Added and implemented OP_JUMP_(STACK|REGISTER)

Uses the stack and register, respectively, to jump to an absolute
address.  The stack based jump pops a word off the stack to perform a
jump, while the register based one uses the operand to figure out
which register to use.

src/inst.c

@@ -117,6 +117,11 @@ const char *opcode_as_cstr(opcode_t code)
   case OP_JUMP_ABS:
     return "JUMP_ABS";
     break;
+  case OP_JUMP_STACK:
+    return "JUMP_STACK";
+    break;
+  case OP_JUMP_REGISTER:
+    return "JUMP_REGISTER";
     break;
   case OP_HALT:
     return "HALT";
@@ -186,6 +191,7 @@ data_type_t get_opcode_data_type(opcode_t opcode)
 
 void inst_print(inst_t instruction, FILE *fp)
 {
+  static_assert(NUMBER_OF_OPCODES == 34, "inst_bytecode_size: Out of date");
   fprintf(fp, "%s(", opcode_as_cstr(instruction.opcode));
   if (OPCODE_IS_TYPE(instruction.opcode, OP_PUSH))
   {
@@ -194,14 +200,19 @@ void inst_print(inst_t instruction, FILE *fp)
     data_print(instruction.operand, type, fp);
   }
   else if (OPCODE_IS_TYPE(instruction.opcode, OP_PUSH_REGISTER) ||
-           OPCODE_IS_TYPE(instruction.opcode, OP_MOV))
+           OPCODE_IS_TYPE(instruction.opcode, OP_MOV) ||
+           instruction.opcode == OP_JUMP_REGISTER)
   {
     fprintf(fp, "reg=0x");
     data_print(instruction.operand, DATA_TYPE_BYTE, fp);
   }
   else if (OPCODE_IS_TYPE(instruction.opcode, OP_DUP))
   {
-    fprintf(fp, "n=");
+    fprintf(fp, "n=%lu", instruction.operand.as_word);
+  }
+  else if (instruction.opcode == OP_JUMP_ABS)
+  {
+    fprintf(fp, "address=0x");
     data_print(instruction.operand, DATA_TYPE_WORD, fp);
   }
   fprintf(fp, ")");
@@ -209,7 +220,7 @@ void inst_print(inst_t instruction, FILE *fp)
 
 size_t inst_bytecode_size(inst_t inst)
 {
-  static_assert(NUMBER_OF_OPCODES == 32, "inst_bytecode_size: Out of date");
+  static_assert(NUMBER_OF_OPCODES == 34, "inst_bytecode_size: Out of date");
   size_t size = 1; // for opcode
   if (OPCODE_IS_TYPE(inst.opcode, OP_PUSH))
   {
@@ -221,7 +232,8 @@ size_t inst_bytecode_size(inst_t inst)
       size += WORD_SIZE;
   }
   else if (OPCODE_IS_TYPE(inst.opcode, OP_PUSH_REGISTER) ||
-           OPCODE_IS_TYPE(inst.opcode, OP_MOV))
+           OPCODE_IS_TYPE(inst.opcode, OP_MOV) ||
+           inst.opcode == OP_JUMP_REGISTER)
     // Only need a byte for the register
     ++size;
   else if (OPCODE_IS_TYPE(inst.opcode, OP_DUP))
@@ -233,7 +245,7 @@ size_t inst_bytecode_size(inst_t inst)
 
 void inst_write_bytecode(inst_t inst, darr_t *darr)
 {
-  static_assert(NUMBER_OF_OPCODES == 32, "inst_write_bytecode: Out of date");
+  static_assert(NUMBER_OF_OPCODES == 34, "inst_write_bytecode: Out of date");
   // Append opcode
   darr_append_byte(darr, inst.opcode);
   // Then append 0 or more operands
@@ -241,9 +253,10 @@ void inst_write_bytecode(inst_t inst, darr_t *darr)
   if (OPCODE_IS_TYPE(inst.opcode, OP_PUSH))
     to_append = (data_type_t)inst.opcode;
   else if (OPCODE_IS_TYPE(inst.opcode, OP_PUSH_REGISTER) ||
-           OPCODE_IS_TYPE(inst.opcode, OP_MOV))
+           OPCODE_IS_TYPE(inst.opcode, OP_MOV) ||
+           inst.opcode == OP_JUMP_REGISTER)
     to_append = DATA_TYPE_BYTE;
-  else if (OPCODE_IS_TYPE(inst.opcode, OP_DUP) || inst.opcode == OP_JUMP)
+  else if (OPCODE_IS_TYPE(inst.opcode, OP_DUP) || inst.opcode == OP_JUMP_ABS)
     to_append = DATA_TYPE_WORD;
 
   switch (to_append)
@@ -305,7 +318,7 @@ data_t read_type_from_darr(darr_t *darr, data_type_t type)
 
 inst_t inst_read_bytecode(darr_t *darr)
 {
-  static_assert(NUMBER_OF_OPCODES == 32, "inst_read_bytecode: Out of date");
+  static_assert(NUMBER_OF_OPCODES == 34, "inst_read_bytecode: Out of date");
   if (darr->used >= darr->available)
     return (inst_t){0};
   inst_t inst     = {0};
@@ -318,7 +331,7 @@ inst_t inst_read_bytecode(darr_t *darr)
     inst.operand = read_type_from_darr(darr, get_opcode_data_type(opcode));
   // Read register (as a byte)
   else if (OPCODE_IS_TYPE(opcode, OP_PUSH_REGISTER) ||
-           OPCODE_IS_TYPE(opcode, OP_MOV))
+           OPCODE_IS_TYPE(opcode, OP_MOV) || inst.opcode == OP_JUMP_STACK)
     inst.operand = read_type_from_darr(darr, DATA_TYPE_BYTE);
   else if (OPCODE_IS_TYPE(opcode, OP_DUP) || opcode == OP_JUMP_ABS)
     inst.operand = read_type_from_darr(darr, DATA_TYPE_WORD);

src/inst.h

@@ -68,6 +68,8 @@ typedef enum
   // Mathematical operations
   // Program control flow
   OP_JUMP_ABS,
+  OP_JUMP_STACK,
+  OP_JUMP_REGISTER,
 
   // Should not be an opcode
   NUMBER_OF_OPCODES,
@@ -129,5 +131,7 @@ inst_t *insts_read_bytecode_file(FILE *, size_t *);
 
 #define INST_JUMP_ABS(OP) \
   ((inst_t){.opcode = OP_JUMP_ABS, .operand = DWORD(OP)})
+#define INST_JUMP_STACK    ((inst_t){.opcode = OP_JUMP_STACK})
+#define INST_JUMP_REGISTER ((inst_t){.opcode = OP_JUMP_REGISTER})
 
 #endif

src/runtime.c

@@ -19,7 +19,7 @@
 
 void vm_execute(vm_t *vm)
 {
-  static_assert(NUMBER_OF_OPCODES == 32, "vm_execute: Out of date");
+  static_assert(NUMBER_OF_OPCODES == 34, "vm_execute: Out of date");
   struct Program *prog = &vm->program;
   if (prog->ptr >= prog->max)
     // TODO: Error (Went past end of program)
@@ -96,6 +96,18 @@ void vm_execute(vm_t *vm)
     // Set prog->ptr to the jump point requested
     prog->ptr = instruction.operand.as_word;
   }
+  else if (instruction.opcode == OP_JUMP_STACK)
+  {
+    // Set prog->ptr to the word on top of the stack
+    prog->ptr = vm_pop_word(vm).as_word;
+  }
+  else if (instruction.opcode == OP_JUMP_REGISTER)
+  {
+    if (instruction.operand.as_byte >= 8)
+      // TODO: Error register is not a valid word register
+      return;
+    prog->ptr = vm->registers.reg[instruction.operand.as_byte];
+  }
   else if (instruction.opcode == OP_HALT)
   {
     // Do nothing here.  Should be caught by callers of vm_execute