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emu: NOT/NEG ops

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This commit is contained in:
Jared Burce
2021-04-08 00:52:12 -07:00
parent 7c2ca230ff
commit 96c869f711
4 changed files with 22 additions and 1 deletions
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3
src/emu/flags.rs
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@@ -40,6 +40,7 @@ impl Flags {
FlagOp::Eager { cf, .. } => cf,
FlagOp::DEC { cf } => cf,
FlagOp::INC { cf } => cf,
FlagOp::NEG { .. } => { self.res != 0 },
FlagOp::POPF => { self.res & 1 << CF_BIT != 0 },
FlagOp::RCL { dst, shamt, bits, old_cf, .. } => {
// for carry-rotate shamt bas been modded to have range [0,bits].
@@ -138,6 +139,7 @@ impl Flags {
FlagOp::Eager { of, .. } => of,
FlagOp::DEC { .. } => { self.res == self.sign_mask - 1 },
FlagOp::INC { .. } => { self.res == self.sign_mask },
FlagOp::NEG { dst } => { self.res == dst && dst != 0 },
FlagOp::POPF => { self.res & 1 << OF_BIT != 0 },
FlagOp::RCL { dst, .. }
| FlagOp::RCR { dst, .. }
@@ -164,6 +166,7 @@ pub enum FlagOp {
Eager { cf: bool, pf: bool, af: bool, zf: bool, sf: bool, of: bool }, // all flags precomputed
DEC { cf: bool },
INC { cf: bool },
NEG { dst: u16 },
POPF, // flags encoded in result
RCL { dst: u16, shamt: u16, bits: u16, old_cf: bool, pf: bool, af: bool, zf: bool, sf: bool },
RCR { dst: u16, shamt: u16, old_cf: bool, pf: bool, af: bool, zf: bool, sf: bool },

6
src/emu/i8088.rs
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@@ -489,7 +489,7 @@ impl i8088 {
0x10 => mov[reg=ss, modrm16] / "2/12+", // MOV ss, r/m16
0x18 => mov[reg=ds, modrm16] / "2/12+", }, // MOV ds, r/m16
0x8F: { 0x00 => pop_modrm[regval=ss, reg=sp, modrm16, convert, bus] / "12/25+" }, // POP r/m16
0x90 => nop[] / 3,
0x90 => nop[] / 3, // NOP
0x91 => xchg[reg=a, reg=c] / 3, // XCHG ax, cx
0x92 => xchg[reg=a, reg=d] / 3, // XCHG ax, dx
0x93 => xchg[reg=a, reg=b] / 3, // XCHG ax, bx
@@ -570,6 +570,10 @@ impl i8088 {
0xF2 => nop[rep=NotEqual, prefix] / 0, // REPNE/REPNZ
0xF3 => nop[rep=Equal, prefix] / 0, // REP/REPE/REPZ
0xF5 => cmc[flags] / 2, // CMC (Complement Carry Flag)
0xF6: { 0x10 => not[form=byte1, modrm8] / "3/24+", // NOT r/m8
0x18 => neg[form=byte1, flags, modrm8] / "3/24+" }, // NEG r/m8
0xF7: { 0x10 => not[form=word1, modrm16] / "3/24+", // NOT r/m16
0x18 => neg[form=word1, flags, modrm16] / "3/24+" }, // NEG r/m16
0xF8 => clc[flags] / 2, // CLC (Clear Carry Flag)
0xF9 => stc[flags] / 2, // STC (Set Carry Flag)
0xFC => cld[flags] / 2, // CLD (Clear Direction Flag)

1
src/emu/operands.rs
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@@ -14,6 +14,7 @@ pub trait Operand: Copy + 'static +
nt::ops::checked::CheckedShr<Output = Self> +
nt::ops::overflowing::OverflowingSub +
nt::ops::wrapping::WrappingAdd +
nt::ops::wrapping::WrappingNeg +
nt::ops::wrapping::WrappingSub +
std::ops::Shl<Output = Self> +
std::ops::Shr<Output = Self>

13
src/emu/operations.rs
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@@ -294,6 +294,19 @@ where for<'a> FarPtr<'a>: RValue<T> + LValue<T>
pub fn nop() {}
pub fn not<T: Operand, LVal: LValue<T>>(mut dst: LVal) {
dst.write(!dst.read());
}
pub fn neg<T: Operand, LVal: LValue<T>>(flags: &mut Flags, mut dst: LVal) {
let dst_before = dst.read();
let res = dst_before.wrapping_neg();
dst.write(res);
flags.update(FlagOp::NEG { dst: dst_before.into() },
res.into(),
T::HI_BIT_MASK.into());
}
pub fn pop<LVal: LValue<u16>>(bus: &mut Bus, ss: u16, mut sp: Reg, mut dst: LVal) {
let ptr = FarPtr { bus: bus, segment: ss, offset: sp.read() };
dst.write(ptr.read());