Only pre-check interrupts and halt in CPU tick

Baekalfen · Sep 20, 2024 · a548e5d · a548e5d
1 parent e0c2a27
commit a548e5d
Show file tree

Hide file tree

Showing 3 changed files with 22 additions and 26 deletions.
diff --git a/pyboy/core/cpu.py b/pyboy/core/cpu.py
@@ -106,35 +106,29 @@ def set_interruptflag(self, flag):
 
     def tick(self, cycles_target):
         _cycles0 = self._cycles
-        self.bail = False
-        while self._cycles - _cycles0 < cycles_target:
-            if self.check_interrupts():
-                self.halted = False
-                # TODO: We return with the cycles it took to handle the interrupt
-                break
-                # return cycles
-
-            if self.halted and self.interrupt_queued:
-                # GBCPUman.pdf page 20
-                # WARNING: The instruction immediately following the HALT instruction is "skipped" when interrupts are
-                # disabled (DI) on the GB,GBP, and SGB.
-                self.halted = False
-                self.PC += 1
-                self.PC &= 0xFFFF
-            elif self.halted:
-                self._cycles += 4 # TODO: Number of cycles for a HALT in effect?
-                break
 
-            self.interrupt_queued = False
+        if self.check_interrupts():
+            self.halted = False
+            # break
+            # TODO: We return with the cycles it took to handle the interrupt
+            # return cycles
+
+        if self.halted and self.interrupt_queued:
+            # GBCPUman.pdf page 20
+            # WARNING: The instruction immediately following the HALT instruction is "skipped" when interrupts are
+            # disabled (DI) on the GB,GBP, and SGB.
+            self.halted = False
+            self.PC += 1
+            self.PC &= 0xFFFF
+        elif self.halted:
+            self._cycles += cycles_target
+            # self._cycles += 4 # TODO: Number of cycles for a HALT in effect?
+            # break
+        self.interrupt_queued = False
 
+        self.bail = False
+        while self._cycles - _cycles0 < cycles_target:
             # TODO: cpu-stuck check for blargg tests?
-            # if cycles_target != 0:
-            #     print(cycles_target)
-
-            # self.cycles_target = cycles_target
-            # if cycles_target == 0:
-            #     return self.fetch_and_execute()
-
             self._cycles += self.fetch_and_execute()
             if self.bail: # Possible cycles-target changes
                 break

diff --git a/pyboy/core/opcodes.py b/pyboy/core/opcodes.py
@@ -1088,6 +1088,7 @@ def LD_75(cpu): # 75 LD (HL),L
 
 def HALT_76(cpu): # 76 HALT
     cpu.halted = True
+    cpu.bail = True
     return 4
 
 

diff --git a/pyboy/core/opcodes_gen.py b/pyboy/core/opcodes_gen.py
@@ -460,6 +460,7 @@ def HALT(self):
         # TODO: Implement HALT bug.
         code.addlines([
             "cpu.halted = True",
+            "cpu.bail = True",
             "return " + self.cycles[0],
         ])
         return code.getcode()