sh4: Fix sh4::Stop() if no interrupts are happening

libswirl/hw/sh4/SuperH4_impl.cpp

@@ -17,7 +17,9 @@ int UpdateSystem()
     if (Sh4cntx.sh4_sched_next < 0)
         sh4_sched_tick(SH4_TIMESLICE);
 
-    return Sh4cntx.interrupt_pend;
+    // Force an interrupt check if the cpu has been stopped
+    // ngen is required to only check the bCpuRun on interrupt processing
+    return Sh4cntx.interrupt_pend | (sh4_int_bCpuRun == false);
 }
 
 int UpdateSystem_INTC()

libswirl/hw/sh4/interpr/sh4_interpreter.cpp

@@ -5,6 +5,7 @@
 #include "types.h"
 
 #include "../sh4_interpreter.h"
+#include "../sh4_interrupts.h"
 #include "../sh4_opcode_list.h"
 #include "../sh4_core.h"
 #include "hw/sh4/sh4_mem.h"
@@ -86,17 +87,25 @@ struct SH4IInterpreter : SuperH4Backend {
 
                     l -= CPU_RATIO;
                 } while (l > 0);
+
                 l += SH4_TIMESLICE;
-                UpdateSystem_INTC();
+
+                // model how the jit works
+                // only check for sh4_int_bCpuRun on interrupts
+                if (UpdateSystem()) {
+                    UpdateINTC();
+                    if (!sh4_int_bCpuRun)
+                        break;
+                }
+
 #if !defined(NO_MMU)
             }
             catch (SH4ThrownException& ex) {
                 Do_Exception(ex.epc, ex.expEvn, ex.callVect);
                 l -= CPU_RATIO * 5;	// an exception requires the instruction pipeline to drain, so approx 5 cycles
             }
 #endif
-
-        } while (sh4_int_bCpuRun);
+        } while (true);
     }
 
     bool Init() { return true; }

libswirl/jit/backend/x64/rec_x64.cpp

@@ -122,6 +122,7 @@ class BlockCompiler : public Xbyak::CodeGenerator
 		emit_Skip(getSize());
 	}
 
+	//TODO: FIXME THIS DOES NOT CONFORM TO NGEN SPEC AROUND INTERRUPT HANDLING
 	void build_mainloop() {
 		Xbyak::Label run_loop, slice_loop, end_loop;
 		// Store callee saved registers (64 bytes) + align stack