emu: near/short JUMP instructions. Use u16+wrapping_add for all rels

src/emu/i8088.rs

@@ -253,11 +253,16 @@ macro_rules! step {
     step!(@arg $cookie, $cpu.$reg.get());
   };
 
+  (@rel8 $cookie:tt, $cpu:expr, $bus:expr, $prefix:tt, $modrm:tt) => { {
+    let rel8 = i8088::next_ip($cpu.cs.get(), &mut $cpu.ip, $bus) as i8;
+    step!(@arg $cookie, rel8 as u16)
+  } };
+
   (@rel16 $cookie:tt, $cpu:expr, $bus:expr, $prefix:tt, $modrm:tt) => { {
     let mut buf = [0; 2];
     buf[0] = i8088::next_ip($cpu.cs.get(), &mut $cpu.ip, $bus);
     buf[1] = i8088::next_ip($cpu.cs.get(), &mut $cpu.ip, $bus);
-    step!(@arg $cookie, LittleEndian::read_i16(&buf))
+    step!(@arg $cookie, LittleEndian::read_i16(&buf) as u16)
   } };
 
   (@rep $cookie:tt, $cpu:expr, $bus:expr,
@@ -393,6 +398,22 @@ impl i8088 {
           0x61 => peek[seg=ds, addr] / 0,      // Fake opcode for debugging
           0x62 _ => assert[modrm8, d8] / 0,    // Fake opcode for debugging
           0x63 _ => assert[modrm16, d16] / 0,  // Fake opcode for debugging
+          0x70 => jo[flags, reg=ip, rel8] / "16/4",   // JO rel8
+          0x71 => jno[flags, reg=ip, rel8] / "16/4",  // JNO rel8
+          0x72 => jb[flags, reg=ip, rel8] / "16/4",   // JB/JNAE/JC rel8
+          0x73 => jae[flags, reg=ip, rel8] / "16/4",  // JNB/JAE/JNC rel8
+          0x74 => jz[flags, reg=ip, rel8] / "16/4",   // JE/JZ rel8
+          0x75 => jnz[flags, reg=ip, rel8] / "16/4",  // JNE/JNZ rel8
+          0x76 => jbe[flags, reg=ip, rel8] / "16/4",  // JBE/JNA rel8
+          0x77 => ja[flags, reg=ip, rel8] / "16/4",   // JNBE/JA rel8
+          0x78 => js[flags, reg=ip, rel8] / "16/4",   // JS rel8
+          0x79 => jns[flags, reg=ip, rel8] / "16/4",  // JNS rel8
+          //0x7A => jpe[flags, reg=ip, rel8] / "16/4",  // JP/JPE rel8  XXX: Parity flag not implemented
+          //0x7B => jpo[flags, reg=ip, rel8] / "16/4",  // JNP/JPO rel8 XXX: Parity flag not implemented
+          0x7C => jl[flags, reg=ip, rel8] / "16/4",   // JL/JNGE rel8
+          0x7D => jge[flags, reg=ip, rel8] / "16/4",  // JNL/JGE rel8
+          0x7E => jle[flags, reg=ip, rel8] / "16/4",  // JLE/JNG rel8
+          0x7F => jg[flags, reg=ip, rel8] / "16/4",   // JNLE/JG rel8
           0x80: { 0x38 => cmp[flags, modrm8, d8] / "4/23+", },
           0x81: { 0x38 => cmp[flags, modrm16, d16] / "4/23+", },
           0x83: { 0x38 => cmp[flags, modrm16, d8_as_d16] / "4/23+", },
@@ -442,6 +463,9 @@ impl i8088 {
           0xBF => mov[reg=di, d16] / 4,
           0xC3 => pop[bus, regval=ss, reg=sp, reg=ip] / 20,  // RET
           0xCD => int[cpu, bus, d8] / 71,
+          0xE3 => jcxz[reg=ip, reg=c, rel8] / "18/6",  // JCXZ rel8
+          0xE9 => jmp[reg=ip, rel16] / 15,  // JMP rel16
+          0xEB => jmp[reg=ip, rel8] / 15,  // JMP rel8
           0xE8 => call[reg=ip, bus, regval=ss, reg=sp, rel16] / 23,
           0xF2 => nop[rep=NotEqual, prefix] / 0,  // REPNE/REPNZ
           0xF3 => nop[rep=Equal, prefix] / 0,     // REP/REPE/REPZ

src/emu/operations.rs

@@ -89,8 +89,8 @@ pub fn peek(addr: &(impl Address + RValue<u8>)) {
   println!("PEEK: @{:#X} = {:#X} ({})", addr.addr(), addr.read(), addr.read());
 }
 
-pub fn call(ip: &mut Reg, bus: &mut Bus, ss: u16, sp: &mut Reg, addr: i16) {
+pub fn call(ip: &mut Reg, bus: &mut Bus, ss: u16, sp: &mut Reg, rel16: u16) {
-  let target = ip.read().wrapping_add(addr as u16);
+  let target = ip.read().wrapping_add(rel16);
   push(bus, ss, sp, ip.read());
   ip.write(target);
 }
@@ -142,6 +142,100 @@ pub fn int(cpu: &mut i8088, bus: &mut Bus, num: &u8) {
   }
 }
 
+pub fn ja(flags: &Flags, ip: &mut Reg, rel8: u16) {
+  if !flags.cf && !flags.zf {
+    ip.write(ip.read().wrapping_add(rel8));
+  }
+}
+
+pub fn jae(flags: &Flags, ip: &mut Reg, rel8: u16) {
+  if !flags.cf {
+    ip.write(ip.read().wrapping_add(rel8));
+  }
+}
+
+pub fn jb(flags: &Flags, ip: &mut Reg, rel8: u16) {
+  if flags.cf {
+    ip.write(ip.read().wrapping_add(rel8));
+  }
+}
+
+pub fn jbe(flags: &Flags, ip: &mut Reg, rel8: u16) {
+  if flags.cf || flags.zf {
+    ip.write(ip.read().wrapping_add(rel8));
+  }
+}
+
+pub fn jcxz(ip: &mut Reg, cx: &mut Reg, rel8: u16) {
+  if cx.read() == 0 {
+    ip.write(ip.read().wrapping_add(rel8));
+  }
+}
+
+pub fn jg(flags: &Flags, ip: &mut Reg, rel8: u16) {
+  if flags.zf && flags.sf == flags.of {
+    ip.write(ip.read().wrapping_add(rel8));
+  }
+}
+
+pub fn jge(flags: &Flags, ip: &mut Reg, rel8: u16) {
+  if flags.sf == flags.of {
+    ip.write(ip.read().wrapping_add(rel8));
+  }
+}
+
+pub fn jl(flags: &Flags, ip: &mut Reg, rel8: u16) {
+  if flags.sf != flags.of {
+    ip.write(ip.read().wrapping_add(rel8));
+  }
+}
+
+pub fn jle(flags: &Flags, ip: &mut Reg, rel8: u16) {
+  if flags.zf || flags.sf != flags.of {
+    ip.write(ip.read().wrapping_add(rel8));
+  }
+}
+
+pub fn jmp(ip: &mut Reg, rel: u16) {
+  ip.write(ip.read().wrapping_add(rel));
+}
+
+pub fn jno(flags: &Flags, ip: &mut Reg, rel8: u16) {
+  if !flags.of {
+    ip.write(ip.read().wrapping_add(rel8));
+  }
+}
+
+pub fn jns(flags: &Flags, ip: &mut Reg, rel8: u16) {
+  if !flags.sf {
+    ip.write(ip.read().wrapping_add(rel8));
+  }
+}
+
+pub fn jnz(flags: &Flags, ip: &mut Reg, rel8: u16) {
+  if !flags.zf {
+    ip.write(ip.read().wrapping_add(rel8));
+  }
+}
+
+pub fn jo(flags: &Flags, ip: &mut Reg, rel8: u16) {
+  if flags.of {
+    ip.write(ip.read().wrapping_add(rel8));
+  }
+}
+
+pub fn js(flags: &Flags, ip: &mut Reg, rel8: u16) {
+  if flags.sf {
+    ip.write(ip.read().wrapping_add(rel8));
+  }
+}
+
+pub fn jz(flags: &Flags, ip: &mut Reg, rel8: u16) {
+  if flags.zf {
+    ip.write(ip.read().wrapping_add(rel8));
+  }
+}
+
 pub fn lea(dst: &mut Reg, addr: &FarPtr) {
   dst.write(addr.offset)
 }