SNES: Const some jump tables, saves 5KB RAM

jobitjoseph · Oct 17, 2022 · b29db1c · b29db1c
1 parent d589510
commit b29db1c
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Showing 7 changed files with 29 additions and 15 deletions.
diff --git a/components/retro-go/rg_system.h b/components/retro-go/rg_system.h
@@ -18,6 +18,7 @@ extern "C" {
 #define SPI_DMA_CH_AUTO 1
 #endif
 #else
+#define EXT_RAM_ATTR
 #define IRAM_ATTR
 #define RTC_NOINIT_ATTR
 #endif

diff --git a/components/snes9x/apu.h b/components/snes9x/apu.h
@@ -79,7 +79,7 @@ bool S9xInitSound(int32_t buffer_ms, int32_t lag_ms);
 void S9xPrintAPUState(void);
 extern uint8_t S9xAPUCycles [256];       /* Scaled cycle lengths */
 extern uint8_t S9xAPUCycleLengths [256]; /* Raw data. */
-extern void (*S9xApuOpcodes [256])(void);
+extern void (* const S9xApuOpcodes [256])(void);
 
 #define APU_VOL_LEFT  0x00
 #define APU_VOL_RIGHT 0x01

diff --git a/components/snes9x/cpuexec.h b/components/snes9x/cpuexec.h
@@ -15,7 +15,7 @@ typedef struct
 typedef struct
 {
    uint8_t*   UNUSED1;
-   SOpcodes*  S9xOpcodes;
+   const SOpcodes*  S9xOpcodes;
    SRegisters Registers;
    uint8_t    _Carry;
    uint8_t    _Zero;
@@ -36,11 +36,11 @@ void S9xDoHBlankProcessing(void);
 void S9xClearIRQ(uint32_t source);
 void S9xSetIRQ(uint32_t source);
 
-extern SOpcodes S9xOpcodesE1   [256];
-extern SOpcodes S9xOpcodesM1X1 [256];
-extern SOpcodes S9xOpcodesM1X0 [256];
-extern SOpcodes S9xOpcodesM0X1 [256];
-extern SOpcodes S9xOpcodesM0X0 [256];
+extern const SOpcodes S9xOpcodesE1   [256];
+extern const SOpcodes S9xOpcodesM1X1 [256];
+extern const SOpcodes S9xOpcodesM1X0 [256];
+extern const SOpcodes S9xOpcodesM0X1 [256];
+extern const SOpcodes S9xOpcodesM0X0 [256];
 
 extern SICPU ICPU;
 

diff --git a/components/snes9x/cpuops.c b/components/snes9x/cpuops.c
@@ -3952,7 +3952,7 @@ static void Op42(void)
 }
 
 /* CPU-S9xOpcodes Definitions */
-SOpcodes S9xOpcodesM1X1[256] =
+const SOpcodes S9xOpcodesM1X1[256] =
 {
    {Op00},      {Op01M1},    {Op02},      {Op03M1},    {Op04M1},
    {Op05M1},    {Op06M1},    {Op07M1},    {Op08},      {Op09M1},
@@ -4008,7 +4008,7 @@ SOpcodes S9xOpcodesM1X1[256] =
    {OpFFM1}
 };
 
-SOpcodes S9xOpcodesE1[256] =
+const SOpcodes S9xOpcodesE1[256] =
 {
     {Op00},	     {Op01M1},    {Op02},      {Op03M1},    {Op04M1},
     {Op05M1},    {Op06M1},    {Op07M1},    {Op08E1},    {Op09M1},
@@ -4064,7 +4064,7 @@ SOpcodes S9xOpcodesE1[256] =
     {OpFFM1}
 };
 
-SOpcodes S9xOpcodesM1X0[256] =
+const SOpcodes S9xOpcodesM1X0[256] =
 {
    {Op00},  {Op01M1},    {Op02},      {Op03M1},    {Op04M1},
    {Op05M1},    {Op06M1},    {Op07M1},    {Op08},      {Op09M1},
@@ -4120,7 +4120,7 @@ SOpcodes S9xOpcodesM1X0[256] =
    {OpFFM1}
 };
 
-SOpcodes S9xOpcodesM0X0[256] =
+const SOpcodes S9xOpcodesM0X0[256] =
 {
    {Op00},  {Op01M0},    {Op02},      {Op03M0},    {Op04M0},
    {Op05M0},    {Op06M0},    {Op07M0},    {Op08},      {Op09M0},
@@ -4176,7 +4176,7 @@ SOpcodes S9xOpcodesM0X0[256] =
    {OpFFM0}
 };
 
-SOpcodes S9xOpcodesM0X1[256] =
+const SOpcodes S9xOpcodesM0X1[256] =
 {
    {Op00},  {Op01M0},    {Op02},      {Op03M0},    {Op04M0},
    {Op05M0},    {Op06M0},    {Op07M0},    {Op08},      {Op09M0},

diff --git a/components/snes9x/memmap.c b/components/snes9x/memmap.c
@@ -30,7 +30,7 @@
 #define MAP_RONLY_SRAM_OR_NONE (Memory.SRAMSize == 0 ? (uint8_t*) MAP_NONE : (uint8_t*) MAP_RONLY_SRAM)
 
 static int32_t retry_count = 0;
-static uint8_t bytes0x2000 [0x2000];
+static uint8_t *bytes0x2000; //  [0x2000];
 static bool is_bsx(uint8_t*);
 static bool bs_name(uint8_t*);
 
@@ -255,7 +255,10 @@ bool S9xInitMemory(void)
    IPPU.TileCache = (uint8_t*) calloc(MAX_2BIT_TILES, 128);
    IPPU.TileCached = (uint8_t*) calloc(MAX_2BIT_TILES, 1);
 
-   if (!Memory.RAM || !Memory.SRAM || !Memory.VRAM || !Memory.ROM || !IPPU.TileCache || !IPPU.TileCached)
+   bytes0x2000 = (uint8_t *)calloc(0x2000, 1);
+
+   if (!Memory.RAM || !Memory.SRAM || !Memory.VRAM || !Memory.ROM
+      || !IPPU.TileCache || !IPPU.TileCached || !bytes0x2000)
    {
       S9xDeinitMemory();
       return false;
@@ -305,6 +308,12 @@ void S9xDeinitMemory(void)
       IPPU.TileCache = NULL;
    }
 
+   if (bytes0x2000)
+   {
+      free(bytes0x2000);
+      bytes0x2000 = NULL;
+   }
+
    /* Ensure that we free the static char
     * array allocated by Safe() */
    Safe(NULL);

diff --git a/components/snes9x/port.h b/components/snes9x/port.h
@@ -8,7 +8,11 @@
 #include <string.h>
 #include <sys/types.h>
 
+#ifdef RETRO_GO
 #include <rg_system.h>
+#else
+#define EXT_RAM_ATTR
+#endif
 
 #ifndef INLINE
 #define INLINE inline

diff --git a/components/snes9x/spc700.c b/components/snes9x/spc700.c
@@ -2641,7 +2641,7 @@ void ApuFB(void)
    IAPU.PC += 2;
 }
 
-void (*S9xApuOpcodes[256])(void) =
+void (*const S9xApuOpcodes[256])(void) =
 {
    Apu00, Apu01, Apu02, Apu03, Apu04, Apu05, Apu06, Apu07,
    Apu08, Apu09, Apu0A, Apu0B, Apu0C, Apu0D, Apu0E, Apu0F,