68040+ cycle count adjustment

diff --git a/newcpu.cpp b/newcpu.cpp
index c05e2193d601d176cf8b972bb0e4daf215ab8874..2fb9506449332142f6193c55be4d5bdc43ede67a 100644 (file)
--- a/newcpu.cpp
+++ b/newcpu.cpp
@@ -2100,6 +2100,9 @@ static void update_68k_cycles (void)
                }
        }
        cycles_mult &= ~0x7f;
+       if (cycles_mult < 0x80) {
+               cycles_mult = 0x80;
+       }
 
        currprefs.cpu_clock_multiplier = changed_prefs.cpu_clock_multiplier;
        currprefs.cpu_frequency = changed_prefs.cpu_frequency;
@@ -5849,6 +5852,7 @@ static void m68k_run_3ce (void)
                check_debugger();
                TRY(prb) {
                        while (!exit) {
+                               evt_t c = get_cycles();
                                r->instruction_pc = m68k_getpc();
                                r->opcode = get_iword_cache_040(0);
                                // "prefetch"
@@ -5866,13 +5870,16 @@ static void m68k_run_3ce (void)
                                                exit = true;
                                }
 
-                               regs.instruction_cnt++;
                                // workaround for situation when all accesses are cached
-                               extracycles++;
-                               if (extracycles >= 8) {
-                                       extracycles = 0;
-                                       x_do_cycles(CYCLE_UNIT);
+                               if (c == get_cycles()) {
+                                       extracycles++;
+                                       if (extracycles >= 4) {
+                                               extracycles = 0;
+                                               x_do_cycles(CYCLE_UNIT);
+                                       }
                                }
+
+                               regs.instruction_cnt++;
                        }
                } CATCH(prb) {
                        bus_error();
@@ -5908,10 +5915,10 @@ static void m68k_run_3p(void)
 
                                (*cpufunctbl_noret[r->opcode])(r->opcode);
 
-                               cpu_cycles = 1 * CYCLE_UNIT;
+                               cpu_cycles = 2 * CYCLE_UNIT;
                                cycles = adjust_cycles(cpu_cycles);
                                regs.instruction_cnt++;
-                               do_cycles(cycles);
+                               x_do_cycles(cycles);
 
                                if (r->spcflags) {
                                        if (do_specialties(0))