Merge optimisations from PocketSNES fork.

2 files changed, 150 insertions, 16 deletions

diff --git a/source/tile.c b/source/tile.c
index 17a2934..31d8380 100644
--- a/source/tile.c
+++ b/source/tile.c
@@ -126,8 +126,78 @@ static uint8_t ConvertTile(uint8_t* pCache, uint32_t TileAddr)
 
 #define PLOT_PIXEL(screen, pixel) (pixel)
 
-static void WRITE_4PIXELS16(int32_t Offset, uint8_t* Pixels, uint16_t* ScreenColors)
+static inline void WRITE_4PIXELS16(int32_t Offset, uint8_t* Pixels, uint16_t* ScreenColors)
 {
+#if defined(__MIPSEL) && defined(__GNUC__) && !defined(NO_ASM)
+	uint16_t *Screen = (uint16_t *) GFX.S + Offset;
+	uint8_t  *Depth = GFX.DB + Offset;
+	uint8_t  Pixel_A, Pixel_B, Pixel_C, Pixel_D;
+	uint8_t  Depth_A, Depth_B, Depth_C, Depth_D;
+	uint8_t  Cond;
+	uint32_t Temp;
+	__asm__ __volatile__ (
+		".set noreorder                        \n"
+		"   lbu   %[In8A], 0(%[In8])           \n"
+		"   lbu   %[In8B], 1(%[In8])           \n"
+		"   lbu   %[In8C], 2(%[In8])           \n"
+		"   lbu   %[In8D], 3(%[In8])           \n"
+		"   lbu   %[ZA], 0(%[Z])               \n"
+		"   lbu   %[ZB], 1(%[Z])               \n"
+		"   lbu   %[ZC], 2(%[Z])               \n"
+		"   lbu   %[ZD], 3(%[Z])               \n"
+		/* If In8A is non-zero (opaque) and ZCompare > ZA, write the pixel to
+		 * the screen from the palette. */
+		"   sltiu %[Temp], %[In8A], 1          \n"
+		"   sltu  %[Cond], %[ZCompare], %[ZA]  \n"
+		"   or    %[Cond], %[Cond], %[Temp]    \n"
+		/* Otherwise skip to the next pixel, B. */
+		"   bne   %[Cond], $0, 2f              \n"
+		/* Load the address of the palette entry (16-bit) corresponding to
+		 * this pixel (partially in the delay slot). */
+		"   sll   %[In8A], %[In8A], 1          \n"
+		"   addu  %[Temp], %[Palette], %[In8A] \n"
+		/* Load the palette entry. While that's being done, store the new
+		 * depth for this pixel. Then store to the screen. */
+		"   lhu   %[Temp], 0(%[Temp])          \n"
+		"   sb    %[ZSet], 0(%[Z])             \n"
+		"   sh    %[Temp], 0(%[Out16])         \n"
+		/* Now do the same for pixel B. */
+		"2: sltiu %[Temp], %[In8B], 1          \n"
+		"   sltu  %[Cond], %[ZCompare], %[ZB]  \n"
+		"   or    %[Cond], %[Cond], %[Temp]    \n"
+		"   bne   %[Cond], $0, 3f              \n"
+		"   sll   %[In8B], %[In8B], 1          \n"
+		"   addu  %[Temp], %[Palette], %[In8B] \n"
+		"   lhu   %[Temp], 0(%[Temp])          \n"
+		"   sb    %[ZSet], 1(%[Z])             \n"
+		"   sh    %[Temp], 2(%[Out16])         \n"
+		/* Now do the same for pixel C. */
+		"3: sltiu %[Temp], %[In8C], 1          \n"
+		"   sltu  %[Cond], %[ZCompare], %[ZC]  \n"
+		"   or    %[Cond], %[Cond], %[Temp]    \n"
+		"   bne   %[Cond], $0, 4f              \n"
+		"   sll   %[In8C], %[In8C], 1          \n"
+		"   addu  %[Temp], %[Palette], %[In8C] \n"
+		"   lhu   %[Temp], 0(%[Temp])          \n"
+		"   sb    %[ZSet], 2(%[Z])             \n"
+		"   sh    %[Temp], 4(%[Out16])         \n"
+		/* Now do the same for pixel D. */
+		"4: sltiu %[Temp], %[In8D], 1          \n"
+		"   sltu  %[Cond], %[ZCompare], %[ZD]  \n"
+		"   or    %[Cond], %[Cond], %[Temp]    \n"
+		"   bne   %[Cond], $0, 5f              \n"
+		"   sll   %[In8D], %[In8D], 1          \n"
+		"   addu  %[Temp], %[Palette], %[In8D] \n"
+		"   lhu   %[Temp], 0(%[Temp])          \n"
+		"   sb    %[ZSet], 3(%[Z])             \n"
+		"   sh    %[Temp], 6(%[Out16])         \n"
+		"5:                                    \n"
+		".set reorder                          \n"
+		: /* output */  [In8A] "=&r" (Pixel_A), [In8B] "=&r" (Pixel_B), [In8C] "=&r" (Pixel_C), [In8D] "=&r" (Pixel_D), [ZA] "=&r" (Depth_A), [ZB] "=&r" (Depth_B), [ZC] "=&r" (Depth_C), [ZD] "=&r" (Depth_D), [Cond] "=&r" (Cond), [Temp] "=&r" (Temp)
+		: /* input */   [Out16] "r" (Screen), [Z] "r" (Depth), [In8] "r" (Pixels), [Palette] "r" (ScreenColors), [ZCompare] "r" (GFX.Z1), [ZSet] "r" (GFX.Z2)
+		: /* clobber */ "memory"
+	);
+#else
    uint8_t  Pixel, N;
    uint16_t* Screen = (uint16_t*) GFX.S + Offset;
    uint8_t*  Depth = GFX.DB + Offset;
@@ -140,10 +210,81 @@ static void WRITE_4PIXELS16(int32_t Offset, uint8_t* Pixels, uint16_t* ScreenCol
          Depth [N] = GFX.Z2;
       }
    }
+#endif
 }
 
-static void WRITE_4PIXELS16_FLIPPED(int32_t Offset, uint8_t* Pixels, uint16_t* ScreenColors)
+static inline void WRITE_4PIXELS16_FLIPPED(int32_t Offset, uint8_t* Pixels, uint16_t* ScreenColors)
 {
+#if defined(__MIPSEL) && defined(__GNUC__) && !defined(NO_ASM)
+	uint16_t *Screen = (uint16_t *) GFX.S + Offset;
+	uint8_t  *Depth = GFX.DB + Offset;
+	uint8_t  Pixel_A, Pixel_B, Pixel_C, Pixel_D;
+	uint8_t  Depth_A, Depth_B, Depth_C, Depth_D;
+	uint8_t  Cond;
+	uint32_t Temp;
+	__asm__ __volatile__ (
+		".set noreorder                        \n"
+		"   lbu   %[In8A], 3(%[In8])           \n"
+		"   lbu   %[In8B], 2(%[In8])           \n"
+		"   lbu   %[In8C], 1(%[In8])           \n"
+		"   lbu   %[In8D], 0(%[In8])           \n"
+		"   lbu   %[ZA], 0(%[Z])               \n"
+		"   lbu   %[ZB], 1(%[Z])               \n"
+		"   lbu   %[ZC], 2(%[Z])               \n"
+		"   lbu   %[ZD], 3(%[Z])               \n"
+		/* If In8A is non-zero (opaque) and ZCompare > ZA, write the pixel to
+		 * the screen from the palette. */
+		"   sltiu %[Temp], %[In8A], 1          \n"
+		"   sltu  %[Cond], %[ZCompare], %[ZA]  \n"
+		"   or    %[Cond], %[Cond], %[Temp]    \n"
+		/* Otherwise skip to the next pixel, B. */
+		"   bne   %[Cond], $0, 2f              \n"
+		/* Load the address of the palette entry (16-bit) corresponding to
+		 * this pixel (partially in the delay slot). */
+		"   sll   %[In8A], %[In8A], 1          \n"
+		"   addu  %[Temp], %[Palette], %[In8A] \n"
+		/* Load the palette entry. While that's being done, store the new
+		 * depth for this pixel. Then store to the screen. */
+		"   lhu   %[Temp], 0(%[Temp])          \n"
+		"   sb    %[ZSet], 0(%[Z])             \n"
+		"   sh    %[Temp], 0(%[Out16])         \n"
+		/* Now do the same for pixel B. */
+		"2: sltiu %[Temp], %[In8B], 1          \n"
+		"   sltu  %[Cond], %[ZCompare], %[ZB]  \n"
+		"   or    %[Cond], %[Cond], %[Temp]    \n"
+		"   bne   %[Cond], $0, 3f              \n"
+		"   sll   %[In8B], %[In8B], 1          \n"
+		"   addu  %[Temp], %[Palette], %[In8B] \n"
+		"   lhu   %[Temp], 0(%[Temp])          \n"
+		"   sb    %[ZSet], 1(%[Z])             \n"
+		"   sh    %[Temp], 2(%[Out16])         \n"
+		/* Now do the same for pixel C. */
+		"3: sltiu %[Temp], %[In8C], 1          \n"
+		"   sltu  %[Cond], %[ZCompare], %[ZC]  \n"
+		"   or    %[Cond], %[Cond], %[Temp]    \n"
+		"   bne   %[Cond], $0, 4f              \n"
+		"   sll   %[In8C], %[In8C], 1          \n"
+		"   addu  %[Temp], %[Palette], %[In8C] \n"
+		"   lhu   %[Temp], 0(%[Temp])          \n"
+		"   sb    %[ZSet], 2(%[Z])             \n"
+		"   sh    %[Temp], 4(%[Out16])         \n"
+		/* Now do the same for pixel D. */
+		"4: sltiu %[Temp], %[In8D], 1          \n"
+		"   sltu  %[Cond], %[ZCompare], %[ZD]  \n"
+		"   or    %[Cond], %[Cond], %[Temp]    \n"
+		"   bne   %[Cond], $0, 5f              \n"
+		"   sll   %[In8D], %[In8D], 1          \n"
+		"   addu  %[Temp], %[Palette], %[In8D] \n"
+		"   lhu   %[Temp], 0(%[Temp])          \n"
+		"   sb    %[ZSet], 3(%[Z])             \n"
+		"   sh    %[Temp], 6(%[Out16])         \n"
+		"5:                                    \n"
+		".set reorder                          \n"
+		: /* output */  [In8A] "=&r" (Pixel_A), [In8B] "=&r" (Pixel_B), [In8C] "=&r" (Pixel_C), [In8D] "=&r" (Pixel_D), [ZA] "=&r" (Depth_A), [ZB] "=&r" (Depth_B), [ZC] "=&r" (Depth_C), [ZD] "=&r" (Depth_D), [Cond] "=&r" (Cond), [Temp] "=&r" (Temp)
+		: /* input */   [Out16] "r" (Screen), [Z] "r" (Depth), [In8] "r" (Pixels), [Palette] "r" (ScreenColors), [ZCompare] "r" (GFX.Z1), [ZSet] "r" (GFX.Z2)
+		: /* clobber */ "memory"
+	);
+#else
    uint8_t  Pixel, N;
    uint16_t* Screen = (uint16_t*) GFX.S + Offset;
    uint8_t*  Depth = GFX.DB + Offset;
@@ -156,6 +297,7 @@ static void WRITE_4PIXELS16_FLIPPED(int32_t Offset, uint8_t* Pixels, uint16_t* S
          Depth [N] = GFX.Z2;
       }
    }
+#endif
 }
 
 static void WRITE_4PIXELS16_HALFWIDTH(int32_t Offset, uint8_t* Pixels, uint16_t* ScreenColors)
diff --git a/source/tile.h b/source/tile.h
index 1dbc1fa..74f6327 100644
--- a/source/tile.h
+++ b/source/tile.h
@@ -36,29 +36,23 @@
        bp = pCache + StartLine; \
        for (l = LineCount; l != 0; l--, bp += 8, Offset += GFX.PPL) \
        { \
-          if (*(uint32_t *) bp) \
-             NORMAL (Offset, bp, ScreenColors); \
-          if (*(uint32_t *) (bp + 4)) \
-             NORMAL (Offset + N, bp + 4, ScreenColors); \
+			NORMAL (Offset, bp, ScreenColors); \
+			NORMAL (Offset + N, bp + 4, ScreenColors); \
        } \
        break; \
     case H_FLIP: \
        bp = pCache + StartLine; \
        for (l = LineCount; l != 0; l--, bp += 8, Offset += GFX.PPL) \
        { \
-          if (*(uint32_t *) (bp + 4)) \
-             FLIPPED (Offset, bp + 4, ScreenColors); \
-          if (*(uint32_t *) bp) \
-             FLIPPED (Offset + N, bp, ScreenColors); \
+			FLIPPED (Offset, bp + 4, ScreenColors); \
+			FLIPPED (Offset + N, bp, ScreenColors); \
        } \
        break; \
     case H_FLIP | V_FLIP: \
        bp = pCache + 56 - StartLine; \
        for (l = LineCount; l != 0; l--, bp -= 8, Offset += GFX.PPL) \
        { \
-          if (*(uint32_t *) (bp + 4)) \
              FLIPPED (Offset, bp + 4, ScreenColors); \
-          if (*(uint32_t *) bp) \
              FLIPPED (Offset + N, bp, ScreenColors); \
        } \
        break; \
@@ -66,10 +60,8 @@
        bp = pCache + 56 - StartLine; \
        for (l = LineCount; l != 0; l--, bp -= 8, Offset += GFX.PPL) \
        { \
-          if (*(uint32_t *) bp) \
-             NORMAL (Offset, bp, ScreenColors); \
-          if (*(uint32_t *) (bp + 4)) \
-             NORMAL (Offset + N, bp + 4, ScreenColors); \
+			NORMAL (Offset, bp, ScreenColors); \
+			NORMAL (Offset + N, bp + 4, ScreenColors); \
        } \
        break; \
     default: \