void vm_exec(VM *vm, bool trace)
{
int a = 0;
int i = 0;
bool b1, b2;
float f,g;
char* c;
PVector_ptr vptr,r,l;
int x, y;
Activation_Record *frame;
Function_metadata *const main = vm_function(vm, "main");
vm_call(vm, main);
// Define VM registers (C compiler probably ignores 'register' nowadays
// but it's good documentation in this case. Keep as locals for
// convenience but write them back to the vm object after each decode/execute.
register addr32 ip = vm->ip;
register int sp = vm->sp;
register int fp = vm->fp;
const byte *code = vm->code;
element *stack = vm->stack;
int opcode = code[ip];
while (opcode != HALT && ip < vm->code_size ) {
if (trace) vm_print_instr(vm, ip);
ip++;
switch (opcode) {
case IADD:
validate_stack_address(sp-1);
y = stack[sp--].i;
x = stack[sp].i;
stack[sp].i = x + y;
break;
case ISUB:
validate_stack_address(sp-1);
y = stack[sp--].i;
x = stack[sp].i;
stack[sp].i = x - y;
break;
case IMUL:
validate_stack_address(sp-1);
y = stack[sp--].i;
x = stack[sp].i;
stack[sp].i = x * y;
break;
case IDIV:
validate_stack_address(sp-1);
y = stack[sp--].i;
x = stack[sp].i;
if (y ==0 ) {
zero_division_error();
break;
}
stack[sp].i = x / y;
break;
case FADD:
validate_stack_address(sp-1);
f = stack[sp--].f;
g = stack[sp].f;
stack[sp].f = g + f;
break;
case FSUB:
validate_stack_address(sp-1);
f = stack[sp--].f;
g = stack[sp].f;
stack[sp].f = g - f;
break;
case FMUL:
validate_stack_address(sp-1);
f = stack[sp--].f;
g = stack[sp].f;
stack[sp].f = g * f;
break;
case FDIV:
validate_stack_address(sp-1);
f = stack[sp--].f;
g = stack[sp].f;
if (f == 0) {
zero_division_error();
break;
}
stack[sp].f = g / f;
break;
case VADD:
validate_stack_address(sp-1);
r = stack[sp--].vptr;
l = stack[sp].vptr;
vptr = Vector_add(l,r);
stack[sp].vptr = vptr;
break;
case VADDI:
validate_stack_address(sp-1);
i = stack[sp--].i;
vptr = stack[sp].vptr;
vptr = Vector_add(vptr,Vector_from_int(i,vptr.vector->length));
stack[sp].vptr = vptr;
break;
case VADDF:
validate_stack_address(sp-1);
f = stack[sp--].f;
vptr = stack[sp].vptr;
vptr = Vector_add(vptr,Vector_from_float(f,vptr.vector->length));
stack[sp].vptr = vptr;
break;
case VSUB:
validate_stack_address(sp-1);
r = stack[sp--].vptr;
l = stack[sp].vptr;
vptr = Vector_sub(l,r);
stack[sp].vptr = vptr;
break;
case VSUBI:
validate_stack_address(sp-1);
i = stack[sp--].i;
vptr = stack[sp].vptr;
vptr = Vector_sub(vptr,Vector_from_int(i,vptr.vector->length));
stack[sp].vptr = vptr;
break;
case VSUBF:
validate_stack_address(sp-1);
f = stack[sp--].f;
vptr = stack[sp].vptr;
vptr = Vector_sub(vptr,Vector_from_float(f,vptr.vector->length));
stack[sp].vptr = vptr;
break;
case VMUL:
validate_stack_address(sp-1);
r = stack[sp--].vptr;
l = stack[sp].vptr;
vptr = Vector_mul(l,r);
stack[sp].vptr = vptr;
break;
case VMULI:
validate_stack_address(sp-1);
i = stack[sp--].i;
vptr = stack[sp].vptr;
vptr = Vector_mul(vptr,Vector_from_int(i,vptr.vector->length));
stack[sp].vptr = vptr;
break;
case VMULF:
validate_stack_address(sp-1);
f = stack[sp--].f;
vptr = stack[sp].vptr;
vptr = Vector_mul(vptr,Vector_from_float(f,vptr.vector->length));
stack[sp].vptr = vptr;
break;
case VDIV:
validate_stack_address(sp-1);
r = stack[sp--].vptr;
l = stack[sp].vptr;
vptr = Vector_div(l,r);
stack[sp].vptr = vptr;
break;
case VDIVI:
validate_stack_address(sp-1);
i = stack[sp--].i;
if (i == 0) {
zero_division_error();
break;
}
vptr = stack[sp].vptr;
vptr = Vector_div(vptr,Vector_from_int(i,vptr.vector->length));
stack[sp].vptr = vptr;
break;
case VDIVF:
validate_stack_address(sp-1);
f = stack[sp--].f;
if (f == 0) {
zero_division_error();
break;
}
vptr = stack[sp].vptr;
vptr = Vector_div(vptr,Vector_from_float(f,vptr.vector->length));
stack[sp].vptr = vptr;
break;
case SADD:
validate_stack_address(sp-1);
char * right = stack[sp--].s;
stack[sp].s = String_add(String_new(stack[sp].s),String_new(right))->str;
break;
case OR :
validate_stack_address(sp-1);
b2 = stack[sp--].b;
b1 = stack[sp].b;
stack[sp].b = b1 || b2;
break;
case AND :
validate_stack_address(sp-1);
b2 = stack[sp--].b;
b1 = stack[sp].b;
stack[sp].b = b1 && b2;
break;
case INEG:
validate_stack_address(sp);
stack[sp].i = -stack[sp].i;
break;
case FNEG:
validate_stack_address(sp);
stack[sp].f = -stack[sp].f;
break;
case NOT:
validate_stack_address(sp);
stack[sp].b = !stack[sp].b;
break;
case I2F:
validate_stack_address(sp);
stack[sp].f = stack[sp].i;
break;
case I2S:
validate_stack_address(sp);
stack[sp].s = String_from_int(stack[sp].i)->str;
break;
case F2I:
validate_stack_address(sp);
stack[sp].i = (int)stack[sp].f;
break;
case F2S:
validate_stack_address(sp);
stack[sp].s = String_from_float((float)stack[sp].f)->str;
break;
case V2S:
validate_stack_address(sp);
vptr = stack[sp].vptr;
stack[sp].s = String_from_vector(vptr)->str;
break;
case IEQ:
validate_stack_address(sp-1);
y = stack[sp--].i;
x = stack[sp].i;
stack[sp].b = x == y;
break;
case INEQ:
validate_stack_address(sp-1);
y = stack[sp--].i;
x = stack[sp].i;
stack[sp].b = x != y;
break;
case ILT:
validate_stack_address(sp-1);
y = stack[sp--].i;
x = stack[sp].i;
stack[sp].b = x < y;
break;
case ILE:
validate_stack_address(sp-1);
y = stack[sp--].i;
x = stack[sp].i;
stack[sp].b = x <= y;
break;
case IGT:
validate_stack_address(sp-1);
y = stack[sp--].i;
x = stack[sp].i;
stack[sp].b = x > y;
break;
case IGE:
validate_stack_address(sp-1);
y = stack[sp--].i;
x = stack[sp].i;
stack[sp].b = x >= y;
break;
case FEQ:
validate_stack_address(sp-1);
g = stack[sp--].f;
f = stack[sp].f;
stack[sp].b = f == g;
break;
case FNEQ:
validate_stack_address(sp-1);
g = stack[sp--].f;
f = stack[sp].f;
stack[sp].b = f != g;
break;
case FLT:
validate_stack_address(sp-1);
g = stack[sp--].f;
f = stack[sp].f;
stack[sp].b = f < g;
break;
case FLE:
validate_stack_address(sp-1);
g = stack[sp--].f;
f = stack[sp].f;
stack[sp].b = f <= g;
break;
case FGT:
validate_stack_address(sp-1);
g = stack[sp--].f;
f = stack[sp].f;
stack[sp].b = f > g;
break;
case FGE:
validate_stack_address(sp-1);
g = stack[sp--].f;
f = stack[sp].f;
stack[sp].b = f >= g;
break;
case SEQ:
validate_stack_address(sp-1);
c = stack[sp--].s;
b1 = String_eq(String_new(stack[sp--].s),String_new(c));
stack[++sp].b = b1;
break;
case SNEQ:
validate_stack_address(sp-1);
c = stack[sp--].s;
b1 = String_neq(String_new(stack[sp--].s),String_new(c));
stack[++sp].b = b1;
break;
case SGT:
validate_stack_address(sp-1);
c = stack[sp--].s;
b1 = String_gt(String_new(stack[sp--].s),String_new(c));
stack[++sp].b = b1;
break;
case SGE:
validate_stack_address(sp-1);
c = stack[sp--].s;
b1 = String_ge(String_new(stack[sp--].s),String_new(c));
stack[++sp].b = b1;
break;
case SLT:
validate_stack_address(sp-1);
c = stack[sp--].s;
b1 = String_lt(String_new(stack[sp--].s),String_new(c));
stack[++sp].b = b1;
break;
case SLE:
validate_stack_address(sp-1);
c = stack[sp--].s;
b1 = String_le(String_new(stack[sp--].s),String_new(c));
stack[++sp].b = b1;
break;
case VEQ:
validate_stack_address(sp-1);
l = stack[sp--].vptr;
r = stack[sp--].vptr;
b1 = Vector_eq(l,r);
stack[++sp].b = b1;
break;
case VNEQ:
validate_stack_address(sp-1);
l = stack[sp--].vptr;
r = stack[sp--].vptr;
b1 = Vector_neq(l,r);
stack[++sp].b = b1;
break;
case BR:
ip += int16(code,ip) - 1;
break;
case BRF:
validate_stack_address(sp);
if ( !stack[sp--].b ) {
int offset = int16(code,ip);
ip += offset - 1;
}
else {
ip += 2;
}
break;
case ICONST:
stack[++sp].i = int32(code,ip);
ip += 4;
break;
case FCONST:
stack[++sp].f = float32(code,ip);
ip += 4;
break;
case SCONST :
i = int16(code,ip);
ip += 2;
stack[++sp].s = vm->strings[i];
break;
case ILOAD:
i = int16(code,ip);
ip += 2;
stack[++sp].i = vm->call_stack[vm->callsp].locals[i].i;
break;
case FLOAD:
i = int16(code,ip);
ip += 2;
stack[++sp].f = vm->call_stack[vm->callsp].locals[i].f;
break;
case VLOAD:
i = int16(code,ip);
ip += 2;
stack[++sp].vptr = vm->call_stack[vm->callsp].locals[i].vptr;
break;
case SLOAD:
i = int16(code,ip);
ip += 2;
stack[++sp].s = vm->call_stack[vm->callsp].locals[i].s;
break;
case STORE:
i = int16(code,ip);
ip += 2;
vm->call_stack[vm->callsp].locals[i] = stack[sp--]; // untyped store; it'll just copy all bits
break;
case VECTOR:
i = stack[sp--].i;
validate_stack_address(sp-i+1);
double *data = (double*)malloc(i*sizeof(double));
for (int j = i-1; j >= 0;j--) { data[j] = stack[sp--].f; }
vptr = Vector_new(data,i);
stack[++sp].vptr = vptr;
break;
case VLOAD_INDEX:
i = stack[sp--].i;
vptr = stack[sp--].vptr;
vm->stack[++sp].f = ith(vptr, i-1);
break;
case STORE_INDEX:
f = stack[sp--].f;
i = stack[sp--].i;
vptr = stack[sp--].vptr;
set_ith(vptr, i-1, f);
break;
case SLOAD_INDEX:
i = stack[sp--].i;
if (i-1 >= strlen(stack[sp].s))
{
fprintf(stderr, "StringIndexOutOfRange: %d\n",(int)strlen(stack[sp].s));
break;
}
c = String_from_char(stack[sp--].s[i-1])->str;
stack[++sp].s = c;
break;
case PUSH_DFLT_RETV:
i = *&vm->call_stack[vm->callsp].func->return_type;
sp = push_default_value(i, sp, stack);
break;
case POP:
sp--;
break;
case CALL:
a = int16(code,ip); // load index of function from code memory
WRITE_BACK_REGISTERS(vm); // (ip has been updated)
vm_call(vm, &vm->functions[a]);
LOAD_REGISTERS(vm);
break;
case RET:
frame = &vm->call_stack[vm->callsp--];
ip = frame->retaddr;
break;
case IPRINT:
validate_stack_address(sp);
printf("%d\n", stack[sp--].i);
break;
case FPRINT:
validate_stack_address(sp);
printf("%1.2f\n", stack[sp--].f);
break;
case BPRINT:
validate_stack_address(sp);
printf("%d\n", stack[sp--].b);
break;
case SPRINT:
validate_stack_address(sp);
printf("%s\n", stack[sp--].s);
break;
case VPRINT:
validate_stack_address(sp);
print_vector(stack[sp--].vptr);
break;
case VLEN:
vptr = stack[sp--].vptr;
i = Vector_len(vptr);
stack[++sp].i = i;
break;
case SLEN:
c = stack[sp--].s;
i = String_len(String_new(c));
stack[++sp].i = i;
break;
case GC_START:
vm->call_stack[vm->callsp].save_gc_roots = gc_num_roots();
break;
case GC_END:
gc_set_num_roots(vm->call_stack[vm->callsp].save_gc_roots);
break;
case SROOT:
gc_add_root((void **)&stack[sp].s);
break;
case VROOT:
gc_add_root((void **)&stack[sp].vptr);
break;
case COPY_VECTOR:
if (vm->call_stack[vm->callsp].locals[i].vptr.vector != NULL) {
stack[sp].vptr = Vector_copy(vm->call_stack[vm->callsp].locals[i].vptr);
}
else if (stack[sp].vptr.vector != NULL) {
stack[sp].vptr = Vector_copy(stack[sp].vptr);
}
else {
fprintf(stderr, "Vector reference cannot be found\n");
}
break;
case NOP : break;
default:
printf("invalid opcode: %d at ip=%d\n", opcode, (ip - 1));
exit(1);
}
WRITE_BACK_REGISTERS(vm);
if (trace) vm_print_stack(vm);
opcode = code[ip];
}
if (trace) vm_print_instr(vm, ip);
if (trace) vm_print_stack(vm);
gc_check();
}
void vm_exec(VM *vm, int startip, bool trace)
{
// registers
int ip; // instruction pointer register
int sp; // stack pointer register
int callsp; // call stack pointer register
int a = 0;
int b = 0;
int addr = 0;
int offset = 0;
ip = startip;
sp = -1;
callsp = -1;
int opcode = vm->code[ip];
while (opcode != HALT && ip < vm->code_size) {
if (trace) vm_print_instr(vm->code, ip);
ip++; //jump to next instruction or to operand
switch (opcode) {
case IADD:
b = vm->stack[sp--]; // 2nd opnd at top of stack
a = vm->stack[sp--]; // 1st opnd 1 below top
vm->stack[++sp] = a + b; // push result
break;
case ISUB:
b = vm->stack[sp--];
a = vm->stack[sp--];
vm->stack[++sp] = a - b;
break;
case IMUL:
b = vm->stack[sp--];
a = vm->stack[sp--];
vm->stack[++sp] = a * b;
break;
case ILT:
b = vm->stack[sp--];
a = vm->stack[sp--];
vm->stack[++sp] = (a < b) ? true : false;
break;
case IEQ:
b = vm->stack[sp--];
a = vm->stack[sp--];
vm->stack[++sp] = (a == b) ? true : false;
break;
case BR:
ip = vm->code[ip];
break;
case BRT:
addr = vm->code[ip++];
if (vm->stack[sp--] == true) ip = addr;
break;
case BRF:
addr = vm->code[ip++];
if (vm->stack[sp--] == false) ip = addr;
break;
case ICONST:
vm->stack[++sp] = vm->code[ip++]; // push operand
break;
case LOAD: // load local or arg; 1st local is fp+1, args are fp-3, fp-4, fp-5, ...
offset = vm->code[ip++];
vm->stack[++sp] = vm->call_stack[callsp].locals[offset];
break;
case GLOAD: // load from global memory
addr = vm->code[ip++];
vm->stack[++sp] = vm->globals[addr];
break;
case STORE:
offset = vm->code[ip++];
vm->call_stack[callsp].locals[offset] = vm->stack[sp--];
break;
case GSTORE:
addr = vm->code[ip++];
vm->globals[addr] = vm->stack[sp--];
break;
case PRINT:
printf("%d\n", vm->stack[sp--]);
break;
case POP:
--sp;
break;
case CALL:
// expects all args on stack
addr = vm->code[ip++]; // index of target function
int nargs = vm->code[ip++]; // how many args got pushed
int nlocals = vm->code[ip++]; // how many locals to allocate
++callsp; // bump stack pointer to reveal space for this call
vm_context_init(&vm->call_stack[callsp], ip, nargs+nlocals);
// copy args into new context
for (int i=0; i<nargs; i++) {
vm->call_stack[callsp].locals[i] = vm->stack[sp-i];
}
sp -= nargs;
ip = addr; // jump to function
break;
case RET:
ip = vm->call_stack[callsp].returnip;
callsp--; // pop context
break;
default:
printf("invalid opcode: %d at ip=%d\n", opcode, (ip - 1));
exit(1);
}
if (trace) vm_print_stack(vm->stack, sp);
opcode = vm->code[ip];
}
if (trace) vm_print_data(vm->globals, vm->nglobals);
}