From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Taiyou06 <kaandindar21@gmail.com>
Date: Mon, 24 Feb 2025 21:11:09 +0100
Subject: [PATCH] Slightly optimized VarInt#write

Use switch case instead of if-else for branches. It makes it able to use
tableswitch instruction for better efficiency.

Improves it around 1% to 5%

diff --git a/net/minecraft/network/VarInt.java b/net/minecraft/network/VarInt.java
index 6f8dd31582f0e1d3a71acc7a142c1f4ec0539d9e..4c9095995e8515c61d54f1c056be35a12a138ef3 100644
--- a/net/minecraft/network/VarInt.java
+++ b/net/minecraft/network/VarInt.java
@@ -52,35 +52,44 @@ public class VarInt {
 
     public static ByteBuf write(ByteBuf buffer, int value) {
         // Gale start - Velocity - optimized VarInt#write
-        if ((value & 0xFFFFFF80) == 0) {
-            buffer.writeByte(value);
-        } else if ((value & 0xFFFFC000) == 0) {
-            int w = (value & 0x7F) << 8
-                | (value >>> 7)
-                | 0x00008000;
-            buffer.writeShort(w);
-        } else if ((value & 0xFFE00000) == 0) {
-            int w = (value & 0x7F) << 16
-                | (value & 0x3F80) << 1
-                | (value >>> 14)
-                | 0x00808000;
-            buffer.writeMedium(w);
-        } else if ((value & 0xF0000000) == 0) {
-            int w = (value & 0x7F) << 24
-                | ((value & 0x3F80) << 9)
-                | (value & 0x1FC000) >> 6
-                | (value >>> 21)
-                | 0x80808000;
-            buffer.writeInt(w);
-        } else {
-            int w = (value & 0x7F) << 24
-                | (value & 0x3F80) << 9
-                | (value & 0x1FC000) >> 6
-                | ((value >>> 21) & 0x7F)
-                | 0x80808080;
-            buffer.writeInt(w);
-            buffer.writeByte(value >>> 28);
+        // Leaf start - Slightly optimized VarInt#write
+        int bytesNeeded = getByteSize(value);
+
+        switch (bytesNeeded) {
+            case 1:
+                buffer.writeByte(value);
+                break;
+            case 2:
+                int w2 = ((value & 0x7F) << 8) | (value >>> 7) | 0x00008000;
+                buffer.writeShort(w2);
+                break;
+            case 3:
+                int w3 = (value & 0x7F) << 16
+                    | (value & 0x3F80) << 1
+                    | (value >>> 14)
+                    | 0x00808000;
+                buffer.writeMedium(w3);
+                break;
+            case 4:
+                int w4 = (value & 0x7F) << 24
+                    | ((value & 0x3F80) << 9)
+                    | (value & 0x1FC000) >> 6
+                    | (value >>> 21)
+                    | 0x80808000;
+                buffer.writeInt(w4);
+                break;
+            case 5:
+                int w5 = (value & 0x7F) << 24
+                    | (value & 0x3F80) << 9
+                    | (value & 0x1FC000) >> 6
+                    | ((value >>> 21) & 0x7F)
+                    | 0x80808080;
+                buffer.writeInt(w5);
+                buffer.writeByte(value >>> 28);
+                break;
         }
+        // Leaf end - Slightly optimized VarInt#write
+
         return buffer;
     }