Add instruction visitor, which traverses memory and choosing instructions

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

src/vm/error.rs

@@ -1,4 +1,4 @@
-use crate::vm::{vm::*, reg::Reg};
+use crate::vm::{inst::InstOp, reg::Reg, vm::*};
 use snafu::Snafu;
 
 #[derive(Snafu, Debug, Clone)]
@@ -7,6 +7,8 @@ pub enum VmError {
     IllegalReg { reg: Reg },
     #[snafu(display("memory address out of bounds: 0x{:016x}", addr))]
     MemOutOfBounds { addr: Addr },
+    #[snafu(display("illegal instruction opcode: 0x{:04x}", op))]
+    IllegalOp { op: InstOp },
 }
 
 pub type Result<T, E = VmError> = std::result::Result<T, E>;

src/vm/mod.rs

@@ -5,4 +5,5 @@ pub mod mem;
 pub mod obj;
 pub mod reg;
 mod tick;
+pub mod visit;
 pub mod vm;

src/vm/tick.rs

@@ -1,134 +1,190 @@
-use crate::vm::{error::*, flags::Flags, inst::*, reg::*, vm::*};
+use crate::vm::{error::*, flags::Flags, inst::*, reg::*, vm::*, visit::*, mem::MemCursor};
 use std::io::stdin;
 
 impl Vm {
     pub fn tick(&mut self) -> Result<()> {
-        let mut cursor = self.mem_cursor(self.ip() as usize);
+        let next_ip = visit_inst(self)?;
-        let op = cursor.next_u16()?;
-        let next_ip;
-
-        macro_rules! math_inst {
-            ($mapping:expr) => {{
-                let (r1, r2) = cursor.next_regs()?;
-                next_ip = cursor.position();
-                let value = ($mapping)(self.get_reg_checked(r1)?, self.get_reg_checked(r2)?);
-                self.set_reg(r1, value);
-            }};
-        }
-        match op {
-            ADD => math_inst!(|w1: u64, w2: u64| w1.wrapping_add(w2)),
-            MUL => math_inst!(|w1: u64, w2: u64| w1.wrapping_mul(w2)),
-            DIV => math_inst!(|w1: u64, w2: u64| w1.wrapping_div(w2)),
-            MOD => math_inst!(|w1: u64, w2: u64| w1 % w2),
-            INEG => todo!(),
-            AND => math_inst!(|w1: u64, w2: u64| w1 & w2),
-            OR => math_inst!(|w1: u64, w2: u64| w1 | w2),
-            INV => {
-                let r1 = cursor.next_reg()?;
-                next_ip = cursor.position();
-                let value = self.get_reg_checked(r1)?;
-                self.set_reg(r1, !value);
-            }
-            NOT => {
-                let r1 = cursor.next_reg()?;
-                next_ip = cursor.position();
-                let value = self.get_reg(r1);
-                self.set_reg(r1, (value == 0) as Word);
-            }
-            XOR => math_inst!(|w1: u64, w2: u64| w1 ^ w2),
-            SHL => math_inst!(|w1: u64, w2: u64| w1 << w2),
-            SHR => math_inst!(|w1: u64, w2: u64| w1 >> w2),
-            CMPEQ => {
-                let (r1, r2) = cursor.next_regs()?;
-                next_ip = cursor.position();
-                let cmp = self.get_reg(r1) == self.get_reg(r2);
-                if cmp {
-                    self.insert_flags(Flags::COMPARE);
-                } else {
-                    self.remove_flags(Flags::COMPARE);
-                }
-            }
-            CMPLT => {
-                let (r1, r2) = cursor.next_regs()?;
-                next_ip = cursor.position();
-                let cmp = self.get_reg(r1) < self.get_reg(r2);
-                if cmp {
-                    self.insert_flags(Flags::COMPARE);
-                } else {
-                    self.remove_flags(Flags::COMPARE);
-                }
-            }
-            JMP => {
-                let r1 = cursor.next_reg()?;
-                next_ip = self.get_reg(r1);
-            }
-            JZ => {
-                let r1 = cursor.next_reg()?;
-                if !self.flags().contains(Flags::COMPARE) {
-                    next_ip = self.get_reg(r1);
-                } else {
-                    next_ip = cursor.position();
-                }
-            }
-            JNZ => {
-                let r1 = cursor.next_reg()?;
-                if self.flags().contains(Flags::COMPARE) {
-                    next_ip = self.get_reg(r1);
-                } else {
-                    next_ip = cursor.position();
-                }
-            }
-            LOAD => {
-                let (r1, r2) = cursor.next_regs()?;
-                next_ip = cursor.position();
-                let value = self.load(r2)?;
-                self.set_reg_checked(r1, value)?;
-            }
-            REGCOPY => math_inst!(|_: u64, w2: u64| w2),
-            STOREIMM64 => {
-                let r1 = cursor.next_reg()?;
-                // skip
-                cursor.next_u32()?;
-                let imm = cursor.next_u64()?;
-                next_ip = cursor.position();
-                self.set_reg(r1, imm);
-            }
-            STOREIMM32 => {
-                let r1 = cursor.next_reg()?;
-                let imm = cursor.next_u32()?;
-                next_ip = cursor.position();
-                self.set_reg(r1, imm as u64);
-            }
-            MEMCOPY => {
-                let (r1, r2) = cursor.next_regs()?;
-                next_ip = cursor.position();
-                let value = self.load(r2)?;
-                self.store(r1, value)?;
-            }
-            STORE => {
-                let (r1, r2) = cursor.next_regs()?;
-                next_ip = cursor.position();
-                let value = self.get_reg(r1);
-                self.store(r2, value)?;
-            }
-            HALT => {
-                next_ip = cursor.position();
-                self.insert_flags(Flags::HALT);
-            }
-            NOP => {
-                next_ip = cursor.position();
-            }
-            _ => panic!("unknown instruction opcode: 0x{:04x}", op),
-        }
-
-        println!("op: {:04x} {}", op, inst_name(op).unwrap());
-        println!("ip: {:05x}", self.ip());
-        println!("next_ip: {:05x}", next_ip);
-        let mut _line = String::new();
-        stdin().read_line(&mut _line).unwrap();
-    
         self.set_reg(IP, next_ip);
-
         Ok(())
     }
+
+    fn next_ip(&self) -> Result<Addr> {
+        let ip = self.ip();
+        let op = self.get_inst_op(ip)?;
+        Ok(ip + (inst_len(op) as u64))
+    }
+
+    fn with_regs<F, B>(&mut self, r1: Reg, r2: Reg, mapping: F) -> B
+        where F: FnOnce(Word, Word) -> B
+    {
+        let w1 = self.get_reg(r1);
+        let w2 = self.get_reg(r2);
+        (mapping)(w1, w2)
+    }
+}
+
+impl InstAcceptor for Vm {
+    type Out = Addr;
+
+    fn cursor(&self) -> MemCursor {
+        self.mem_cursor(self.ip() as usize)
+    }
+
+    fn add(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        let out = self.with_regs(r1, r2, |w1, w2| w1.wrapping_add(w2));
+        self.set_reg(r1, out);
+        self.next_ip()
+    }
+
+    fn mul(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        let out = self.with_regs(r1, r2, |w1, w2| w1.wrapping_mul(w2));
+        self.set_reg(r1, out);
+        self.next_ip()
+    }
+
+    fn div(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        // TODO : check w2 == 0 and throw error/exception
+        let out = self.with_regs(r1, r2, |w1, w2| w1 / w2);
+        self.set_reg(r1, out);
+        self.next_ip()
+    }
+
+    fn mod_(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        // TODO : check w2 == 0 and throw error/exception
+        let out = self.with_regs(r1, r2, |w1, w2| w1 % w2);
+        self.set_reg(r1, out);
+        self.next_ip()
+    }
+
+    fn ineg(&mut self, r1: Reg) -> Result<Self::Out> {
+        let w1 = self.get_reg(r1);
+        self.set_reg(r1, (!w1).wrapping_add(1));
+        self.next_ip()
+    }
+
+    fn and(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        let out = self.with_regs(r1, r2, |w1, w2| w1 & w2);
+        self.set_reg(r1, out);
+        self.next_ip()
+    }
+
+    fn or(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        let out = self.with_regs(r1, r2, |w1, w2| w1 | w2);
+        self.set_reg(r1, out);
+        self.next_ip()
+    }
+
+    fn inv(&mut self, r1: Reg) -> Result<Self::Out> {
+        let w1 = self.get_reg(r1);
+        self.set_reg(r1, !w1);
+        self.next_ip()
+    }
+
+    fn not(&mut self, r1: Reg) -> Result<Self::Out> {
+        let w1 = self.get_reg(r1);
+        self.set_reg(r1, (w1 == 0) as Word);
+        self.next_ip()
+    }
+
+    fn xor(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        let out = self.with_regs(r1, r2, |w1, w2| w1 ^ w2);
+        self.set_reg(r1, out);
+        self.next_ip()
+    }
+
+    fn shl(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        let out = self.with_regs(r1, r2, |w1, w2| w1 << w2);
+        self.set_reg(r1, out);
+        self.next_ip()
+    }
+
+    fn shr(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        let out = self.with_regs(r1, r2, |w1, w2| w1 >> w2);
+        self.set_reg(r1, out);
+        self.next_ip()
+    }
+
+    fn cmpeq(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        let cmp = self.with_regs(r1, r2, |w1, w2| w1 == w2); 
+        if cmp {
+            self.insert_flags(Flags::COMPARE);
+        } else {
+            self.remove_flags(Flags::COMPARE);
+        }
+        self.next_ip()
+    }
+
+    fn cmplt(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        let cmp = self.with_regs(r1, r2, |w1, w2| w1 < w2); 
+        if cmp {
+            self.insert_flags(Flags::COMPARE);
+        } else {
+            self.remove_flags(Flags::COMPARE);
+        }
+        self.next_ip()
+    }
+
+    fn jmp(&mut self, r1: Reg) -> Result<Self::Out> {
+        let addr = self.get_reg(r1);
+        Ok(addr)
+    }
+
+    fn jz(&mut self, r1: Reg) -> Result<Self::Out> {
+        if !self.flags().contains(Flags::COMPARE) {
+            Ok(self.get_reg(r1))
+        } else {
+            self.next_ip()
+        }
+    }
+
+    fn jnz(&mut self, r1: Reg) -> Result<Self::Out> {
+        if self.flags().contains(Flags::COMPARE) {
+            Ok(self.get_reg(r1))
+        } else {
+            self.next_ip()
+        }
+    }
+
+    fn load(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        let value = Vm::load(self, r2)?;
+        self.set_reg_checked(r1, value)?;
+        self.next_ip()
+    }
+
+    fn regcopy(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        let value = self.get_reg_checked(r2)?;
+        self.set_reg_checked(r1, value)?;
+        self.next_ip()
+    }
+
+    fn storeimm64(&mut self, r1: Reg, w1: Word) -> Result<Self::Out> {
+        self.set_reg_checked(r1, w1)?;
+        self.next_ip()
+    }
+
+    fn storeimm32(&mut self, r1: Reg, w1: HalfWord) -> Result<Self::Out> {
+        self.set_reg_checked(r1, w1 as Word)?;
+        self.next_ip()
+    }
+
+    fn memcopy(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        let value = Vm::load(self, r2)?;
+        self.store(r1, value)?;
+        self.next_ip()
+    }
+
+    fn store(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        let value = self.get_reg_checked(r1)?;
+        self.store(r2, value)?;
+        self.next_ip()
+    }
+
+    fn halt(&mut self) -> Result<Self::Out> {
+        self.insert_flags(Flags::HALT);
+        self.next_ip()
+    }
+
+    fn nop(&mut self) -> Result<Self::Out> {
+        self.next_ip()
+    }
 }

src/vm/visit.rs

@@ -0,0 +1,95 @@
+use crate::vm::{
+    error::*,
+    inst::*,
+    mem::MemCursor,
+    reg::Reg,
+    vm::{HalfWord, Word},
+};
+
+pub trait InstAcceptor {
+    type Out;
+
+    fn cursor(&self) -> MemCursor;
+    fn add(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out>;
+    fn mul(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out>;
+    fn div(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out>;
+    fn mod_(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out>;
+    fn ineg(&mut self, r1: Reg) -> Result<Self::Out>;
+    fn and(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out>;
+    fn or(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out>;
+    fn inv(&mut self, r1: Reg) -> Result<Self::Out>;
+    fn not(&mut self, r1: Reg) -> Result<Self::Out>;
+    fn xor(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out>;
+    fn shl(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out>;
+    fn shr(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out>;
+    fn cmpeq(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out>;
+    fn cmplt(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out>;
+    fn jmp(&mut self, r1: Reg) -> Result<Self::Out>;
+    fn jz(&mut self, r1: Reg) -> Result<Self::Out>;
+    fn jnz(&mut self, r1: Reg) -> Result<Self::Out>;
+    fn load(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out>;
+    fn regcopy(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out>;
+    fn storeimm64(&mut self, r1: Reg, w1: Word) -> Result<Self::Out>;
+    fn storeimm32(&mut self, r1: Reg, w1: HalfWord) -> Result<Self::Out>;
+    fn memcopy(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out>;
+    fn store(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out>;
+    fn halt(&mut self) -> Result<Self::Out>;
+    fn nop(&mut self) -> Result<Self::Out>;
+}
+
+pub fn visit_inst<A: InstAcceptor>(acceptor: &mut A) -> Result<A::Out> {
+    let mut cursor = acceptor.cursor();
+    let op = cursor.next_u16()?;
+
+    macro_rules! r1_r2_inst {
+        ($fun:ident) => {{
+            let (r1, r2) = cursor.next_regs()?;
+            acceptor.$fun(r1, r2)
+        }};
+    }
+    macro_rules! r1_inst {
+        ($fun:ident) => {{
+            let r1 = cursor.next_reg()?;
+            acceptor.$fun(r1)
+        }};
+    }
+
+    match op {
+        ADD => r1_r2_inst!(add),
+        MUL => r1_r2_inst!(mul),
+        DIV => r1_r2_inst!(div),
+        MOD => r1_r2_inst!(mod_),
+        INEG => r1_inst!(ineg),
+        AND => r1_r2_inst!(and),
+        OR => r1_r2_inst!(or),
+        INV => r1_inst!(inv),
+        NOT => r1_inst!(not),
+        XOR => r1_r2_inst!(xor),
+        SHL => r1_r2_inst!(shl),
+        SHR => r1_r2_inst!(shr),
+        CMPEQ => r1_r2_inst!(cmpeq),
+        CMPLT => r1_r2_inst!(cmplt),
+        JMP => r1_inst!(jmp),
+        JZ => r1_inst!(jz),
+        JNZ => r1_inst!(jnz),
+        LOAD => r1_r2_inst!(load),
+        REGCOPY => r1_r2_inst!(regcopy),
+        STOREIMM64 => {
+            let r1 = cursor.next_reg()?;
+            // skip
+            cursor.next_u32()?;
+            let imm = cursor.next_u64()?;
+            acceptor.storeimm64(r1, imm)
+        }
+        STOREIMM32 => {
+            let r1 = cursor.next_reg()?;
+            let imm = cursor.next_u32()?;
+            acceptor.storeimm32(r1, imm)
+        }
+        MEMCOPY => r1_r2_inst!(memcopy),
+        STORE => r1_r2_inst!(store),
+        HALT => acceptor.halt(),
+        NOP => acceptor.nop(),
+        _ => Err(VmError::IllegalOp { op }),
+    }
+}

src/vm/vm.rs

@@ -1,4 +1,4 @@
-use crate::vm::{error::*, flags::*, mem::*, obj::obj::*, reg::*};
+use crate::vm::{error::*, flags::*, inst::InstOp, mem::*, obj::obj::*, reg::*};
 use byteorder::{WriteBytesExt, LE};
 use std::{io::Cursor, mem};
 
@@ -101,6 +101,11 @@ impl Vm {
         Ok(self.mem_cursor(addr as usize).next_u32().unwrap())
     }
 
+    pub fn get_inst_op(&self, addr: Addr) -> Result<InstOp> {
+        self.check_read(addr, 2)?;
+        Ok(self.mem_cursor(addr as usize).next_u16().unwrap())
+    }
+
     pub fn get_byte(&self, addr: Addr) -> Result<u8> {
         self.check_addr(addr)?;
         Ok(self.mem_cursor(addr as usize).next_u8().unwrap())