diff --git a/generators/x86_64.py b/generators/x86_64.py
index e6d11e4..e704b08 100644
--- a/generators/x86_64.py
+++ b/generators/x86_64.py
@@ -429,4 +429,4 @@ class X86_64Generator(Generator):
 			f.write("section .text\n")
 
 			optimizer = X86_64Optimizer(self.lines)
-			f.write(optimizer.peephole())
\ No newline at end of file
+			f.writelines(optimizer.peephole())
\ No newline at end of file
diff --git a/optimizers/optimizer.py b/optimizers/optimizer.py
index e334197..05a3c2c 100644
--- a/optimizers/optimizer.py
+++ b/optimizers/optimizer.py
@@ -1,11 +1,81 @@
+from typing import List, Dict, NamedTuple, Union
+import re
+
+
+class Instruction(NamedTuple):
+    opcode: str
+    operands: List[str]
+
+class PeepholeRule(NamedTuple):
+    match: List[Instruction]
+    replace: List[Instruction]
+
 class Optimizer:
-	def __init__(self, lines: list[str]):
+	def __init__(self, lines: list[str], window_size: int = 5):
 		self.lines = lines
 		self.final_str = ""
 
-		# sliding window pos
-		self.pos = 0
+		# sliding window
+		self.window_size = window_size
+		self.rules: list[PeepholeRule] = []
+
+	def match_instruction(self, pattern: Instruction, instr: Instruction, bindings: Dict[str, str]) -> bool:
+		if pattern.opcode != instr.opcode:
+			return False
+		if len(pattern.operands) != len(instr.operands):
+			return False
+
+		for p_op, i_op in zip(pattern.operands, instr.operands):
+			if p_op.isidentifier():  # wildcard like 'x'
+				if p_op in bindings:
+					if bindings[p_op] != i_op:
+						return False
+				else:
+					bindings[p_op] = i_op
+			else:
+				if p_op != i_op:
+					return False
+		return True
+
+	def match_window(self, patterns: List[Instruction], window: List[Instruction]) -> Union[Dict[str, str], None]:
+		if len(patterns) != len(window):
+			return None
+		bindings = {}
+		for p, i in zip(patterns, window):
+			if not self.match_instruction(p, i, bindings):
+				return None
+		return bindings
 		
+	def parse_instruction(self, line: str) -> Instruction:
+		# Assumes format: OPCODE operand1, operand2
+		parts = line.strip().split(None, 1)
+		opcode = parts[0]
+		operands = re.split(r'\s*,\s*', parts[1]) if len(parts) > 1 else []
+		return Instruction(opcode, operands)
+	
+	def apply_replacement(self, replacements: List[Instruction], bindings: dict[str, str]) -> List[Instruction]:
+		result = []
+		for pattern in replacements:
+			operands = [bindings.get(op, op) for op in pattern.operands]
+			result.append(Instruction(pattern.opcode, operands))
+		return result
 
 	def peephole(self):
-		pass
\ No newline at end of file
+		self.lines = [self.parse_instruction(line) for line in self.lines]
+
+		i = 0
+		while i < len(self.lines):
+			matched = False
+			for rule in self.rules:
+				window = self.lines[i:i+len(rule.match)]
+				bindings = self.match_window(rule.match, window)
+				if bindings is not None:
+					replacement_instrs = self.apply_replacement(rule.replace, bindings)
+					self.lines[i:i + len(rule.match)] = replacement_instrs
+					matched = True
+					break
+			if not matched:
+				i += 1
+		
+		self.lines = [f"{line.opcode} {', '.join(line.operands)}\n" for line in self.lines]
+		return self.lines
\ No newline at end of file
diff --git a/optimizers/x86_64.py b/optimizers/x86_64.py
index bda678f..709b628 100644
--- a/optimizers/x86_64.py
+++ b/optimizers/x86_64.py
@@ -1,11 +1,59 @@
-from optimizers.optimizer import Optimizer
+from optimizers.optimizer import Optimizer, PeepholeRule, Instruction
 
 class X86_64Optimizer(Optimizer):
-	def peephole(self):
-		lines = []
-
-		for line in self.lines:
-			lines.append(line)
-
-		self.final_str = ''.join(lines)
-		return self.final_str
\ No newline at end of file
+	def __init__(self, lines, window_size = 5):
+		super().__init__(lines, window_size)
+		self.rules = [
+			PeepholeRule(
+				match=[
+					Instruction("setg",["al"]),
+					Instruction("movzx", ["rax", "al"]),
+					Instruction("push", ["rax"]),
+					Instruction("mov", ["eax", "x"]),
+					Instruction("test", ["eax", "eax"]),
+					Instruction("jnz", ["y"])
+				],
+				replace=[
+					Instruction("jg", ["y"])
+				]
+			),
+			PeepholeRule(
+				match=[
+					Instruction("setl",["al"]),
+					Instruction("movzx", ["rax", "al"]),
+					Instruction("push", ["rax"]),
+					Instruction("mov", ["eax", "x"]),
+					Instruction("test", ["eax", "eax"]),
+					Instruction("jnz", ["y"])
+				],
+				replace=[
+					Instruction("jl", ["y"])
+				]
+			),
+			PeepholeRule(
+				match=[
+					Instruction("sete",["al"]),
+					Instruction("movzx", ["rax", "al"]),
+					Instruction("push", ["rax"]),
+					Instruction("mov", ["eax", "x"]),
+					Instruction("test", ["eax", "eax"]),
+					Instruction("jnz", ["y"])
+				],
+				replace=[
+					Instruction("je", ["y"])
+				]
+			),
+			PeepholeRule(
+				match=[
+					Instruction("setne",["al"]),
+					Instruction("movzx", ["rax", "al"]),
+					Instruction("push", ["rax"]),
+					Instruction("mov", ["eax", "x"]),
+					Instruction("test", ["eax", "eax"]),
+					Instruction("jnz", ["y"])
+				],
+				replace=[
+					Instruction("jne", ["y"])
+				]
+			),
+		]
\ No newline at end of file
diff --git a/out b/out
index 07f4e0f..a9a5b34 100644
Binary files a/out and b/out differ
diff --git a/out.asm b/out.asm
index 8d2d1a9..e8f9ea2 100644
--- a/out.asm
+++ b/out.asm
@@ -1,27 +1,34 @@
 ; ~~~ Auto generated by the GroundPY compiler for Linux x86_64 targets. ~~~
 
 section .data
+.LC0: db "yes", 10, 0
+.LC1: equ $ - .LC0
+.LC2: db "no", 10, 0
+.LC3: equ $ - .LC2
 section .text
 global _start
-_start:
-	mov rax, 0
-	push rax
-	mov rax, 0
-	push rax
-	.loop:
-	mov rax, [rsp + 8]
-	add rax, 1
-	mov QWORD [rsp + 8], rax
-	mov rax, 100000000
-	mov rbx, [rsp + 8]
-	cmp rax, rbx
-	setg al
-	movzx rax, al
-	mov QWORD [rsp + 0], rax
-	mov eax, [rsp + 0]
-	test eax, eax
-	jnz .loop
-	mov rax, 60
-	mov rdi, [rsp + 0]
-	syscall
-	
\ No newline at end of file
+_start: 
+mov rax, 123
+push rax
+mov rax, 100000000
+mov rbx, [rsp + 0]
+cmp rax, rbx
+jg .yes
+.yes: 
+mov rsi, .LC0
+mov rdx, .LC1
+mov rax, 1
+mov rdi, 1
+syscall 
+mov rax, 60
+mov rdi, 0
+syscall 
+.no: 
+mov rsi, .LC2
+mov rdx, .LC3
+mov rax, 1
+mov rdi, 1
+syscall 
+mov rax, 60
+mov rdi, 0
+syscall 
diff --git a/test2.grnd b/test2.grnd
index 4e4bd78..4966a87 100644
--- a/test2.grnd
+++ b/test2.grnd
@@ -1,7 +1,9 @@
-set &x 0
-set &cond 0
-@loop
-add $x 1 &x
+set &x 123
 greater 100000000 $x &cond
-if $cond %loop
-end $cond
\ No newline at end of file
+if $cond %yes
+@yes
+stdout "yes\n"
+end 0
+@no
+stdout "no\n"
+end 0
\ No newline at end of file