Created address translation fast path for code reads, separated slow path into separa...

diff --git a/emulator.c b/emulator.c
index 802761794a7f237c2b9e2f227f2c4be26e2062e0..1be7bcd00ebb3e58229ac6a725a9ae801378e272 100644 (file)
--- a/emulator.c
+++ b/emulator.c
@@ -4,6 +4,7 @@
 #include "emulator.h"
 #include "platforms/platforms.h"
 #include "input/input.h"
+#include "m68kcpu.h"
 
 #include "platforms/amiga/Gayle.h"
 #include "platforms/amiga/amiga-registers.h"
@@ -43,6 +44,7 @@ unsigned char write_ranges;
 unsigned int write_addr[8];
 unsigned int write_upper[8];
 unsigned char *write_data[8];
+address_translation_cache code_translation_cache = {0};
 
 int kb_hook_enabled = 0;
 int mouse_hook_enabled = 0;

diff --git a/m68kcpu.c b/m68kcpu.c
index 7883bddcef8e786366180e6bbf827cf35e449c94..4a4fc39d12bb6a6a9c9b6b6584191d13c608059f 100644 (file)
--- a/m68kcpu.c
+++ b/m68kcpu.c
@@ -1208,7 +1208,7 @@ inline unsigned int  m68k_read_immediate_16(unsigned int address) {
                }
        }
 #endif
-       
+
        return m68k_read_memory_16(address);
 }
 inline unsigned int  m68k_read_immediate_32(unsigned int address) {
@@ -1230,7 +1230,7 @@ inline unsigned int  m68k_read_pcrelative_8(unsigned int address) {
                        return read_data[i][address - read_addr[i]];
                }
        }
-       
+
        return m68k_read_memory_8(address);
 }
 inline unsigned int  m68k_read_pcrelative_16(unsigned int address) {
@@ -1253,8 +1253,65 @@ inline unsigned int  m68k_read_pcrelative_32(unsigned int address) {
 }
 #endif
 
+
+uint m68ki_read_imm6_addr_slowpath(uint32_t address, address_translation_cache *cache)
+{
+       for (int i = 0; i < read_ranges; i++) {
+               if(address >= read_addr[i] && address < read_upper[i]) {
+            cache->lower = read_addr[i];
+            cache->upper = read_upper[i];
+            cache->data = read_data[i];
+                       REG_PC += 2;
+                       return be16toh(((unsigned short *)(read_data[i] + (address - read_addr[i])))[0]);
+               }
+       }
+
+       m68ki_set_fc(FLAG_S | FUNCTION_CODE_USER_PROGRAM); /* auto-disable (see m68kcpu.h) */
+       m68ki_cpu.mmu_tmp_fc = FLAG_S | FUNCTION_CODE_USER_PROGRAM;
+       m68ki_cpu.mmu_tmp_rw = 1;
+       m68ki_cpu.mmu_tmp_sz = M68K_SZ_WORD;
+       m68ki_check_address_error(REG_PC, MODE_READ, FLAG_S | FUNCTION_CODE_USER_PROGRAM); /* auto-disable (see m68kcpu.h) */
+
+#if M68K_EMULATE_PREFETCH
+{
+       uint result;
+       if(REG_PC != CPU_PREF_ADDR)
+       {
+               CPU_PREF_DATA = m68ki_ic_readimm16(REG_PC);
+               CPU_PREF_ADDR = m68ki_cpu.mmu_tmp_buserror_occurred ? ((uint32)~0) : REG_PC;
+       }
+       result = MASK_OUT_ABOVE_16(CPU_PREF_DATA);
+       REG_PC += 2;
+       if (!m68ki_cpu.mmu_tmp_buserror_occurred) {
+               // prefetch only if no bus error occurred in opcode fetch
+               CPU_PREF_DATA = m68ki_ic_readimm16(REG_PC);
+               CPU_PREF_ADDR = m68ki_cpu.mmu_tmp_buserror_occurred ? ((uint32)~0) : REG_PC;
+               // ignore bus error on prefetch
+               m68ki_cpu.mmu_tmp_buserror_occurred = 0;
+       }
+       return result;
+}
+#else
+
+       uint32_t address = ADDRESS_68K(REG_PC);
+       REG_PC += 2;
+
+       for (int i = 0; i < read_ranges; i++) {
+               if(address >= read_addr[i] && address < read_upper[i]) {
+                       return be16toh(((unsigned short *)(read_data[i] + (address - read_addr[i])))[0]);
+               }
+       }
+
+       return m68k_read_immediate_16(address);
+#endif /* M68K_EMULATE_PREFETCH */
+}
+
+
+
 void m68k_add_ram_range(uint32_t addr, uint32_t upper, unsigned char *ptr)
 {
+    code_translation_cache.lower = 0;
+    code_translation_cache.upper = 0;
        if ((addr == 0 && upper == 0) || upper < addr)
                return;
 
@@ -1300,6 +1357,8 @@ void m68k_add_ram_range(uint32_t addr, uint32_t upper, unsigned char *ptr)
 
 void m68k_add_rom_range(uint32_t addr, uint32_t upper, unsigned char *ptr)
 {
+    code_translation_cache.lower = 0;
+    code_translation_cache.upper = 0;
        if ((addr == 0 && upper == 0) || upper < addr)
                return;
 

diff --git a/m68kcpu.h b/m68kcpu.h
index 0be9551eb59f710ed440cd18cfbf22d80d99cd75..38d6b9f8eff29a54dea4a5869c852ae79a38b957 100644 (file)
--- a/m68kcpu.h
+++ b/m68kcpu.h
@@ -1075,6 +1075,13 @@ char* m68ki_disassemble_quick(unsigned int pc, unsigned int cpu_type);
 
 
 /* ---------------------------- Read Immediate ---------------------------- */
+typedef struct
+{
+    unsigned int lower;
+    unsigned int upper;
+    unsigned char *data;
+} address_translation_cache;
+
 
 extern unsigned char read_ranges;
 extern unsigned int read_addr[8];
@@ -1085,6 +1092,8 @@ extern unsigned int write_addr[8];
 extern unsigned int write_upper[8];
 extern unsigned char *write_data[8];
 
+extern address_translation_cache code_translation_cache;
+
 // clear the instruction cache
 inline void m68ki_ic_clear()
 {
@@ -1152,56 +1161,24 @@ static inline uint32 m68ki_ic_readimm16(uint32 address)
 /* Handles all immediate reads, does address error check, function code setting,
  * and prefetching if they are enabled in m68kconf.h
  */
-static inline uint m68ki_read_imm_16(void)
-{
-       uint32_t address = ADDRESS_68K(REG_PC);
-       for (int i = 0; i < read_ranges; i++) {
-               if(address >= read_addr[i] && address < read_upper[i]) {
-                       REG_PC += 2;
-                       return be16toh(((unsigned short *)(read_data[i] + (address - read_addr[i])))[0]);
-               }
-       }
+uint m68ki_read_imm6_addr_slowpath(uint32_t address, address_translation_cache *cache);
 
-       m68ki_set_fc(FLAG_S | FUNCTION_CODE_USER_PROGRAM); /* auto-disable (see m68kcpu.h) */
-       m68ki_cpu.mmu_tmp_fc = FLAG_S | FUNCTION_CODE_USER_PROGRAM;
-       m68ki_cpu.mmu_tmp_rw = 1;
-       m68ki_cpu.mmu_tmp_sz = M68K_SZ_WORD;
-       m68ki_check_address_error(REG_PC, MODE_READ, FLAG_S | FUNCTION_CODE_USER_PROGRAM); /* auto-disable (see m68kcpu.h) */
 
-#if M68K_EMULATE_PREFETCH
-{
-       uint result;
-       if(REG_PC != CPU_PREF_ADDR)
-       {
-               CPU_PREF_DATA = m68ki_ic_readimm16(REG_PC);
-               CPU_PREF_ADDR = m68ki_cpu.mmu_tmp_buserror_occurred ? ((uint32)~0) : REG_PC;
-       }
-       result = MASK_OUT_ABOVE_16(CPU_PREF_DATA);
-       REG_PC += 2;
-       if (!m68ki_cpu.mmu_tmp_buserror_occurred) {
-               // prefetch only if no bus error occurred in opcode fetch
-               CPU_PREF_DATA = m68ki_ic_readimm16(REG_PC);
-               CPU_PREF_ADDR = m68ki_cpu.mmu_tmp_buserror_occurred ? ((uint32)~0) : REG_PC;
-               // ignore bus error on prefetch
-               m68ki_cpu.mmu_tmp_buserror_occurred = 0;
-       }
-       return result;
-}
-#else
 
+static inline uint m68ki_read_imm_16(void)
+{
        uint32_t address = ADDRESS_68K(REG_PC);
-       REG_PC += 2;
 
-       for (int i = 0; i < read_ranges; i++) {
-               if(address >= read_addr[i] && address < read_upper[i]) {
-                       return be16toh(((unsigned short *)(read_data[i] + (address - read_addr[i])))[0]);
-               }
-       }
-
-       return m68k_read_immediate_16(address);
-#endif /* M68K_EMULATE_PREFETCH */
+    address_translation_cache *cache = &code_translation_cache;
+    if(address >= cache->lower && address < cache->upper)
+    {
+        REG_PC += 2;
+        return be16toh(((unsigned short *)(cache->data + (address - cache->lower)))[0]);
+    }
+    return m68ki_read_imm6_addr_slowpath(address, cache);
 }
 
+
 static inline uint m68ki_read_imm_8(void)
 {
        /* map read immediate 8 to read immediate 16 */