[VM][I386_NP21][WIP] Implement more accuracy around variable clock.

diff --git a/source/src/vm/i386_np21.cpp b/source/src/vm/i386_np21.cpp
index 460bc23..99347c2 100644 (file)
--- a/source/src/vm/i386_np21.cpp
+++ b/source/src/vm/i386_np21.cpp
@@ -357,51 +357,49 @@ int I386::run(int cycles)
 {
        // Prefer to run as one step (cycles == -1). 20220210 K.O
        __LIKELY_IF(cycles == -1) {
-               int passed_cycles;
+               if(_SINGLE_MODE_DMA) {
+                       __LIKELY_IF(device_dma != NULL) {
+                               device_dma->do_dma();
+                       }
+               }
+               int __cycles;
                __UNLIKELY_IF(busreq) {
                        // don't run cpu!
-//#ifdef SINGLE_MODE_DMA
-                       __LIKELY_IF(_SINGLE_MODE_DMA) {
-                               if(device_dma != NULL) device_dma->do_dma();
-                       }
-//#endif
-                       // 80386 CPI: 4.9
-                       int __cycles = 5;
-                       if(extra_cycles > 0) {
-                               __cycles += extra_cycles;
-                               extra_cycles = 0;
-                       }
-                       __UNLIKELY_IF(_USE_DEBUGGER) {
-                               total_cycles += __cycles;
-                       }
-                       cpu_wait(5, i386_memory_wait);
-                       return __cycles;
+                       // 80386 CPI: 4.9, minimum clocks may be 5.
+                       __cycles = 5;
                } else {
                        // run only one opcode
-                       int __cycles = run_one_opecode();
-                       int tmp_extra_cycles = 0;
-                       if(extra_cycles > 0) {
-                               tmp_extra_cycles = extra_cycles;
-                               extra_cycles = 0;
-                       }
-                       __UNLIKELY_IF(_USE_DEBUGGER) {
-                               total_cycles += __cycles;
+                       __cycles = run_one_opecode();
+                       __UNLIKELY_IF(__cycles < 1) {
+                               __cycles = 1;
                        }
-                       cpu_wait(__cycles, i386_memory_wait);
-                       return __cycles + tmp_extra_cycles;
                }
+               int tmp_extra_cycles = 0;
+               __UNLIKELY_IF(extra_cycles > 0) {
+                       tmp_extra_cycles = extra_cycles;
+                       extra_cycles = 0;
+               }
+               __UNLIKELY_IF(_USE_DEBUGGER) {
+                       total_cycles += __cycles;
+               }
+               cpu_wait(__cycles, i386_memory_wait); // OK?
+               return __cycles + tmp_extra_cycles;
 //#ifdef USE_DEBUGGER
 //#endif
        } else {
                // Secondary
-//             remained_cycles += cycles + extra_cycles;
                remained_cycles += cycles;
-               extra_cycles = 0;
+               int tmp_extra_cycles = 0;
+               __UNLIKELY_IF(extra_cycles > 0) {
+                       tmp_extra_cycles = extra_cycles;
+                       extra_cycles = 0;
+               }
                int first_cycles = remained_cycles;
 
                // run cpu while given clocks
                __LIKELY_IF(!(busreq)) {
                        while(remained_cycles > 0 && !busreq) {
+                               // ToDo: for _SINGLE_MODE_DMA 20230305 K.O
                                remained_cycles -= run_one_opecode();
                                //                      remained_cycles -= run(-1);
                                __UNLIKELY_IF(busreq) break;
@@ -418,7 +416,7 @@ int I386::run(int cycles)
                }
                int passed_cycles = first_cycles - remained_cycles;
                //cpu_wait(passed_cycles, i386_memory_wait);
-               return passed_cycles;
+               return passed_cycles + tmp_extra_cycles;
        }
 }