Bundled libwebp updated to version 0.6.0

This commit imports libwebp 0.6.0, including AUTHORS, COPYING, ChangeLog,
NEWS, PATENTS, README and src directories. In src, only includes header
and source files.

Upstream changes since 0.5.1 have been merged in.
Also updated version in qt_attribution.json.

Conflicts:
	src/3rdparty/libwebp.pri
	src/3rdparty/libwebp/qt_attribution.json
	src/3rdparty/libwebp/src/webp/config.h

Change-Id: I001aa7a3fabf0130b54f9005c23aa822bc1d0ec1
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

1 files changed, 64 insertions, 77 deletions

diff --git a/src/3rdparty/libwebp/src/dsp/alpha_processing_sse2.c b/src/3rdparty/libwebp/src/dsp/alpha_processing_sse2.c
index 5acb481..83dc559 100644
--- a/src/3rdparty/libwebp/src/dsp/alpha_processing_sse2.c
+++ b/src/3rdparty/libwebp/src/dsp/alpha_processing_sse2.c
@@ -150,46 +150,46 @@ static int ExtractAlpha(const uint8_t* argb, int argb_stride,
 #define PREMULTIPLY(x, m) (((x) * (m)) >> 23)
 
 // We can't use a 'const int' for the SHUFFLE value, because it has to be an
-// immediate in the _mm_shufflexx_epi16() instruction. We really a macro here.
-#define APPLY_ALPHA(RGBX, SHUFFLE, MASK, MULT) do {             \
-  const __m128i argb0 = _mm_loadl_epi64((__m128i*)&(RGBX));     \
-  const __m128i argb1 = _mm_unpacklo_epi8(argb0, zero);         \
-  const __m128i alpha0 = _mm_and_si128(argb1, MASK);            \
-  const __m128i alpha1 = _mm_shufflelo_epi16(alpha0, SHUFFLE);  \
-  const __m128i alpha2 = _mm_shufflehi_epi16(alpha1, SHUFFLE);  \
-  /* alpha2 = [0 a0 a0 a0][0 a1 a1 a1] */                       \
-  const __m128i scale0 = _mm_mullo_epi16(alpha2, MULT);         \
-  const __m128i scale1 = _mm_mulhi_epu16(alpha2, MULT);         \
-  const __m128i argb2 = _mm_mulhi_epu16(argb1, scale0);         \
-  const __m128i argb3 = _mm_mullo_epi16(argb1, scale1);         \
-  const __m128i argb4 = _mm_adds_epu16(argb2, argb3);           \
-  const __m128i argb5 = _mm_srli_epi16(argb4, 7);               \
-  const __m128i argb6 = _mm_or_si128(argb5, alpha0);            \
-  const __m128i argb7 = _mm_packus_epi16(argb6, zero);          \
-  _mm_storel_epi64((__m128i*)&(RGBX), argb7);                   \
+// immediate in the _mm_shufflexx_epi16() instruction. We really need a macro.
+// We use: v / 255 = (v * 0x8081) >> 23, where v = alpha * {r,g,b} is a 16bit
+// value.
+#define APPLY_ALPHA(RGBX, SHUFFLE) do {                              \
+  const __m128i argb0 = _mm_loadu_si128((const __m128i*)&(RGBX));    \
+  const __m128i argb1_lo = _mm_unpacklo_epi8(argb0, zero);           \
+  const __m128i argb1_hi = _mm_unpackhi_epi8(argb0, zero);           \
+  const __m128i alpha0_lo = _mm_or_si128(argb1_lo, kMask);           \
+  const __m128i alpha0_hi = _mm_or_si128(argb1_hi, kMask);           \
+  const __m128i alpha1_lo = _mm_shufflelo_epi16(alpha0_lo, SHUFFLE); \
+  const __m128i alpha1_hi = _mm_shufflelo_epi16(alpha0_hi, SHUFFLE); \
+  const __m128i alpha2_lo = _mm_shufflehi_epi16(alpha1_lo, SHUFFLE); \
+  const __m128i alpha2_hi = _mm_shufflehi_epi16(alpha1_hi, SHUFFLE); \
+  /* alpha2 = [ff a0 a0 a0][ff a1 a1 a1] */                          \
+  const __m128i A0_lo = _mm_mullo_epi16(alpha2_lo, argb1_lo);        \
+  const __m128i A0_hi = _mm_mullo_epi16(alpha2_hi, argb1_hi);        \
+  const __m128i A1_lo = _mm_mulhi_epu16(A0_lo, kMult);               \
+  const __m128i A1_hi = _mm_mulhi_epu16(A0_hi, kMult);               \
+  const __m128i A2_lo = _mm_srli_epi16(A1_lo, 7);                    \
+  const __m128i A2_hi = _mm_srli_epi16(A1_hi, 7);                    \
+  const __m128i A3 = _mm_packus_epi16(A2_lo, A2_hi);                 \
+  _mm_storeu_si128((__m128i*)&(RGBX), A3);                           \
 } while (0)
 
-static void ApplyAlphaMultiply(uint8_t* rgba, int alpha_first,
-                               int w, int h, int stride) {
+static void ApplyAlphaMultiply_SSE2(uint8_t* rgba, int alpha_first,
+                                    int w, int h, int stride) {
   const __m128i zero = _mm_setzero_si128();
-  const int kSpan = 2;
-  const int w2 = w & ~(kSpan - 1);
+  const __m128i kMult = _mm_set1_epi16(0x8081u);
+  const __m128i kMask = _mm_set_epi16(0, 0xff, 0xff, 0, 0, 0xff, 0xff, 0);
+  const int kSpan = 4;
   while (h-- > 0) {
     uint32_t* const rgbx = (uint32_t*)rgba;
     int i;
     if (!alpha_first) {
-      const __m128i kMask = _mm_set_epi16(0xff, 0, 0, 0, 0xff, 0, 0, 0);
-      const __m128i kMult =
-          _mm_set_epi16(0, 0x8081, 0x8081, 0x8081, 0, 0x8081, 0x8081, 0x8081);
-      for (i = 0; i < w2; i += kSpan) {
-        APPLY_ALPHA(rgbx[i], _MM_SHUFFLE(0, 3, 3, 3), kMask, kMult);
+      for (i = 0; i + kSpan <= w; i += kSpan) {
+        APPLY_ALPHA(rgbx[i], _MM_SHUFFLE(2, 3, 3, 3));
       }
     } else {
-      const __m128i kMask = _mm_set_epi16(0, 0, 0, 0xff, 0, 0, 0, 0xff);
-      const __m128i kMult =
-          _mm_set_epi16(0x8081, 0x8081, 0x8081, 0, 0x8081, 0x8081, 0x8081, 0);
-      for (i = 0; i < w2; i += kSpan) {
-        APPLY_ALPHA(rgbx[i], _MM_SHUFFLE(0, 0, 0, 3), kMask, kMult);
+      for (i = 0; i + kSpan <= w; i += kSpan) {
+        APPLY_ALPHA(rgbx[i], _MM_SHUFFLE(0, 0, 0, 1));
       }
     }
     // Finish with left-overs.
@@ -213,64 +213,51 @@ static void ApplyAlphaMultiply(uint8_t* rgba, int alpha_first,
 // -----------------------------------------------------------------------------
 // Apply alpha value to rows
 
-// We use: kINV255 = (1 << 24) / 255 = 0x010101
-// So: a * kINV255 = (a << 16) | [(a << 8) | a]
-// -> _mm_mulhi_epu16() takes care of the (a<<16) part,
-// and _mm_mullo_epu16(a * 0x0101,...) takes care of the "(a << 8) | a" one.
-
-static void MultARGBRow(uint32_t* const ptr, int width, int inverse) {
+static void MultARGBRow_SSE2(uint32_t* const ptr, int width, int inverse) {
   int x = 0;
   if (!inverse) {
     const int kSpan = 2;
     const __m128i zero = _mm_setzero_si128();
-    const __m128i kRound =
-        _mm_set_epi16(0, 1 << 7, 1 << 7, 1 << 7, 0, 1 << 7, 1 << 7, 1 << 7);
-    const __m128i kMult =
-        _mm_set_epi16(0, 0x0101, 0x0101, 0x0101, 0, 0x0101, 0x0101, 0x0101);
-    const __m128i kOne64 = _mm_set_epi16(1u << 8, 0, 0, 0, 1u << 8, 0, 0, 0);
-    const int w2 = width & ~(kSpan - 1);
-    for (x = 0; x < w2; x += kSpan) {
-      const __m128i argb0 = _mm_loadl_epi64((__m128i*)&ptr[x]);
-      const __m128i argb1 = _mm_unpacklo_epi8(argb0, zero);
-      const __m128i tmp0 = _mm_shufflelo_epi16(argb1, _MM_SHUFFLE(3, 3, 3, 3));
-      const __m128i tmp1 = _mm_shufflehi_epi16(tmp0, _MM_SHUFFLE(3, 3, 3, 3));
-      const __m128i tmp2 = _mm_srli_epi64(tmp1, 16);
-      const __m128i scale0 = _mm_mullo_epi16(tmp1, kMult);
-      const __m128i scale1 = _mm_or_si128(tmp2, kOne64);
-      const __m128i argb2 = _mm_mulhi_epu16(argb1, scale0);
-      const __m128i argb3 = _mm_mullo_epi16(argb1, scale1);
-      const __m128i argb4 = _mm_adds_epu16(argb2, argb3);
-      const __m128i argb5 = _mm_adds_epu16(argb4, kRound);
-      const __m128i argb6 = _mm_srli_epi16(argb5, 8);
-      const __m128i argb7 = _mm_packus_epi16(argb6, zero);
-      _mm_storel_epi64((__m128i*)&ptr[x], argb7);
+    const __m128i k128 = _mm_set1_epi16(128);
+    const __m128i kMult = _mm_set1_epi16(0x0101);
+    const __m128i kMask = _mm_set_epi16(0, 0xff, 0, 0, 0, 0xff, 0, 0);
+    for (x = 0; x + kSpan <= width; x += kSpan) {
+      // To compute 'result = (int)(a * x / 255. + .5)', we use:
+      //   tmp = a * v + 128, result = (tmp * 0x0101u) >> 16
+      const __m128i A0 = _mm_loadl_epi64((const __m128i*)&ptr[x]);
+      const __m128i A1 = _mm_unpacklo_epi8(A0, zero);
+      const __m128i A2 = _mm_or_si128(A1, kMask);
+      const __m128i A3 = _mm_shufflelo_epi16(A2, _MM_SHUFFLE(2, 3, 3, 3));
+      const __m128i A4 = _mm_shufflehi_epi16(A3, _MM_SHUFFLE(2, 3, 3, 3));
+      // here, A4 = [ff a0 a0 a0][ff a1 a1 a1]
+      const __m128i A5 = _mm_mullo_epi16(A4, A1);
+      const __m128i A6 = _mm_add_epi16(A5, k128);
+      const __m128i A7 = _mm_mulhi_epu16(A6, kMult);
+      const __m128i A10 = _mm_packus_epi16(A7, zero);
+      _mm_storel_epi64((__m128i*)&ptr[x], A10);
     }
   }
   width -= x;
   if (width > 0) WebPMultARGBRowC(ptr + x, width, inverse);
 }
 
-static void MultRow(uint8_t* const ptr, const uint8_t* const alpha,
-                    int width, int inverse) {
+static void MultRow_SSE2(uint8_t* const ptr, const uint8_t* const alpha,
+                         int width, int inverse) {
   int x = 0;
   if (!inverse) {
-    const int kSpan = 8;
     const __m128i zero = _mm_setzero_si128();
-    const __m128i kRound = _mm_set1_epi16(1 << 7);
-    const int w2 = width & ~(kSpan - 1);
-    for (x = 0; x < w2; x += kSpan) {
+    const __m128i k128 = _mm_set1_epi16(128);
+    const __m128i kMult = _mm_set1_epi16(0x0101);
+    for (x = 0; x + 8 <= width; x += 8) {
       const __m128i v0 = _mm_loadl_epi64((__m128i*)&ptr[x]);
+      const __m128i a0 = _mm_loadl_epi64((const __m128i*)&alpha[x]);
       const __m128i v1 = _mm_unpacklo_epi8(v0, zero);
-      const __m128i alpha0 = _mm_loadl_epi64((const __m128i*)&alpha[x]);
-      const __m128i alpha1 = _mm_unpacklo_epi8(alpha0, zero);
-      const __m128i alpha2 = _mm_unpacklo_epi8(alpha0, alpha0);
-      const __m128i v2 = _mm_mulhi_epu16(v1, alpha2);
-      const __m128i v3 = _mm_mullo_epi16(v1, alpha1);
-      const __m128i v4 = _mm_adds_epu16(v2, v3);
-      const __m128i v5 = _mm_adds_epu16(v4, kRound);
-      const __m128i v6 = _mm_srli_epi16(v5, 8);
-      const __m128i v7 = _mm_packus_epi16(v6, zero);
-      _mm_storel_epi64((__m128i*)&ptr[x], v7);
+      const __m128i a1 = _mm_unpacklo_epi8(a0, zero);
+      const __m128i v2 = _mm_mullo_epi16(v1, a1);
+      const __m128i v3 = _mm_add_epi16(v2, k128);
+      const __m128i v4 = _mm_mulhi_epu16(v3, kMult);
+      const __m128i v5 = _mm_packus_epi16(v4, zero);
+      _mm_storel_epi64((__m128i*)&ptr[x], v5);
     }
   }
   width -= x;
@@ -283,9 +270,9 @@ static void MultRow(uint8_t* const ptr, const uint8_t* const alpha,
 extern void WebPInitAlphaProcessingSSE2(void);
 
 WEBP_TSAN_IGNORE_FUNCTION void WebPInitAlphaProcessingSSE2(void) {
-  WebPMultARGBRow = MultARGBRow;
-  WebPMultRow = MultRow;
-  WebPApplyAlphaMultiply = ApplyAlphaMultiply;
+  WebPMultARGBRow = MultARGBRow_SSE2;
+  WebPMultRow = MultRow_SSE2;
+  WebPApplyAlphaMultiply = ApplyAlphaMultiply_SSE2;
   WebPDispatchAlpha = DispatchAlpha;
   WebPDispatchAlphaToGreen = DispatchAlphaToGreen;
   WebPExtractAlpha = ExtractAlpha;