diff --git a/task1/CodegenImpl.java b/task1/CodegenImpl.java
new file mode 100644
index 0000000..f6845a2
--- /dev/null
+++ b/task1/CodegenImpl.java
@@ -0,0 +1,214 @@
+public class CodegenImpl implements Codegen {
+	private int labelCounter = 0;
+	
+	public CodegenImpl() {}
+	
+	public String codegen(Program p) throws CodegenException {
+		return "";
+	}
+
+	private String generateLabel() {
+		return String.format("branch_%d", labelCounter++);
+	}
+
+	public String compileDeclaration(Declaration d) throws CodegenException {
+		return String.format("%s_%d:\n", d.id, d.numOfArgs)
+		+ compileExp(d.body)
+		+ "ret\n";
+	}
+
+	public String compileExp(Exp e) throws CodegenException {
+		if (e instanceof IntLiteral) {
+			return String.format("li a0,%d\n", ((IntLiteral) e).n);
+		} else if (e instanceof If) {
+			If eIf = (If) e;
+
+			String thenLabel = generateLabel();
+			String elseLabel = generateLabel();
+			String finalizeLabel = generateLabel();
+			
+			return compileFullComp(eIf.l, eIf.r, eIf.comp, thenLabel, elseLabel)
+			+ thenLabel + ": " + compileExp(eIf.thenBody)
+			+ "j " + finalizeLabel + "\n"
+			+ elseLabel + ": " + compileExp(eIf.elseBody)
+			+ finalizeLabel + ": " + "lw s1,(sp)\n"
+			+ "addi sp,sp,4\n";
+		} else if (e instanceof Binexp) {
+			Binexp b = (Binexp) e;
+
+			return compileExp(b.l)
+			+ "sw s1,-4(sp)\n"
+			+ "addi sp,sp,-4\n"
+			+ "mv s1,a0\n"
+			+ compileExp(b.r)
+			+ "mv t1,a0\n"
+			+ compileExpBinop(b.binop);
+		} else if (e instanceof Variable) {
+			int offset = ((Variable) e).x;
+			
+			return String.format("lw a0,%d(fp)\n", offset * 4);
+		} else if (e instanceof Invoke) {
+			return compileCall((Invoke) e, false);
+		} else if (e instanceof Seq) {
+			String result = "";
+			Seq statements = (Seq) e;
+
+			if (statements.r instanceof Invoke) {
+				// tail call
+				result = compileCall((Invoke) statements.r, true);
+			} else {
+				result = compileExp(statements.r);
+			}
+
+			return compileExp(statements.l) + result;
+		} else if (e instanceof While) {
+			While eWhile = (While) e;
+
+			String startLabel = generateLabel();
+			String bodyLabel = generateLabel();
+			String exitLabel = generateLabel();
+			
+			return "sw s2,-4(sp)\n"
+			+ "sw s3,-8(sp)\n"
+			+ "addi sp,sp,-8\n"
+			+ "la s2," + startLabel + "\n"
+			+ "la s3," + exitLabel + "\n"
+			+ startLabel + ": " + compileFullComp(eWhile.l, eWhile.r, eWhile.comp, bodyLabel, exitLabel)
+			+ bodyLabel + ": " + compileExp(eWhile.body)
+			+ "lw s1,(sp)\n"
+			+ "addi sp,sp,4\n"
+			+ "j " + startLabel + "\n"
+			+ exitLabel + ": lw s1,(sp)\n"
+			+ "lw s3,4(sp)\n"
+			+ "lw s2,8(sp)\n"
+			+ "addi sp,sp,12\n";
+		} else if (e instanceof RepeatUntil) {
+			RepeatUntil eUntil = (RepeatUntil) e;
+
+			String compLabel = generateLabel();
+			String bodyLabel = generateLabel();
+			String exitLabel = generateLabel();
+			String breakLabel = generateLabel();
+
+			return "sw s2,-8(sp)\n"
+			+ "sw s3,-4(sp)\n"
+			+ "addi sp,sp,-8\n"
+			+ "la s2," + bodyLabel + "\n" // TODO: does this jump to the check?
+			+ "la s3," + breakLabel + "\n"
+			+ bodyLabel + ": " + compileExp(eUntil.body)
+			+ "sw s4,-4(sp)\n"
+			+ "addi sp,sp,-4\n"
+			+ "mv s4,a0\n"
+			+ compileFullComp(eUntil.l, eUntil.r, eUntil.comp, exitLabel, compLabel)
+			+ compLabel + ": lw s1,(sp)\n"
+			+ "lw s4,4(sp)\n"
+			+ "addi sp,sp,8\n"
+			+ "j " + bodyLabel + "\n"
+			+ breakLabel + ": sw s1,-8(sp)\n"
+			+ "sw s4,-4(sp)\n"
+			+ "addi sp,sp,-8\n"
+			+ "mv s4,a0\n"
+			+ exitLabel + ": lw s1,(sp)\n"
+			+ "mv a0,s4\n" // body result to accumulator
+			+ "lw s4,4(sp)\n" // restore previous s4
+			+ "lw s2,8(sp)\n"
+			+ "lw s3,12(sp)\n"
+			+ "addi sp,sp,16\n";
+		} else if (e instanceof Assign) {
+			Assign assign = (Assign) e;
+
+			return compileExp(assign.e)
+			+ String.format("sw a0,%d(fp)", assign.x * 4);
+		} else if (e instanceof Continue) {
+			return "jr s2\n";
+		} else if (e instanceof Break) {
+			return "jr s3\n";
+		} else if (e instanceof Skip) {
+			return "nop\n";
+		}
+
+		throw new CodegenException("Unsupported expression!");
+	}
+
+	public String compileCall(Invoke call, boolean tailCall) throws CodegenException {
+		int argLen = call.args.size();
+		String methodLabel = String.format("%s_%d", call.name, argLen);
+		StringBuilder builder = new StringBuilder();
+
+		// Store return address & current stack pointer
+		builder.append("mv s3,sp\n");
+		builder.append("sw ra,-4(sp)\n");
+		builder.append("addi sp,sp,-4\n");
+
+		for (int i = argLen - 1; i >= 0; i--) {
+			Exp argExp = call.args.get(i);
+
+			builder.append(compileExp(argExp));
+			builder.append(
+				"sw a0,-4(sp)\n"
+				+ "addi sp,sp,-4\n"
+			);
+		}
+
+		// push old frame pointer & start-of-frame pointer
+		builder.append("sw fp,-4(sp)\n");
+		builder.append("sw s3,-8(sp)\n");
+		builder.append("addi sp,sp,-8\n");
+
+		builder.append(
+			// set frame pointer to start of arguments
+			"addi fp,sp,8\n"
+			+ "call " + methodLabel + "\n"
+			// restore old frame pointer & stack pointer
+			+ "lw fp,4(sp)\n"
+			+ "lw sp,(sp)\n"
+			+ "lw ra,-4(sp)\n"
+		);
+
+		return builder.toString();
+	}
+
+	public String compileFullComp(Exp left, Exp right, Comp c, String successLabel, String failLabel) throws CodegenException {
+		return compileExp(left)
+			+ "sw s1,-4(sp)\n"
+			+ "addi sp,sp,-4\n"
+			+ "mv s1,a0\n"
+			+ compileExp(right)
+			+ "mv t1,a0\n"
+			+ compileComp(c, successLabel, failLabel);
+	}
+
+	public String compileComp(Comp c, String thenLabel, String elseLabel) throws CodegenException {
+		String instruction = "";
+		
+		if (c instanceof Equals) {
+			instruction = "beq";
+		} else if (c instanceof Less) {
+			instruction = "blt";
+		} else if (c instanceof LessEq) {
+			instruction = "ble";
+		} else if (c instanceof Greater) {
+			instruction = "bgt";
+		} else if (c instanceof GreaterEq) {
+			instruction = "bge";
+		} else {
+			throw new CodegenException("Unsupported comparison!");
+		}
+
+		return String.format("%s s1,t1,%s\nb %s\n", instruction, thenLabel, elseLabel);
+	}
+
+	public String compileExpBinop(Binop bin) throws CodegenException {
+		if (bin instanceof Plus) {
+			return "add a0,s1,t1\n";
+		} else if (bin instanceof Minus) {
+			return "sub a0,s1,t1\n";
+		} else if (bin instanceof Times) {
+			return "mul a0,s1,t1\n";
+		} else if (bin instanceof Div) {
+			return "div a0,s1,t1\n";
+		}
+
+		throw new CodegenException("Unsupported bin-op! " + bin);
+	}
+}
diff --git a/task1/codegen1.java b/task1/codegen1.java
index 891239a..58dfb13 100644
--- a/task1/codegen1.java
+++ b/task1/codegen1.java
@@ -6,4 +6,4 @@
 // welcome to add new classes! Please put them into separate files.
 
 class Task1 {
-    public static Codegen create () throws CodegenException { ... } }
+    public static Codegen create () throws CodegenException { return new CodegenImpl(); } }