Added SSE accelerated RGB565 to 32-bit pixel conversions

src/video/SDL_blit_N.c

@@ -38,7 +38,7 @@
 // Functions to blit from N-bit surfaces to other surfaces
 
 #define BLIT_FEATURE_NONE                       0x00
-#define BLIT_FEATURE_HAS_MMX                    0x01
+#define BLIT_FEATURE_HAS_SSE41                  0x01
 #define BLIT_FEATURE_HAS_ALTIVEC                0x02
 #define BLIT_FEATURE_ALTIVEC_DONT_USE_PREFETCH  0x04
 
@@ -875,8 +875,8 @@ static Uint32 GetBlitFeatures(void)
     static Uint32 features = ~0u;
     if (features == ~0u) {
         features = (0
-                    // Feature 1 is has-MMX
-                    | ((SDL_HasMMX()) ? BLIT_FEATURE_HAS_MMX : 0)
+                    // Feature 1 is has-SSE41
+                    | ((SDL_HasSSE41()) ? BLIT_FEATURE_HAS_SSE41 : 0)
                     // Feature 2 is has-AltiVec
                     | ((SDL_HasAltiVec()) ? BLIT_FEATURE_HAS_ALTIVEC : 0)
                     // Feature 4 is dont-use-prefetch
@@ -890,8 +890,8 @@ static Uint32 GetBlitFeatures(void)
 #pragma altivec_model off
 #endif
 #else
-// Feature 1 is has-MMX
-#define GetBlitFeatures() ((SDL_HasMMX() ? BLIT_FEATURE_HAS_MMX : 0))
+// Feature 1 is has-SSE41
+#define GetBlitFeatures() ((SDL_HasSSE41() ? BLIT_FEATURE_HAS_SSE41 : 0))
 #endif
 
 // This is now endian dependent
@@ -1163,6 +1163,109 @@ static void Blit_XRGB8888_RGB565(SDL_BlitInfo *info)
 #endif // USE_DUFFS_LOOP
 }
 
+#ifdef SDL_SSE4_1_INTRINSICS
+
+static void SDL_TARGETING("sse4.1") Blit_RGB565_32_SSE41(SDL_BlitInfo *info, int Rshift, int Gshift, int Bshift, int Amask)
+{
+    int c;
+    int width, height;
+    const Uint16 *src;
+    Uint32 *dst;
+    int srcskip, dstskip;
+    Uint8 r, g, b;
+
+    // Set up some basic variables
+    width = info->dst_w;
+    height = info->dst_h;
+    src = (const Uint16 *)info->src;
+    srcskip = info->src_skip / 2;
+    dst = (Uint32 *)info->dst;
+    dstskip = info->dst_skip / 4;
+
+    while (height--) {
+        // Copy in 4 pixel chunks
+        for (c = width / 4; c; --c) {
+            // Load 4 16-bit RGB565 pixels into an SSE register
+            __m128i pixels_rgb565 = _mm_loadu_si128((__m128i*)src);
+
+            // Extract Red components (5 bits)
+            __m128i red_5bit = _mm_and_si128(pixels_rgb565, _mm_set1_epi16(0xF800)); // Mask for Red
+            red_5bit = _mm_srli_epi16(red_5bit, 11); // Shift to get 5-bit value
+            __m128i red_8bit = _mm_cvtepu16_epi32(red_5bit); // Convert to 32-bit and zero-extend
+            red_8bit = _mm_slli_epi32(red_8bit, 3); // Scale to 8 bits (multiply by 8)
+            red_8bit = _mm_or_si128(red_8bit, _mm_srli_epi32(red_8bit, 5)); // Replicate top 3 bits for better scaling
+
+            // Extract Green components (6 bits)
+            __m128i green_6bit = _mm_and_si128(pixels_rgb565, _mm_set1_epi16(0x07E0)); // Mask for Green
+            green_6bit = _mm_srli_epi16(green_6bit, 5); // Shift to get 6-bit value
+            __m128i green_8bit = _mm_cvtepu16_epi32(green_6bit); // Convert to 32-bit and zero-extend
+            green_8bit = _mm_slli_epi32(green_8bit, 2); // Scale to 8 bits (multiply by 4)
+            green_8bit = _mm_or_si128(green_8bit, _mm_srli_epi32(green_8bit, 6)); // Replicate top 2 bits
+
+            // Extract Blue components (5 bits)
+            __m128i blue_5bit = _mm_and_si128(pixels_rgb565, _mm_set1_epi16(0x001F)); // Mask for Blue
+            __m128i blue_8bit = _mm_cvtepu16_epi32(blue_5bit); // Convert to 32-bit and zero-extend
+            blue_8bit = _mm_slli_epi32(blue_8bit, 3); // Scale to 8 bits (multiply by 8)
+            blue_8bit = _mm_or_si128(blue_8bit, _mm_srli_epi32(blue_8bit, 5)); // Replicate top 3 bits
+
+            // Set Alpha to opaque (0xFF)
+            __m128i alpha_8bit = _mm_set1_epi32(Amask);
+
+            // Combine into 32-bit values
+            __m128i argb_pixels_low = _mm_or_si128(alpha_8bit, _mm_slli_epi32(red_8bit, Rshift));
+            argb_pixels_low = _mm_or_si128(argb_pixels_low, _mm_slli_epi32(green_8bit, Gshift));
+            argb_pixels_low = _mm_or_si128(argb_pixels_low, _mm_slli_epi32(blue_8bit, Bshift));
+
+            // Store the results
+            _mm_storeu_si128((__m128i*)dst, argb_pixels_low);
+            src += 4;
+            dst += 4;
+        }
+        // Get any leftovers
+        switch (width & 3) {
+        case 3:
+            RGB_FROM_RGB565(*src, r, g, b);
+            *dst++ = (r << Rshift) | (g << Gshift) | (b << Bshift) | Amask;
+            ++src;
+            SDL_FALLTHROUGH;
+        case 2:
+            RGB_FROM_RGB565(*src, r, g, b);
+            *dst++ = (r << Rshift) | (g << Gshift) | (b << Bshift) | Amask;
+            ++src;
+            SDL_FALLTHROUGH;
+        case 1:
+            RGB_FROM_RGB565(*src, r, g, b);
+            *dst++ = (r << Rshift) | (g << Gshift) | (b << Bshift) | Amask;
+            ++src;
+            break;
+        }
+        src += srcskip;
+        dst += dstskip;
+    }
+}
+
+static void Blit_RGB565_ARGB8888_SSE41(SDL_BlitInfo * info)
+{
+    Blit_RGB565_32_SSE41(info, 16, 8, 0, 0xFF000000);
+}
+
+static void Blit_RGB565_ABGR8888_SSE41(SDL_BlitInfo * info)
+{
+    Blit_RGB565_32_SSE41(info, 0, 8, 16, 0xFF000000);
+}
+
+static void Blit_RGB565_RGBA8888_SSE41(SDL_BlitInfo * info)
+{
+    Blit_RGB565_32_SSE41(info, 24, 16, 8, 0x000000FF);
+}
+
+static void Blit_RGB565_BGRA8888_SSE41(SDL_BlitInfo * info)
+{
+    Blit_RGB565_32_SSE41(info, 8, 16, 24, 0x000000FF);
+}
+
+#endif // SDL_SSE4_1_INTRINSICS
+
 #ifdef SDL_HAVE_BLIT_N_RGB565
 
 // Special optimized blit for RGB 5-6-5 --> 32-bit RGB surfaces
@@ -2700,6 +2803,16 @@ static const struct blit_table normal_blit_2[] = {
     { 0x00007C00, 0x000003E0, 0x0000001F, 4, 0x00000000, 0x00000000, 0x00000000,
       BLIT_FEATURE_HAS_ALTIVEC, Blit_RGB555_32Altivec, NO_ALPHA | COPY_ALPHA | SET_ALPHA },
 #endif
+#ifdef SDL_SSE4_1_INTRINSICS
+    { 0x0000F800, 0x000007E0, 0x0000001F, 4, 0x00FF0000, 0x0000FF00, 0x000000FF,
+      BLIT_FEATURE_HAS_SSE41, Blit_RGB565_ARGB8888_SSE41, NO_ALPHA | COPY_ALPHA | SET_ALPHA },
+    { 0x0000F800, 0x000007E0, 0x0000001F, 4, 0x000000FF, 0x0000FF00, 0x00FF0000,
+      BLIT_FEATURE_HAS_SSE41, Blit_RGB565_ABGR8888_SSE41, NO_ALPHA | COPY_ALPHA | SET_ALPHA },
+    { 0x0000F800, 0x000007E0, 0x0000001F, 4, 0xFF000000, 0x00FF0000, 0x0000FF00,
+      BLIT_FEATURE_HAS_SSE41, Blit_RGB565_RGBA8888_SSE41, NO_ALPHA | COPY_ALPHA | SET_ALPHA },
+    { 0x0000F800, 0x000007E0, 0x0000001F, 4, 0x0000FF00, 0x00FF0000, 0xFF000000,
+      BLIT_FEATURE_HAS_SSE41, Blit_RGB565_BGRA8888_SSE41, NO_ALPHA | COPY_ALPHA | SET_ALPHA },
+#endif
 #ifdef SDL_HAVE_BLIT_N_RGB565
     { 0x0000F800, 0x000007E0, 0x0000001F, 4, 0x00FF0000, 0x0000FF00, 0x000000FF,
       0, Blit_RGB565_ARGB8888, NO_ALPHA | COPY_ALPHA | SET_ALPHA },