3 files changed, 147 insertions, 5 deletions

diff --git a/src/vm/core.js b/src/vm/core.js
index 074e156..6303ee5 100644
--- a/src/vm/core.js
+++ b/src/vm/core.js
@@ -31,13 +31,13 @@ class Core {
 				return this.normalize(pc, address.value);
 			case AddrMode.Indirect: {
 				let loc = this.normalize(pc, address.value);
-				let b = this.data[loc];
+				let b = this.data[loc].b.value;
 				return this.normalize(loc, b);
 			}
 			case AddrMode.Predecrement: {
 				let loc = this.normalize(pc, address.value);
-				this.data[loc].b -= 1;
-				let b = this.data[loc].b;
+				this.data[loc].b.value -= 1;
+				let b = this.data[loc].b.value;
 				return this.normalize(loc, b);
 			}
 			default:
@@ -46,7 +46,8 @@ class Core {
 	}
 
 	getValue(pc, address) {
-		return this.data[this.getLocation(pc, address)];
+		const index = this.getLocation(pc, address);
+		return this.data[index];
 	}
 }
 
diff --git a/src/vm/instruction.js b/src/vm/instruction.js
index c991643..c9048e1 100644
--- a/src/vm/instruction.js
+++ b/src/vm/instruction.js
@@ -22,3 +22,18 @@ exports.MOV = function(core, pc, ins) {
 
 	return [pc + 1];
 }
+
+
+exports.ADD = function(core, pc, ins) {
+	if (ins.a.mode === AddrMode.Immediate) {
+		const dst = core.getValue(pc, ins.b);
+		dst.b.value += ins.a.value;
+	} else {
+		const src = core.getValue(pc, ins.a);
+		const dst = core.getValue(pc, ins.b);
+		dst.a.value += src.a.value;
+		dst.b.value += src.b.value;
+	}
+
+	return [pc + 1];
+}
diff --git a/src/vm/instruction.test.js b/src/vm/instruction.test.js
index 3535b76..fd402e4 100644
--- a/src/vm/instruction.test.js
+++ b/src/vm/instruction.test.js
@@ -1,7 +1,7 @@
 'use strict';
 
 const { Core } = require('./core.js');
-const { DAT, MOV } = require('./instruction.js');
+const { DAT, MOV, ADD } = require('./instruction.js');
 
 
 const CORESIZE = 8000;
@@ -47,5 +47,131 @@ test('MOV correctly moves a B-field', () => {
 		a: { mode: 'immediate', value: 0 },
 		b: { mode: 'immediate', value: 100 },
 	});
+});
+
 
+test('MOV correctly handles indirection', () => {
+	const core = new Core(CORESIZE);
+	const pc = 20;
+	core.data[pc-1] = {
+		opcode: 'DAT',
+		a: { mode: 'immediate', value: 0 },
+		b: { mode: 'immediate', value: 2 },
+	};
+	core.data[pc] = {
+		opcode: 'MOV',
+		a: { mode: 'immediate', value: 100 },
+		b: { mode: 'indirect', value: -1 },
+	};
+	const ins = core.data[pc];
+	expect(core.data[pc+1].opcode).toBe('DAT');
+	expect(MOV(core, pc, ins)).toEqual([pc+1]);
+	expect(core.data[pc-1]).toEqual({	
+		opcode: 'DAT',
+		a: { mode: 'immediate', value: 0 },
+		b: { mode: 'immediate', value: 2 },
+	});
+
+	expect(core.data[pc+1]).toEqual({	
+		opcode: 'DAT',
+		a: { mode: 'immediate', value: 0 },
+		b: { mode: 'immediate', value: 100 },
+	});
+
+});
+
+
+
+
+test('MOV correctly handles predecrement indirection', () => {
+	const core = new Core(CORESIZE);
+	const pc = 20;
+	core.data[pc] = {
+		opcode: 'MOV',
+		a: { mode: 'immediate', value: 100 },
+		b: { mode: 'predecrement', value: -1 },
+	};
+	const ins = core.data[pc];
+	expect(core.data[pc+1].opcode).toBe('DAT');
+	expect(MOV(core, pc, ins)).toEqual([pc+1]);
+	expect(core.data[pc-1]).toEqual({	
+		opcode: 'DAT',
+		a: { mode: 'immediate', value: 0 },
+		b: { mode: 'immediate', value: -1 },
+	});
+
+	expect(core.data[pc-2]).toEqual({	
+		opcode: 'DAT',
+		a: { mode: 'immediate', value: 0 },
+		b: { mode: 'immediate', value: 100 },
+	});
+
+});
+
+
+test('ADD correctly adds two full instructions', () => {
+	const core = new Core(CORESIZE);
+	const pc = 20;
+	core.data[pc] = {
+		opcode: 'ADD',
+		a: { mode: 'direct', value: 1 },
+		b: { mode: 'direct', value: 2 },
+	};
+	core.data[pc+1] = {
+		opcode: 'DAT',
+		a: { mode: 'immediate', value: 10 },
+		b: { mode: 'immediate', value: 20 },
+	};
+	core.data[pc+2] = {
+		opcode: 'DAT',
+		a: { mode: 'immediate', value: 3 },
+		b: { mode: 'immediate', value: 4 },
+	};
+	const ins = core.data[pc];
+
+	expect(ADD(core, pc, ins)).toEqual([pc+1]);
+	expect(core.data[pc+1]).toEqual({
+		opcode: 'DAT',
+		a: { mode: 'immediate', value: 10 },
+		b: { mode: 'immediate', value: 20 },
+	});
+	expect(core.data[pc+2]).toEqual({
+		opcode: 'DAT',
+		a: { mode: 'immediate', value: 13 },
+		b: { mode: 'immediate', value: 24 },
+	});
+});
+
+
+test('ADD correctly adds B-field', () => {
+	const core = new Core(CORESIZE);
+	const pc = 20;
+	core.data[pc] = {
+		opcode: 'ADD',
+		a: { mode: 'immediate', value: 1 },
+		b: { mode: 'direct', value: 2 },
+	};
+	core.data[pc+1] = {
+		opcode: 'DAT',
+		a: { mode: 'immediate', value: 10 },
+		b: { mode: 'immediate', value: 20 },
+	};
+	core.data[pc+2] = {
+		opcode: 'DAT',
+		a: { mode: 'immediate', value: 3 },
+		b: { mode: 'immediate', value: 4 },
+	};
+	const ins = core.data[pc];
+
+	expect(ADD(core, pc, ins)).toEqual([pc+1]);
+	expect(core.data[pc+1]).toEqual({
+		opcode: 'DAT',
+		a: { mode: 'immediate', value: 10 },
+		b: { mode: 'immediate', value: 20 },
+	});
+	expect(core.data[pc+2]).toEqual({
+		opcode: 'DAT',
+		a: { mode: 'immediate', value: 3 },
+		b: { mode: 'immediate', value: 5 },
+	});
 });