Store the result of OP_POP in the last register as a word

Instead of making routines to handle data in the `ret` register, just
store the result of POP into the last word register.

This means we are no longer using vm_pop_* or POP_ROUTINES for the
vm_execute script on OP_POP: instead we'll just use vm_mov_* which
automatically pops the datum for us, while moving the datum to the
last register.
This commit is contained in:
2023-10-22 17:01:15 +01:00
parent 95723f36d2
commit 47c7d6baf7
3 changed files with 111 additions and 23 deletions

View File

@@ -38,16 +38,66 @@ void vm_execute(vm_t *vm)
}
else if (OPCODE_IS_TYPE(instruction.opcode, OP_POP))
{
// NOTE: We use the `ret` register for the result of this pop
data_t d = POP_ROUTINES[instruction.opcode](vm);
vm->registers.ret = d.as_word;
// NOTE: We use the first register to hold the result of this pop
data_type_t type = OPCODE_DATA_TYPE(instruction.opcode, OP_POP);
data_t datum = vm_peek(vm, type);
switch (type)
{
case DATA_TYPE_NIL:
break;
case DATA_TYPE_BYTE:
vm_mov_byte(vm, (VM_REGISTERS * 8) - 1);
break;
case DATA_TYPE_HWORD:
vm_mov_hword(vm, (VM_REGISTERS * 4) - 1);
break;
case DATA_TYPE_WORD:
vm_mov_hword(vm, VM_REGISTERS - 1);
break;
}
vm->registers.ret = datum.as_word;
prog->ptr++;
}
else if (OPCODE_IS_TYPE(instruction.opcode, OP_MOV))
{
data_t d =
MOV_ROUTINES[instruction.opcode](vm, instruction.operand.as_word);
vm->registers.ret = d.as_word; // will do type punning for me
vm->registers.ret = d.as_word;
prog->ptr++;
}
else if (OPCODE_IS_TYPE(instruction.opcode, OP_NOT))
{
NOT_ROUTINES[instruction.opcode](vm);
vm->registers.ret =
vm_peek(vm, OPCODE_DATA_TYPE(instruction.opcode, OP_NOT)).as_word;
prog->ptr++;
}
else if (OPCODE_IS_TYPE(instruction.opcode, OP_OR))
{
OR_ROUTINES[instruction.opcode](vm);
vm->registers.ret =
vm_peek(vm, OPCODE_DATA_TYPE(instruction.opcode, OP_OR)).as_word;
prog->ptr++;
}
else if (OPCODE_IS_TYPE(instruction.opcode, OP_AND))
{
AND_ROUTINES[instruction.opcode](vm);
vm->registers.ret =
vm_peek(vm, OPCODE_DATA_TYPE(instruction.opcode, OP_AND)).as_word;
prog->ptr++;
}
else if (OPCODE_IS_TYPE(instruction.opcode, OP_XOR))
{
XOR_ROUTINES[instruction.opcode](vm);
vm->registers.ret =
vm_peek(vm, OPCODE_DATA_TYPE(instruction.opcode, OP_XOR)).as_word;
prog->ptr++;
}
else if (OPCODE_IS_TYPE(instruction.opcode, OP_EQ))
{
EQ_ROUTINES[instruction.opcode](vm);
vm->registers.ret =
vm_peek(vm, OPCODE_DATA_TYPE(instruction.opcode, OP_EQ)).as_word;
prog->ptr++;
}
else if (instruction.opcode == OP_HALT)
@@ -174,6 +224,48 @@ void vm_print_all(vm_t *vm, FILE *fp)
fp);
}
data_t vm_peek(vm_t *vm, data_type_t type)
{
switch (type)
{
case DATA_TYPE_NIL:
return DBYTE(0);
break;
case DATA_TYPE_BYTE:
if (vm->stack.ptr == 0)
return DBYTE(0);
return DBYTE(vm->stack.data[vm->stack.ptr - 1]);
break;
case DATA_TYPE_HWORD:
if (vm->stack.ptr < HWORD_SIZE)
// TODO: Error STACK_UNDERFLOW
return DHWORD(0);
hword h = 0;
for (size_t i = 0; i < HWORD_SIZE; ++i)
{
byte b = vm->stack.data[vm->stack.ptr - 1 - i];
h = h | (((word)b) << (i * 8));
}
return DWORD(h);
break;
case DATA_TYPE_WORD:
if (vm->stack.ptr < WORD_SIZE)
// TODO: Error STACK_UNDERFLOW
return DWORD(0);
word w = 0;
for (size_t i = 0; i < WORD_SIZE; ++i)
{
byte b = vm->stack.data[vm->stack.ptr - 1 - i];
w = w | (((word)b) << (i * 8));
}
return DWORD(w);
break;
default:
return DBYTE(0);
break;
}
}
void vm_push_byte(vm_t *vm, data_t b)
{
if (vm->stack.ptr >= vm->stack.max)
@@ -223,11 +315,7 @@ void vm_push_byte_register(vm_t *vm, byte reg)
return;
// Interpret each word based register as 8 byte registers
word ind = reg / 8;
word nth_byte = reg % 8;
word reg_ptr = vm->registers.reg[ind];
byte b = WORD_NTH_BYTE(reg_ptr, nth_byte);
byte b = WORD_NTH_BYTE(vm->registers.reg[reg / 8], reg % 8);
vm_push_byte(vm, DBYTE(b));
}
@@ -241,10 +329,7 @@ void vm_push_hword_register(vm_t *vm, byte reg)
// TODO: Error STACK_OVERFLOW
return;
// Interpret each word based register as 2 hword registers
word ind = reg / 2;
word nth_hword = reg % 2;
word reg_ptr = vm->registers.reg[ind];
hword hw = WORD_NTH_HWORD(reg_ptr, nth_hword);
hword hw = WORD_NTH_HWORD(vm->registers.reg[reg / 2], reg % 2);
vm_push_hword(vm, DHWORD(hw));
}
@@ -269,7 +354,7 @@ data_t vm_mov_byte(vm_t *vm, byte reg)
return DBYTE(0);
data_t ret = vm_pop_byte(vm);
word *reg_ptr = &vm->registers.reg[reg / 8];
*reg_ptr = (*reg_ptr) | ((word)ret.as_word) << ((reg % 8) * 8);
*reg_ptr = (*reg_ptr) | (ret.as_word << ((reg % 8) * 8));
return ret;
}
@@ -283,7 +368,7 @@ data_t vm_mov_hword(vm_t *vm, byte reg)
return DHWORD(0);
data_t ret = vm_pop_hword(vm);
word *reg_ptr = &vm->registers.reg[reg / 2];
*reg_ptr = (*reg_ptr) | ((word)ret.as_word) << ((reg % 2) * 2);
*reg_ptr = (*reg_ptr) | (ret.as_word << ((reg % 2) * 2));
return ret;
}