Fix up Musashi performance with prefetch enabled

Mapped memory ranges should always be given preference, since they can't actually cause a bus error or affect any read/write operations over the 68k bus.

diff --git a/m68kcpu.h b/m68kcpu.h
index 680aa714b3678b3c5c02a6b5576488b9a2971fa9..0be9551eb59f710ed440cd18cfbf22d80d99cd75 100644 (file)
--- a/m68kcpu.h
+++ b/m68kcpu.h
@@ -1154,6 +1154,14 @@ static inline uint32 m68ki_ic_readimm16(uint32 address)
  */
 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]);
+               }
+       }
+
        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;
@@ -1208,6 +1216,13 @@ static inline uint m68ki_read_imm_32(void)
 //         address = pmmu_translate_addr(address,1);
 #endif
 #endif
+       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 += 4;
+                       return be32toh(((unsigned int *)(read_data[i] + (address - read_addr[i])))[0]);
+               }
+       }
 
 #if M68K_EMULATE_PREFETCH
        uint temp_val;