You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
98 lines
3.4 KiB
98 lines
3.4 KiB
use crate::run_thread::{ThreadToken, RunThread};
|
|
use asm::instr::{Op, Cond};
|
|
use crate::fault::Fault;
|
|
use crate::frame::StackFrame;
|
|
use asm::data::literal::{Value, is_positive, is_negative};
|
|
|
|
pub type CyclesSpent = usize;
|
|
|
|
pub struct EvalRes {
|
|
pub cycles: u8,
|
|
pub advance: i64,
|
|
}
|
|
|
|
impl RunThread {
|
|
pub fn eval_op(&mut self) -> Result<EvalRes, Fault> {
|
|
let mut cycles = 1;
|
|
let mut advance = 1;
|
|
|
|
let mut frame = &mut self.frame;
|
|
|
|
let op = self.program.read(frame.pc);
|
|
debug!("{} | {:?}", frame.pc, op);
|
|
|
|
/* Operations can be given different execution times when run in slow mode. */
|
|
/* Presently, all that do anything use 1 cycle. */
|
|
|
|
match op {
|
|
Op::Nop => {}
|
|
Op::FarLabel(_) | Op::Routine(_) => {
|
|
/* this is nop, but without any cost - just markers */
|
|
cycles = 0;
|
|
}
|
|
Op::Barrier(msg) => {
|
|
return Err(Fault::Barrier {
|
|
msg: msg.clone().unwrap_or_else(|| "No msg".into())
|
|
})
|
|
}
|
|
Op::Fault(msg) => {
|
|
return Err(Fault::FaultInstr {
|
|
msg: msg.clone().unwrap_or_else(|| "No msg".into())
|
|
})
|
|
}
|
|
Op::FarJump(_) => unimplemented!(),
|
|
Op::Call(_, _) => unimplemented!(),
|
|
Op::Ret(_) => unimplemented!(),
|
|
Op::Skip(val) => {
|
|
let steps = frame.read(*val)?;
|
|
advance = i64::from_ne_bytes(steps.to_ne_bytes());
|
|
}
|
|
Op::SkipIf(cond, val) => {
|
|
if frame.status.test(*cond) {
|
|
let steps = frame.read(*val)?;
|
|
advance = i64::from_ne_bytes(steps.to_ne_bytes());
|
|
}
|
|
}
|
|
Op::Mov(dst, src) => {
|
|
let val = frame.read(*src)?;
|
|
frame.write(*dst, val)?;
|
|
}
|
|
Op::Cmp(a, b) => {
|
|
frame.status.clear();
|
|
let a = frame.read(*a)?;
|
|
let b = frame.read(*b)?;
|
|
frame.status.equal = a == b;
|
|
frame.status.zero = a == 0 && b == 0;
|
|
frame.status.lower = a < b;
|
|
frame.status.greater = a > b;
|
|
frame.status.positive = is_positive(a) && is_positive(b);
|
|
frame.status.negative = is_negative(a) && is_negative(b);
|
|
}
|
|
Op::Inc(reg) => {
|
|
frame.status.clear();
|
|
let mut val = frame.read(reg.as_rd())?;
|
|
val = val.wrapping_add(1);
|
|
frame.status.overflow = (val == 0);
|
|
frame.status.zero = (val == 0);
|
|
frame.status.positive = is_positive(val);
|
|
frame.status.negative = is_negative(val);
|
|
frame.write(*reg, val)?;
|
|
}
|
|
Op::Dec(reg) => {
|
|
frame.status.clear();
|
|
let mut val = frame.read(reg.as_rd())?;
|
|
frame.status.overflow = (val == 0); // will overflow
|
|
val = val.wrapping_sub(1);
|
|
frame.status.zero = (val == 0);
|
|
frame.status.positive = is_positive(val);
|
|
frame.status.negative = is_negative(val);
|
|
frame.write(*reg, val)?;
|
|
}
|
|
}
|
|
|
|
Ok(EvalRes {
|
|
cycles,
|
|
advance,
|
|
})
|
|
}
|
|
}
|
|
|