fix: align pointer parsing with spec

Previously pointer parsing was completely wrong.
Now split into Pointer32 for immediates with
segment;offset and Pointer16 for short jumps, which
use DS or ES as segment and the Pointer16 value
as offset.

src/instructions.rs

@@ -1,7 +1,7 @@
 //! Internal abstraction of the 8086 instructions.
 
 use crate::{
-    operands::{Byte, MemoryIndex, ModRmTarget, Pointer, Word},
+    operands::{Byte, MemoryIndex, ModRmTarget, Pointer16, Pointer32, Word},
     register::{Register, SegmentRegister},
 };
 use core::fmt;
@@ -202,16 +202,16 @@ pub enum Mnemonic {
     CBW,
     CWD,
     // CALL
-    CALL_p(Pointer),
+    CALL_p(Pointer32),
     CALL_v(isize),
     CALL_Mod(ModRmTarget),
-    CALL_Mp(ModRmTarget, Pointer),
+    CALL_Mp(Pointer16),
     // JUMP
-    JMP_p(Pointer),
+    JMP_p(Pointer32),
     JMP_b(isize), // parses IByte, but stores as isize
     JMP_v(isize), // parwses IWord, but stores as isize
     JMP_Mod(ModRmTarget),
-    JMP_Mp(ModRmTarget, Pointer),
+    JMP_Mp(Pointer16),
     // WAIT
     WAIT,
     // Push/Pop Flags
@@ -237,8 +237,8 @@ pub enum Mnemonic {
     RETF,
     IRET,
     // Load ES/DS Register
-    LES(ModRmTarget, Pointer),
-    LDS(ModRmTarget, Pointer),
+    LES(Register, Pointer16),
+    LDS(Register, Pointer16),
     // NOT
     NOT(ModRmTarget),
     // NEG
@@ -444,13 +444,13 @@ impl fmt::Display for Mnemonic {
             Self::CALL_p(ptr) => write!(f, "call {ptr}"),
             Self::CALL_v(word) => write!(f, "call {word:#04x}"),
             Self::CALL_Mod(target) => write!(f, "call {target}"),
-            Self::CALL_Mp(target, ptr) => write!(f, "call {target}, {ptr}"),
+            Self::CALL_Mp(ptr) => write!(f, "call {ptr}"),
 
             Self::JMP_p(ptr) => write!(f, "jmp {ptr}"),
             Self::JMP_b(byte) => write!(f, "jmp {byte:#04x}"),
             Self::JMP_v(word) => write!(f, "jmp {word:#04x}"),
             Self::JMP_Mod(target) => write!(f, "jmp {target}"),
-            Self::JMP_Mp(target, ptr) => write!(f, "jmp {target}, {ptr}"),
+            Self::JMP_Mp(ptr) => write!(f, "jmp {ptr}"),
 
             Self::WAIT => write!(f, "wait"),
 
@@ -476,8 +476,8 @@ impl fmt::Display for Mnemonic {
             Self::RETF => write!(f, "retf"),
             Self::IRET => write!(f, "iret"),
 
-            Self::LES(target, ptr) => write!(f, "les {target}, {ptr}"),
-            Self::LDS(target, ptr) => write!(f, "lds {target}, {ptr}"),
+            Self::LES(reg, mem) => write!(f, "les {reg}, ptr {mem}"),
+            Self::LDS(reg, mem) => write!(f, "lds {reg}, ptr {mem}"),
 
             Self::NOT(target) => write!(f, "not {target}"),
             Self::NEG(target) => write!(f, "neg {target}"),