change how flags works

src/emu.c

@@ -5,13 +5,14 @@ static inline Instruction fetchInst(Emulator* emu) {
 }
 
 static inline void updateFlagsRegister(Emulator* emu, int32_t value) {
-    if (value == 0) {
-        emu->regs[REG_F] = FLAG_ZERO;
-    } else if (value < 0) {
-        emu->regs[REG_F] = FLAG_NEGATIVE;
-    } else if (value > UINT16_MAX) {
-        emu->regs[REG_F] = FLAG_OVERFLOW;
-    }
+
+    FlagsRegister flags = (FlagsRegister)emu->regs[REG_F];
+
+    flags.fields.zero = value == 0;
+    flags.fields.negative = value < 0;
+    flags.fields.overflow = value > UINT16_MAX;
+    
+    emu->regs[REG_F] = flags.raw;
 }
 
 static inline void updateDevices(Emulator* emu) {

src/emu.h

@@ -24,9 +24,21 @@ typedef struct {
     uint32_t ihp;
     uint32_t sp;
 
+    bool irq;
     bool halted;
 } Emulator;
 
+typedef union {
+    struct {
+        uint16_t zero : 1;
+        uint16_t overflow : 1;
+        uint16_t negative : 1;
+        uint16_t interrupts : 1;
+    } fields;
+    
+    uint16_t raw;
+} FlagsRegister;
+
 // -- FUNCTIONS -- //
 Emulator* initEmulator(uint32_t memorySize);
 void freeEmulator(Emulator* emu);