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ft(interpreter): impl adc and sbb

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This commit is contained in:
Marco Thomas
2025-06-11 16:31:07 +09:00
parent 11a365a8b1
commit 269c4cc54b
2 changed files with 108 additions and 23 deletions
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82
src/interpreter/computer.rs
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@@ -11,7 +11,7 @@ pub enum Operand {
ModRmTarget(ModRmTarget),
}
type Result = ImmediateOperand;
type ArithmeticResult = ImmediateOperand;
type Lhs = ImmediateOperand;
type Rhs = ImmediateOperand;
@@ -33,8 +33,8 @@ impl Computer {
/// Perform binary `dest` = `dest` + `src`. Sets flags.
pub fn add(&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) = |flags, result, lhs, rhs| {
let op: fn(Lhs, Rhs) -> ArithmeticResult = |lhs, rhs| lhs + rhs;
let flag_set: fn(&mut Flags, ArithmeticResult, Lhs, Rhs) = |flags, result, lhs, rhs| {
flags.cf = result < rhs;
flags.of = lhs.msb() && rhs.msb() != result.msb();
flags.zf = result.zero();
@@ -46,8 +46,8 @@ 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) = |flags, result, lhs, rhs| {
let op: fn(Lhs, Rhs) -> ArithmeticResult = |lhs, rhs| lhs - rhs;
let flag_set: fn(&mut Flags, ArithmeticResult, Lhs, Rhs) = |flags, result, lhs, rhs| {
flags.cf = lhs < rhs;
flags.of = lhs.msb() != rhs.msb() && lhs.msb() != result.msb();
flags.zf = result.zero();
@@ -59,8 +59,8 @@ impl Computer {
/// 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) = |flags, result, _, _| {
let op: fn(Lhs, Rhs) -> ArithmeticResult = |lhs, rhs| lhs | rhs;
let flag_set: fn(&mut Flags, ArithmeticResult, Lhs, Rhs) = |flags, result, _, _| {
flags.cf = false;
flags.of = false;
flags.zf = result.zero();
@@ -72,8 +72,8 @@ impl Computer {
/// 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) = |flags, result, _, _rhs| {
let op: fn(Lhs, Rhs) -> ArithmeticResult = |lhs, rhs| lhs & rhs;
let flag_set: fn(&mut Flags, ArithmeticResult, Lhs, Rhs) = |flags, result, _, _rhs| {
flags.cf = false;
flags.of = false;
flags.zf = result.zero();
@@ -85,8 +85,8 @@ impl Computer {
/// 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) = |flags, result, _, _| {
let op: fn(Lhs, Rhs) -> ArithmeticResult = |lhs, rhs| lhs ^ rhs;
let flag_set: fn(&mut Flags, ArithmeticResult, Lhs, Rhs) = |flags, result, _, _| {
flags.cf = false;
flags.of = false;
flags.zf = result.zero();
@@ -99,8 +99,8 @@ impl Computer {
/// Perform compare operation, which acts like [`Self::sub()`], but without
/// 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) = |flags, result, lhs, rhs| {
let op: fn(Lhs, Rhs) -> ArithmeticResult = |lhs, rhs| lhs - rhs;
let flag_set: fn(&mut Flags, ArithmeticResult, Lhs, Rhs) = |flags, result, lhs, rhs| {
flags.cf = lhs < rhs;
flags.of = lhs.msb() != rhs.msb() && lhs.msb() != result.msb();
flags.zf = result.zero();
@@ -110,14 +110,58 @@ impl Computer {
self.op(op, flag_set, false, dest, src);
}
/// Perform `dest` = `dest` + `src` + CF. Sets flags.
pub fn adc(&mut self, dest: ModRmTarget, src: Operand) {
let cf = self.flags.cf as u8;
// cheating, by flattening into immediates, but this allows to easily add the opt. carry
let src_with_carry = match src {
Operand::Immediate(immediate_operand) => Operand::Immediate(immediate_operand + cf),
Operand::ModRmTarget(mod_rm_target) => Operand::Immediate(match mod_rm_target {
ModRmTarget::Memory(idx) => self.memory.read(&self.regs, idx) + cf,
ModRmTarget::Register(reg) => self.regs.read(reg) + cf,
}),
};
let op: fn(Lhs, Rhs) -> ArithmeticResult = |lhs, rhs| lhs + rhs;
let flag_set: fn(&mut Flags, ArithmeticResult, Lhs, Rhs) = |flags, result, lhs, rhs| {
flags.cf = result < rhs;
flags.of = lhs.msb() && rhs.msb() != result.msb();
flags.zf = result.zero();
flags.sf = result.msb();
flags.pf = result.parity();
};
self.op(op, flag_set, true, dest, src_with_carry);
}
/// Perform `dest` = `dest` - (`src` + CF). Sets flags.
pub fn sbb(&mut self, dest: ModRmTarget, src: Operand) {
let cf = self.flags.cf as u8;
// cheating, by flattening into immediates, but this allows to easily add the opt. carry
let src_with_carry = match src {
Operand::Immediate(immediate_operand) => Operand::Immediate(immediate_operand + cf),
Operand::ModRmTarget(mod_rm_target) => Operand::Immediate(match mod_rm_target {
ModRmTarget::Memory(idx) => self.memory.read(&self.regs, idx) + cf,
ModRmTarget::Register(reg) => self.regs.read(reg) + cf,
}),
};
let op: fn(Lhs, Rhs) -> ArithmeticResult = |lhs, rhs| lhs - rhs;
let flag_set: fn(&mut Flags, ArithmeticResult, Lhs, Rhs) = |flags, result, lhs, rhs| {
flags.cf = result < rhs;
flags.of = lhs.msb() && rhs.msb() != result.msb();
flags.zf = result.zero();
flags.sf = result.msb();
flags.pf = result.parity();
};
self.op(op, flag_set, true, dest, src_with_carry);
}
/// Applies a binary operator [`O`] to the value of two [`Operand`]s, saves
/// it to `dest`, if `write` is set, and sets flags, according to [`F`].
/// A result can never be saved to an immediate Operand, so `dest` can only
/// be a [`ModRmTarget`].
fn op<O, F>(&mut self, op: O, flag_set: F, write: bool, dest: ModRmTarget, src: Operand)
where
O: Fn(Lhs, Rhs) -> Result,
F: Fn(&mut Flags, Result, Lhs, Rhs),
O: Fn(Lhs, Rhs) -> ArithmeticResult,
F: Fn(&mut Flags, ArithmeticResult, Lhs, Rhs),
{
match src {
Operand::ModRmTarget(src_target) => {
@@ -138,8 +182,8 @@ impl Computer {
dest: ModRmTarget,
src: ModRmTarget,
) where
O: Fn(Lhs, Rhs) -> Result,
F: Fn(&mut Flags, Result, Lhs, Rhs),
O: Fn(Lhs, Rhs) -> ArithmeticResult,
F: Fn(&mut Flags, ArithmeticResult, Lhs, Rhs),
{
match dest {
ModRmTarget::Memory(dest_memory_idx) => match src {
@@ -194,8 +238,8 @@ impl Computer {
dest: ModRmTarget,
src: ImmediateOperand,
) where
O: Fn(Lhs, Rhs) -> Result,
F: Fn(&mut Flags, Result, Lhs, Rhs),
O: Fn(Lhs, Rhs) -> ArithmeticResult,
F: Fn(&mut Flags, ArithmeticResult, Lhs, Rhs),
{
match dest {
ModRmTarget::Memory(dest_mem) => {