Added an actual starting point for xSp and xBp

src/interp.c

@@ -98,6 +98,8 @@ int load_program(const char *fname) {
   FILE *f = fopen(fname, "rb");
   int byte;
   xPc = 0x4000000000000000;
+  xSp = 0xFFFFFFFFFFFFFF00;
+  xBp = 0xFFFFFFFFFFFFFF00;
   uint64_t i = xPc;
   while ((byte = fgetc(f)) != EOF) {
     memory_set8(i, byte);
@@ -160,7 +162,6 @@ int main(int argc, char **argv) {
           ((uint64_t)x7 <<  8) +
           ((uint64_t)x8 <<  0);
         registers[reg] = val;
-        //printf("Moved value 0x%lX into r%d\n", val, reg);
         registers[0] = 0;
         break;
       }
@@ -185,6 +186,19 @@ int main(int argc, char **argv) {
         negativeFlag = (val < 0);
         break;
       }
+      case 0x7D: { // Cmp64
+        unsigned char regA = inputs[0];
+        unsigned char regB = inputs[1];
+
+        uint64_t valA = registers[regA];
+        uint64_t valB = registers[regB];
+
+        zeroFlag = (valA == valB);      
+        parityFlag = (valA-valB)&1;
+        positiveFlag = (valA > valB);      
+        negativeFlag = (valA < valB);      
+        break;
+      }
       case 0x94: { // Mov64
         unsigned char dst = inputs[0];
         unsigned char src = inputs[1];
@@ -234,6 +248,14 @@ int main(int argc, char **argv) {
         }
         break;
       }
+      case 0xC3: { // JmpIP
+        unsigned char addr = inputs[0];
+        if (positiveFlag) {
+          if (DEBUG) printf("Jump!\n");
+          xPc = registers[addr];
+        }
+        break;
+      }
       case 0x46: { // Call
         unsigned char addr = inputs[0];
         xSp -= 8;