libwebp: update to 0.5.0

third_party/libwebp/dsp/rescaler_sse2.c

Index: third_party/libwebp/dsp/rescaler_sse2.c
diff --git a/third_party/libwebp/dsp/rescaler_sse2.c b/third_party/libwebp/dsp/rescaler_sse2.c
new file mode 100644
index 0000000000000000000000000000000000000000..5ea4ddb208d501b3d1c088940c19f131033d98a3
--- /dev/null
+++ b/third_party/libwebp/dsp/rescaler_sse2.c
@@ -0,0 +1,374 @@
+// Copyright 2015 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.
+// -----------------------------------------------------------------------------
+//
+// SSE2 Rescaling functions
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include "./dsp.h"
+
+#if defined(WEBP_USE_SSE2)
+#include <emmintrin.h>
+
+#include <assert.h>
+#include "../utils/rescaler.h"
+
+//------------------------------------------------------------------------------
+// Implementations of critical functions ImportRow / ExportRow
+
+#define ROUNDER (WEBP_RESCALER_ONE >> 1)
+#define MULT_FIX(x, y) (((uint64_t)(x) * (y) + ROUNDER) >> WEBP_RESCALER_RFIX)
+
+// input: 8 bytes ABCDEFGH -> output: A0E0B0F0C0G0D0H0
+static void LoadTwoPixels(const uint8_t* const src, __m128i* out) {
+  const __m128i zero = _mm_setzero_si128();
+  const __m128i A = _mm_loadl_epi64((const __m128i*)(src));  // ABCDEFGH
+  const __m128i B = _mm_unpacklo_epi8(A, zero);              // A0B0C0D0E0F0G0H0
+  const __m128i C = _mm_srli_si128(B, 8);                    // E0F0G0H0
+  *out = _mm_unpacklo_epi16(B, C);
+}
+
+// input: 8 bytes ABCDEFGH -> output: A0B0C0D0E0F0G0H0
+static void LoadHeightPixels(const uint8_t* const src, __m128i* out) {
+  const __m128i zero = _mm_setzero_si128();
+  const __m128i A = _mm_loadl_epi64((const __m128i*)(src));  // ABCDEFGH
+  *out = _mm_unpacklo_epi8(A, zero);
+}
+
+static void RescalerImportRowExpandSSE2(WebPRescaler* const wrk,
+                                        const uint8_t* src) {
+  rescaler_t* frow = wrk->frow;
+  const rescaler_t* const frow_end = frow + wrk->dst_width * wrk->num_channels;
+  const int x_add = wrk->x_add;
+  int accum = x_add;
+  __m128i cur_pixels;
+
+  assert(!WebPRescalerInputDone(wrk));
+  assert(wrk->x_expand);
+  if (wrk->num_channels == 4) {
+    if (wrk->src_width < 2) {
+      WebPRescalerImportRowExpandC(wrk, src);
+      return;
+    }
+    LoadTwoPixels(src, &cur_pixels);
+    src += 4;
+    while (1) {
+      const __m128i mult = _mm_set1_epi32(((x_add - accum) << 16) | accum);
+      const __m128i out = _mm_madd_epi16(cur_pixels, mult);
+      _mm_storeu_si128((__m128i*)frow, out);
+      frow += 4;
+      if (frow >= frow_end) break;
+      accum -= wrk->x_sub;
+      if (accum < 0) {
+        LoadTwoPixels(src, &cur_pixels);
+        src += 4;
+        accum += x_add;
+      }
+    }
+  } else {
+    int left;
+    const uint8_t* const src_limit = src + wrk->src_width - 8;
+    if (wrk->src_width < 8) {
+      WebPRescalerImportRowExpandC(wrk, src);
+      return;
+    }
+    LoadHeightPixels(src, &cur_pixels);
+    src += 7;
+    left = 7;
+    while (1) {
+      const __m128i mult = _mm_cvtsi32_si128(((x_add - accum) << 16) | accum);
+      const __m128i out = _mm_madd_epi16(cur_pixels, mult);
+      assert(sizeof(*frow) == sizeof(uint32_t));
+      WebPUint32ToMem((uint8_t*)frow, _mm_cvtsi128_si32(out));
+      frow += 1;
+      if (frow >= frow_end) break;
+      accum -= wrk->x_sub;
+      if (accum < 0) {
+        if (--left) {
+          cur_pixels = _mm_srli_si128(cur_pixels, 2);
+        } else if (src <= src_limit) {
+          LoadHeightPixels(src, &cur_pixels);
+          src += 7;
+          left = 7;
+        } else {   // tail
+          cur_pixels = _mm_srli_si128(cur_pixels, 2);
+          cur_pixels = _mm_insert_epi16(cur_pixels, src[1], 1);
+          src += 1;
+          left = 1;
+        }
+        accum += x_add;
+      }
+    }
+  }
+  assert(accum == 0);
+}
+
+static void RescalerImportRowShrinkSSE2(WebPRescaler* const wrk,
+                                        const uint8_t* src) {
+  const int x_sub = wrk->x_sub;
+  int accum = 0;
+  const __m128i zero = _mm_setzero_si128();
+  const __m128i mult0 = _mm_set1_epi16(x_sub);
+  const __m128i mult1 = _mm_set1_epi32(wrk->fx_scale);
+  const __m128i rounder = _mm_set_epi32(0, ROUNDER, 0, ROUNDER);
+  __m128i sum = zero;
+  rescaler_t* frow = wrk->frow;
+  const rescaler_t* const frow_end = wrk->frow + 4 * wrk->dst_width;
+
+  if (wrk->num_channels != 4 || wrk->x_add > (x_sub << 7)) {
+    WebPRescalerImportRowShrinkC(wrk, src);
+    return;
+  }
+  assert(!WebPRescalerInputDone(wrk));
+  assert(!wrk->x_expand);
+
+  for (; frow < frow_end; frow += 4) {
+    __m128i base = zero;
+    accum += wrk->x_add;
+    while (accum > 0) {
+      const __m128i A = _mm_cvtsi32_si128(WebPMemToUint32(src));
+      src += 4;
+      base = _mm_unpacklo_epi8(A, zero);
+      // To avoid overflow, we need: base * x_add / x_sub < 32768
+      // => x_add < x_sub << 7. That's a 1/128 reduction ratio limit.
+      sum = _mm_add_epi16(sum, base);
+      accum -= x_sub;
+    }
+    {    // Emit next horizontal pixel.
+      const __m128i mult = _mm_set1_epi16(-accum);
+      const __m128i frac0 = _mm_mullo_epi16(base, mult);  // 16b x 16b -> 32b
+      const __m128i frac1 = _mm_mulhi_epu16(base, mult);
+      const __m128i frac = _mm_unpacklo_epi16(frac0, frac1);  // frac is 32b
+      const __m128i A0 = _mm_mullo_epi16(sum, mult0);
+      const __m128i A1 = _mm_mulhi_epu16(sum, mult0);
+      const __m128i B0 = _mm_unpacklo_epi16(A0, A1);      // sum * x_sub
+      const __m128i frow_out = _mm_sub_epi32(B0, frac);   // sum * x_sub - frac
+      const __m128i D0 = _mm_srli_epi64(frac, 32);
+      const __m128i D1 = _mm_mul_epu32(frac, mult1);      // 32b x 16b -> 64b
+      const __m128i D2 = _mm_mul_epu32(D0, mult1);
+      const __m128i E1 = _mm_add_epi64(D1, rounder);
+      const __m128i E2 = _mm_add_epi64(D2, rounder);
+      const __m128i F1 = _mm_shuffle_epi32(E1, 1 | (3 << 2));
+      const __m128i F2 = _mm_shuffle_epi32(E2, 1 | (3 << 2));
+      const __m128i G = _mm_unpacklo_epi32(F1, F2);
+      sum = _mm_packs_epi32(G, zero);
+      _mm_storeu_si128((__m128i*)frow, frow_out);
+    }
+  }
+  assert(accum == 0);
+}
+
+//------------------------------------------------------------------------------
+// Row export
+
+// load *src as epi64, multiply by mult and store result in [out0 ... out3]
+static WEBP_INLINE void LoadDispatchAndMult(const rescaler_t* const src,
+                                            const __m128i* const mult,
+                                            __m128i* const out0,
+                                            __m128i* const out1,
+                                            __m128i* const out2,
+                                            __m128i* const out3) {
+  const __m128i A0 = _mm_loadu_si128((const __m128i*)(src + 0));
+  const __m128i A1 = _mm_loadu_si128((const __m128i*)(src + 4));
+  const __m128i A2 = _mm_srli_epi64(A0, 32);
+  const __m128i A3 = _mm_srli_epi64(A1, 32);
+  if (mult != NULL) {
+    *out0 = _mm_mul_epu32(A0, *mult);
+    *out1 = _mm_mul_epu32(A1, *mult);
+    *out2 = _mm_mul_epu32(A2, *mult);
+    *out3 = _mm_mul_epu32(A3, *mult);
+  } else {
+    *out0 = A0;
+    *out1 = A1;
+    *out2 = A2;
+    *out3 = A3;
+  }
+}
+
+static WEBP_INLINE void ProcessRow(const __m128i* const A0,
+                                   const __m128i* const A1,
+                                   const __m128i* const A2,
+                                   const __m128i* const A3,
+                                   const __m128i* const mult,
+                                   uint8_t* const dst) {
+  const __m128i rounder = _mm_set_epi32(0, ROUNDER, 0, ROUNDER);
+  const __m128i mask = _mm_set_epi32(0xffffffffu, 0, 0xffffffffu, 0);
+  const __m128i B0 = _mm_mul_epu32(*A0, *mult);
+  const __m128i B1 = _mm_mul_epu32(*A1, *mult);
+  const __m128i B2 = _mm_mul_epu32(*A2, *mult);
+  const __m128i B3 = _mm_mul_epu32(*A3, *mult);
+  const __m128i C0 = _mm_add_epi64(B0, rounder);
+  const __m128i C1 = _mm_add_epi64(B1, rounder);
+  const __m128i C2 = _mm_add_epi64(B2, rounder);
+  const __m128i C3 = _mm_add_epi64(B3, rounder);
+  const __m128i D0 = _mm_srli_epi64(C0, WEBP_RESCALER_RFIX);
+  const __m128i D1 = _mm_srli_epi64(C1, WEBP_RESCALER_RFIX);
+#if (WEBP_RESCALER_FIX < 32)
+  const __m128i D2 =
+      _mm_and_si128(_mm_slli_epi64(C2, 32 - WEBP_RESCALER_RFIX), mask);
+  const __m128i D3 =
+      _mm_and_si128(_mm_slli_epi64(C3, 32 - WEBP_RESCALER_RFIX), mask);
+#else
+  const __m128i D2 = _mm_and_si128(C2, mask);
+  const __m128i D3 = _mm_and_si128(C3, mask);
+#endif
+  const __m128i E0 = _mm_or_si128(D0, D2);
+  const __m128i E1 = _mm_or_si128(D1, D3);
+  const __m128i F = _mm_packs_epi32(E0, E1);
+  const __m128i G = _mm_packus_epi16(F, F);
+  _mm_storel_epi64((__m128i*)dst, G);
+}
+
+static void RescalerExportRowExpandSSE2(WebPRescaler* const wrk) {
+  int x_out;
+  uint8_t* const dst = wrk->dst;
+  rescaler_t* const irow = wrk->irow;
+  const int x_out_max = wrk->dst_width * wrk->num_channels;
+  const rescaler_t* const frow = wrk->frow;
+  const __m128i mult = _mm_set_epi32(0, wrk->fy_scale, 0, wrk->fy_scale);
+
+  assert(!WebPRescalerOutputDone(wrk));
+  assert(wrk->y_accum <= 0 && wrk->y_sub + wrk->y_accum >= 0);
+  assert(wrk->y_expand);
+  if (wrk->y_accum == 0) {
+    for (x_out = 0; x_out + 8 <= x_out_max; x_out += 8) {
+      __m128i A0, A1, A2, A3;
+      LoadDispatchAndMult(frow + x_out, NULL, &A0, &A1, &A2, &A3);
+      ProcessRow(&A0, &A1, &A2, &A3, &mult, dst + x_out);
+    }
+    for (; x_out < x_out_max; ++x_out) {
+      const uint32_t J = frow[x_out];
+      const int v = (int)MULT_FIX(J, wrk->fy_scale);
+      assert(v >= 0 && v <= 255);
+      dst[x_out] = v;
+    }
+  } else {
+    const uint32_t B = WEBP_RESCALER_FRAC(-wrk->y_accum, wrk->y_sub);
+    const uint32_t A = (uint32_t)(WEBP_RESCALER_ONE - B);
+    const __m128i mA = _mm_set_epi32(0, A, 0, A);
+    const __m128i mB = _mm_set_epi32(0, B, 0, B);
+    const __m128i rounder = _mm_set_epi32(0, ROUNDER, 0, ROUNDER);
+    for (x_out = 0; x_out + 8 <= x_out_max; x_out += 8) {
+      __m128i A0, A1, A2, A3, B0, B1, B2, B3;
+      LoadDispatchAndMult(frow + x_out, &mA, &A0, &A1, &A2, &A3);
+      LoadDispatchAndMult(irow + x_out, &mB, &B0, &B1, &B2, &B3);
+      {
+        const __m128i C0 = _mm_add_epi64(A0, B0);
+        const __m128i C1 = _mm_add_epi64(A1, B1);
+        const __m128i C2 = _mm_add_epi64(A2, B2);
+        const __m128i C3 = _mm_add_epi64(A3, B3);
+        const __m128i D0 = _mm_add_epi64(C0, rounder);
+        const __m128i D1 = _mm_add_epi64(C1, rounder);
+        const __m128i D2 = _mm_add_epi64(C2, rounder);
+        const __m128i D3 = _mm_add_epi64(C3, rounder);
+        const __m128i E0 = _mm_srli_epi64(D0, WEBP_RESCALER_RFIX);
+        const __m128i E1 = _mm_srli_epi64(D1, WEBP_RESCALER_RFIX);
+        const __m128i E2 = _mm_srli_epi64(D2, WEBP_RESCALER_RFIX);
+        const __m128i E3 = _mm_srli_epi64(D3, WEBP_RESCALER_RFIX);
+        ProcessRow(&E0, &E1, &E2, &E3, &mult, dst + x_out);
+      }
+    }
+    for (; x_out < x_out_max; ++x_out) {
+      const uint64_t I = (uint64_t)A * frow[x_out]
+                       + (uint64_t)B * irow[x_out];
+      const uint32_t J = (uint32_t)((I + ROUNDER) >> WEBP_RESCALER_RFIX);
+      const int v = (int)MULT_FIX(J, wrk->fy_scale);
+      assert(v >= 0 && v <= 255);
+      dst[x_out] = v;
+    }
+  }
+}
+
+static void RescalerExportRowShrinkSSE2(WebPRescaler* const wrk) {
+  int x_out;
+  uint8_t* const dst = wrk->dst;
+  rescaler_t* const irow = wrk->irow;
+  const int x_out_max = wrk->dst_width * wrk->num_channels;
+  const rescaler_t* const frow = wrk->frow;
+  const uint32_t yscale = wrk->fy_scale * (-wrk->y_accum);
+  assert(!WebPRescalerOutputDone(wrk));
+  assert(wrk->y_accum <= 0);
+  assert(!wrk->y_expand);
+  if (yscale) {
+    const int scale_xy = wrk->fxy_scale;
+    const __m128i mult_xy = _mm_set_epi32(0, scale_xy, 0, scale_xy);
+    const __m128i mult_y = _mm_set_epi32(0, yscale, 0, yscale);
+    const __m128i rounder = _mm_set_epi32(0, ROUNDER, 0, ROUNDER);
+    for (x_out = 0; x_out + 8 <= x_out_max; x_out += 8) {
+      __m128i A0, A1, A2, A3, B0, B1, B2, B3;
+      LoadDispatchAndMult(irow + x_out, NULL, &A0, &A1, &A2, &A3);
+      LoadDispatchAndMult(frow + x_out, &mult_y, &B0, &B1, &B2, &B3);
+      {
+        const __m128i C0 = _mm_add_epi64(B0, rounder);
+        const __m128i C1 = _mm_add_epi64(B1, rounder);
+        const __m128i C2 = _mm_add_epi64(B2, rounder);
+        const __m128i C3 = _mm_add_epi64(B3, rounder);
+        const __m128i D0 = _mm_srli_epi64(C0, WEBP_RESCALER_RFIX);   // = frac
+        const __m128i D1 = _mm_srli_epi64(C1, WEBP_RESCALER_RFIX);
+        const __m128i D2 = _mm_srli_epi64(C2, WEBP_RESCALER_RFIX);
+        const __m128i D3 = _mm_srli_epi64(C3, WEBP_RESCALER_RFIX);
+        const __m128i E0 = _mm_sub_epi64(A0, D0);   // irow[x] - frac
+        const __m128i E1 = _mm_sub_epi64(A1, D1);
+        const __m128i E2 = _mm_sub_epi64(A2, D2);
+        const __m128i E3 = _mm_sub_epi64(A3, D3);
+        const __m128i F2 = _mm_slli_epi64(D2, 32);
+        const __m128i F3 = _mm_slli_epi64(D3, 32);
+        const __m128i G0 = _mm_or_si128(D0, F2);
+        const __m128i G1 = _mm_or_si128(D1, F3);
+        _mm_storeu_si128((__m128i*)(irow + x_out + 0), G0);
+        _mm_storeu_si128((__m128i*)(irow + x_out + 4), G1);
+        ProcessRow(&E0, &E1, &E2, &E3, &mult_xy, dst + x_out);
+      }
+    }
+    for (; x_out < x_out_max; ++x_out) {
+      const uint32_t frac = (int)MULT_FIX(frow[x_out], yscale);
+      const int v = (int)MULT_FIX(irow[x_out] - frac, wrk->fxy_scale);
+      assert(v >= 0 && v <= 255);
+      dst[x_out] = v;
+      irow[x_out] = frac;   // new fractional start
+    }
+  } else {
+    const uint32_t scale = wrk->fxy_scale;
+    const __m128i mult = _mm_set_epi32(0, scale, 0, scale);
+    const __m128i zero = _mm_setzero_si128();
+    for (x_out = 0; x_out + 8 <= x_out_max; x_out += 8) {
+      __m128i A0, A1, A2, A3;
+      LoadDispatchAndMult(irow + x_out, NULL, &A0, &A1, &A2, &A3);
+      _mm_storeu_si128((__m128i*)(irow + x_out + 0), zero);
+      _mm_storeu_si128((__m128i*)(irow + x_out + 4), zero);
+      ProcessRow(&A0, &A1, &A2, &A3, &mult, dst + x_out);
+    }
+    for (; x_out < x_out_max; ++x_out) {
+      const int v = (int)MULT_FIX(irow[x_out], scale);
+      assert(v >= 0 && v <= 255);
+      dst[x_out] = v;
+      irow[x_out] = 0;
+    }
+  }
+}
+
+#undef MULT_FIX
+#undef ROUNDER
+
+//------------------------------------------------------------------------------
+
+extern void WebPRescalerDspInitSSE2(void);
+
+WEBP_TSAN_IGNORE_FUNCTION void WebPRescalerDspInitSSE2(void) {
+  WebPRescalerImportRowExpand = RescalerImportRowExpandSSE2;
+  WebPRescalerImportRowShrink = RescalerImportRowShrinkSSE2;
+  WebPRescalerExportRowExpand = RescalerExportRowExpandSSE2;
+  WebPRescalerExportRowShrink = RescalerExportRowShrinkSSE2;
+}
+
+#else  // !WEBP_USE_SSE2
+
+WEBP_DSP_INIT_STUB(WebPRescalerDspInitSSE2)
+
+#endif  // WEBP_USE_SSE2