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 /*

  * Copyright 2012 The Android Open Source Project

  *

  * Use of this source code is governed by a BSD-style license that can be

  * found in the LICENSE file.

  */

 #include "SkBitmapProcState_opts_SSSE3.h"

 #include "SkPaint.h"

 #include "SkUtils.h"

 /* With the exception of the Android framework we always build the SSSE3 functions

  * and enable the caller to determine SSSE3 support.  However for the Android framework

  * if the device does not support SSSE3 then the compiler will not supply the required

  * -mssse3 option needed to build this file, so instead we provide a stub implementation.

  */

 #if !defined(SK_BUILD_FOR_ANDROID_FRAMEWORK) || SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSSE3

 #include <tmmintrin.h>  // SSSE3

 // adding anonymous namespace seemed to force gcc to inline directly the

 // instantiation, instead of creating the functions

 // S32_generic_D32_filter_DX_SSSE3<true> and

 // S32_generic_D32_filter_DX_SSSE3<false> which were then called by the

 // external functions.

 namespace {

 // In this file, variations for alpha and non alpha versions are implemented

 // with a template, as it makes the code more compact and a bit easier to

 // maintain, while making the compiler generate the same exact code as with

 // two functions that only differ by a few lines.

 // Prepare all necessary constants for a round of processing for two pixel

 // pairs.

 // @param xy is the location where the xy parameters for four pixels should be

 //           read from. It is identical in concept with argument two of

 //           S32_{opaque}_D32_filter_DX methods.

 // @param mask_3FFF vector of 32 bit constants containing 3FFF,

 //                  suitable to mask the bottom 14 bits of a XY value.

 // @param mask_000F vector of 32 bit constants containing 000F,

 //                  suitable to mask the bottom 4 bits of a XY value.

 // @param sixteen_8bit vector of 8 bit components containing the value 16.

 // @param mask_dist_select vector of 8 bit components containing the shuffling

 //                         parameters to reorder x[0-3] parameters.

 // @param all_x_result vector of 8 bit components that will contain the

 //              (4x(x3), 4x(x2), 4x(x1), 4x(x0)) upon return.

 // @param sixteen_minus_x vector of 8 bit components, containing

 //              (4x(16 - x3), 4x(16 - x2), 4x(16 - x1), 4x(16 - x0))

 inline void PrepareConstantsTwoPixelPairs(const uint32_t* xy,

                                           const __m128i& mask_3FFF,

                                           const __m128i& mask_000F,

                                           const __m128i& sixteen_8bit,

                                           const __m128i& mask_dist_select,

                                           __m128i* all_x_result,

                                           __m128i* sixteen_minus_x,

                                           int* x0,

                                           int* x1) {

     const __m128i xx = _mm_loadu_si128(reinterpret_cast<const __m128i *>(xy));

     // 4 delta X

     // (x03, x02, x01, x00)

     const __m128i x0_wide = _mm_srli_epi32(xx, 18);

     // (x13, x12, x11, x10)

     const __m128i x1_wide = _mm_and_si128(xx, mask_3FFF);

     _mm_storeu_si128(reinterpret_cast<__m128i *>(x0), x0_wide);

     _mm_storeu_si128(reinterpret_cast<__m128i *>(x1), x1_wide);

     __m128i all_x = _mm_and_si128(_mm_srli_epi32(xx, 14), mask_000F);

     // (4x(x3), 4x(x2), 4x(x1), 4x(x0))

     all_x = _mm_shuffle_epi8(all_x, mask_dist_select);

     *all_x_result = all_x;

     // (4x(16-x3), 4x(16-x2), 4x(16-x1), 4x(16-x0))

     *sixteen_minus_x = _mm_sub_epi8(sixteen_8bit, all_x);

 }

 // Prepare all necessary constants for a round of processing for two pixel

 // pairs.

 // @param xy is the location where the xy parameters for four pixels should be

 //           read from. It is identical in concept with argument two of

 //           S32_{opaque}_D32_filter_DXDY methods.

 // @param mask_3FFF vector of 32 bit constants containing 3FFF,

 //                  suitable to mask the bottom 14 bits of a XY value.

 // @param mask_000F vector of 32 bit constants containing 000F,

 //                  suitable to mask the bottom 4 bits of a XY value.

 // @param sixteen_8bit vector of 8 bit components containing the value 16.

 // @param mask_dist_select vector of 8 bit components containing the shuffling

 //                         parameters to reorder x[0-3] parameters.

 // @param all_xy_result vector of 8 bit components that will contain the

 //              (4x(y1), 4x(y0), 4x(x1), 4x(x0)) upon return.

 // @param sixteen_minus_x vector of 8 bit components, containing

 //              (4x(16-y1), 4x(16-y0), 4x(16-x1), 4x(16-x0)).

 inline void PrepareConstantsTwoPixelPairsDXDY(const uint32_t* xy,

                                               const __m128i& mask_3FFF,

                                               const __m128i& mask_000F,

                                               const __m128i& sixteen_8bit,

                                               const __m128i& mask_dist_select,

                                               __m128i* all_xy_result,

                                               __m128i* sixteen_minus_xy,

                                               int* xy0, int* xy1) {

     const __m128i xy_wide =

                         _mm_loadu_si128(reinterpret_cast<const __m128i *>(xy));

     // (x10, y10, x00, y00)

     __m128i xy0_wide = _mm_srli_epi32(xy_wide, 18);

     // (y10, y00, x10, x00)

     xy0_wide =  _mm_shuffle_epi32(xy0_wide, _MM_SHUFFLE(2, 0, 3, 1));

     // (x11, y11, x01, y01)

     __m128i xy1_wide = _mm_and_si128(xy_wide, mask_3FFF);

     // (y11, y01, x11, x01)

     xy1_wide = _mm_shuffle_epi32(xy1_wide, _MM_SHUFFLE(2, 0, 3, 1));

     _mm_storeu_si128(reinterpret_cast<__m128i *>(xy0), xy0_wide);

     _mm_storeu_si128(reinterpret_cast<__m128i *>(xy1), xy1_wide);

     // (x1, y1, x0, y0)

     __m128i all_xy = _mm_and_si128(_mm_srli_epi32(xy_wide, 14), mask_000F);

     // (y1, y0, x1, x0)

     all_xy = _mm_shuffle_epi32(all_xy, _MM_SHUFFLE(2, 0, 3, 1));

     // (4x(y1), 4x(y0), 4x(x1), 4x(x0))

     all_xy = _mm_shuffle_epi8(all_xy, mask_dist_select);

     *all_xy_result = all_xy;

     // (4x(16-y1), 4x(16-y0), 4x(16-x1), 4x(16-x0))

     *sixteen_minus_xy = _mm_sub_epi8(sixteen_8bit, all_xy);

 }

 // Helper function used when processing one pixel pair.

 // @param pixel0..3 are the four input pixels

 // @param scale_x vector of 8 bit components to multiply the pixel[0:3]. This

 //                will contain (4x(x1, 16-x1), 4x(x0, 16-x0))

 //                or (4x(x3, 16-x3), 4x(x2, 16-x2))

 // @return a vector of 16 bit components containing:

 // (Aa2 * (16 - x1) + Aa3 * x1, ... , Ra0 * (16 - x0) + Ra1 * x0)

 inline __m128i ProcessPixelPairHelper(uint32_t pixel0,

                                       uint32_t pixel1,

                                       uint32_t pixel2,

                                       uint32_t pixel3,

                                       const __m128i& scale_x) {

     __m128i a0, a1, a2, a3;

     // Load 2 pairs of pixels

     a0 = _mm_cvtsi32_si128(pixel0);

     a1 = _mm_cvtsi32_si128(pixel1);

     // Interleave pixels.

     // (0, 0, 0, 0, 0, 0, 0, 0, Aa1, Aa0, Ba1, Ba0, Ga1, Ga0, Ra1, Ra0)

     a0 = _mm_unpacklo_epi8(a0, a1);

     a2 = _mm_cvtsi32_si128(pixel2);

     a3 = _mm_cvtsi32_si128(pixel3);

     // (0, 0, 0, 0, 0, 0, 0, 0, Aa3, Aa2, Ba3, Ba2, Ga3, Ga2, Ra3, Ra2)

     a2 = _mm_unpacklo_epi8(a2, a3);

     // two pairs of pixel pairs, interleaved.

     // (Aa3, Aa2, Ba3, Ba2, Ga3, Ga2, Ra3, Ra2,

     //  Aa1, Aa0, Ba1, Ba0, Ga1, Ga0, Ra1, Ra0)

     a0 = _mm_unpacklo_epi64(a0, a2);

     // multiply and sum to 16 bit components.

     // (Aa2 * (16 - x1) + Aa3 * x1, ... , Ra0 * (16 - x0) + Ra1 * x0)

     // At that point, we use up a bit less than 12 bits for each 16 bit

     // component:

     // All components are less than 255. So,

     // C0 * (16 - x) + C1 * x <= 255 * (16 - x) + 255 * x = 255 * 16.

     return _mm_maddubs_epi16(a0, scale_x);

 }

 // Scale back the results after multiplications to the [0:255] range, and scale

 // by alpha when has_alpha is true.

 // Depending on whether one set or two sets of multiplications had been applied,

 // the results have to be shifted by four places (dividing by 16), or shifted

 // by eight places (dividing by 256), since each multiplication is by a quantity

 // in the range [0:16].

 template<bool has_alpha, int scale>

 inline __m128i ScaleFourPixels(__m128i* pixels,

                                const __m128i& alpha) {

     // Divide each 16 bit component by 16 (or 256 depending on scale).

     *pixels = _mm_srli_epi16(*pixels, scale);

     if (has_alpha) {

         // Multiply by alpha.

         *pixels = _mm_mullo_epi16(*pixels, alpha);

         // Divide each 16 bit component by 256.

         *pixels = _mm_srli_epi16(*pixels, 8);

     }

     return *pixels;

 }

 // Wrapper to calculate two output pixels from four input pixels. The

 // arguments are the same as ProcessPixelPairHelper. Technically, there are

 // eight input pixels, but since sub_y == 0, the factors applied to half of the

 // pixels is zero (sub_y), and are therefore omitted here to save on some

 // processing.

 // @param alpha when has_alpha is true, scale all resulting components by this

 //              value.

 // @return a vector of 16 bit components containing:

 // ((Aa2 * (16 - x1) + Aa3 * x1) * alpha, ...,

 // (Ra0 * (16 - x0) + Ra1 * x0) * alpha) (when has_alpha is true)

 // otherwise

 // (Aa2 * (16 - x1) + Aa3 * x1, ... , Ra0 * (16 - x0) + Ra1 * x0)

 // In both cases, the results are renormalized (divided by 16) to match the

 // expected formats when storing back the results into memory.

 template<bool has_alpha>

 inline __m128i ProcessPixelPairZeroSubY(uint32_t pixel0,

                                         uint32_t pixel1,

                                         uint32_t pixel2,

                                         uint32_t pixel3,

                                         const __m128i& scale_x,

                                         const __m128i& alpha) {

     __m128i sum = ProcessPixelPairHelper(pixel0, pixel1, pixel2, pixel3,

                                          scale_x);

     return ScaleFourPixels<has_alpha, 4>(&sum, alpha);

 }

 // Same as ProcessPixelPairZeroSubY, expect processing one output pixel at a

 // time instead of two. As in the above function, only two pixels are needed

 // to generate a single pixel since sub_y == 0.

 // @return same as ProcessPixelPairZeroSubY, except that only the bottom 4

 // 16 bit components are set.

 template<bool has_alpha>

 inline __m128i ProcessOnePixelZeroSubY(uint32_t pixel0,

                                        uint32_t pixel1,

                                        __m128i scale_x,

                                        __m128i alpha) {

     __m128i a0 = _mm_cvtsi32_si128(pixel0);

     __m128i a1 = _mm_cvtsi32_si128(pixel1);

     // Interleave

     a0 = _mm_unpacklo_epi8(a0, a1);

     // (a0 * (16-x) + a1 * x)

     __m128i sum = _mm_maddubs_epi16(a0, scale_x);

     return ScaleFourPixels<has_alpha, 4>(&sum, alpha);

 }

 // Methods when sub_y != 0

 // Same as ProcessPixelPairHelper, except that the values are scaled by y.

 // @param y vector of 16 bit components containing 'y' values. There are two

 //        cases in practice, where y will contain the sub_y constant, or will

 //        contain the 16 - sub_y constant.

 // @return vector of 16 bit components containing:

 // (y * (Aa2 * (16 - x1) + Aa3 * x1), ... , y * (Ra0 * (16 - x0) + Ra1 * x0))

 inline __m128i ProcessPixelPair(uint32_t pixel0,

                                 uint32_t pixel1,

                                 uint32_t pixel2,

                                 uint32_t pixel3,

                                 const __m128i& scale_x,

                                 const __m128i& y) {

     __m128i sum = ProcessPixelPairHelper(pixel0, pixel1, pixel2, pixel3,

                                          scale_x);

     // first row times 16-y or y depending on whether 'y' represents one or

     // the other.

     // Values will be up to 255 * 16 * 16 = 65280.

     // (y * (Aa2 * (16 - x1) + Aa3 * x1), ... ,

     //  y * (Ra0 * (16 - x0) + Ra1 * x0))

     sum = _mm_mullo_epi16(sum, y);

     return sum;

 }

 // Process two pixel pairs out of eight input pixels.

 // In other methods, the distinct pixels are passed one by one, but in this

 // case, the rows, and index offsets to the pixels into the row are passed

 // to generate the 8 pixels.

 // @param row0..1 top and bottom row where to find input pixels.

 // @param x0..1 offsets into the row for all eight input pixels.

 // @param all_y vector of 16 bit components containing the constant sub_y

 // @param neg_y vector of 16 bit components containing the constant 16 - sub_y

 // @param alpha vector of 16 bit components containing the alpha value to scale

 //        the results by, when has_alpha is true.

 // @return

 // (alpha * ((16-y) * (Aa2  * (16-x1) + Aa3  * x1) +

 //             y    * (Aa2' * (16-x1) + Aa3' * x1)),

 // ...

 //  alpha * ((16-y) * (Ra0  * (16-x0) + Ra1 * x0) +

 //             y    * (Ra0' * (16-x0) + Ra1' * x0))

 // With the factor alpha removed when has_alpha is false.

 // The values are scaled back to 16 bit components, but with only the bottom

 // 8 bits being set.

 template<bool has_alpha>

 inline __m128i ProcessTwoPixelPairs(const uint32_t* row0,

                                     const uint32_t* row1,

                                     const int* x0,

                                     const int* x1,

                                     const __m128i& scale_x,

                                     const __m128i& all_y,

                                     const __m128i& neg_y,

                                     const __m128i& alpha) {

     __m128i sum0 = ProcessPixelPair(

         row0[x0[0]], row0[x1[0]], row0[x0[1]], row0[x1[1]],

         scale_x, neg_y);

     __m128i sum1 = ProcessPixelPair(

         row1[x0[0]], row1[x1[0]], row1[x0[1]], row1[x1[1]],

         scale_x, all_y);

     // 2 samples fully summed.

     // ((16-y) * (Aa2 * (16-x1) + Aa3 * x1) +

     //  y * (Aa2' * (16-x1) + Aa3' * x1),

     // ...

     //  (16-y) * (Ra0 * (16 - x0) + Ra1 * x0)) +

     //  y * (Ra0' * (16-x0) + Ra1' * x0))

     // Each component, again can be at most 256 * 255 = 65280, so no overflow.

     sum0 = _mm_add_epi16(sum0, sum1);

     return ScaleFourPixels<has_alpha, 8>(&sum0, alpha);

 }

 // Similar to ProcessTwoPixelPairs except the pixel indexes.

 template<bool has_alpha>

 inline __m128i ProcessTwoPixelPairsDXDY(const uint32_t* row00,

                                         const uint32_t* row01,

                                         const uint32_t* row10,

                                         const uint32_t* row11,

                                         const int* xy0,

                                         const int* xy1,

                                         const __m128i& scale_x,

                                         const __m128i& all_y,

                                         const __m128i& neg_y,

                                         const __m128i& alpha) {

     // first row

     __m128i sum0 = ProcessPixelPair(

         row00[xy0[0]], row00[xy1[0]], row10[xy0[1]], row10[xy1[1]],

         scale_x, neg_y);

     // second row

     __m128i sum1 = ProcessPixelPair(

         row01[xy0[0]], row01[xy1[0]], row11[xy0[1]], row11[xy1[1]],

         scale_x, all_y);

     // 2 samples fully summed.

     // ((16-y1) * (Aa2 * (16-x1) + Aa3 * x1) +

     //  y0 * (Aa2' * (16-x1) + Aa3' * x1),

     // ...

     //  (16-y0) * (Ra0 * (16 - x0) + Ra1 * x0)) +

     //  y0 * (Ra0' * (16-x0) + Ra1' * x0))

     // Each component, again can be at most 256 * 255 = 65280, so no overflow.

     sum0 = _mm_add_epi16(sum0, sum1);

     return ScaleFourPixels<has_alpha, 8>(&sum0, alpha);

 }

 // Same as ProcessPixelPair, except that performing the math one output pixel

 // at a time. This means that only the bottom four 16 bit components are set.

 inline __m128i ProcessOnePixel(uint32_t pixel0, uint32_t pixel1,

                                const __m128i& scale_x, const __m128i& y) {

     __m128i a0 = _mm_cvtsi32_si128(pixel0);

     __m128i a1 = _mm_cvtsi32_si128(pixel1);

     // Interleave

     // (0, 0, 0, 0, 0, 0, 0, 0, Aa1, Aa0, Ba1, Ba0, Ga1, Ga0, Ra1, Ra0)

     a0 = _mm_unpacklo_epi8(a0, a1);

     // (a0 * (16-x) + a1 * x)

     a0 = _mm_maddubs_epi16(a0, scale_x);

     // scale row by y

     return _mm_mullo_epi16(a0, y);

 }

 // Notes about the various tricks that are used in this implementation:

 // - specialization for sub_y == 0.

 // Statistically, 1/16th of the samples will have sub_y == 0. When this

 // happens, the math goes from:

 // (16 - x)*(16 - y)*a00 + x*(16 - y)*a01 + (16 - x)*y*a10 + x*y*a11

 // to:

 // (16 - x)*a00 + 16*x*a01

 // much simpler. The simplification makes for an easy boost in performance.

 // - calculating 4 output pixels at a time.

 //  This allows loading the coefficients x0 and x1 and shuffling them to the

 // optimum location only once per loop, instead of twice per loop.

 // This also allows us to store the four pixels with a single store.

 // - Use of 2 special SSSE3 instructions (comparatively to the SSE2 instruction

 // version):

 // _mm_shuffle_epi8 : this allows us to spread the coefficients x[0-3] loaded

 // in 32 bit values to 8 bit values repeated four times.

 // _mm_maddubs_epi16 : this allows us to perform multiplications and additions

 // in one swoop of 8bit values storing the results in 16 bit values. This

 // instruction is actually crucial for the speed of the implementation since

 // as one can see in the SSE2 implementation, all inputs have to be used as

 // 16 bits because the results are 16 bits. This basically allows us to process

 // twice as many pixel components per iteration.

 //

 // As a result, this method behaves faster than the traditional SSE2. The actual

 // boost varies greatly on the underlying architecture.

 template<bool has_alpha>

 void S32_generic_D32_filter_DX_SSSE3(const SkBitmapProcState& s,

                                      const uint32_t* xy,

                                      int count, uint32_t* colors) {

     SkASSERT(count > 0 && colors != NULL);

     SkASSERT(s.fFilterLevel != SkPaint::kNone_FilterLevel);

     SkASSERT(s.fBitmap->config() == SkBitmap::kARGB_8888_Config);

     if (has_alpha) {

         SkASSERT(s.fAlphaScale < 256);

     } else {

         SkASSERT(s.fAlphaScale == 256);

     }

     const uint8_t* src_addr =

             static_cast<const uint8_t*>(s.fBitmap->getPixels());

     const size_t rb = s.fBitmap->rowBytes();

     const uint32_t XY = *xy++;

     const unsigned y0 = XY >> 14;

     const uint32_t* row0 =

             reinterpret_cast<const uint32_t*>(src_addr + (y0 >> 4) * rb);

     const uint32_t* row1 =

             reinterpret_cast<const uint32_t*>(src_addr + (XY & 0x3FFF) * rb);

     const unsigned sub_y = y0 & 0xF;

     // vector constants

     const __m128i mask_dist_select = _mm_set_epi8(12, 12, 12, 12,

                                                   8,  8,  8,  8,

                                                   4,  4,  4,  4,

                                                   0,  0,  0,  0);

     const __m128i mask_3FFF = _mm_set1_epi32(0x3FFF);

     const __m128i mask_000F = _mm_set1_epi32(0x000F);

     const __m128i sixteen_8bit = _mm_set1_epi8(16);

     // (0, 0, 0, 0, 0, 0, 0, 0)

     const __m128i zero = _mm_setzero_si128();

     __m128i alpha = _mm_setzero_si128();

     if (has_alpha)

         // 8x(alpha)

         alpha = _mm_set1_epi16(s.fAlphaScale);

     if (sub_y == 0) {

         // Unroll 4x, interleave bytes, use pmaddubsw (all_x is small)

         while (count > 3) {

             count -= 4;

             int x0[4];

             int x1[4];

             __m128i all_x, sixteen_minus_x;

             PrepareConstantsTwoPixelPairs(xy, mask_3FFF, mask_000F,

                                           sixteen_8bit, mask_dist_select,

                                           &all_x, &sixteen_minus_x, x0, x1);

             xy += 4;

             // First pair of pixel pairs.

             // (4x(x1, 16-x1), 4x(x0, 16-x0))

             __m128i scale_x;

             scale_x = _mm_unpacklo_epi8(sixteen_minus_x, all_x);

             __m128i sum0 = ProcessPixelPairZeroSubY<has_alpha>(

                 row0[x0[0]], row0[x1[0]], row0[x0[1]], row0[x1[1]],

                 scale_x, alpha);

             // second pair of pixel pairs

             // (4x (x3, 16-x3), 4x (16-x2, x2))

             scale_x = _mm_unpackhi_epi8(sixteen_minus_x, all_x);

             __m128i sum1 = ProcessPixelPairZeroSubY<has_alpha>(

                 row0[x0[2]], row0[x1[2]], row0[x0[3]], row0[x1[3]],

                 scale_x, alpha);

             // Pack lower 4 16 bit values of sum into lower 4 bytes.

             sum0 = _mm_packus_epi16(sum0, sum1);

             // Extract low int and store.

             _mm_storeu_si128(reinterpret_cast<__m128i *>(colors), sum0);

             colors += 4;

         }

         // handle remainder

         while (count-- > 0) {

             uint32_t xx = *xy++;  // x0:14 | 4 | x1:14

             unsigned x0 = xx >> 18;

             unsigned x1 = xx & 0x3FFF;

             // 16x(x)

             const __m128i all_x = _mm_set1_epi8((xx >> 14) & 0x0F);

             // (16x(16-x))

             __m128i scale_x = _mm_sub_epi8(sixteen_8bit, all_x);

             scale_x = _mm_unpacklo_epi8(scale_x, all_x);

             __m128i sum = ProcessOnePixelZeroSubY<has_alpha>(

                 row0[x0], row0[x1],

                 scale_x, alpha);

             // Pack lower 4 16 bit values of sum into lower 4 bytes.

             sum = _mm_packus_epi16(sum, zero);

             // Extract low int and store.

             *colors++ = _mm_cvtsi128_si32(sum);

         }

     } else {  // more general case, y != 0

         // 8x(16)

         const __m128i sixteen_16bit = _mm_set1_epi16(16);

         // 8x (y)

         const __m128i all_y = _mm_set1_epi16(sub_y);

         // 8x (16-y)

         const __m128i neg_y = _mm_sub_epi16(sixteen_16bit, all_y);

         // Unroll 4x, interleave bytes, use pmaddubsw (all_x is small)

         while (count > 3) {

             count -= 4;

             int x0[4];

             int x1[4];

             __m128i all_x, sixteen_minus_x;

             PrepareConstantsTwoPixelPairs(xy, mask_3FFF, mask_000F,

                                           sixteen_8bit, mask_dist_select,

                                           &all_x, &sixteen_minus_x, x0, x1);

             xy += 4;

             // First pair of pixel pairs

             // (4x(x1, 16-x1), 4x(x0, 16-x0))

             __m128i scale_x;

             scale_x = _mm_unpacklo_epi8(sixteen_minus_x, all_x);

             __m128i sum0 = ProcessTwoPixelPairs<has_alpha>(

                 row0, row1, x0, x1,

                 scale_x, all_y, neg_y, alpha);

             // second pair of pixel pairs

             // (4x (x3, 16-x3), 4x (16-x2, x2))

             scale_x = _mm_unpackhi_epi8(sixteen_minus_x, all_x);

             __m128i sum1 = ProcessTwoPixelPairs<has_alpha>(

                 row0, row1, x0 + 2, x1 + 2,

                 scale_x, all_y, neg_y, alpha);

             // Do the final packing of the two results

             // Pack lower 4 16 bit values of sum into lower 4 bytes.

             sum0 = _mm_packus_epi16(sum0, sum1);

             // Extract low int and store.

             _mm_storeu_si128(reinterpret_cast<__m128i *>(colors), sum0);

             colors += 4;

         }

         // Left over.

         while (count-- > 0) {

             const uint32_t xx = *xy++;  // x0:14 | 4 | x1:14

             const unsigned x0 = xx >> 18;

             const unsigned x1 = xx & 0x3FFF;

             // 16x(x)

             const __m128i all_x = _mm_set1_epi8((xx >> 14) & 0x0F);

             // 16x (16-x)

             __m128i scale_x = _mm_sub_epi8(sixteen_8bit, all_x);

             // (8x (x, 16-x))

             scale_x = _mm_unpacklo_epi8(scale_x, all_x);

             // first row.

             __m128i sum0 = ProcessOnePixel(row0[x0], row0[x1], scale_x, neg_y);

             // second row.

             __m128i sum1 = ProcessOnePixel(row1[x0], row1[x1], scale_x, all_y);

             // Add both rows for full sample

             sum0 = _mm_add_epi16(sum0, sum1);

             sum0 = ScaleFourPixels<has_alpha, 8>(&sum0, alpha);

             // Pack lower 4 16 bit values of sum into lower 4 bytes.

             sum0 = _mm_packus_epi16(sum0, zero);

             // Extract low int and store.

             *colors++ = _mm_cvtsi128_si32(sum0);

         }

     }

 }

 /*

  * Similar to S32_generic_D32_filter_DX_SSSE3, we do not need to handle the

  * special case suby == 0 as suby is changing in every loop.

  */

 template<bool has_alpha>

 void S32_generic_D32_filter_DXDY_SSSE3(const SkBitmapProcState& s,

                                        const uint32_t* xy,

                                        int count, uint32_t* colors) {

     SkASSERT(count > 0 && colors != NULL);

     SkASSERT(s.fFilterLevel != SkPaint::kNone_FilterLevel);

     SkASSERT(s.fBitmap->config() == SkBitmap::kARGB_8888_Config);

     if (has_alpha) {

         SkASSERT(s.fAlphaScale < 256);

     } else {

         SkASSERT(s.fAlphaScale == 256);

     }

     const uint8_t* src_addr =

                         static_cast<const uint8_t*>(s.fBitmap->getPixels());

     const size_t rb = s.fBitmap->rowBytes();

     // vector constants

     const __m128i mask_dist_select = _mm_set_epi8(12, 12, 12, 12,

                                                   8,  8,  8,  8,

                                                   4,  4,  4,  4,

                                                   0,  0,  0,  0);

     const __m128i mask_3FFF = _mm_set1_epi32(0x3FFF);

     const __m128i mask_000F = _mm_set1_epi32(0x000F);

     const __m128i sixteen_8bit = _mm_set1_epi8(16);

     __m128i alpha;

     if (has_alpha) {

         // 8x(alpha)

         alpha = _mm_set1_epi16(s.fAlphaScale);

     }

     // Unroll 2x, interleave bytes, use pmaddubsw (all_x is small)

     while (count >= 2) {

         int xy0[4];

         int xy1[4];

         __m128i all_xy, sixteen_minus_xy;

         PrepareConstantsTwoPixelPairsDXDY(xy, mask_3FFF, mask_000F,

                                           sixteen_8bit, mask_dist_select,

                                          &all_xy, &sixteen_minus_xy, xy0, xy1);

         // (4x(x1, 16-x1), 4x(x0, 16-x0))

         __m128i scale_x = _mm_unpacklo_epi8(sixteen_minus_xy, all_xy);

         // (4x(0, y1), 4x(0, y0))

         __m128i all_y = _mm_unpackhi_epi8(all_xy, _mm_setzero_si128());

         __m128i neg_y = _mm_sub_epi16(_mm_set1_epi16(16), all_y);

         const uint32_t* row00 =

                     reinterpret_cast<const uint32_t*>(src_addr + xy0[2] * rb);

         const uint32_t* row01 =

                     reinterpret_cast<const uint32_t*>(src_addr + xy1[2] * rb);

         const uint32_t* row10 =

                     reinterpret_cast<const uint32_t*>(src_addr + xy0[3] * rb);

         const uint32_t* row11 =

                     reinterpret_cast<const uint32_t*>(src_addr + xy1[3] * rb);

         __m128i sum0 = ProcessTwoPixelPairsDXDY<has_alpha>(

                                         row00, row01, row10, row11, xy0, xy1,

                                         scale_x, all_y, neg_y, alpha);

         // Pack lower 4 16 bit values of sum into lower 4 bytes.

         sum0 = _mm_packus_epi16(sum0, _mm_setzero_si128());

         // Extract low int and store.

         _mm_storel_epi64(reinterpret_cast<__m128i *>(colors), sum0);

         xy += 4;

         colors += 2;

         count -= 2;

     }

     // Handle the remainder

     while (count-- > 0) {

         uint32_t data = *xy++;

         unsigned y0 = data >> 14;

         unsigned y1 = data & 0x3FFF;

         unsigned subY = y0 & 0xF;

         y0 >>= 4;

         data = *xy++;

         unsigned x0 = data >> 14;

         unsigned x1 = data & 0x3FFF;

         unsigned subX = x0 & 0xF;

         x0 >>= 4;

         const uint32_t* row0 =

                         reinterpret_cast<const uint32_t*>(src_addr + y0 * rb);

         const uint32_t* row1 =

                         reinterpret_cast<const uint32_t*>(src_addr + y1 * rb);

         // 16x(x)

         const __m128i all_x = _mm_set1_epi8(subX);

         // 16x (16-x)

         __m128i scale_x = _mm_sub_epi8(sixteen_8bit, all_x);

         // (8x (x, 16-x))

         scale_x = _mm_unpacklo_epi8(scale_x, all_x);

         // 8x(16)

         const __m128i sixteen_16bit = _mm_set1_epi16(16);

         // 8x (y)

         const __m128i all_y = _mm_set1_epi16(subY);

         // 8x (16-y)

         const __m128i neg_y = _mm_sub_epi16(sixteen_16bit, all_y);

         // first row.

         __m128i sum0 = ProcessOnePixel(row0[x0], row0[x1], scale_x, neg_y);

         // second row.

         __m128i sum1 = ProcessOnePixel(row1[x0], row1[x1], scale_x, all_y);

         // Add both rows for full sample

         sum0 = _mm_add_epi16(sum0, sum1);

         sum0 = ScaleFourPixels<has_alpha, 8>(&sum0, alpha);

         // Pack lower 4 16 bit values of sum into lower 4 bytes.

         sum0 = _mm_packus_epi16(sum0, _mm_setzero_si128());

         // Extract low int and store.

         *colors++ = _mm_cvtsi128_si32(sum0);

     }

 }

 }  // namepace

 void S32_opaque_D32_filter_DX_SSSE3(const SkBitmapProcState& s,

                                     const uint32_t* xy,

                                     int count, uint32_t* colors) {

     S32_generic_D32_filter_DX_SSSE3<false>(s, xy, count, colors);

 }

 void S32_alpha_D32_filter_DX_SSSE3(const SkBitmapProcState& s,

                                    const uint32_t* xy,

                                    int count, uint32_t* colors) {

     S32_generic_D32_filter_DX_SSSE3<true>(s, xy, count, colors);

 }

 void S32_opaque_D32_filter_DXDY_SSSE3(const SkBitmapProcState& s,

                                     const uint32_t* xy,

                                     int count, uint32_t* colors) {

     S32_generic_D32_filter_DXDY_SSSE3<false>(s, xy, count, colors);

 }

 void S32_alpha_D32_filter_DXDY_SSSE3(const SkBitmapProcState& s,

                                    const uint32_t* xy,

                                    int count, uint32_t* colors) {

     S32_generic_D32_filter_DXDY_SSSE3<true>(s, xy, count, colors);

 }

 #else // !defined(SK_BUILD_FOR_ANDROID_FRAMEWORK) || SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSSE3

 void S32_opaque_D32_filter_DX_SSSE3(const SkBitmapProcState& s,

                                     const uint32_t* xy,

                                     int count, uint32_t* colors) {

     sk_throw();

 }

 void S32_alpha_D32_filter_DX_SSSE3(const SkBitmapProcState& s,

                                    const uint32_t* xy,

                                    int count, uint32_t* colors) {

     sk_throw();

 }

 void S32_opaque_D32_filter_DXDY_SSSE3(const SkBitmapProcState& s,

                                     const uint32_t* xy,

                                     int count, uint32_t* colors) {

     sk_throw();

 }

 void S32_alpha_D32_filter_DXDY_SSSE3(const SkBitmapProcState& s,

                                    const uint32_t* xy,

                                    int count, uint32_t* colors) {

     sk_throw();

 }

 #endif