Added high bitdepth sse2 transform functions

Also removes some spurious changes in common/vp9_blockd.h which
was introduced by a rebase issue between nextgen and master branches.

Change-Id: If359f0e9a71bca9c2ba685a87a355873536bb282
(cherry picked from commit 005d80cd05269a299cd2f7ddbc3d4d8b791aebba)
(cherry picked from commit 08d2f548007fd8d6fd41da8ef7fdb488b6485af3)
(cherry picked from commit 4230c2306c194c058f56433a5275aa02a2e71d56)
diff --git a/vp9/encoder/x86/vp9_dct_impl_sse2.c b/vp9/encoder/x86/vp9_dct_impl_sse2.c
new file mode 100644
index 0000000..3fdde83
--- /dev/null
+++ b/vp9/encoder/x86/vp9_dct_impl_sse2.c
@@ -0,0 +1,1011 @@
+/*
+ *  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 <emmintrin.h>  // SSE2
+#include "vp9/common/vp9_idct.h"  // for cospi constants
+#include "vp9/encoder/vp9_dct.h"
+#include "vp9/encoder/x86/vp9_dct_sse2.h"
+#include "vpx_ports/mem.h"
+
+#if DCT_HIGH_BIT_DEPTH
+#define ADD_EPI16 _mm_adds_epi16
+#define SUB_EPI16 _mm_subs_epi16
+
+#else
+#define ADD_EPI16 _mm_add_epi16
+#define SUB_EPI16 _mm_sub_epi16
+#endif
+
+void FDCT4x4_2D(const int16_t *input, tran_low_t *output, int stride) {
+  // This 2D transform implements 4 vertical 1D transforms followed
+  // by 4 horizontal 1D transforms.  The multiplies and adds are as given
+  // by Chen, Smith and Fralick ('77).  The commands for moving the data
+  // around have been minimized by hand.
+  // For the purposes of the comments, the 16 inputs are referred to at i0
+  // through iF (in raster order), intermediate variables are a0, b0, c0
+  // through f, and correspond to the in-place computations mapped to input
+  // locations.  The outputs, o0 through oF are labeled according to the
+  // output locations.
+
+  // Constants
+  // These are the coefficients used for the multiplies.
+  // In the comments, pN means cos(N pi /64) and mN is -cos(N pi /64),
+  // where cospi_N_64 = cos(N pi /64)
+  const __m128i k__cospi_A = _mm_setr_epi16(cospi_16_64, cospi_16_64,
+                                            cospi_16_64, cospi_16_64,
+                                            cospi_16_64, -cospi_16_64,
+                                            cospi_16_64, -cospi_16_64);
+  const __m128i k__cospi_B = _mm_setr_epi16(cospi_16_64, -cospi_16_64,
+                                            cospi_16_64, -cospi_16_64,
+                                            cospi_16_64, cospi_16_64,
+                                            cospi_16_64, cospi_16_64);
+  const __m128i k__cospi_C = _mm_setr_epi16(cospi_8_64, cospi_24_64,
+                                            cospi_8_64, cospi_24_64,
+                                            cospi_24_64, -cospi_8_64,
+                                            cospi_24_64, -cospi_8_64);
+  const __m128i k__cospi_D = _mm_setr_epi16(cospi_24_64, -cospi_8_64,
+                                            cospi_24_64, -cospi_8_64,
+                                            cospi_8_64, cospi_24_64,
+                                            cospi_8_64, cospi_24_64);
+  const __m128i k__cospi_E = _mm_setr_epi16(cospi_16_64, cospi_16_64,
+                                            cospi_16_64, cospi_16_64,
+                                            cospi_16_64, cospi_16_64,
+                                            cospi_16_64, cospi_16_64);
+  const __m128i k__cospi_F = _mm_setr_epi16(cospi_16_64, -cospi_16_64,
+                                            cospi_16_64, -cospi_16_64,
+                                            cospi_16_64, -cospi_16_64,
+                                            cospi_16_64, -cospi_16_64);
+  const __m128i k__cospi_G = _mm_setr_epi16(cospi_8_64, cospi_24_64,
+                                            cospi_8_64, cospi_24_64,
+                                            -cospi_8_64, -cospi_24_64,
+                                            -cospi_8_64, -cospi_24_64);
+  const __m128i k__cospi_H = _mm_setr_epi16(cospi_24_64, -cospi_8_64,
+                                            cospi_24_64, -cospi_8_64,
+                                            -cospi_24_64, cospi_8_64,
+                                            -cospi_24_64, cospi_8_64);
+
+  const __m128i k__DCT_CONST_ROUNDING = _mm_set1_epi32(DCT_CONST_ROUNDING);
+  // This second rounding constant saves doing some extra adds at the end
+  const __m128i k__DCT_CONST_ROUNDING2 = _mm_set1_epi32(DCT_CONST_ROUNDING
+                                               +(DCT_CONST_ROUNDING << 1));
+  const int DCT_CONST_BITS2 =  DCT_CONST_BITS+2;
+  const __m128i k__nonzero_bias_a = _mm_setr_epi16(0, 1, 1, 1, 1, 1, 1, 1);
+  const __m128i k__nonzero_bias_b = _mm_setr_epi16(1, 0, 0, 0, 0, 0, 0, 0);
+  __m128i in0, in1;
+#if DCT_HIGH_BIT_DEPTH
+  __m128i cmp0, cmp1;
+  int test, overflow;
+#endif
+
+  // Load inputs.
+  in0  = _mm_loadl_epi64((const __m128i *)(input +  0 * stride));
+  in1  = _mm_loadl_epi64((const __m128i *)(input +  1 * stride));
+  in1  = _mm_unpacklo_epi64(in1, _mm_loadl_epi64((const __m128i *)
+                                                 (input +  2 * stride)));
+  in0  = _mm_unpacklo_epi64(in0, _mm_loadl_epi64((const __m128i *)
+                                                 (input +  3 * stride)));
+  // in0 = [i0 i1 i2 i3 iC iD iE iF]
+  // in1 = [i4 i5 i6 i7 i8 i9 iA iB]
+#if DCT_HIGH_BIT_DEPTH
+  // Check inputs small enough to use optimised code
+  cmp0 = _mm_xor_si128(_mm_cmpgt_epi16(in0, _mm_set1_epi16(0x3ff)),
+                       _mm_cmplt_epi16(in0, _mm_set1_epi16(0xfc00)));
+  cmp1 = _mm_xor_si128(_mm_cmpgt_epi16(in1, _mm_set1_epi16(0x3ff)),
+                       _mm_cmplt_epi16(in1, _mm_set1_epi16(0xfc00)));
+  test = _mm_movemask_epi8(_mm_or_si128(cmp0, cmp1));
+  if (test) {
+    vp9_highbd_fdct4x4_c(input, output, stride);
+    return;
+  }
+#endif  // DCT_HIGH_BIT_DEPTH
+
+  // multiply by 16 to give some extra precision
+  in0 = _mm_slli_epi16(in0, 4);
+  in1 = _mm_slli_epi16(in1, 4);
+  // if (i == 0 && input[0]) input[0] += 1;
+  // add 1 to the upper left pixel if it is non-zero, which helps reduce
+  // the round-trip error
+  {
+    // The mask will only contain whether the first value is zero, all
+    // other comparison will fail as something shifted by 4 (above << 4)
+    // can never be equal to one. To increment in the non-zero case, we
+    // add the mask and one for the first element:
+    //   - if zero, mask = -1, v = v - 1 + 1 = v
+    //   - if non-zero, mask = 0, v = v + 0 + 1 = v + 1
+    __m128i mask = _mm_cmpeq_epi16(in0, k__nonzero_bias_a);
+    in0 = _mm_add_epi16(in0, mask);
+    in0 = _mm_add_epi16(in0, k__nonzero_bias_b);
+  }
+  // There are 4 total stages, alternating between an add/subtract stage
+  // followed by an multiply-and-add stage.
+  {
+    // Stage 1: Add/subtract
+
+    // in0 = [i0 i1 i2 i3 iC iD iE iF]
+    // in1 = [i4 i5 i6 i7 i8 i9 iA iB]
+    const __m128i r0 = _mm_unpacklo_epi16(in0, in1);
+    const __m128i r1 = _mm_unpackhi_epi16(in0, in1);
+    // r0 = [i0 i4 i1 i5 i2 i6 i3 i7]
+    // r1 = [iC i8 iD i9 iE iA iF iB]
+    const __m128i r2 = _mm_shuffle_epi32(r0, 0xB4);
+    const __m128i r3 = _mm_shuffle_epi32(r1, 0xB4);
+    // r2 = [i0 i4 i1 i5 i3 i7 i2 i6]
+    // r3 = [iC i8 iD i9 iF iB iE iA]
+
+    const __m128i t0 = _mm_add_epi16(r2, r3);
+    const __m128i t1 = _mm_sub_epi16(r2, r3);
+    // t0 = [a0 a4 a1 a5 a3 a7 a2 a6]
+    // t1 = [aC a8 aD a9 aF aB aE aA]
+
+    // Stage 2: multiply by constants (which gets us into 32 bits).
+    // The constants needed here are:
+    // k__cospi_A = [p16 p16 p16 p16 p16 m16 p16 m16]
+    // k__cospi_B = [p16 m16 p16 m16 p16 p16 p16 p16]
+    // k__cospi_C = [p08 p24 p08 p24 p24 m08 p24 m08]
+    // k__cospi_D = [p24 m08 p24 m08 p08 p24 p08 p24]
+    const __m128i u0 = _mm_madd_epi16(t0, k__cospi_A);
+    const __m128i u2 = _mm_madd_epi16(t0, k__cospi_B);
+    const __m128i u1 = _mm_madd_epi16(t1, k__cospi_C);
+    const __m128i u3 = _mm_madd_epi16(t1, k__cospi_D);
+    // Then add and right-shift to get back to 16-bit range
+    const __m128i v0 = _mm_add_epi32(u0, k__DCT_CONST_ROUNDING);
+    const __m128i v1 = _mm_add_epi32(u1, k__DCT_CONST_ROUNDING);
+    const __m128i v2 = _mm_add_epi32(u2, k__DCT_CONST_ROUNDING);
+    const __m128i v3 = _mm_add_epi32(u3, k__DCT_CONST_ROUNDING);
+    const __m128i w0 = _mm_srai_epi32(v0, DCT_CONST_BITS);
+    const __m128i w1 = _mm_srai_epi32(v1, DCT_CONST_BITS);
+    const __m128i w2 = _mm_srai_epi32(v2, DCT_CONST_BITS);
+    const __m128i w3 = _mm_srai_epi32(v3, DCT_CONST_BITS);
+    // w0 = [b0 b1 b7 b6]
+    // w1 = [b8 b9 bF bE]
+    // w2 = [b4 b5 b3 b2]
+    // w3 = [bC bD bB bA]
+    const __m128i x0 = _mm_packs_epi32(w0, w1);
+    const __m128i x1 = _mm_packs_epi32(w2, w3);
+#if DCT_HIGH_BIT_DEPTH
+    overflow = check_epi16_overflow_x2(x0, x1);
+    if (overflow) {
+      vp9_highbd_fdct4x4_c(input, output, stride);
+      return;
+    }
+#endif  // DCT_HIGH_BIT_DEPTH
+    // x0 = [b0 b1 b7 b6 b8 b9 bF bE]
+    // x1 = [b4 b5 b3 b2 bC bD bB bA]
+    in0 = _mm_shuffle_epi32(x0, 0xD8);
+    in1 = _mm_shuffle_epi32(x1, 0x8D);
+    // in0 = [b0 b1 b8 b9 b7 b6 bF bE]
+    // in1 = [b3 b2 bB bA b4 b5 bC bD]
+  }
+  {
+    // vertical DCTs finished. Now we do the horizontal DCTs.
+    // Stage 3: Add/subtract
+
+    const __m128i t0 = ADD_EPI16(in0, in1);
+    const __m128i t1 = SUB_EPI16(in0, in1);
+    // t0 = [c0 c1 c8 c9  c4  c5  cC  cD]
+    // t1 = [c3 c2 cB cA -c7 -c6 -cF -cE]
+#if DCT_HIGH_BIT_DEPTH
+    overflow = check_epi16_overflow_x2(t0, t1);
+    if (overflow) {
+      vp9_highbd_fdct4x4_c(input, output, stride);
+      return;
+    }
+#endif  // DCT_HIGH_BIT_DEPTH
+
+    // Stage 4: multiply by constants (which gets us into 32 bits).
+    {
+      // The constants needed here are:
+      // k__cospi_E = [p16 p16 p16 p16 p16 p16 p16 p16]
+      // k__cospi_F = [p16 m16 p16 m16 p16 m16 p16 m16]
+      // k__cospi_G = [p08 p24 p08 p24 m08 m24 m08 m24]
+      // k__cospi_H = [p24 m08 p24 m08 m24 p08 m24 p08]
+      const __m128i u0 = _mm_madd_epi16(t0, k__cospi_E);
+      const __m128i u1 = _mm_madd_epi16(t0, k__cospi_F);
+      const __m128i u2 = _mm_madd_epi16(t1, k__cospi_G);
+      const __m128i u3 = _mm_madd_epi16(t1, k__cospi_H);
+      // Then add and right-shift to get back to 16-bit range
+      // but this combines the final right-shift as well to save operations
+      // This unusual rounding operations is to maintain bit-accurate
+      // compatibility with the c version of this function which has two
+      // rounding steps in a row.
+      const __m128i v0 = _mm_add_epi32(u0, k__DCT_CONST_ROUNDING2);
+      const __m128i v1 = _mm_add_epi32(u1, k__DCT_CONST_ROUNDING2);
+      const __m128i v2 = _mm_add_epi32(u2, k__DCT_CONST_ROUNDING2);
+      const __m128i v3 = _mm_add_epi32(u3, k__DCT_CONST_ROUNDING2);
+      const __m128i w0 = _mm_srai_epi32(v0, DCT_CONST_BITS2);
+      const __m128i w1 = _mm_srai_epi32(v1, DCT_CONST_BITS2);
+      const __m128i w2 = _mm_srai_epi32(v2, DCT_CONST_BITS2);
+      const __m128i w3 = _mm_srai_epi32(v3, DCT_CONST_BITS2);
+      // w0 = [o0 o4 o8 oC]
+      // w1 = [o2 o6 oA oE]
+      // w2 = [o1 o5 o9 oD]
+      // w3 = [o3 o7 oB oF]
+      // remember the o's are numbered according to the correct output location
+      const __m128i x0 = _mm_packs_epi32(w0, w1);
+      const __m128i x1 = _mm_packs_epi32(w2, w3);
+#if DCT_HIGH_BIT_DEPTH
+      overflow = check_epi16_overflow_x2(x0, x1);
+      if (overflow) {
+        vp9_highbd_fdct4x4_c(input, output, stride);
+        return;
+      }
+#endif  // DCT_HIGH_BIT_DEPTH
+      {
+        // x0 = [o0 o4 o8 oC o2 o6 oA oE]
+        // x1 = [o1 o5 o9 oD o3 o7 oB oF]
+        const __m128i y0 = _mm_unpacklo_epi16(x0, x1);
+        const __m128i y1 = _mm_unpackhi_epi16(x0, x1);
+        // y0 = [o0 o1 o4 o5 o8 o9 oC oD]
+        // y1 = [o2 o3 o6 o7 oA oB oE oF]
+        in0 = _mm_unpacklo_epi32(y0, y1);
+        // in0 = [o0 o1 o2 o3 o4 o5 o6 o7]
+        in1 = _mm_unpackhi_epi32(y0, y1);
+        // in1 = [o8 o9 oA oB oC oD oE oF]
+      }
+    }
+  }
+  // Post-condition (v + 1) >> 2 is now incorporated into previous
+  // add and right-shift commands.  Only 2 store instructions needed
+  // because we are using the fact that 1/3 are stored just after 0/2.
+  storeu_output(in0, output + 0 * 4);
+  storeu_output(in1, output + 2 * 4);
+}
+
+
+void FDCT8x8_2D(const int16_t *input, tran_low_t *output, int stride) {
+  int pass;
+  // Constants
+  //    When we use them, in one case, they are all the same. In all others
+  //    it's a pair of them that we need to repeat four times. This is done
+  //    by constructing the 32 bit constant corresponding to that pair.
+  const __m128i k__cospi_p16_p16 = _mm_set1_epi16(cospi_16_64);
+  const __m128i k__cospi_p16_m16 = pair_set_epi16(cospi_16_64, -cospi_16_64);
+  const __m128i k__cospi_p24_p08 = pair_set_epi16(cospi_24_64, cospi_8_64);
+  const __m128i k__cospi_m08_p24 = pair_set_epi16(-cospi_8_64, cospi_24_64);
+  const __m128i k__cospi_p28_p04 = pair_set_epi16(cospi_28_64, cospi_4_64);
+  const __m128i k__cospi_m04_p28 = pair_set_epi16(-cospi_4_64, cospi_28_64);
+  const __m128i k__cospi_p12_p20 = pair_set_epi16(cospi_12_64, cospi_20_64);
+  const __m128i k__cospi_m20_p12 = pair_set_epi16(-cospi_20_64, cospi_12_64);
+  const __m128i k__DCT_CONST_ROUNDING = _mm_set1_epi32(DCT_CONST_ROUNDING);
+#if DCT_HIGH_BIT_DEPTH
+  int overflow;
+#endif
+  // Load input
+  __m128i in0  = _mm_load_si128((const __m128i *)(input + 0 * stride));
+  __m128i in1  = _mm_load_si128((const __m128i *)(input + 1 * stride));
+  __m128i in2  = _mm_load_si128((const __m128i *)(input + 2 * stride));
+  __m128i in3  = _mm_load_si128((const __m128i *)(input + 3 * stride));
+  __m128i in4  = _mm_load_si128((const __m128i *)(input + 4 * stride));
+  __m128i in5  = _mm_load_si128((const __m128i *)(input + 5 * stride));
+  __m128i in6  = _mm_load_si128((const __m128i *)(input + 6 * stride));
+  __m128i in7  = _mm_load_si128((const __m128i *)(input + 7 * stride));
+  // Pre-condition input (shift by two)
+  in0 = _mm_slli_epi16(in0, 2);
+  in1 = _mm_slli_epi16(in1, 2);
+  in2 = _mm_slli_epi16(in2, 2);
+  in3 = _mm_slli_epi16(in3, 2);
+  in4 = _mm_slli_epi16(in4, 2);
+  in5 = _mm_slli_epi16(in5, 2);
+  in6 = _mm_slli_epi16(in6, 2);
+  in7 = _mm_slli_epi16(in7, 2);
+
+  // We do two passes, first the columns, then the rows. The results of the
+  // first pass are transposed so that the same column code can be reused. The
+  // results of the second pass are also transposed so that the rows (processed
+  // as columns) are put back in row positions.
+  for (pass = 0; pass < 2; pass++) {
+    // To store results of each pass before the transpose.
+    __m128i res0, res1, res2, res3, res4, res5, res6, res7;
+    // Add/subtract
+    const __m128i q0 = ADD_EPI16(in0, in7);
+    const __m128i q1 = ADD_EPI16(in1, in6);
+    const __m128i q2 = ADD_EPI16(in2, in5);
+    const __m128i q3 = ADD_EPI16(in3, in4);
+    const __m128i q4 = SUB_EPI16(in3, in4);
+    const __m128i q5 = SUB_EPI16(in2, in5);
+    const __m128i q6 = SUB_EPI16(in1, in6);
+    const __m128i q7 = SUB_EPI16(in0, in7);
+#if DCT_HIGH_BIT_DEPTH
+    if (pass == 1) {
+      overflow = check_epi16_overflow_x8(q0, q1, q2, q3, q4, q5, q6, q7);
+      if (overflow) {
+        vp9_highbd_fdct8x8_c(input, output, stride);
+        return;
+      }
+    }
+#endif  // DCT_HIGH_BIT_DEPTH
+    // Work on first four results
+    {
+      // Add/subtract
+      const __m128i r0 = ADD_EPI16(q0, q3);
+      const __m128i r1 = ADD_EPI16(q1, q2);
+      const __m128i r2 = SUB_EPI16(q1, q2);
+      const __m128i r3 = SUB_EPI16(q0, q3);
+#if DCT_HIGH_BIT_DEPTH
+      overflow = check_epi16_overflow_x4(r0, r1, r2, r3);
+      if (overflow) {
+        vp9_highbd_fdct8x8_c(input, output, stride);
+        return;
+      }
+#endif  // DCT_HIGH_BIT_DEPTH
+      // Interleave to do the multiply by constants which gets us into 32bits
+      {
+        const __m128i t0 = _mm_unpacklo_epi16(r0, r1);
+        const __m128i t1 = _mm_unpackhi_epi16(r0, r1);
+        const __m128i t2 = _mm_unpacklo_epi16(r2, r3);
+        const __m128i t3 = _mm_unpackhi_epi16(r2, r3);
+        const __m128i u0 = _mm_madd_epi16(t0, k__cospi_p16_p16);
+        const __m128i u1 = _mm_madd_epi16(t1, k__cospi_p16_p16);
+        const __m128i u2 = _mm_madd_epi16(t0, k__cospi_p16_m16);
+        const __m128i u3 = _mm_madd_epi16(t1, k__cospi_p16_m16);
+        const __m128i u4 = _mm_madd_epi16(t2, k__cospi_p24_p08);
+        const __m128i u5 = _mm_madd_epi16(t3, k__cospi_p24_p08);
+        const __m128i u6 = _mm_madd_epi16(t2, k__cospi_m08_p24);
+        const __m128i u7 = _mm_madd_epi16(t3, k__cospi_m08_p24);
+        // dct_const_round_shift
+        const __m128i v0 = _mm_add_epi32(u0, k__DCT_CONST_ROUNDING);
+        const __m128i v1 = _mm_add_epi32(u1, k__DCT_CONST_ROUNDING);
+        const __m128i v2 = _mm_add_epi32(u2, k__DCT_CONST_ROUNDING);
+        const __m128i v3 = _mm_add_epi32(u3, k__DCT_CONST_ROUNDING);
+        const __m128i v4 = _mm_add_epi32(u4, k__DCT_CONST_ROUNDING);
+        const __m128i v5 = _mm_add_epi32(u5, k__DCT_CONST_ROUNDING);
+        const __m128i v6 = _mm_add_epi32(u6, k__DCT_CONST_ROUNDING);
+        const __m128i v7 = _mm_add_epi32(u7, k__DCT_CONST_ROUNDING);
+        const __m128i w0 = _mm_srai_epi32(v0, DCT_CONST_BITS);
+        const __m128i w1 = _mm_srai_epi32(v1, DCT_CONST_BITS);
+        const __m128i w2 = _mm_srai_epi32(v2, DCT_CONST_BITS);
+        const __m128i w3 = _mm_srai_epi32(v3, DCT_CONST_BITS);
+        const __m128i w4 = _mm_srai_epi32(v4, DCT_CONST_BITS);
+        const __m128i w5 = _mm_srai_epi32(v5, DCT_CONST_BITS);
+        const __m128i w6 = _mm_srai_epi32(v6, DCT_CONST_BITS);
+        const __m128i w7 = _mm_srai_epi32(v7, DCT_CONST_BITS);
+        // Combine
+        res0 = _mm_packs_epi32(w0, w1);
+        res4 = _mm_packs_epi32(w2, w3);
+        res2 = _mm_packs_epi32(w4, w5);
+        res6 = _mm_packs_epi32(w6, w7);
+#if DCT_HIGH_BIT_DEPTH
+        overflow = check_epi16_overflow_x4(res0, res4, res2, res6);
+        if (overflow) {
+          vp9_highbd_fdct8x8_c(input, output, stride);
+          return;
+        }
+#endif  // DCT_HIGH_BIT_DEPTH
+      }
+    }
+    // Work on next four results
+    {
+      // Interleave to do the multiply by constants which gets us into 32bits
+      const __m128i d0 = _mm_unpacklo_epi16(q6, q5);
+      const __m128i d1 = _mm_unpackhi_epi16(q6, q5);
+      const __m128i e0 = _mm_madd_epi16(d0, k__cospi_p16_m16);
+      const __m128i e1 = _mm_madd_epi16(d1, k__cospi_p16_m16);
+      const __m128i e2 = _mm_madd_epi16(d0, k__cospi_p16_p16);
+      const __m128i e3 = _mm_madd_epi16(d1, k__cospi_p16_p16);
+      // dct_const_round_shift
+      const __m128i f0 = _mm_add_epi32(e0, k__DCT_CONST_ROUNDING);
+      const __m128i f1 = _mm_add_epi32(e1, k__DCT_CONST_ROUNDING);
+      const __m128i f2 = _mm_add_epi32(e2, k__DCT_CONST_ROUNDING);
+      const __m128i f3 = _mm_add_epi32(e3, k__DCT_CONST_ROUNDING);
+      const __m128i s0 = _mm_srai_epi32(f0, DCT_CONST_BITS);
+      const __m128i s1 = _mm_srai_epi32(f1, DCT_CONST_BITS);
+      const __m128i s2 = _mm_srai_epi32(f2, DCT_CONST_BITS);
+      const __m128i s3 = _mm_srai_epi32(f3, DCT_CONST_BITS);
+      // Combine
+      const __m128i r0 = _mm_packs_epi32(s0, s1);
+      const __m128i r1 = _mm_packs_epi32(s2, s3);
+#if DCT_HIGH_BIT_DEPTH
+      overflow = check_epi16_overflow_x2(r0, r1);
+      if (overflow) {
+        vp9_highbd_fdct8x8_c(input, output, stride);
+        return;
+      }
+#endif  // DCT_HIGH_BIT_DEPTH
+      {
+        // Add/subtract
+        const __m128i x0 = ADD_EPI16(q4, r0);
+        const __m128i x1 = SUB_EPI16(q4, r0);
+        const __m128i x2 = SUB_EPI16(q7, r1);
+        const __m128i x3 = ADD_EPI16(q7, r1);
+#if DCT_HIGH_BIT_DEPTH
+        overflow = check_epi16_overflow_x4(x0, x1, x2, x3);
+        if (overflow) {
+          vp9_highbd_fdct8x8_c(input, output, stride);
+          return;
+        }
+#endif  // DCT_HIGH_BIT_DEPTH
+        // Interleave to do the multiply by constants which gets us into 32bits
+        {
+          const __m128i t0 = _mm_unpacklo_epi16(x0, x3);
+          const __m128i t1 = _mm_unpackhi_epi16(x0, x3);
+          const __m128i t2 = _mm_unpacklo_epi16(x1, x2);
+          const __m128i t3 = _mm_unpackhi_epi16(x1, x2);
+          const __m128i u0 = _mm_madd_epi16(t0, k__cospi_p28_p04);
+          const __m128i u1 = _mm_madd_epi16(t1, k__cospi_p28_p04);
+          const __m128i u2 = _mm_madd_epi16(t0, k__cospi_m04_p28);
+          const __m128i u3 = _mm_madd_epi16(t1, k__cospi_m04_p28);
+          const __m128i u4 = _mm_madd_epi16(t2, k__cospi_p12_p20);
+          const __m128i u5 = _mm_madd_epi16(t3, k__cospi_p12_p20);
+          const __m128i u6 = _mm_madd_epi16(t2, k__cospi_m20_p12);
+          const __m128i u7 = _mm_madd_epi16(t3, k__cospi_m20_p12);
+          // dct_const_round_shift
+          const __m128i v0 = _mm_add_epi32(u0, k__DCT_CONST_ROUNDING);
+          const __m128i v1 = _mm_add_epi32(u1, k__DCT_CONST_ROUNDING);
+          const __m128i v2 = _mm_add_epi32(u2, k__DCT_CONST_ROUNDING);
+          const __m128i v3 = _mm_add_epi32(u3, k__DCT_CONST_ROUNDING);
+          const __m128i v4 = _mm_add_epi32(u4, k__DCT_CONST_ROUNDING);
+          const __m128i v5 = _mm_add_epi32(u5, k__DCT_CONST_ROUNDING);
+          const __m128i v6 = _mm_add_epi32(u6, k__DCT_CONST_ROUNDING);
+          const __m128i v7 = _mm_add_epi32(u7, k__DCT_CONST_ROUNDING);
+          const __m128i w0 = _mm_srai_epi32(v0, DCT_CONST_BITS);
+          const __m128i w1 = _mm_srai_epi32(v1, DCT_CONST_BITS);
+          const __m128i w2 = _mm_srai_epi32(v2, DCT_CONST_BITS);
+          const __m128i w3 = _mm_srai_epi32(v3, DCT_CONST_BITS);
+          const __m128i w4 = _mm_srai_epi32(v4, DCT_CONST_BITS);
+          const __m128i w5 = _mm_srai_epi32(v5, DCT_CONST_BITS);
+          const __m128i w6 = _mm_srai_epi32(v6, DCT_CONST_BITS);
+          const __m128i w7 = _mm_srai_epi32(v7, DCT_CONST_BITS);
+          // Combine
+          res1 = _mm_packs_epi32(w0, w1);
+          res7 = _mm_packs_epi32(w2, w3);
+          res5 = _mm_packs_epi32(w4, w5);
+          res3 = _mm_packs_epi32(w6, w7);
+#if DCT_HIGH_BIT_DEPTH
+          overflow = check_epi16_overflow_x4(res1, res7, res5, res3);
+          if (overflow) {
+            vp9_highbd_fdct8x8_c(input, output, stride);
+            return;
+          }
+#endif  // DCT_HIGH_BIT_DEPTH
+        }
+      }
+    }
+    // Transpose the 8x8.
+    {
+      // 00 01 02 03 04 05 06 07
+      // 10 11 12 13 14 15 16 17
+      // 20 21 22 23 24 25 26 27
+      // 30 31 32 33 34 35 36 37
+      // 40 41 42 43 44 45 46 47
+      // 50 51 52 53 54 55 56 57
+      // 60 61 62 63 64 65 66 67
+      // 70 71 72 73 74 75 76 77
+      const __m128i tr0_0 = _mm_unpacklo_epi16(res0, res1);
+      const __m128i tr0_1 = _mm_unpacklo_epi16(res2, res3);
+      const __m128i tr0_2 = _mm_unpackhi_epi16(res0, res1);
+      const __m128i tr0_3 = _mm_unpackhi_epi16(res2, res3);
+      const __m128i tr0_4 = _mm_unpacklo_epi16(res4, res5);
+      const __m128i tr0_5 = _mm_unpacklo_epi16(res6, res7);
+      const __m128i tr0_6 = _mm_unpackhi_epi16(res4, res5);
+      const __m128i tr0_7 = _mm_unpackhi_epi16(res6, res7);
+      // 00 10 01 11 02 12 03 13
+      // 20 30 21 31 22 32 23 33
+      // 04 14 05 15 06 16 07 17
+      // 24 34 25 35 26 36 27 37
+      // 40 50 41 51 42 52 43 53
+      // 60 70 61 71 62 72 63 73
+      // 54 54 55 55 56 56 57 57
+      // 64 74 65 75 66 76 67 77
+      const __m128i tr1_0 = _mm_unpacklo_epi32(tr0_0, tr0_1);
+      const __m128i tr1_1 = _mm_unpacklo_epi32(tr0_2, tr0_3);
+      const __m128i tr1_2 = _mm_unpackhi_epi32(tr0_0, tr0_1);
+      const __m128i tr1_3 = _mm_unpackhi_epi32(tr0_2, tr0_3);
+      const __m128i tr1_4 = _mm_unpacklo_epi32(tr0_4, tr0_5);
+      const __m128i tr1_5 = _mm_unpacklo_epi32(tr0_6, tr0_7);
+      const __m128i tr1_6 = _mm_unpackhi_epi32(tr0_4, tr0_5);
+      const __m128i tr1_7 = _mm_unpackhi_epi32(tr0_6, tr0_7);
+      // 00 10 20 30 01 11 21 31
+      // 40 50 60 70 41 51 61 71
+      // 02 12 22 32 03 13 23 33
+      // 42 52 62 72 43 53 63 73
+      // 04 14 24 34 05 15 21 36
+      // 44 54 64 74 45 55 61 76
+      // 06 16 26 36 07 17 27 37
+      // 46 56 66 76 47 57 67 77
+      in0 = _mm_unpacklo_epi64(tr1_0, tr1_4);
+      in1 = _mm_unpackhi_epi64(tr1_0, tr1_4);
+      in2 = _mm_unpacklo_epi64(tr1_2, tr1_6);
+      in3 = _mm_unpackhi_epi64(tr1_2, tr1_6);
+      in4 = _mm_unpacklo_epi64(tr1_1, tr1_5);
+      in5 = _mm_unpackhi_epi64(tr1_1, tr1_5);
+      in6 = _mm_unpacklo_epi64(tr1_3, tr1_7);
+      in7 = _mm_unpackhi_epi64(tr1_3, tr1_7);
+      // 00 10 20 30 40 50 60 70
+      // 01 11 21 31 41 51 61 71
+      // 02 12 22 32 42 52 62 72
+      // 03 13 23 33 43 53 63 73
+      // 04 14 24 34 44 54 64 74
+      // 05 15 25 35 45 55 65 75
+      // 06 16 26 36 46 56 66 76
+      // 07 17 27 37 47 57 67 77
+    }
+  }
+  // Post-condition output and store it
+  {
+    // Post-condition (division by two)
+    //    division of two 16 bits signed numbers using shifts
+    //    n / 2 = (n - (n >> 15)) >> 1
+    const __m128i sign_in0 = _mm_srai_epi16(in0, 15);
+    const __m128i sign_in1 = _mm_srai_epi16(in1, 15);
+    const __m128i sign_in2 = _mm_srai_epi16(in2, 15);
+    const __m128i sign_in3 = _mm_srai_epi16(in3, 15);
+    const __m128i sign_in4 = _mm_srai_epi16(in4, 15);
+    const __m128i sign_in5 = _mm_srai_epi16(in5, 15);
+    const __m128i sign_in6 = _mm_srai_epi16(in6, 15);
+    const __m128i sign_in7 = _mm_srai_epi16(in7, 15);
+    in0 = _mm_sub_epi16(in0, sign_in0);
+    in1 = _mm_sub_epi16(in1, sign_in1);
+    in2 = _mm_sub_epi16(in2, sign_in2);
+    in3 = _mm_sub_epi16(in3, sign_in3);
+    in4 = _mm_sub_epi16(in4, sign_in4);
+    in5 = _mm_sub_epi16(in5, sign_in5);
+    in6 = _mm_sub_epi16(in6, sign_in6);
+    in7 = _mm_sub_epi16(in7, sign_in7);
+    in0 = _mm_srai_epi16(in0, 1);
+    in1 = _mm_srai_epi16(in1, 1);
+    in2 = _mm_srai_epi16(in2, 1);
+    in3 = _mm_srai_epi16(in3, 1);
+    in4 = _mm_srai_epi16(in4, 1);
+    in5 = _mm_srai_epi16(in5, 1);
+    in6 = _mm_srai_epi16(in6, 1);
+    in7 = _mm_srai_epi16(in7, 1);
+    // store results
+    store_output(in0, (output + 0 * 8));
+    store_output(in1, (output + 1 * 8));
+    store_output(in2, (output + 2 * 8));
+    store_output(in3, (output + 3 * 8));
+    store_output(in4, (output + 4 * 8));
+    store_output(in5, (output + 5 * 8));
+    store_output(in6, (output + 6 * 8));
+    store_output(in7, (output + 7 * 8));
+  }
+}
+
+void FDCT16x16_2D(const int16_t *input, tran_low_t *output, int stride) {
+  // The 2D transform is done with two passes which are actually pretty
+  // similar. In the first one, we transform the columns and transpose
+  // the results. In the second one, we transform the rows. To achieve that,
+  // as the first pass results are transposed, we transpose the columns (that
+  // is the transposed rows) and transpose the results (so that it goes back
+  // in normal/row positions).
+  int pass;
+  // We need an intermediate buffer between passes.
+  DECLARE_ALIGNED_ARRAY(16, int16_t, intermediate, 256);
+  const int16_t *in = input;
+  int16_t *out0 = intermediate;
+  tran_low_t *out1 = output;
+  // Constants
+  //    When we use them, in one case, they are all the same. In all others
+  //    it's a pair of them that we need to repeat four times. This is done
+  //    by constructing the 32 bit constant corresponding to that pair.
+  const __m128i k__cospi_p16_p16 = _mm_set1_epi16(cospi_16_64);
+  const __m128i k__cospi_p16_m16 = pair_set_epi16(cospi_16_64, -cospi_16_64);
+  const __m128i k__cospi_p24_p08 = pair_set_epi16(cospi_24_64, cospi_8_64);
+  const __m128i k__cospi_p08_m24 = pair_set_epi16(cospi_8_64, -cospi_24_64);
+  const __m128i k__cospi_m08_p24 = pair_set_epi16(-cospi_8_64, cospi_24_64);
+  const __m128i k__cospi_p28_p04 = pair_set_epi16(cospi_28_64, cospi_4_64);
+  const __m128i k__cospi_m04_p28 = pair_set_epi16(-cospi_4_64, cospi_28_64);
+  const __m128i k__cospi_p12_p20 = pair_set_epi16(cospi_12_64, cospi_20_64);
+  const __m128i k__cospi_m20_p12 = pair_set_epi16(-cospi_20_64, cospi_12_64);
+  const __m128i k__cospi_p30_p02 = pair_set_epi16(cospi_30_64, cospi_2_64);
+  const __m128i k__cospi_p14_p18 = pair_set_epi16(cospi_14_64, cospi_18_64);
+  const __m128i k__cospi_m02_p30 = pair_set_epi16(-cospi_2_64, cospi_30_64);
+  const __m128i k__cospi_m18_p14 = pair_set_epi16(-cospi_18_64, cospi_14_64);
+  const __m128i k__cospi_p22_p10 = pair_set_epi16(cospi_22_64, cospi_10_64);
+  const __m128i k__cospi_p06_p26 = pair_set_epi16(cospi_6_64, cospi_26_64);
+  const __m128i k__cospi_m10_p22 = pair_set_epi16(-cospi_10_64, cospi_22_64);
+  const __m128i k__cospi_m26_p06 = pair_set_epi16(-cospi_26_64, cospi_6_64);
+  const __m128i k__DCT_CONST_ROUNDING = _mm_set1_epi32(DCT_CONST_ROUNDING);
+  const __m128i kOne = _mm_set1_epi16(1);
+  // Do the two transform/transpose passes
+  for (pass = 0; pass < 2; ++pass) {
+    // We process eight columns (transposed rows in second pass) at a time.
+    int column_start;
+#if DCT_HIGH_BIT_DEPTH
+    int overflow;
+#endif
+    for (column_start = 0; column_start < 16; column_start += 8) {
+      __m128i in00, in01, in02, in03, in04, in05, in06, in07;
+      __m128i in08, in09, in10, in11, in12, in13, in14, in15;
+      __m128i input0, input1, input2, input3, input4, input5, input6, input7;
+      __m128i step1_0, step1_1, step1_2, step1_3;
+      __m128i step1_4, step1_5, step1_6, step1_7;
+      __m128i step2_1, step2_2, step2_3, step2_4, step2_5, step2_6;
+      __m128i step3_0, step3_1, step3_2, step3_3;
+      __m128i step3_4, step3_5, step3_6, step3_7;
+      __m128i res00, res01, res02, res03, res04, res05, res06, res07;
+      __m128i res08, res09, res10, res11, res12, res13, res14, res15;
+      // Load and pre-condition input.
+      if (0 == pass) {
+        in00  = _mm_load_si128((const __m128i *)(in +  0 * stride));
+        in01  = _mm_load_si128((const __m128i *)(in +  1 * stride));
+        in02  = _mm_load_si128((const __m128i *)(in +  2 * stride));
+        in03  = _mm_load_si128((const __m128i *)(in +  3 * stride));
+        in04  = _mm_load_si128((const __m128i *)(in +  4 * stride));
+        in05  = _mm_load_si128((const __m128i *)(in +  5 * stride));
+        in06  = _mm_load_si128((const __m128i *)(in +  6 * stride));
+        in07  = _mm_load_si128((const __m128i *)(in +  7 * stride));
+        in08  = _mm_load_si128((const __m128i *)(in +  8 * stride));
+        in09  = _mm_load_si128((const __m128i *)(in +  9 * stride));
+        in10  = _mm_load_si128((const __m128i *)(in + 10 * stride));
+        in11  = _mm_load_si128((const __m128i *)(in + 11 * stride));
+        in12  = _mm_load_si128((const __m128i *)(in + 12 * stride));
+        in13  = _mm_load_si128((const __m128i *)(in + 13 * stride));
+        in14  = _mm_load_si128((const __m128i *)(in + 14 * stride));
+        in15  = _mm_load_si128((const __m128i *)(in + 15 * stride));
+        // x = x << 2
+        in00 = _mm_slli_epi16(in00, 2);
+        in01 = _mm_slli_epi16(in01, 2);
+        in02 = _mm_slli_epi16(in02, 2);
+        in03 = _mm_slli_epi16(in03, 2);
+        in04 = _mm_slli_epi16(in04, 2);
+        in05 = _mm_slli_epi16(in05, 2);
+        in06 = _mm_slli_epi16(in06, 2);
+        in07 = _mm_slli_epi16(in07, 2);
+        in08 = _mm_slli_epi16(in08, 2);
+        in09 = _mm_slli_epi16(in09, 2);
+        in10 = _mm_slli_epi16(in10, 2);
+        in11 = _mm_slli_epi16(in11, 2);
+        in12 = _mm_slli_epi16(in12, 2);
+        in13 = _mm_slli_epi16(in13, 2);
+        in14 = _mm_slli_epi16(in14, 2);
+        in15 = _mm_slli_epi16(in15, 2);
+      } else {
+        in00  = _mm_load_si128((const __m128i *)(in +  0 * 16));
+        in01  = _mm_load_si128((const __m128i *)(in +  1 * 16));
+        in02  = _mm_load_si128((const __m128i *)(in +  2 * 16));
+        in03  = _mm_load_si128((const __m128i *)(in +  3 * 16));
+        in04  = _mm_load_si128((const __m128i *)(in +  4 * 16));
+        in05  = _mm_load_si128((const __m128i *)(in +  5 * 16));
+        in06  = _mm_load_si128((const __m128i *)(in +  6 * 16));
+        in07  = _mm_load_si128((const __m128i *)(in +  7 * 16));
+        in08  = _mm_load_si128((const __m128i *)(in +  8 * 16));
+        in09  = _mm_load_si128((const __m128i *)(in +  9 * 16));
+        in10  = _mm_load_si128((const __m128i *)(in + 10 * 16));
+        in11  = _mm_load_si128((const __m128i *)(in + 11 * 16));
+        in12  = _mm_load_si128((const __m128i *)(in + 12 * 16));
+        in13  = _mm_load_si128((const __m128i *)(in + 13 * 16));
+        in14  = _mm_load_si128((const __m128i *)(in + 14 * 16));
+        in15  = _mm_load_si128((const __m128i *)(in + 15 * 16));
+        // x = (x + 1) >> 2
+        in00 = _mm_add_epi16(in00, kOne);
+        in01 = _mm_add_epi16(in01, kOne);
+        in02 = _mm_add_epi16(in02, kOne);
+        in03 = _mm_add_epi16(in03, kOne);
+        in04 = _mm_add_epi16(in04, kOne);
+        in05 = _mm_add_epi16(in05, kOne);
+        in06 = _mm_add_epi16(in06, kOne);
+        in07 = _mm_add_epi16(in07, kOne);
+        in08 = _mm_add_epi16(in08, kOne);
+        in09 = _mm_add_epi16(in09, kOne);
+        in10 = _mm_add_epi16(in10, kOne);
+        in11 = _mm_add_epi16(in11, kOne);
+        in12 = _mm_add_epi16(in12, kOne);
+        in13 = _mm_add_epi16(in13, kOne);
+        in14 = _mm_add_epi16(in14, kOne);
+        in15 = _mm_add_epi16(in15, kOne);
+        in00 = _mm_srai_epi16(in00, 2);
+        in01 = _mm_srai_epi16(in01, 2);
+        in02 = _mm_srai_epi16(in02, 2);
+        in03 = _mm_srai_epi16(in03, 2);
+        in04 = _mm_srai_epi16(in04, 2);
+        in05 = _mm_srai_epi16(in05, 2);
+        in06 = _mm_srai_epi16(in06, 2);
+        in07 = _mm_srai_epi16(in07, 2);
+        in08 = _mm_srai_epi16(in08, 2);
+        in09 = _mm_srai_epi16(in09, 2);
+        in10 = _mm_srai_epi16(in10, 2);
+        in11 = _mm_srai_epi16(in11, 2);
+        in12 = _mm_srai_epi16(in12, 2);
+        in13 = _mm_srai_epi16(in13, 2);
+        in14 = _mm_srai_epi16(in14, 2);
+        in15 = _mm_srai_epi16(in15, 2);
+      }
+      in += 8;
+      // Calculate input for the first 8 results.
+      {
+        input0 = ADD_EPI16(in00, in15);
+        input1 = ADD_EPI16(in01, in14);
+        input2 = ADD_EPI16(in02, in13);
+        input3 = ADD_EPI16(in03, in12);
+        input4 = ADD_EPI16(in04, in11);
+        input5 = ADD_EPI16(in05, in10);
+        input6 = ADD_EPI16(in06, in09);
+        input7 = ADD_EPI16(in07, in08);
+#if DCT_HIGH_BIT_DEPTH
+        overflow = check_epi16_overflow_x8(input0, input1, input2, input3,
+                           input4, input5, input6, input7);
+        if (overflow) {
+          vp9_highbd_fdct16x16_c(input, output, stride);
+          return;
+        }
+#endif  // DCT_HIGH_BIT_DEPTH
+      }
+      // Calculate input for the next 8 results.
+      {
+        step1_0 = SUB_EPI16(in07, in08);
+        step1_1 = SUB_EPI16(in06, in09);
+        step1_2 = SUB_EPI16(in05, in10);
+        step1_3 = SUB_EPI16(in04, in11);
+        step1_4 = SUB_EPI16(in03, in12);
+        step1_5 = SUB_EPI16(in02, in13);
+        step1_6 = SUB_EPI16(in01, in14);
+        step1_7 = SUB_EPI16(in00, in15);
+#if DCT_HIGH_BIT_DEPTH
+        overflow = check_epi16_overflow_x8(step1_0, step1_1, step1_2, step1_3,
+                           step1_4, step1_5, step1_6, step1_7);
+        if (overflow) {
+          vp9_highbd_fdct16x16_c(input, output, stride);
+          return;
+        }
+#endif  // DCT_HIGH_BIT_DEPTH
+      }
+      // Work on the first eight values; fdct8(input, even_results);
+      {
+        // Add/subtract
+        const __m128i q0 = ADD_EPI16(input0, input7);
+        const __m128i q1 = ADD_EPI16(input1, input6);
+        const __m128i q2 = ADD_EPI16(input2, input5);
+        const __m128i q3 = ADD_EPI16(input3, input4);
+        const __m128i q4 = SUB_EPI16(input3, input4);
+        const __m128i q5 = SUB_EPI16(input2, input5);
+        const __m128i q6 = SUB_EPI16(input1, input6);
+        const __m128i q7 = SUB_EPI16(input0, input7);
+#if DCT_HIGH_BIT_DEPTH
+        overflow = check_epi16_overflow_x8(q0, q1, q2, q3, q4, q5, q6, q7);
+        if (overflow) {
+          vp9_highbd_fdct16x16_c(input, output, stride);
+          return;
+        }
+#endif  // DCT_HIGH_BIT_DEPTH
+        // Work on first four results
+        {
+          // Add/subtract
+          const __m128i r0 = ADD_EPI16(q0, q3);
+          const __m128i r1 = ADD_EPI16(q1, q2);
+          const __m128i r2 = SUB_EPI16(q1, q2);
+          const __m128i r3 = SUB_EPI16(q0, q3);
+#if DCT_HIGH_BIT_DEPTH
+          overflow = check_epi16_overflow_x4(r0, r1, r2, r3);
+          if (overflow) {
+            vp9_highbd_fdct16x16_c(input, output, stride);
+            return;
+          }
+#endif  // DCT_HIGH_BIT_DEPTH
+          // Interleave to do the multiply by constants which gets us
+          // into 32 bits.
+          {
+            const __m128i t0 = _mm_unpacklo_epi16(r0, r1);
+            const __m128i t1 = _mm_unpackhi_epi16(r0, r1);
+            const __m128i t2 = _mm_unpacklo_epi16(r2, r3);
+            const __m128i t3 = _mm_unpackhi_epi16(r2, r3);
+            res00 = mult_round_shift(t0, t1, k__cospi_p16_p16,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+            res08 = mult_round_shift(t0, t1, k__cospi_p16_m16,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+            res04 = mult_round_shift(t2, t3, k__cospi_p24_p08,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+            res12 = mult_round_shift(t2, t3, k__cospi_m08_p24,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+#if DCT_HIGH_BIT_DEPTH
+            overflow = check_epi16_overflow_x4(res00, res08, res04, res12);
+            if (overflow) {
+              vp9_highbd_fdct16x16_c(input, output, stride);
+              return;
+            }
+#endif  // DCT_HIGH_BIT_DEPTH
+          }
+        }
+        // Work on next four results
+        {
+          // Interleave to do the multiply by constants which gets us
+          // into 32 bits.
+          const __m128i d0 = _mm_unpacklo_epi16(q6, q5);
+          const __m128i d1 = _mm_unpackhi_epi16(q6, q5);
+          const __m128i r0 = mult_round_shift(d0, d1, k__cospi_p16_m16,
+                                k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+          const __m128i r1 = mult_round_shift(d0, d1, k__cospi_p16_p16,
+                                k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+#if DCT_HIGH_BIT_DEPTH
+          overflow = check_epi16_overflow_x2(r0, r1);
+          if (overflow) {
+            vp9_highbd_fdct16x16_c(input, output, stride);
+            return;
+          }
+#endif  // DCT_HIGH_BIT_DEPTH
+          {
+            // Add/subtract
+            const __m128i x0 = ADD_EPI16(q4, r0);
+            const __m128i x1 = SUB_EPI16(q4, r0);
+            const __m128i x2 = SUB_EPI16(q7, r1);
+            const __m128i x3 = ADD_EPI16(q7, r1);
+#if DCT_HIGH_BIT_DEPTH
+            overflow = check_epi16_overflow_x4(x0, x1, x2, x3);
+            if (overflow) {
+              vp9_highbd_fdct16x16_c(input, output, stride);
+              return;
+            }
+#endif  // DCT_HIGH_BIT_DEPTH
+            // Interleave to do the multiply by constants which gets us
+            // into 32 bits.
+            {
+              const __m128i t0 = _mm_unpacklo_epi16(x0, x3);
+              const __m128i t1 = _mm_unpackhi_epi16(x0, x3);
+              const __m128i t2 = _mm_unpacklo_epi16(x1, x2);
+              const __m128i t3 = _mm_unpackhi_epi16(x1, x2);
+              res02 = mult_round_shift(t0, t1, k__cospi_p28_p04,
+                                k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+              res14 = mult_round_shift(t0, t1, k__cospi_m04_p28,
+                                k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+              res10 = mult_round_shift(t2, t3, k__cospi_p12_p20,
+                                k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+              res06 = mult_round_shift(t2, t3, k__cospi_m20_p12,
+                                k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+#if DCT_HIGH_BIT_DEPTH
+              overflow = check_epi16_overflow_x4(res02, res14, res10, res06);
+              if (overflow) {
+                vp9_highbd_fdct16x16_c(input, output, stride);
+                return;
+              }
+#endif  // DCT_HIGH_BIT_DEPTH
+            }
+          }
+        }
+      }
+      // Work on the next eight values; step1 -> odd_results
+      {
+        // step 2
+        {
+          const __m128i t0 = _mm_unpacklo_epi16(step1_5, step1_2);
+          const __m128i t1 = _mm_unpackhi_epi16(step1_5, step1_2);
+          const __m128i t2 = _mm_unpacklo_epi16(step1_4, step1_3);
+          const __m128i t3 = _mm_unpackhi_epi16(step1_4, step1_3);
+          step2_2 = mult_round_shift(t0, t1, k__cospi_p16_m16,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+          step2_3 = mult_round_shift(t2, t3, k__cospi_p16_m16,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+          step2_5 = mult_round_shift(t0, t1, k__cospi_p16_p16,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+          step2_4 = mult_round_shift(t2, t3, k__cospi_p16_p16,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+#if DCT_HIGH_BIT_DEPTH
+          overflow = check_epi16_overflow_x4(step2_2, step2_3, step2_5,
+                                             step2_4);
+          if (overflow) {
+            vp9_highbd_fdct16x16_c(input, output, stride);
+            return;
+          }
+#endif  // DCT_HIGH_BIT_DEPTH
+        }
+        // step 3
+        {
+          step3_0 = ADD_EPI16(step1_0, step2_3);
+          step3_1 = ADD_EPI16(step1_1, step2_2);
+          step3_2 = SUB_EPI16(step1_1, step2_2);
+          step3_3 = SUB_EPI16(step1_0, step2_3);
+          step3_4 = SUB_EPI16(step1_7, step2_4);
+          step3_5 = SUB_EPI16(step1_6, step2_5);
+          step3_6 = ADD_EPI16(step1_6, step2_5);
+          step3_7 = ADD_EPI16(step1_7, step2_4);
+#if DCT_HIGH_BIT_DEPTH
+          overflow = check_epi16_overflow_x8(step3_0, step3_1, step3_2, step3_3,
+                             step3_4, step3_5, step3_6, step3_7);
+          if (overflow) {
+            vp9_highbd_fdct16x16_c(input, output, stride);
+            return;
+          }
+#endif  // DCT_HIGH_BIT_DEPTH
+        }
+        // step 4
+        {
+          const __m128i t0 = _mm_unpacklo_epi16(step3_1, step3_6);
+          const __m128i t1 = _mm_unpackhi_epi16(step3_1, step3_6);
+          const __m128i t2 = _mm_unpacklo_epi16(step3_2, step3_5);
+          const __m128i t3 = _mm_unpackhi_epi16(step3_2, step3_5);
+          step2_1 = mult_round_shift(t0, t1, k__cospi_m08_p24,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+          step2_2 = mult_round_shift(t2, t3, k__cospi_p24_p08,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+          step2_6 = mult_round_shift(t0, t1, k__cospi_p24_p08,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+          step2_5 = mult_round_shift(t2, t3, k__cospi_p08_m24,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+#if DCT_HIGH_BIT_DEPTH
+          overflow = check_epi16_overflow_x4(step2_1, step2_2, step2_6,
+                                             step2_5);
+          if (overflow) {
+            vp9_highbd_fdct16x16_c(input, output, stride);
+            return;
+          }
+#endif  // DCT_HIGH_BIT_DEPTH
+        }
+        // step 5
+        {
+          step1_0 = ADD_EPI16(step3_0, step2_1);
+          step1_1 = SUB_EPI16(step3_0, step2_1);
+          step1_2 = ADD_EPI16(step3_3, step2_2);
+          step1_3 = SUB_EPI16(step3_3, step2_2);
+          step1_4 = SUB_EPI16(step3_4, step2_5);
+          step1_5 = ADD_EPI16(step3_4, step2_5);
+          step1_6 = SUB_EPI16(step3_7, step2_6);
+          step1_7 = ADD_EPI16(step3_7, step2_6);
+#if DCT_HIGH_BIT_DEPTH
+          overflow = check_epi16_overflow_x8(step1_0, step1_1, step1_2, step1_3,
+                             step1_4, step1_5, step1_6, step1_7);
+          if (overflow) {
+            vp9_highbd_fdct16x16_c(input, output, stride);
+            return;
+          }
+#endif  // DCT_HIGH_BIT_DEPTH
+        }
+        // step 6
+        {
+          const __m128i t0 = _mm_unpacklo_epi16(step1_0, step1_7);
+          const __m128i t1 = _mm_unpackhi_epi16(step1_0, step1_7);
+          const __m128i t2 = _mm_unpacklo_epi16(step1_1, step1_6);
+          const __m128i t3 = _mm_unpackhi_epi16(step1_1, step1_6);
+          res01 = mult_round_shift(t0, t1, k__cospi_p30_p02,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+          res09 = mult_round_shift(t2, t3, k__cospi_p14_p18,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+          res15 = mult_round_shift(t0, t1, k__cospi_m02_p30,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+          res07 = mult_round_shift(t2, t3, k__cospi_m18_p14,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+#if DCT_HIGH_BIT_DEPTH
+          overflow = check_epi16_overflow_x4(res01, res09, res15, res07);
+          if (overflow) {
+            vp9_highbd_fdct16x16_c(input, output, stride);
+            return;
+          }
+#endif  // DCT_HIGH_BIT_DEPTH
+        }
+        {
+          const __m128i t0 = _mm_unpacklo_epi16(step1_2, step1_5);
+          const __m128i t1 = _mm_unpackhi_epi16(step1_2, step1_5);
+          const __m128i t2 = _mm_unpacklo_epi16(step1_3, step1_4);
+          const __m128i t3 = _mm_unpackhi_epi16(step1_3, step1_4);
+          res05 = mult_round_shift(t0, t1, k__cospi_p22_p10,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+          res13 = mult_round_shift(t2, t3, k__cospi_p06_p26,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+          res11 = mult_round_shift(t0, t1, k__cospi_m10_p22,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+          res03 = mult_round_shift(t2, t3, k__cospi_m26_p06,
+                                     k__DCT_CONST_ROUNDING, DCT_CONST_BITS);
+#if DCT_HIGH_BIT_DEPTH
+          overflow = check_epi16_overflow_x4(res05, res13, res11, res03);
+          if (overflow) {
+            vp9_highbd_fdct16x16_c(input, output, stride);
+            return;
+          }
+#endif  // DCT_HIGH_BIT_DEPTH
+        }
+      }
+      // Transpose the results, do it as two 8x8 transposes.
+      transpose_and_output8x8(res00, res01, res02, res03,
+                              res04, res05, res06, res07,
+                              pass, out0, out1);
+      transpose_and_output8x8(res08, res09, res10, res11,
+                              res12, res13, res14, res15,
+                              pass, out0 + 8, out1 + 8);
+      if (pass == 0) {
+        out0 += 8*16;
+      } else {
+        out1 += 8*16;
+      }
+    }
+    // Setup in/out for next pass.
+    in = intermediate;
+  }
+}
+
+#undef ADD_EPI16
+#undef SUB_EPI16