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emu: Operand trait over u8/u16, d8_as_d16 argtype

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This commit is contained in:
Jared Burce
2021-03-17 21:38:13 -07:00
parent ae1f3da4b2
commit dcf96ec5b3
5 changed files with 63 additions and 56 deletions
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50
src/emu/operations.rs
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@@ -4,7 +4,7 @@ use emu::byteorder::{ByteOrder, LittleEndian};
use emu::dos;
use emu::i8088::{Flags, RepPrefix, i8088};
use emu::operands::{Addr, Address, HiBit, LValue, Reg, RValue};
use emu::operands::{Addr, Address, LValue, Operand, Reg, RValue};
use emu::pc::Bus;
use emu::util::segoff_to_addr;
@@ -55,30 +55,30 @@ macro_rules! string_op {
// Decide if this can realistically be generalized
macro_rules! update_flags {
// Base Case
(@recur $flags:expr, $dst:ident, $carry:ident) => {};
(@recur $flags:expr, $t:ty, $dst:ident, $carry:ident) => {};
(@af $flags:expr, $dst:ident, $carry:ident) => { /* XXX: Adjust/AuxCarry esoteric? (mostly for BCD?), might not need */ };
(@cf $flags:expr, $dst:ident, $carry:ident) => { $flags.cf = $carry };
(@of $flags:expr, $dst:ident, $carry:ident) => { compile_error!("compute flags.of outside macro"); };
(@pf $flags:expr, $dst:ident, $carry:ident) => { /* XXX: parity looks esoteric, might not need */ };
(@sf $flags:expr, $dst:ident, $carry:ident) => { $flags.sf = $dst.hi_bit(); };
(@zf $flags:expr, $dst:ident, $carry:ident) => { $flags.zf = $dst == 0; };
(@af $flags:expr, $t:ty, $dst:ident, $carry:ident) => { /* XXX: Adjust/AuxCarry esoteric? (mostly for BCD?), might not need */ };
(@cf $flags:expr, $t:ty, $dst:ident, $carry:ident) => { $flags.cf = $carry };
(@of $flags:expr, $t:ty, $dst:ident, $carry:ident) => { compile_error!("compute flags.of outside macro"); };
(@pf $flags:expr, $t:ty, $dst:ident, $carry:ident) => { /* XXX: parity looks esoteric, might not need */ };
(@sf $flags:expr, $t:ty, $dst:ident, $carry:ident) => { $flags.sf = $dst.hi_bit(); };
(@zf $flags:expr, $t:ty, $dst:ident, $carry:ident) => { $flags.zf = $dst == <$t>::zero(); };
// Recursive step
(@recur $flags:expr, $dst:ident, $carry:ident, $next:ident $(, $rest:ident)* ) => {
update_flags!(@$next $flags, $dst, $carry);
update_flags!(@recur $flags, $dst, $carry $(, $rest)*);
(@recur $flags:expr, $t:ty, $dst:ident, $carry:ident, $next:ident $(, $rest:ident)* ) => {
update_flags!(@$next $flags, $t, $dst, $carry);
update_flags!(@recur $flags, $t, $dst, $carry $(, $rest)*);
};
// Entry Point
($flags:expr, $eval:expr $(, $flagnames:ident)* ) => { {
($flags:expr, $t:ty, $eval:expr $(, $flagnames:ident)* ) => { {
let (dst, carry) = $eval;
update_flags!(@recur $flags, dst, carry $(, $flagnames)*);
update_flags!(@recur $flags, $t, dst, carry $(, $flagnames)*);
dst
} }
}
pub fn assert<T: Debug + Eq>(loc: &impl RValue<T>, val: &impl RValue<T>) {
pub fn assert<T: Operand + Debug>(loc: &impl RValue<T>, val: &impl RValue<T>) {
assert_eq!(loc.read(), val.read(),
"ASSERT instruction failed: {:#2X?} != {:#2X?}", loc.read(), val.read());
println!("ASSERT pass: {:#2X?} == {:#2X?}", loc.read(), val.read());
@@ -98,18 +98,10 @@ pub fn call(ip: &mut Reg, ss: u16, sp: &mut Reg, mem: &mut [u8], addr: i16) {
ip.write(target);
}
pub fn cmpb(flags: &mut Flags, dst: &impl RValue<u8>, src: &impl RValue<u8>) {
pub fn cmp<T: Operand>(flags: &mut Flags, dst: &impl RValue<T>, src: &impl RValue<T>) {
let (dst, src) = (dst.read(), src.read());
let after = update_flags!(flags, dst.overflowing_sub(src), af, cf, pf, sf, zf);
flags.of = 0 != 0x80 & // In the sign bit...
(src ^ dst) & // ...operands have different signs...
(dst ^ after); // ...and destination sign-bit changed
}
pub fn cmpw(flags: &mut Flags, dst: &impl RValue<u16>, src: &impl RValue<u16>) {
let (dst, src) = (dst.read(), src.read());
let after = update_flags!(flags, dst.overflowing_sub(src), af, cf, pf, sf, zf);
flags.of = 0 != 0x8000 & // In the sign bit...
let after = update_flags!(flags, T, dst.overflowing_sub(&src), af, cf, pf, sf, zf);
flags.of = T::zero() != T::HI_BIT_MASK & // In the (maybe) sign bit...
(src ^ dst) & // ...operands have different signs...
(dst ^ after); // ...and destination sign-bit changed
}
@@ -126,7 +118,7 @@ pub fn cmpsb(flags: &mut Flags,
let src = <Addr as RValue<u8>>::read(&Addr { bus: bus, segment: seg, offset: si.read() });
let dst = <Addr as RValue<u8>>::read(&Addr { bus: bus, segment: es.read(), offset: di.read() });
cmpb(flags, &dst, &src);
cmp(flags, &dst, &src);
});
}
@@ -142,7 +134,7 @@ pub fn cmpsw(flags: &mut Flags,
let src = <Addr as RValue<u16>>::read(&Addr { bus: bus, segment: seg, offset: si.read() });
let dst = <Addr as RValue<u16>>::read(&Addr { bus: bus, segment: es.read(), offset: di.read() });
cmpw(flags, &dst, &src);
cmp(flags, &dst, &src);
});
}
@@ -242,7 +234,7 @@ pub fn scasb(flags: &mut Flags,
needle: &impl RValue<u8>) {
string_op!((u8, flags, rep, cx, di=di, zf=flags.zf), {
let elem = Addr { bus: bus, segment: es.read(), offset: di.read() };
cmpb(flags, &elem, needle);
cmp(flags, &elem, needle);
});
}
@@ -255,7 +247,7 @@ pub fn scasw(flags: &mut Flags,
needle: &impl RValue<u16>) {
string_op!((u16, flags, rep, cx, di=di, zf=flags.zf), {
let elem = Addr { bus: bus, segment: es.read(), offset: di.read() };
cmpw(flags, &elem, needle);
cmp(flags, &elem, needle);
});
}