Initial start on equality checks

docs/spec.md

@@ -6,15 +6,22 @@ Corten is based on Fletcher Haynes's [So you want to build a language VM](https:
 
 ## Instruction Set 
 
-| Register | Opcode |
-| --- | --- |
-| 0 | LOAD |
+| Opcode | Function | Comment |
+| --- | --- | --- |
+| 0 | LOAD | Load program |
 | 1 | ADD |
 | 2 | SUB |
 | 3 | MUL |
 | 4 | DIV |
-| 6 | HLT |
-| 5 | JMP |
-| 8 | JMPF |
-| 9 | JMPB |
-| _ | IGL |
+| 6 | HLT | Halt |
+| 5 | JMP | Jump |
+| 8 | JMPF | Jump forward |
+| 9 | JMPB | Jump backward |
+| 10 | EQ | Equal |
+| 11 | NEQ | Not equal |
+| 12 | GTE | Greater then or equal to |
+| 13 | GT | Greater then |
+| 14 | LTE | Less then or equal |
+| 15 | LT | Less then
+| 16 | JMPE | Jump if equal |
+| _ | IGL | Illegal action |

src/instruction.rs

@@ -1,4 +1,4 @@
-use crate::instruction::Opcode::LOAD;
+#![allow(dead_code)]
 
 #[derive(Debug, PartialEq)]
 pub enum Opcode {
@@ -9,7 +9,26 @@ pub enum Opcode {
     SUB,
     MUL,
     DIV,
+    /// Equal
+    EQ,
+    /// Not equal
+    NEQ,
+    /// Greater then
+    GT,
+    /// Less then
+    LT,
+    /// Greater then or equal to
+    GTE,
+    /// less then or equal
+    LTE,
+    /// jump if equal
+    JMPE,
+    /// Jump
     JMP,
+    /// Jump forward
+    JMPF,
+    /// Jump backward
+    JMPB,
 }
 
 impl From<u8> for Opcode {
@@ -22,6 +41,15 @@ impl From<u8> for Opcode {
             4 => Opcode::DIV,
             6 => Opcode::HLT,
             7 => Opcode::JMP,
+            8 => Opcode::JMPF,
+            9 => Opcode::JMPB,
+            10 => Opcode::EQ,
+            11 => Opcode::NEQ,
+            12 => Opcode::GTE,
+            13 => Opcode::GT,
+            14 => Opcode::LTE,
+            15 => Opcode::LT,
+            16 => Opcode::JMPE,
             _ => Opcode::IGL,
         }
     }

src/vm.rs

@@ -6,6 +6,7 @@ pub struct VM {
     pc: usize,
     program: Vec<u8>,
     remainder: u32,
+    equal_flag: bool,
 }
 
 impl VM {
@@ -15,6 +16,7 @@ impl VM {
             pc: 0,
             program: vec![],
             remainder: 0,
+            equal_flag: false
         }
     }
 
@@ -63,6 +65,7 @@ impl VM {
             }
             Opcode::IGL => {
                 println!("Unrecognized opcode found! Terminating!");
+                return false;
             }
             Opcode::ADD => {
                 let reg1 = self.registers[self.next_8_bits() as usize];
@@ -89,6 +92,21 @@ impl VM {
                 let reg2 = self.registers[self.next_8_bits() as usize];
                 self.registers[self.next_8_bits() as usize] = reg1 - reg2;
             }
+            Opcode::JMPF => {
+                let target = self.registers[self.next_8_bits() as usize];
+                self.pc += target as usize;
+            }
+            Opcode::JMPB => {
+                let target = self.registers[self.next_8_bits() as usize];
+                self.pc -= target as usize;
+            }
+            Opcode::EQ => {}
+            Opcode::NEQ => {}
+            Opcode::GT => {}
+            Opcode::LT => {}
+            Opcode::GTE => {}
+            Opcode::LTE => {}
+            Opcode::JMPE => {}
         }
         true
     }
@@ -121,6 +139,30 @@ mod vm_tests {
         assert_eq!(vm.pc, 1);
     }
 
+    #[test]
+    fn test_add_opcode() {
+        let mut vm = get_test_vm();
+        vm.program = vec![1, 0, 1, 2];
+        vm.run();
+        assert_eq!(vm.registers[2], 15);
+    }
+
+    #[test]
+    fn test_sub_opcode() {
+        let mut vm = get_test_vm();
+        vm.program = vec![2, 1, 0, 2];
+        vm.run();
+        assert_eq!(vm.registers[2], 5);
+    }
+
+    #[test]
+    fn test_div_opcode() {
+        let mut vm = get_test_vm();
+        vm.program = vec![4, 1, 0, 2];
+        vm.run();
+        assert_eq!(vm.registers[2], 2);
+    }
+
     #[test]
     fn test_opcode_igl() {
         let mut vm = get_test_vm();
@@ -139,6 +181,25 @@ mod vm_tests {
         assert_eq!(vm.pc, 1);
     }
 
+    #[test]
+    fn test_jmpf_opcode() {
+        let mut vm = get_test_vm();
+        vm.registers[0] = 2;
+        vm.program = vec![8, 0, 0, 0, 6, 0, 0, 0];
+        vm.run_once();
+        assert_eq!(vm.pc, 4);
+    }
+
+    #[test]
+    fn test_jmpb_opcode() {
+        let mut vm = get_test_vm();
+        vm.registers[1] = 6;
+        vm.program = vec![0, 0, 0, 10, 9, 1, 0, 0];
+        vm.run_once();
+        vm.run_once();
+        assert_eq!(vm.pc, 0);
+    }
+
     #[test]
     fn test_load_opcode() {
         let mut vm = get_test_vm();