From f38bd3d69ee1f57581bc319f40ac0e90daeab69a Mon Sep 17 00:00:00 2001
From: nitrix <me@nitrix.one>
Date: Tue, 21 Mar 2023 00:22:11 +0100
Subject: [PATCH] GenASM: Use leave instead of mov and pop for returning from a
 function.

---
 src/main/java/de/hsrm/compiler/Klang/asm/ASM.java         | 4 ++++
 .../java/de/hsrm/compiler/Klang/asm/mnemonics/Leave.java  | 8 ++++++++
 src/main/java/de/hsrm/compiler/Klang/visitors/GenASM.java | 3 +--
 3 files changed, 13 insertions(+), 2 deletions(-)
 create mode 100644 src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Leave.java

diff --git a/src/main/java/de/hsrm/compiler/Klang/asm/ASM.java b/src/main/java/de/hsrm/compiler/Klang/asm/ASM.java
index c0d6909..d741be7 100644
--- a/src/main/java/de/hsrm/compiler/Klang/asm/ASM.java
+++ b/src/main/java/de/hsrm/compiler/Klang/asm/ASM.java
@@ -172,6 +172,10 @@ public class ASM {
     mnemonics.add(new Cqto());
   }
 
+  public void leave() {
+    mnemonics.add(new Leave());
+  }
+
   public void ret() {
     mnemonics.add(new Ret());
   }
diff --git a/src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Leave.java b/src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Leave.java
new file mode 100644
index 0000000..282ff74
--- /dev/null
+++ b/src/main/java/de/hsrm/compiler/Klang/asm/mnemonics/Leave.java
@@ -0,0 +1,8 @@
+package de.hsrm.compiler.Klang.asm.mnemonics;
+
+public class Leave extends NoOperandMnemonic {
+    @Override
+    public String toAsm() {
+        return "leave";
+    }
+}
diff --git a/src/main/java/de/hsrm/compiler/Klang/visitors/GenASM.java b/src/main/java/de/hsrm/compiler/Klang/visitors/GenASM.java
index 5bc32f2..df059c4 100644
--- a/src/main/java/de/hsrm/compiler/Klang/visitors/GenASM.java
+++ b/src/main/java/de/hsrm/compiler/Klang/visitors/GenASM.java
@@ -551,8 +551,7 @@ public class GenASM implements Visitor<Void> {
   @Override
   public Void visit(ReturnStatement e) {
     e.expression.welcome(this);
-    asm.mov("q", "%rbp", "%rsp");
-    asm.pop("q", "%rbp");
+    asm.leave();
     asm.ret();
     return null;
   }