Completed add, sub, cmp and jump simulations

8086_sim/flag_access.cpp

@@ -0,0 +1,57 @@
+#include "include/flag_access.h"
+#include "include/aliases.h"
+#include <stdio.h>
+
+const char *get_flag_string(flag_access flag);
+
+static bool flags[FLAG_COUNT] = {false};
+
+bool get_flag(flag_access flag) {
+  if (flag < FLAG_COUNT) {
+    return flags[flag];
+  }
+
+  return false;
+}
+
+void set_flags(u16 value) {
+  if (value == 0) {
+    flags[FLAG_ZERO] = true;
+    flags[FLAG_SIGN] = false;
+  } else if ((value & 0x8000) == 0x8000) {
+    flags[FLAG_ZERO] = false;
+    flags[FLAG_SIGN] = true;
+  } else {
+    flags[FLAG_ZERO] = false;
+    flags[FLAG_SIGN] = false;
+  }
+}
+
+void print_flags() {
+  printf("\t");
+
+  for (u32 i = 0; i < FLAG_COUNT; ++i) {
+    if (flags[i]) {
+      printf("%s", get_flag_string((flag_access)i));
+    }
+  }
+
+  printf("\n");
+}
+
+const char *get_flag_string(flag_access flag) {
+  const char *output = "";
+
+  switch (flag) {
+  case FLAG_ZERO:
+    output = "Z";
+    break;
+  case FLAG_SIGN:
+    output = "S";
+    break;
+  default:
+    break;
+  }
+
+  return output;
+}