marcothms/8086-rs
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ft(interpreter): set flags for arithmatic operations

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Marco Thomas
2025-06-11 15:55:33 +09:00
parent c9bf8fdc46
commit 11a365a8b1
3 changed files with 47 additions and 17 deletions
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42
src/interpreter/computer.rs
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@@ -47,28 +47,52 @@ impl Computer {
/// Perform binary `dest` = `dest` - `src`. Sets flags.
pub fn sub(&mut self, dest: ModRmTarget, src: Operand) {
let op: fn(Lhs, Rhs) -> Result = |lhs, rhs| lhs - rhs;
let flag_set: fn(&mut Flags, Result, Lhs, Rhs) = |_, _, _, _| ();
let flag_set: fn(&mut Flags, Result, Lhs, Rhs) = |flags, result, lhs, rhs| {
flags.cf = lhs < rhs;
flags.of = lhs.msb() != rhs.msb() && lhs.msb() != result.msb();
flags.zf = result.zero();
flags.sf = result.msb();
flags.pf = result.parity();
};
self.op(op, flag_set, true, dest, src);
}
/// Perform binary `dest` = `dest` | `src`. Sets flags.
pub fn or(&mut self, dest: ModRmTarget, src: Operand) {
let op: fn(Lhs, Rhs) -> Result = |lhs, rhs| lhs | rhs;
let flag_set: fn(&mut Flags, Result, Lhs, Rhs) = |_, _, _, _| ();
let flag_set: fn(&mut Flags, Result, Lhs, Rhs) = |flags, result, _, _| {
flags.cf = false;
flags.of = false;
flags.zf = result.zero();
flags.sf = result.msb();
flags.pf = result.parity();
};
self.op(op, flag_set, true, dest, src);
}
/// Perform binary `dest` = `dest` & `src`. Sets flags.
pub fn and(&mut self, dest: ModRmTarget, src: Operand) {
let op: fn(Lhs, Rhs) -> Result = |lhs, rhs| lhs & rhs;
let flag_set: fn(&mut Flags, Result, Lhs, Rhs) = |_, _, _, _| ();
let flag_set: fn(&mut Flags, Result, Lhs, Rhs) = |flags, result, _, _rhs| {
flags.cf = false;
flags.of = false;
flags.zf = result.zero();
flags.sf = result.msb();
flags.pf = result.parity();
};
self.op(op, flag_set, true, dest, src);
}
/// Perform binary `dest` = `dest` ^ `src`. Sets flags.
pub fn xor(&mut self, dest: ModRmTarget, src: Operand) {
let op: fn(Lhs, Rhs) -> Result = |lhs, rhs| lhs ^ rhs;
let flag_set: fn(&mut Flags, Result, Lhs, Rhs) = |_, _, _, _| ();
let flag_set: fn(&mut Flags, Result, Lhs, Rhs) = |flags, result, _, _| {
flags.cf = false;
flags.of = false;
flags.zf = result.zero();
flags.sf = result.msb();
flags.pf = result.parity();
};
self.op(op, flag_set, true, dest, src);
}
@@ -76,7 +100,13 @@ impl Computer {
/// saving the result and only setting [`Self::flags`].
pub fn cmp(&mut self, dest: ModRmTarget, src: Operand) {
let op: fn(Lhs, Rhs) -> Result = |lhs, rhs| lhs - rhs;
let flag_set: fn(&mut Flags, Result, Lhs, Rhs) = |_, _, _, _| ();
let flag_set: fn(&mut Flags, Result, Lhs, Rhs) = |flags, result, lhs, rhs| {
flags.cf = lhs < rhs;
flags.of = lhs.msb() != rhs.msb() && lhs.msb() != result.msb();
flags.zf = result.zero();
flags.sf = result.msb();
flags.pf = result.parity();
};
self.op(op, flag_set, false, dest, src);
}
@@ -196,5 +226,5 @@ impl fmt::Display for Computer {
#[cfg(test)]
mod tests {
use super::*;
// use super::*;
}