diff --git a/04_semantics_and_running/main.py b/04_semantics_and_running/main.py
index 9a935fb..2b41778 100644
--- a/04_semantics_and_running/main.py
+++ b/04_semantics_and_running/main.py
@@ -341,6 +341,7 @@ class CompileData:
                         continue
                     instructions.pop(i)
                     changed = True
+                if changed: continue
 
                 i = 0
                 # Optimize movq to register followed by pushq register
@@ -355,6 +356,7 @@ class CompileData:
                     instructions.pop(i + 1)
                     i -= 1
                     changed = True
+                if changed: continue
 
                 i = 0
                 # Optimize movq to rax followed by movq from rax
@@ -375,6 +377,34 @@ class CompileData:
                     instructions.pop(i + 1)
                     i -= 1
                     changed = True
+                if changed: continue
+
+                i = 0
+                # Optimize addq/subq for immediate 1
+                while i < len(instructions):
+                    if instructions[i].opcode not in ['addq', 'subq']:
+                        i += 1
+                        continue
+                    if instructions[i].operands[0] != '$1':
+                        i += 1
+                        continue
+                    new_opcode = 'incq' if instructions[i].opcode == 'addq' else 'decq'
+                    instructions[i] = Instruction(new_opcode, [instructions[i].operands[1]])
+                    changed = True
+                if changed: continue
+
+                i = 0
+                # Optimize zeroing of register
+                while i < len(instructions):
+                    if instructions[i].opcode != 'movq':
+                        i += 1
+                        continue
+                    if instructions[i].operands[0] != '$0' or instructions[i].operands[1][0] != '%':
+                        i += 1
+                        continue
+                    instructions[i] = Instruction('xorq', [instructions[i].operands[1], instructions[i].operands[1]])
+                    changed = True
+                if changed: continue
 
     def add_builtin_functions(self) -> None:
         today = []