diff --git a/asm/amd64/amd64.go b/asm/amd64/amd64.go
index 89853dc..3026291 100644
--- a/asm/amd64/amd64.go
+++ b/asm/amd64/amd64.go
@@ -49,15 +49,24 @@ func (f *Function) Emit() string {
 	return builder.String()
 }
 
+type CondCode string
+
+const (
+	Equal    CondCode = "e"
+	NotEqual CondCode = "ne"
+)
+
 type Opcode string
 
 const (
 
 	// Two operands
-	Mov  Opcode = "mov" // Lhs: dst, Rhs: src, or better said intel syntax
-	Add  Opcode = "add"
-	Sub  Opcode = "sub"
-	Imul Opcode = "imul"
+	Mov   Opcode = "mov" // Lhs: dst, Rhs: src, or better said intel syntax
+	Add   Opcode = "add"
+	Sub   Opcode = "sub"
+	Imul  Opcode = "imul"
+	Cmp   Opcode = "cmp"
+	SetCC Opcode = "setcc"
 
 	// One operand
 	Idiv Opcode = "idiv"
@@ -67,7 +76,11 @@ const (
 	Cdq Opcode = "cdq"
 )
 
-type Instruction struct {
+type Instruction interface {
+	InstructionString() string
+}
+
+type SimpleInstruction struct {
 	Opcode Opcode
 	// Dst
 	Lhs Operand
@@ -75,8 +88,7 @@ type Instruction struct {
 	Rhs Operand
 }
 
-func (i *Instruction) InstructionString() string {
-
+func (i *SimpleInstruction) InstructionString() string {
 	if i.Opcode == Ret {
 		return fmt.Sprintf("mov rsp, rbp\n  pop rbp\n  ret\n")
 	}
@@ -95,6 +107,15 @@ func (i *Instruction) InstructionString() string {
 	return fmt.Sprintf("%s %s, %s", i.Opcode, i.Lhs.OperandString(Eight), i.Rhs.OperandString(Eight))
 }
 
+type SetCCInstruction struct {
+	Cond CondCode
+	Dst  Operand
+}
+
+func (si *SetCCInstruction) InstructionString() string {
+	return fmt.Sprintf("set%s %s", si.Cond, si.Dst.OperandString(Eight))
+}
+
 type OperandSize int
 
 type Operand interface {
diff --git a/asm/amd64/amd64_test.go b/asm/amd64/amd64_test.go
index 4f1cc9c..f556ded 100644
--- a/asm/amd64/amd64_test.go
+++ b/asm/amd64/amd64_test.go
@@ -1,6 +1,7 @@
 package amd64
 
 import (
+	_ "embed"
 	"strings"
 	"testing"
 
@@ -21,6 +22,9 @@ func TestOperands(t *testing.T) {
 	}
 }
 
+//go:embed basic_test.txt
+var basicTest string
+
 func TestCodegen(t *testing.T) {
 	program := &ttir.Program{
 		Functions: []ttir.Function{
@@ -55,8 +59,7 @@ func TestCodegen(t *testing.T) {
 	expectProgram(t, expectedProgram, actualProgram)
 
 	actual := actualProgram.Emit()
-
-	expected := executableAsmHeader + "main:\n  mov rax, 0\n  ret\n"
+	expected := basicTest
 	if strings.Trim(actual, " \n\t") != strings.Trim(expected, " \n\t") {
 		t.Errorf("Expected program to be:\n>>%s<<\nbut got:\n>>%s<<\n", expected, actual)
 	}
@@ -130,6 +133,26 @@ func expectOperand(t *testing.T, expected Operand, actual Operand) {
 		if expected != actual {
 			t.Errorf("Expected Immediate %q but got %q", expected, actual)
 		}
+	case Stack:
+		actual, ok := actual.(Stack)
+
+		if !ok {
+			t.Errorf("Expected Stack but got %T", actual)
+		}
+
+		if expected != actual {
+			t.Errorf("Expected Stack value %q but got %q", expected, actual)
+		}
+	case Pseudo:
+		actual, ok := actual.(Pseudo)
+
+		if !ok {
+			t.Errorf("Expected Stack but got %T", actual)
+		}
+
+		if expected != actual {
+			t.Errorf("Expected Stack value %q but got %q", expected, actual)
+		}
 	default:
 		t.Errorf("Unknown operand type %T", expected)
 	}
diff --git a/asm/amd64/basic_test.txt b/asm/amd64/basic_test.txt
new file mode 100644
index 0000000..573ff7e
--- /dev/null
+++ b/asm/amd64/basic_test.txt
@@ -0,0 +1,17 @@
+format ELF64 executable
+segment readable executable
+entry _start
+_start:
+  call main
+  mov rdi, rax
+  mov rax, 60
+  syscall
+main:
+  push rbp
+  mov rbp, rsp
+  add rsp, 0
+  mov rax, 0
+  mov rsp, rbp
+  pop rbp
+  ret
+
diff --git a/asm/amd64/codegen.go b/asm/amd64/codegen.go
index bde3a6f..a9f65de 100644
--- a/asm/amd64/codegen.go
+++ b/asm/amd64/codegen.go
@@ -52,12 +52,12 @@ func cgInstruction(i ttir.Instruction) []Instruction {
 	switch i := i.(type) {
 	case *ttir.Ret:
 		return []Instruction{
-			{
+			&SimpleInstruction{
 				Opcode: Mov,
 				Lhs:    AX,
 				Rhs:    toAsmOperand(i.Op),
 			},
-			{
+			&SimpleInstruction{
 				Opcode: Ret,
 			},
 		}
@@ -70,6 +70,32 @@ func cgInstruction(i ttir.Instruction) []Instruction {
 
 func cgBinary(b *ttir.Binary) []Instruction {
 	switch b.Operator {
+	case ast.Equal, ast.NotEqual:
+		var condCode CondCode
+
+		switch b.Operator {
+		case ast.Equal:
+			condCode = Equal
+		case ast.NotEqual:
+			condCode = NotEqual
+		}
+
+		return []Instruction{
+			&SimpleInstruction{
+				Opcode: Cmp,
+				Lhs:    toAsmOperand(b.Lhs),
+				Rhs:    toAsmOperand(b.Rhs),
+			},
+			&SimpleInstruction{
+				Opcode: Mov,
+				Lhs:    toAsmOperand(b.Dst),
+				Rhs:    Imm(0),
+			},
+			&SetCCInstruction{
+				Cond: condCode,
+				Dst:  toAsmOperand(b.Dst),
+			},
+		}
 	case ast.Add, ast.Subtract, ast.Multiply:
 		var opcode Opcode
 		switch b.Operator {
@@ -82,15 +108,15 @@ func cgBinary(b *ttir.Binary) []Instruction {
 		}
 
 		return []Instruction{
-			{Opcode: Mov, Lhs: toAsmOperand(b.Dst), Rhs: toAsmOperand(b.Lhs)},
-			{Opcode: opcode, Lhs: toAsmOperand(b.Dst), Rhs: toAsmOperand(b.Rhs)},
+			&SimpleInstruction{Opcode: Mov, Lhs: toAsmOperand(b.Dst), Rhs: toAsmOperand(b.Lhs)},
+			&SimpleInstruction{Opcode: opcode, Lhs: toAsmOperand(b.Dst), Rhs: toAsmOperand(b.Rhs)},
 		}
 	case ast.Divide:
 		return []Instruction{
-			{Opcode: Mov, Lhs: Register(AX), Rhs: toAsmOperand(b.Lhs)},
-			{Opcode: Cdq},
-			{Opcode: Idiv, Lhs: toAsmOperand(b.Rhs)},
-			{Opcode: Mov, Lhs: toAsmOperand(b.Dst), Rhs: Register(AX)},
+			&SimpleInstruction{Opcode: Mov, Lhs: Register(AX), Rhs: toAsmOperand(b.Lhs)},
+			&SimpleInstruction{Opcode: Cdq},
+			&SimpleInstruction{Opcode: Idiv, Lhs: toAsmOperand(b.Rhs)},
+			&SimpleInstruction{Opcode: Mov, Lhs: toAsmOperand(b.Dst), Rhs: Register(AX)},
 		}
 	}
 
@@ -128,15 +154,26 @@ func rpFunction(f Function) Function {
 
 func rpInstruction(i Instruction, r *replacePseudoPass) Instruction {
 
-	newInstruction := Instruction{Opcode: i.Opcode}
-	if i.Lhs != nil {
-		newInstruction.Lhs = pseudoToStack(i.Lhs, r)
-	}
-	if i.Rhs != nil {
-		newInstruction.Rhs = pseudoToStack(i.Rhs, r)
+	switch i := i.(type) {
+	case *SimpleInstruction:
+
+		newInstruction := &SimpleInstruction{Opcode: i.Opcode}
+		if i.Lhs != nil {
+			newInstruction.Lhs = pseudoToStack(i.Lhs, r)
+		}
+		if i.Rhs != nil {
+			newInstruction.Rhs = pseudoToStack(i.Rhs, r)
+		}
+
+		return newInstruction
+	case *SetCCInstruction:
+		return &SetCCInstruction{
+			Cond: i.Cond,
+			Dst:  pseudoToStack(i.Dst, r),
+		}
 	}
 
-	return newInstruction
+	panic("invalid instruction")
 }
 
 func pseudoToStack(op Operand, r *replacePseudoPass) Operand {
@@ -177,40 +214,70 @@ func fixupFunction(f Function) Function {
 
 func fixupInstruction(i Instruction) []Instruction {
 
-	switch i.Opcode {
-	case Mov:
-		if lhs, ok := i.Lhs.(Stack); ok {
-			if rhs, ok := i.Rhs.(Stack); ok {
+	switch i := i.(type) {
+	case *SimpleInstruction:
+		switch i.Opcode {
+		case Mov:
+			if lhs, ok := i.Lhs.(Stack); ok {
+				if rhs, ok := i.Rhs.(Stack); ok {
+					return []Instruction{
+						&SimpleInstruction{Opcode: Mov, Lhs: Register(R10), Rhs: rhs},
+						&SimpleInstruction{Opcode: Mov, Lhs: lhs, Rhs: Register(R10)},
+					}
+				}
+			}
+		case Imul:
+			if lhs, ok := i.Lhs.(Stack); ok {
 				return []Instruction{
-					{Opcode: Mov, Lhs: Register(R10), Rhs: rhs},
-					{Opcode: Mov, Lhs: lhs, Rhs: Register(R10)},
+					&SimpleInstruction{Opcode: Mov, Lhs: Register(R11), Rhs: lhs},
+					&SimpleInstruction{Opcode: Imul, Lhs: Register(R11), Rhs: i.Rhs},
+					&SimpleInstruction{Opcode: Mov, Lhs: lhs, Rhs: Register(R11)},
+				}
+			}
+			fallthrough
+		case Add, Sub, Idiv /* Imul (fallthrough) */ :
+			if lhs, ok := i.Lhs.(Stack); ok {
+				if rhs, ok := i.Rhs.(Stack); ok {
+					return []Instruction{
+						&SimpleInstruction{Opcode: Mov, Lhs: Register(R10), Rhs: rhs},
+						&SimpleInstruction{Opcode: i.Opcode, Lhs: lhs, Rhs: Register(R10)},
+					}
+				}
+			} else if lhs, ok := i.Lhs.(Imm); ok && i.Opcode == Idiv {
+				return []Instruction{
+					&SimpleInstruction{Opcode: Mov, Lhs: Register(R10), Rhs: lhs},
+					&SimpleInstruction{Opcode: Idiv, Lhs: Register(R10)},
+				}
+			}
+		case Cmp:
+			if lhs, ok := i.Lhs.(Stack); ok {
+				if rhs, ok := i.Rhs.(Stack); ok {
+					return []Instruction{
+						&SimpleInstruction{Opcode: Mov, Lhs: Register(R10), Rhs: rhs},
+						&SimpleInstruction{Opcode: i.Opcode, Lhs: lhs, Rhs: Register(R10)},
+					}
+				}
+			} else if rhs, ok := i.Rhs.(Imm); ok {
+				return []Instruction{
+					&SimpleInstruction{
+						Opcode: Mov,
+						Lhs:    Register(R11),
+						Rhs:    Imm(rhs),
+					},
+					&SimpleInstruction{
+						Opcode: Cmp,
+						Lhs:    i.Lhs,
+						Rhs:    Register(R11),
+					},
 				}
 			}
 		}
-	case Imul:
-		if lhs, ok := i.Lhs.(Stack); ok {
-			return []Instruction{
-				{Opcode: Mov, Lhs: Register(R11), Rhs: lhs},
-				{Opcode: Imul, Lhs: Register(R11), Rhs: i.Rhs},
-				{Opcode: Mov, Lhs: lhs, Rhs: Register(R11)},
-			}
-		}
-		fallthrough
-	case Add, Sub, Idiv /* Imul (fallthrough) */ :
-		if lhs, ok := i.Lhs.(Stack); ok {
-			if rhs, ok := i.Rhs.(Stack); ok {
-				return []Instruction{
-					{Opcode: Mov, Lhs: Register(R10), Rhs: rhs},
-					{Opcode: i.Opcode, Lhs: lhs, Rhs: Register(R10)},
-				}
-			}
-		} else if lhs, ok := i.Lhs.(Imm); ok && i.Opcode == Idiv {
-			return []Instruction{
-				{Opcode: Mov, Lhs: Register(R10), Rhs: lhs},
-				{Opcode: Idiv, Lhs: Register(R10)},
-			}
-		}
+
+		return []Instruction{i}
+	case *SetCCInstruction:
+
+		return []Instruction{i}
 	}
 
-	return []Instruction{i}
+	panic("invalid instruction")
 }
diff --git a/ast/ast.go b/ast/ast.go
index 35a328e..6a287ab 100644
--- a/ast/ast.go
+++ b/ast/ast.go
@@ -82,6 +82,8 @@ const (
 	Subtract
 	Multiply
 	Divide
+	Equal
+	NotEqual
 )
 
 func (bo BinaryOperator) SymbolString() string {
@@ -94,6 +96,10 @@ func (bo BinaryOperator) SymbolString() string {
 		return "*"
 	case Divide:
 		return "/"
+	case Equal:
+		return "=="
+	case NotEqual:
+		return "!="
 	}
 	return "<INVALID BINARY OPERATOR>"
 }
diff --git a/language.md b/language.md
new file mode 100644
index 0000000..980ad74
--- /dev/null
+++ b/language.md
@@ -0,0 +1,12 @@
+# tt
+
+## Syntax
+
+```tt
+
+// Return type is i64
+fn main() = {
+    let i = 34;
+    i
+};
+```
diff --git a/lexer/lexer.go b/lexer/lexer.go
index 649d1e8..69acd52 100644
--- a/lexer/lexer.go
+++ b/lexer/lexer.go
@@ -66,6 +66,14 @@ func (l *Lexer) NextToken() token.Token {
 	case ';':
 		tok = l.newToken(token.Semicolon)
 	case '=':
+		if l.peekByte() == '=' {
+			pos := l.position
+			l.readChar()
+			l.readChar()
+			tok.Type = token.DoubleEqual
+			tok.Literal = l.input[pos:l.position]
+			return tok
+		}
 		tok = l.newToken(token.Equal)
 	case '(':
 		tok = l.newToken(token.OpenParen)
@@ -79,6 +87,16 @@ func (l *Lexer) NextToken() token.Token {
 		tok = l.newToken(token.Asterisk)
 	case '/':
 		tok = l.newToken(token.Slash)
+	case '!':
+		if l.peekByte() == '=' {
+			pos := l.position
+			l.readChar()
+			l.readChar()
+			tok.Type = token.NotEqual
+			tok.Literal = l.input[pos:l.position]
+			return tok
+		}
+		tok = l.newToken(token.Illegal)
 	case -1:
 		tok.Literal = ""
 		tok.Type = token.Eof
@@ -140,6 +158,14 @@ func (l *Lexer) readChar() (err error) {
 	return
 }
 
+func (l *Lexer) peekByte() byte {
+	if l.readPosition < len(l.input) {
+		return l.input[l.readPosition]
+	} else {
+		return 0
+	}
+}
+
 func (l *Lexer) readIdentifier() string {
 	startPos := l.position
 
diff --git a/lexer/lexer_test.go b/lexer/lexer_test.go
index 3f5453c..fa444ed 100644
--- a/lexer/lexer_test.go
+++ b/lexer/lexer_test.go
@@ -40,7 +40,7 @@ func runLexerTest(t *testing.T, test lexerTest) {
 
 func TestBasicFunctionality(t *testing.T) {
 	runLexerTest(t, lexerTest{
-		input: "fn main() = 0;",
+		input: "fn main() = 0 + 3;",
 		expectedToken: []token.Token{
 			{Type: token.Fn, Literal: "fn"},
 			{Type: token.Ident, Literal: "main"},
@@ -48,6 +48,8 @@ func TestBasicFunctionality(t *testing.T) {
 			{Type: token.CloseParen, Literal: ")"},
 			{Type: token.Equal, Literal: "="},
 			{Type: token.Int, Literal: "0"},
+			{Type: token.Plus, Literal: "+"},
+			{Type: token.Int, Literal: "3"},
 			{Type: token.Semicolon, Literal: ";"},
 			{Type: token.Eof, Literal: ""},
 		},
diff --git a/parser/parser.go b/parser/parser.go
index a9c5be2..5f72c0e 100644
--- a/parser/parser.go
+++ b/parser/parser.go
@@ -51,6 +51,8 @@ func New(l *lexer.Lexer) *Parser {
 	p.registerInfixFn(token.Minus, p.parseBinaryExpression)
 	p.registerInfixFn(token.Asterisk, p.parseBinaryExpression)
 	p.registerInfixFn(token.Slash, p.parseBinaryExpression)
+	p.registerInfixFn(token.Equal, p.parseBinaryExpression)
+	p.registerInfixFn(token.NotEqual, p.parseBinaryExpression)
 
 	p.nextToken()
 	p.nextToken()
@@ -239,6 +241,10 @@ func (p *Parser) parseBinaryExpression(lhs ast.Expression) ast.Expression {
 		op = ast.Multiply
 	case token.Slash:
 		op = ast.Divide
+	case token.DoubleEqual:
+		op = ast.Equal
+	case token.NotEqual:
+		op = ast.NotEqual
 	default:
 		return p.exprError(p.curToken, "invalid token for binary expression %s", p.curToken.Type)
 	}
diff --git a/token/token.go b/token/token.go
index bc1c128..85d31b7 100644
--- a/token/token.go
+++ b/token/token.go
@@ -30,10 +30,14 @@ const (
 	Equal      TokenType = "="
 	OpenParen  TokenType = "("
 	CloseParen TokenType = ")"
-	Plus       TokenType = "+"
-	Minus      TokenType = "-"
-	Asterisk   TokenType = "*"
-	Slash      TokenType = "/"
+
+	// Binary Operators
+	Plus        TokenType = "+"
+	Minus       TokenType = "-"
+	Asterisk    TokenType = "*"
+	Slash       TokenType = "/"
+	DoubleEqual TokenType = "=="
+	NotEqual    TokenType = "!="
 
 	// Keywords
 	Fn TokenType = "FN"
diff --git a/ttir/emit.go b/ttir/emit.go
index 0c65b40..c685f68 100644
--- a/ttir/emit.go
+++ b/ttir/emit.go
@@ -3,6 +3,7 @@ package ttir
 import (
 	"fmt"
 
+	"robaertschi.xyz/robaertschi/tt/ast"
 	"robaertschi.xyz/robaertschi/tt/tast"
 )
 
@@ -41,13 +42,15 @@ func emitExpression(expr tast.Expression) (Operand, []Instruction) {
 	case *tast.IntegerExpression:
 		return &Constant{Value: expr.Value}, []Instruction{}
 	case *tast.BinaryExpression:
-		lhsDst, instructions := emitExpression(expr.Lhs)
-		rhsDst, rhsInstructions := emitExpression(expr.Rhs)
-		instructions = append(instructions, rhsInstructions...)
-		dst := &Var{Value: temp()}
-		instructions = append(instructions, &Binary{Operator: expr.Operator, Lhs: lhsDst, Rhs: rhsDst, Dst: dst})
-		return dst, instructions
-
+		switch expr.Operator {
+		default:
+			lhsDst, instructions := emitExpression(expr.Lhs)
+			rhsDst, rhsInstructions := emitExpression(expr.Rhs)
+			instructions = append(instructions, rhsInstructions...)
+			dst := &Var{Value: temp()}
+			instructions = append(instructions, &Binary{Operator: expr.Operator, Lhs: lhsDst, Rhs: rhsDst, Dst: dst})
+			return dst, instructions
+		}
 	}
 	panic("unhandled tast.Expression case in ir emitter")
 }
diff --git a/ttir/ttir.go b/ttir/ttir.go
index 61caf9a..360baa7 100644
--- a/ttir/ttir.go
+++ b/ttir/ttir.go
@@ -60,6 +60,40 @@ func (b *Binary) String() string {
 }
 func (b *Binary) instruction() {}
 
+type JumpIfZero struct {
+	Value Operand
+	Label string
+}
+
+func (jiz *JumpIfZero) String() string {
+	return fmt.Sprintf("jz %v, %v\n", jiz.Value, jiz.Label)
+}
+func (jiz *JumpIfZero) instruction() {}
+
+type JumpIfNotZero struct {
+	Value Operand
+	Label string
+}
+
+func (jiz *JumpIfNotZero) String() string {
+	return fmt.Sprintf("jnz %v, %v\n", jiz.Value, jiz.Label)
+}
+func (jiz *JumpIfNotZero) instruction() {}
+
+type Jump string
+
+func (j Jump) String() string {
+	return fmt.Sprintf("jmp %v\n", string(j))
+}
+func (j Jump) instruction() {}
+
+type Label string
+
+func (l Label) String() string {
+	return fmt.Sprintf("%v:\n", string(l))
+}
+func (l Label) instruction() {}
+
 type Operand interface {
 	String() string
 	operand()