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implement other load opcodes

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This commit is contained in:
dogeystamp 2024-01-06 14:25:19 -05:00
parent 0597b1d4f8
commit c137839e86
Signed by: dogeystamp
GPG Key ID: 7225FE3592EFFA38
1 changed files with 31 additions and 6 deletions
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37
src/vm/instruction.rs
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@ -71,15 +71,15 @@ pub fn execute_instruction(vm: &mut VM, instr: u16) {
match opcode {
OpCode::BR => todo!("BR"),
OpCode::ADD => todo!("ADD"),
OpCode::LD => todo!("LD"),
OpCode::LD => op_ld(vm, instr),
OpCode::ST => todo!("ST"),
OpCode::JSR => todo!("JSR"),
OpCode::AND => todo!("AND"),
OpCode::LDR => todo!("LDR"),
OpCode::LDR => op_ldr(vm, instr),
OpCode::STR => todo!("STR"),
OpCode::RTI => todo!("RTI"),
OpCode::NOT => todo!("NOT"),
OpCode::LDI => todo!("LDI"),
OpCode::LDI => op_ldi(vm, instr),
OpCode::STI => todo!("STI"),
OpCode::JMP => todo!("JMP"),
OpCode::RES => todo!("RES"),
@ -101,9 +101,34 @@ fn sign_extend(x: u16, bits: usize) -> u16 {
fn no_op(vm: &mut VM, instr: u16) {}
fn op_lea(vm: &mut VM, instr: u16) {
let dr = (instr >> 8) & 0b111;
let offset = sign_extend(instr & 0xff, 9);
vm.registers.set_reg(dr, vm.registers.pc + offset);
let dr = (instr >> 9) & 0b111;
let offset = sign_extend(instr & 0x1ff, 9);
vm.registers.set_reg_with_cond(dr, vm.registers.pc + offset);
}
fn op_ld(vm: &mut VM, instr: u16) {
let dr = (instr >> 9) & 0b111;
let offset = sign_extend(instr & 0x1ff, 9);
vm.registers.set_reg_with_cond(dr, vm.mem.get_mem(vm.registers.pc + offset));
}
fn op_ldi(vm: &mut VM, instr: u16) {
let dr = (instr >> 9) & 0b111;
let offset = sign_extend(instr & 0x1ff, 9);
let indirect = vm.mem.get_mem(vm.registers.pc + offset);
vm.registers.set_reg_with_cond(dr, vm.mem.get_mem(indirect));
}
fn op_ldr(vm: &mut VM, instr: u16) {
let dr = (instr >> 9) & 0b111;
let base_r = (instr >> 6) & 0b111;
let offset = sign_extend(instr & 0x3f, 6);
let addr = vm.registers.get_reg(base_r) + offset;
vm.registers.set_reg_with_cond(dr, vm.mem.get_mem(addr));
}
fn op_trap(vm: &mut VM, instr: u16) {