+    "vqsub.s16       d5, d22, d21                \n"
+
+    "vzip.16         q1, q2                      \n"
+    "vzip.16         q1, q2                      \n"
+
+    "vswp            d3, d4                      \n"
+
+    /* q8 = {tmp[4], tmp[12]} * kC1 * 2 >> 16
+     * q9 = {tmp[4], tmp[12]} * kC2 >> 16
+     */
+    "vqdmulh.s16     q8, q2, d0[0]               \n"
+    "vqdmulh.s16     q9, q2, d0[1]               \n"
+
+    /* d22 = a = tmp[0] + tmp[8]
+     * d23 = b = tmp[0] - tmp[8]
+     */
+    "vqadd.s16       d22, d2, d3                 \n"
+    "vqsub.s16       d23, d2, d3                 \n"
+
+    /* See long winded explanations prior */
+    "vshr.s16        q8, q8, #1                  \n"
+    "vqadd.s16       q8, q2, q8                  \n"
+
+    /* d20 = c = in[4]*kC2 - in[12]*kC1
+     * d21 = d = in[4]*kC1 + in[12]*kC2
+     */
+    "vqsub.s16       d20, d18, d17               \n"
+    "vqadd.s16       d21, d19, d16               \n"
+
+    /* d2 = tmp[0] = a + d
+     * d3 = tmp[1] = b + c
+     * d4 = tmp[2] = b - c
+     * d5 = tmp[3] = a - d
+     */
+    "vqadd.s16       d2, d22, d21                \n"
+    "vqadd.s16       d3, d23, d20                \n"
+    "vqsub.s16       d4, d23, d20                \n"
+    "vqsub.s16       d5, d22, d21                \n"
+
+    "vld1.32         d6[0], [%[dst]], %[kBPS]    \n"
+    "vld1.32         d6[1], [%[dst]], %[kBPS]    \n"
+    "vld1.32         d7[0], [%[dst]], %[kBPS]    \n"
+    "vld1.32         d7[1], [%[dst]], %[kBPS]    \n"
+
+    "sub         %[dst], %[dst], %[kBPS], lsl #2 \n"
+
+    /* (val) + 4 >> 3 */
+    "vrshr.s16       d2, d2, #3                  \n"
+    "vrshr.s16       d3, d3, #3                  \n"
+    "vrshr.s16       d4, d4, #3                  \n"
+    "vrshr.s16       d5, d5, #3                  \n"
+
+    "vzip.16         q1, q2                      \n"
+    "vzip.16         q1, q2                      \n"
+
+    /* Must accumulate before saturating */
+    "vmovl.u8        q8, d6                      \n"
+    "vmovl.u8        q9, d7                      \n"
+
+    "vqadd.s16       q1, q1, q8                  \n"
+    "vqadd.s16       q2, q2, q9                  \n"
+
+    "vqmovun.s16     d0, q1                      \n"
+    "vqmovun.s16     d1, q2                      \n"
+
+    "vst1.32         d0[0], [%[dst]], %[kBPS]    \n"
+    "vst1.32         d0[1], [%[dst]], %[kBPS]    \n"
+    "vst1.32         d1[0], [%[dst]], %[kBPS]    \n"
+    "vst1.32         d1[1], [%[dst]]             \n"
+
+    : [in] "+r"(in), [dst] "+r"(dst)  /* modified registers */
+    : [kBPS] "r"(kBPS), [constants] "r"(constants)  /* constants */
+    : "memory", "q0", "q1", "q2", "q8", "q9", "q10", "q11"  /* clobbered */
+  );
+}
+
+#endif    // WEBP_USE_INTRINSICS
+
+static void TransformTwo(const int16_t* in, uint8_t* dst, int do_two) {
+  TransformOne(in, dst);
+  if (do_two) {
+    TransformOne(in + 16, dst + 4);
+  }
+}
+
+static void TransformDC(const int16_t* in, uint8_t* dst) {
+  const int16x8_t DC = vdupq_n_s16(in[0]);
+  Add4x4(DC, DC, dst);
+}
+
+//------------------------------------------------------------------------------
+
+#define STORE_WHT(dst, col, rows) do {                  \
+  *dst = vgetq_lane_s32(rows.val[0], col); (dst) += 16; \
+  *dst = vgetq_lane_s32(rows.val[1], col); (dst) += 16; \
+  *dst = vgetq_lane_s32(rows.val[2], col); (dst) += 16; \
+  *dst = vgetq_lane_s32(rows.val[3], col); (dst) += 16; \
+} while (0)
+
+static void TransformWHT(const int16_t* in, int16_t* out) {
+  int32x4x4_t tmp;
+
+  {
+    // Load the source.
+    const int16x4_t in00_03 = vld1_s16(in + 0);
+    const int16x4_t in04_07 = vld1_s16(in + 4);
+    const int16x4_t in08_11 = vld1_s16(in + 8);
+    const int16x4_t in12_15 = vld1_s16(in + 12);
+    const int32x4_t a0 = vaddl_s16(in00_03, in12_15);  // in[0..3] + in[12..15]
+    const int32x4_t a1 = vaddl_s16(in04_07, in08_11);  // in[4..7] + in[8..11]
+    const int32x4_t a2 = vsubl_s16(in04_07, in08_11);  // in[4..7] - in[8..11]
+    const int32x4_t a3 = vsubl_s16(in00_03, in12_15);  // in[0..3] - in[12..15]
+    tmp.val[0] = vaddq_s32(a0, a1);
+    tmp.val[1] = vaddq_s32(a3, a2);
+    tmp.val[2] = vsubq_s32(a0, a1);
+    tmp.val[3] = vsubq_s32(a3, a2);
+    // Arrange the temporary results column-wise.
+    tmp = Transpose4x4(tmp);
+  }
+
+  {
+    const int32x4_t kCst3 = vdupq_n_s32(3);
+    const int32x4_t dc = vaddq_s32(tmp.val[0], kCst3);  // add rounder
+    const int32x4_t a0 = vaddq_s32(dc, tmp.val[3]);
+    const int32x4_t a1 = vaddq_s32(tmp.val[1], tmp.val[2]);
+    const int32x4_t a2 = vsubq_s32(tmp.val[1], tmp.val[2]);
+    const int32x4_t a3 = vsubq_s32(dc, tmp.val[3]);
+
+    tmp.val[0] = vaddq_s32(a0, a1);
+    tmp.val[1] = vaddq_s32(a3, a2);
+    tmp.val[2] = vsubq_s32(a0, a1);
+    tmp.val[3] = vsubq_s32(a3, a2);
+
+    // right shift the results by 3.
+    tmp.val[0] = vshrq_n_s32(tmp.val[0], 3);
+    tmp.val[1] = vshrq_n_s32(tmp.val[1], 3);
+    tmp.val[2] = vshrq_n_s32(tmp.val[2], 3);
+    tmp.val[3] = vshrq_n_s32(tmp.val[3], 3);
+
+    STORE_WHT(out, 0, tmp);
+    STORE_WHT(out, 1, tmp);
+    STORE_WHT(out, 2, tmp);
+    STORE_WHT(out, 3, tmp);
+  }
+}
+
+#undef STORE_WHT
+
+//------------------------------------------------------------------------------
+
+#define MUL(a, b) (((a) * (b)) >> 16)
+static void TransformAC3(const int16_t* in, uint8_t* dst) {
+  static const int kC1_full = 20091 + (1 << 16);
+  static const int kC2_full = 35468;
+  const int16x4_t A = vld1_dup_s16(in);
+  const int16x4_t c4 = vdup_n_s16(MUL(in[4], kC2_full));
+  const int16x4_t d4 = vdup_n_s16(MUL(in[4], kC1_full));
+  const int c1 = MUL(in[1], kC2_full);
+  const int d1 = MUL(in[1], kC1_full);
+  const uint64_t cd = (uint64_t)( d1 & 0xffff) <<  0 |
+                      (uint64_t)( c1 & 0xffff) << 16 |
+                      (uint64_t)(-c1 & 0xffff) << 32 |
+                      (uint64_t)(-d1 & 0xffff) << 48;
+  const int16x4_t CD = vcreate_s16(cd);
+  const int16x4_t B = vqadd_s16(A, CD);
+  const int16x8_t m0_m1 = vcombine_s16(vqadd_s16(B, d4), vqadd_s16(B, c4));
+  const int16x8_t m2_m3 = vcombine_s16(vqsub_s16(B, c4), vqsub_s16(B, d4));
+  Add4x4(m0_m1, m2_m3, dst);
+}
+#undef MUL
+
+//------------------------------------------------------------------------------
+// 4x4
+
+static void DC4(uint8_t* dst) {    // DC
+  const uint8x8_t A = vld1_u8(dst - BPS);  // top row
+  const uint16x4_t p0 = vpaddl_u8(A);  // cascading summation of the top
+  const uint16x4_t p1 = vpadd_u16(p0, p0);
+  const uint16x8_t L0 = vmovl_u8(vld1_u8(dst + 0 * BPS - 1));
+  const uint16x8_t L1 = vmovl_u8(vld1_u8(dst + 1 * BPS - 1));
+  const uint16x8_t L2 = vmovl_u8(vld1_u8(dst + 2 * BPS - 1));
+  const uint16x8_t L3 = vmovl_u8(vld1_u8(dst + 3 * BPS - 1));
+  const uint16x8_t s0 = vaddq_u16(L0, L1);
+  const uint16x8_t s1 = vaddq_u16(L2, L3);
+  const uint16x8_t s01 = vaddq_u16(s0, s1);
+  const uint16x8_t sum = vaddq_u16(s01, vcombine_u16(p1, p1));
+  const uint8x8_t dc0 = vrshrn_n_u16(sum, 3);  // (sum + 4) >> 3
+  const uint8x8_t dc = vdup_lane_u8(dc0, 0);
+  int i;
+  for (i = 0; i < 4; ++i) {
+    vst1_lane_u32((uint32_t*)(dst + i * BPS), vreinterpret_u32_u8(dc), 0);
+  }
+}
+
+// TrueMotion (4x4 + 8x8)
+static WEBP_INLINE void TrueMotion(uint8_t* dst, int size) {
+  const uint8x8_t TL = vld1_dup_u8(dst - BPS - 1);  // top-left pixel 'A[-1]'
+  const uint8x8_t T = vld1_u8(dst - BPS);  // top row 'A[0..3]'
+  const int16x8_t d = vreinterpretq_s16_u16(vsubl_u8(T, TL));  // A[c] - A[-1]
+  int y;
+  for (y = 0; y < size; y += 4) {
+    // left edge
+    const int16x8_t L0 = ConvertU8ToS16(vld1_dup_u8(dst + 0 * BPS - 1));
+    const int16x8_t L1 = ConvertU8ToS16(vld1_dup_u8(dst + 1 * BPS - 1));
+    const int16x8_t L2 = ConvertU8ToS16(vld1_dup_u8(dst + 2 * BPS - 1));
+    const int16x8_t L3 = ConvertU8ToS16(vld1_dup_u8(dst + 3 * BPS - 1));
+    const int16x8_t r0 = vaddq_s16(L0, d);  // L[r] + A[c] - A[-1]
+    const int16x8_t r1 = vaddq_s16(L1, d);
+    const int16x8_t r2 = vaddq_s16(L2, d);
+    const int16x8_t r3 = vaddq_s16(L3, d);
+    // Saturate and store the result.
+    const uint32x2_t r0_u32 = vreinterpret_u32_u8(vqmovun_s16(r0));
+    const uint32x2_t r1_u32 = vreinterpret_u32_u8(vqmovun_s16(r1));
+    const uint32x2_t r2_u32 = vreinterpret_u32_u8(vqmovun_s16(r2));
+    const uint32x2_t r3_u32 = vreinterpret_u32_u8(vqmovun_s16(r3));
+    if (size == 4) {
+      vst1_lane_u32((uint32_t*)(dst + 0 * BPS), r0_u32, 0);
+      vst1_lane_u32((uint32_t*)(dst + 1 * BPS), r1_u32, 0);
+      vst1_lane_u32((uint32_t*)(dst + 2 * BPS), r2_u32, 0);
+      vst1_lane_u32((uint32_t*)(dst + 3 * BPS), r3_u32, 0);
+    } else {
+      vst1_u32((uint32_t*)(dst + 0 * BPS), r0_u32);
+      vst1_u32((uint32_t*)(dst + 1 * BPS), r1_u32);
+      vst1_u32((uint32_t*)(dst + 2 * BPS), r2_u32);
+      vst1_u32((uint32_t*)(dst + 3 * BPS), r3_u32);
+    }
+    dst += 4 * BPS;
+  }
+}
+
+static void TM4(uint8_t* dst) { TrueMotion(dst, 4); }
+
+static void VE4(uint8_t* dst) {    // vertical
+  // NB: avoid vld1_u64 here as an alignment hint may be added -> SIGBUS.
+  const uint64x1_t A0 = vreinterpret_u64_u8(vld1_u8(dst - BPS - 1));  // top row
+  const uint64x1_t A1 = vshr_n_u64(A0, 8);
+  const uint64x1_t A2 = vshr_n_u64(A0, 16);
+  const uint8x8_t ABCDEFGH = vreinterpret_u8_u64(A0);
+  const uint8x8_t BCDEFGH0 = vreinterpret_u8_u64(A1);
+  const uint8x8_t CDEFGH00 = vreinterpret_u8_u64(A2);
+  const uint8x8_t b = vhadd_u8(ABCDEFGH, CDEFGH00);
+  const uint8x8_t avg = vrhadd_u8(b, BCDEFGH0);
+  int i;
+  for (i = 0; i < 4; ++i) {
+    vst1_lane_u32((uint32_t*)(dst + i * BPS), vreinterpret_u32_u8(avg), 0);
+  }
+}
+
+static void RD4(uint8_t* dst) {   // Down-right
+  const uint8x8_t XABCD_u8 = vld1_u8(dst - BPS - 1);
+  const uint64x1_t XABCD = vreinterpret_u64_u8(XABCD_u8);
+  const uint64x1_t ____XABC = vshl_n_u64(XABCD, 32);
+  const uint32_t I = dst[-1 + 0 * BPS];
+  const uint32_t J = dst[-1 + 1 * BPS];
+  const uint32_t K = dst[-1 + 2 * BPS];
+  const uint32_t L = dst[-1 + 3 * BPS];
+  const uint64x1_t LKJI____ = vcreate_u64(L | (K << 8) | (J << 16) | (I << 24));
+  const uint64x1_t LKJIXABC = vorr_u64(LKJI____, ____XABC);
+  const uint8x8_t KJIXABC_ = vreinterpret_u8_u64(vshr_n_u64(LKJIXABC, 8));
+  const uint8x8_t JIXABC__ = vreinterpret_u8_u64(vshr_n_u64(LKJIXABC, 16));
+  const uint8_t D = vget_lane_u8(XABCD_u8, 4);
+  const uint8x8_t JIXABCD_ = vset_lane_u8(D, JIXABC__, 6);
+  const uint8x8_t LKJIXABC_u8 = vreinterpret_u8_u64(LKJIXABC);
+  const uint8x8_t avg1 = vhadd_u8(JIXABCD_, LKJIXABC_u8);
+  const uint8x8_t avg2 = vrhadd_u8(avg1, KJIXABC_);
+  const uint64x1_t avg2_u64 = vreinterpret_u64_u8(avg2);
+  const uint32x2_t r3 = vreinterpret_u32_u8(avg2);
+  const uint32x2_t r2 = vreinterpret_u32_u64(vshr_n_u64(avg2_u64, 8));
+  const uint32x2_t r1 = vreinterpret_u32_u64(vshr_n_u64(avg2_u64, 16));
+  const uint32x2_t r0 = vreinterpret_u32_u64(vshr_n_u64(avg2_u64, 24));
+  vst1_lane_u32((uint32_t*)(dst + 0 * BPS), r0, 0);
+  vst1_lane_u32((uint32_t*)(dst + 1 * BPS), r1, 0);
+  vst1_lane_u32((uint32_t*)(dst + 2 * BPS), r2, 0);
+  vst1_lane_u32((uint32_t*)(dst + 3 * BPS), r3, 0);
+}
+
+static void LD4(uint8_t* dst) {    // Down-left
+  // Note using the same shift trick as VE4() is slower here.
+  const uint8x8_t ABCDEFGH = vld1_u8(dst - BPS + 0);
+  const uint8x8_t BCDEFGH0 = vld1_u8(dst - BPS + 1);
+  const uint8x8_t CDEFGH00 = vld1_u8(dst - BPS + 2);
+  const uint8x8_t CDEFGHH0 = vset_lane_u8(dst[-BPS + 7], CDEFGH00, 6);
+  const uint8x8_t avg1 = vhadd_u8(ABCDEFGH, CDEFGHH0);
+  const uint8x8_t avg2 = vrhadd_u8(avg1, BCDEFGH0);
+  const uint64x1_t avg2_u64 = vreinterpret_u64_u8(avg2);
+  const uint32x2_t r0 = vreinterpret_u32_u8(avg2);
+  const uint32x2_t r1 = vreinterpret_u32_u64(vshr_n_u64(avg2_u64, 8));
+  const uint32x2_t r2 = vreinterpret_u32_u64(vshr_n_u64(avg2_u64, 16));
+  const uint32x2_t r3 = vreinterpret_u32_u64(vshr_n_u64(avg2_u64, 24));
+  vst1_lane_u32((uint32_t*)(dst + 0 * BPS), r0, 0);
+  vst1_lane_u32((uint32_t*)(dst + 1 * BPS), r1, 0);
+  vst1_lane_u32((uint32_t*)(dst + 2 * BPS), r2, 0);
+  vst1_lane_u32((uint32_t*)(dst + 3 * BPS), r3, 0);
+}
+
+//------------------------------------------------------------------------------
+// Chroma
+
+static void VE8uv(uint8_t* dst) {    // vertical
+  const uint8x8_t top = vld1_u8(dst - BPS);
+  int j;
+  for (j = 0; j < 8; ++j) {
+    vst1_u8(dst + j * BPS, top);
+  }
+}
+
+static void HE8uv(uint8_t* dst) {    // horizontal
+  int j;
+  for (j = 0; j < 8; ++j) {
+    const uint8x8_t left = vld1_dup_u8(dst - 1);
+    vst1_u8(dst, left);
+    dst += BPS;
+  }
+}
+
+static WEBP_INLINE void DC8(uint8_t* dst, int do_top, int do_left) {
+  uint16x8_t sum_top;
+  uint16x8_t sum_left;
+  uint8x8_t dc0;
+
+  if (do_top) {
+    const uint8x8_t A = vld1_u8(dst - BPS);  // top row
+    const uint16x4_t p0 = vpaddl_u8(A);  // cascading summation of the top
+    const uint16x4_t p1 = vpadd_u16(p0, p0);
+    const uint16x4_t p2 = vpadd_u16(p1, p1);
+    sum_top = vcombine_u16(p2, p2);
+  }
+
+  if (do_left) {
+    const uint16x8_t L0 = vmovl_u8(vld1_u8(dst + 0 * BPS - 1));
+    const uint16x8_t L1 = vmovl_u8(vld1_u8(dst + 1 * BPS - 1));
+    const uint16x8_t L2 = vmovl_u8(vld1_u8(dst + 2 * BPS - 1));
+    const uint16x8_t L3 = vmovl_u8(vld1_u8(dst + 3 * BPS - 1));
+    const uint16x8_t L4 = vmovl_u8(vld1_u8(dst + 4 * BPS - 1));
+    const uint16x8_t L5 = vmovl_u8(vld1_u8(dst + 5 * BPS - 1));
+    const uint16x8_t L6 = vmovl_u8(vld1_u8(dst + 6 * BPS - 1));
+    const uint16x8_t L7 = vmovl_u8(vld1_u8(dst + 7 * BPS - 1));
+    const uint16x8_t s0 = vaddq_u16(L0, L1);
+    const uint16x8_t s1 = vaddq_u16(L2, L3);
+    const uint16x8_t s2 = vaddq_u16(L4, L5);
+    const uint16x8_t s3 = vaddq_u16(L6, L7);
+    const uint16x8_t s01 = vaddq_u16(s0, s1);
+    const uint16x8_t s23 = vaddq_u16(s2, s3);
+    sum_left = vaddq_u16(s01, s23);
+  }
+
+  if (do_top && do_left) {
+    const uint16x8_t sum = vaddq_u16(sum_left, sum_top);
+    dc0 = vrshrn_n_u16(sum, 4);
+  } else if (do_top) {
+    dc0 = vrshrn_n_u16(sum_top, 3);
+  } else if (do_left) {
+    dc0 = vrshrn_n_u16(sum_left, 3);
+  } else {
+    dc0 = vdup_n_u8(0x80);
+  }
+
+  {
+    const uint8x8_t dc = vdup_lane_u8(dc0, 0);
+    int i;
+    for (i = 0; i < 8; ++i) {
+      vst1_u32((uint32_t*)(dst + i * BPS), vreinterpret_u32_u8(dc));
+    }
+  }
+}
+
+static void DC8uv(uint8_t* dst) { DC8(dst, 1, 1); }
+static void DC8uvNoTop(uint8_t* dst) { DC8(dst, 0, 1); }
+static void DC8uvNoLeft(uint8_t* dst) { DC8(dst, 1, 0); }
+static void DC8uvNoTopLeft(uint8_t* dst) { DC8(dst, 0, 0); }
+
+static void TM8uv(uint8_t* dst) { TrueMotion(dst, 8); }
+
+//------------------------------------------------------------------------------
+// 16x16
+
+static void VE16(uint8_t* dst) {     // vertical
+  const uint8x16_t top = vld1q_u8(dst - BPS);
+  int j;
+  for (j = 0; j < 16; ++j) {
+    vst1q_u8(dst + j * BPS, top);
+  }
+}
+
+static void HE16(uint8_t* dst) {     // horizontal
+  int j;
+  for (j = 0; j < 16; ++j) {
+    const uint8x16_t left = vld1q_dup_u8(dst - 1);
+    vst1q_u8(dst, left);
+    dst += BPS;
+  }
+}
+
+static WEBP_INLINE void DC16(uint8_t* dst, int do_top, int do_left) {
+  uint16x8_t sum_top;
+  uint16x8_t sum_left;
+  uint8x8_t dc0;
+
+  if (do_top) {
+    const uint8x16_t A = vld1q_u8(dst - BPS);  // top row
+    const uint16x8_t p0 = vpaddlq_u8(A);  // cascading summation of the top
+    const uint16x4_t p1 = vadd_u16(vget_low_u16(p0), vget_high_u16(p0));
+    const uint16x4_t p2 = vpadd_u16(p1, p1);
+    const uint16x4_t p3 = vpadd_u16(p2, p2);
+    sum_top = vcombine_u16(p3, p3);
+  }
+
+  if (do_left) {
+    int i;
+    sum_left = vdupq_n_u16(0);
+    for (i = 0; i < 16; i += 8) {
+      const uint16x8_t L0 = vmovl_u8(vld1_u8(dst + (i + 0) * BPS - 1));
+      const uint16x8_t L1 = vmovl_u8(vld1_u8(dst + (i + 1) * BPS - 1));
+      const uint16x8_t L2 = vmovl_u8(vld1_u8(dst + (i + 2) * BPS - 1));
+      const uint16x8_t L3 = vmovl_u8(vld1_u8(dst + (i + 3) * BPS - 1));
+      const uint16x8_t L4 = vmovl_u8(vld1_u8(dst + (i + 4) * BPS - 1));
+      const uint16x8_t L5 = vmovl_u8(vld1_u8(dst + (i + 5) * BPS - 1));
+      const uint16x8_t L6 = vmovl_u8(vld1_u8(dst + (i + 6) * BPS - 1));
+      const uint16x8_t L7 = vmovl_u8(vld1_u8(dst + (i + 7) * BPS - 1));
+      const uint16x8_t s0 = vaddq_u16(L0, L1);
+      const uint16x8_t s1 = vaddq_u16(L2, L3);
+      const uint16x8_t s2 = vaddq_u16(L4, L5);
+      const uint16x8_t s3 = vaddq_u16(L6, L7);
+      const uint16x8_t s01 = vaddq_u16(s0, s1);
+      const uint16x8_t s23 = vaddq_u16(s2, s3);
+      const uint16x8_t sum = vaddq_u16(s01, s23);
+      sum_left = vaddq_u16(sum_left, sum);
+    }
+  }
+
+  if (do_top && do_left) {
+    const uint16x8_t sum = vaddq_u16(sum_left, sum_top);
+    dc0 = vrshrn_n_u16(sum, 5);
+  } else if (do_top) {
+    dc0 = vrshrn_n_u16(sum_top, 4);
+  } else if (do_left) {
+    dc0 = vrshrn_n_u16(sum_left, 4);
+  } else {
+    dc0 = vdup_n_u8(0x80);
+  }
+
+  {
+    const uint8x16_t dc = vdupq_lane_u8(dc0, 0);
+    int i;
+    for (i = 0; i < 16; ++i) {
+      vst1q_u8(dst + i * BPS, dc);
+    }
+  }
+}
+
+static void DC16TopLeft(uint8_t* dst) { DC16(dst, 1, 1); }
+static void DC16NoTop(uint8_t* dst) { DC16(dst, 0, 1); }
+static void DC16NoLeft(uint8_t* dst) { DC16(dst, 1, 0); }
+static void DC16NoTopLeft(uint8_t* dst) { DC16(dst, 0, 0); }
+
+static void TM16(uint8_t* dst) {
+  const uint8x8_t TL = vld1_dup_u8(dst - BPS - 1);  // top-left pixel 'A[-1]'
+  const uint8x16_t T = vld1q_u8(dst - BPS);  // top row 'A[0..15]'
+  // A[c] - A[-1]
+  const int16x8_t d_lo = vreinterpretq_s16_u16(vsubl_u8(vget_low_u8(T), TL));
+  const int16x8_t d_hi = vreinterpretq_s16_u16(vsubl_u8(vget_high_u8(T), TL));
+  int y;
+  for (y = 0; y < 16; y += 4) {
+    // left edge
+    const int16x8_t L0 = ConvertU8ToS16(vld1_dup_u8(dst + 0 * BPS - 1));
+    const int16x8_t L1 = ConvertU8ToS16(vld1_dup_u8(dst + 1 * BPS - 1));
+    const int16x8_t L2 = ConvertU8ToS16(vld1_dup_u8(dst + 2 * BPS - 1));
+    const int16x8_t L3 = ConvertU8ToS16(vld1_dup_u8(dst + 3 * BPS - 1));
+    const int16x8_t r0_lo = vaddq_s16(L0, d_lo);  // L[r] + A[c] - A[-1]
+    const int16x8_t r1_lo = vaddq_s16(L1, d_lo);
+    const int16x8_t r2_lo = vaddq_s16(L2, d_lo);
+    const int16x8_t r3_lo = vaddq_s16(L3, d_lo);
+    const int16x8_t r0_hi = vaddq_s16(L0, d_hi);
+    const int16x8_t r1_hi = vaddq_s16(L1, d_hi);
+    const int16x8_t r2_hi = vaddq_s16(L2, d_hi);
+    const int16x8_t r3_hi = vaddq_s16(L3, d_hi);
+    // Saturate and store the result.
+    const uint8x16_t row0 = vcombine_u8(vqmovun_s16(r0_lo), vqmovun_s16(r0_hi));
+    const uint8x16_t row1 = vcombine_u8(vqmovun_s16(r1_lo), vqmovun_s16(r1_hi));
+    const uint8x16_t row2 = vcombine_u8(vqmovun_s16(r2_lo), vqmovun_s16(r2_hi));
+    const uint8x16_t row3 = vcombine_u8(vqmovun_s16(r3_lo), vqmovun_s16(r3_hi));
+    vst1q_u8(dst + 0 * BPS, row0);
+    vst1q_u8(dst + 1 * BPS, row1);
+    vst1q_u8(dst + 2 * BPS, row2);
+    vst1q_u8(dst + 3 * BPS, row3);
+    dst += 4 * BPS;
+  }
+}
+
+//------------------------------------------------------------------------------
+// Entry point
+
+extern void VP8DspInitNEON(void);
+
+WEBP_TSAN_IGNORE_FUNCTION void VP8DspInitNEON(void) {
+  VP8Transform = TransformTwo;
+  VP8TransformAC3 = TransformAC3;
+  VP8TransformDC = TransformDC;
+  VP8TransformWHT = TransformWHT;
+
+  VP8VFilter16 = VFilter16;
+  VP8VFilter16i = VFilter16i;
+  VP8HFilter16 = HFilter16;
+#if !defined(WORK_AROUND_GCC)
+  VP8HFilter16i = HFilter16i;
+#endif
+  VP8VFilter8 = VFilter8;
+  VP8VFilter8i = VFilter8i;
+#if !defined(WORK_AROUND_GCC)
+  VP8HFilter8 = HFilter8;
+  VP8HFilter8i = HFilter8i;
+#endif
+  VP8SimpleVFilter16 = SimpleVFilter16;
+  VP8SimpleHFilter16 = SimpleHFilter16;
+  VP8SimpleVFilter16i = SimpleVFilter16i;
+  VP8SimpleHFilter16i = SimpleHFilter16i;
+
+  VP8PredLuma4[0] = DC4;
+  VP8PredLuma4[1] = TM4;
+  VP8PredLuma4[2] = VE4;
+  VP8PredLuma4[4] = RD4;
+  VP8PredLuma4[6] = LD4;
+
+  VP8PredLuma16[0] = DC16TopLeft;
+  VP8PredLuma16[1] = TM16;
+  VP8PredLuma16[2] = VE16;
+  VP8PredLuma16[3] = HE16;
+  VP8PredLuma16[4] = DC16NoTop;
+  VP8PredLuma16[5] = DC16NoLeft;
+  VP8PredLuma16[6] = DC16NoTopLeft;
+
+  VP8PredChroma8[0] = DC8uv;
+  VP8PredChroma8[1] = TM8uv;
+  VP8PredChroma8[2] = VE8uv;
+  VP8PredChroma8[3] = HE8uv;
+  VP8PredChroma8[4] = DC8uvNoTop;
+  VP8PredChroma8[5] = DC8uvNoLeft;
+  VP8PredChroma8[6] = DC8uvNoTopLeft;
+}
+
+#else  // !WEBP_USE_NEON
+
+WEBP_DSP_INIT_STUB(VP8DspInitNEON)
+
+#endif  // WEBP_USE_NEON