SSE2 implementation of VP8PackARGB

Change-Id: I40c0e26a6a2701216e4ddebcf793aa535677f437

src/dsp/argb_sse2.c

@@ -0,0 +1,62 @@
+// Copyright 2014 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.
+// -----------------------------------------------------------------------------
+//
+//   ARGB making functions (SSE2 version).
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include "./dsp.h"
+
+#if defined(WEBP_USE_SSE2)
+
+#include <assert.h>
+#include <emmintrin.h>
+#include <string.h>
+
+static WEBP_INLINE uint32_t MakeARGB32(int a, int r, int g, int b) {
+  return (((uint32_t)a << 24) | (r << 16) | (g << 8) | b);
+}
+
+static void PackARGB(const uint8_t* a, const uint8_t* r, const uint8_t* g,
+                     const uint8_t* b, int len, uint32_t* out) {
+  if (g == r + 1) {  // RGBA input order. Need to swap R and B.
+    int i = 0;
+    const int len4 = len & ~3;
+    const __m128i mask = _mm_set1_epi32(0x00ff00ffu);
+    assert(b == r + 2);
+    assert(a == r + 3);
+    for (; i < len4; i += 4) {
+      const __m128i A = _mm_loadu_si128((__m128i*)(r + 4 * i));
+      const __m128i B = _mm_and_si128(A, mask);     // R 0 B 0
+      const __m128i C = _mm_andnot_si128(mask, A);  // 0 G 0 A
+      const __m128i D = _mm_shufflelo_epi16(B, _MM_SHUFFLE(2, 3, 0, 1));
+      const __m128i E = _mm_shufflehi_epi16(D, _MM_SHUFFLE(2, 3, 0, 1));
+      const __m128i F = _mm_or_si128(E, C);
+      _mm_storeu_si128((__m128i*)(out + i), F);
+    }
+    for (; i < len; ++i) {
+      out[i] = MakeARGB32(a[4 * i], r[4 * i], g[4 * i], b[4 * i]);
+    }
+  } else {
+    assert(g == b + 1);
+    assert(r == b + 2);
+    assert(a == b + 3);
+    memcpy(out, b, len * 4);
+  }
+}
+
+#endif    // WEBP_USE_SSE2
+
+extern void VP8EncDspARGBInitSSE2(void);
+
+WEBP_TSAN_IGNORE_FUNCTION void VP8EncDspARGBInitSSE2(void) {
+#if defined(WEBP_USE_SSE2)
+  VP8PackARGB = PackARGB;
+#endif
+}