Paper/Spigot-Server-Patches/0537-Optimize-Bit-Operations-by-inlining.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Thu, 4 Jun 2020 02:24:49 -0400
Subject: [PATCH] Optimize Bit Operations by inlining

Inline bit operations and reduce instruction count to make these hot
operations faster

diff --git a/src/main/java/net/minecraft/server/BlockPosition.java b/src/main/java/net/minecraft/server/BlockPosition.java
index 3bf17ccdaef21322b787db538d569e0bc614ef22..4c64798fbc50f4d8b08502ba865c5fde5c968e62 100644
--- a/src/main/java/net/minecraft/server/BlockPosition.java
+++ b/src/main/java/net/minecraft/server/BlockPosition.java
@@ -75,38 +75,34 @@ public class BlockPosition extends BaseBlockPosition implements MinecraftSeriali
         return dynamicops.createIntList(IntStream.of(new int[]{this.getX(), this.getY(), this.getZ()}));
     }
 
+    public static long getAdjacent(int baseX, int baseY, int baseZ, EnumDirection enumdirection) { return asLong(baseX + enumdirection.getAdjacentX(), baseY + enumdirection.getAdjacentY(), baseZ + enumdirection.getAdjacentZ()); } // Paper
     public static long a(long i, EnumDirection enumdirection) {
         return a(i, enumdirection.getAdjacentX(), enumdirection.getAdjacentY(), enumdirection.getAdjacentZ());
     }
 
     public static long a(long i, int j, int k, int l) {
-        return a(b(i) + j, c(i) + k, d(i) + l);
+        return a((int) (i >> 38) + j, (int) ((i << 52) >> 52) + k, (int) ((i << 26) >> 38) + l); // Paper - simplify/inline
     }
 
     public static int b(long i) {
-        return (int) (i << 64 - BlockPosition.k - BlockPosition.c >> 64 - BlockPosition.c);
+        return (int) (i >> 38); // Paper - simplify/inline
     }
 
     public static int c(long i) {
-        return (int) (i << 64 - BlockPosition.f >> 64 - BlockPosition.f);
+        return (int) ((i << 52) >> 52); // Paper - simplify/inline
     }
 
     public static int d(long i) {
-        return (int) (i << 64 - BlockPosition.j - BlockPosition.d >> 64 - BlockPosition.d);
+        return (int) ((i << 26) >> 38);  // Paper - simplify/inline
     }
 
     public static BlockPosition fromLong(long i) {
-        return new BlockPosition(b(i), c(i), d(i));
+        return new BlockPosition((int) (i >> 38), (int) ((i << 52) >> 52), (int) ((i << 26) >> 38)); // Paper - simplify/inline
     }
 
     public static long asLong(int x, int y, int z) { return a(x, y, z); } // Paper - OBFHELPER
     public static long a(int i, int j, int k) {
-        long l = 0L;
-
-        l |= ((long) i & BlockPosition.g) << BlockPosition.k;
-        l |= ((long) j & BlockPosition.h) << 0;
-        l |= ((long) k & BlockPosition.i) << BlockPosition.j;
-        return l;
+        return (((long) i & (long) 67108863) << 38) | (((long) j & (long) 4095)) | (((long) k & (long) 67108863) << 12); // Paper - inline constants and simplify
     }
 
     public static long f(long i) {
diff --git a/src/main/java/net/minecraft/server/SectionPosition.java b/src/main/java/net/minecraft/server/SectionPosition.java
index ca3f63f5e5e4e926de562b4bfbbf72ad8a6b943f..c415736282de6d4d0f87135c24999c4bbf993901 100644
--- a/src/main/java/net/minecraft/server/SectionPosition.java
+++ b/src/main/java/net/minecraft/server/SectionPosition.java
@@ -16,7 +16,7 @@ public class SectionPosition extends BaseBlockPosition {
     }
 
     public static SectionPosition a(BlockPosition blockposition) {
-        return new SectionPosition(a(blockposition.getX()), a(blockposition.getY()), a(blockposition.getZ()));
+        return new SectionPosition(blockposition.getX() >> 4, blockposition.getY() >> 4, blockposition.getZ() >> 4); // Paper
     }
 
     public static SectionPosition a(ChunkCoordIntPair chunkcoordintpair, int i) {
@@ -28,7 +28,7 @@ public class SectionPosition extends BaseBlockPosition {
     }
 
     public static SectionPosition a(long i) {
-        return new SectionPosition(b(i), c(i), d(i));
+        return new SectionPosition((int) (i >> 42), (int) (i << 44 >> 44), (int) (i << 22 >> 42)); // Paper
     }
 
     public static long a(long i, EnumDirection enumdirection) {
@@ -36,7 +36,7 @@ public class SectionPosition extends BaseBlockPosition {
     }
 
     public static long a(long i, int j, int k, int l) {
-        return b(b(i) + j, c(i) + k, d(i) + l);
+        return (((long) ((int) (i >> 42) + j) & 4194303L) << 42) | (((long) ((int) (i << 44 >> 44) + k) & 1048575L)) | (((long) ((int) (i << 22 >> 42) + l) & 4194303L) << 20); // Simplify to reduce instruction count
     }
 
     public static int a(int i) {
@@ -48,11 +48,7 @@ public class SectionPosition extends BaseBlockPosition {
     }
 
     public static short b(BlockPosition blockposition) {
-        int i = b(blockposition.getX());
-        int j = b(blockposition.getY());
-        int k = b(blockposition.getZ());
-
-        return (short) (i << 8 | k << 4 | j);
+        return (short) ((blockposition.x & 15) << 8 | (blockposition.z & 15) << 4 | blockposition.y & 15); // Paper - simplify/inline
     }
 
     public static int c(int i) {
@@ -60,7 +56,7 @@ public class SectionPosition extends BaseBlockPosition {
     }
 
     public static int b(long i) {
-        return (int) (i << 0 >> 42);
+        return (int) (i >> 42); // Paper
     }
 
     public static int c(long i) {
@@ -71,44 +67,46 @@ public class SectionPosition extends BaseBlockPosition {
         return (int) (i << 22 >> 42);
     }
 
-    public int a() {
-        return this.getX();
+    public final int a() { // Paper
+        return x; // Paper
     }
 
-    public int b() {
-        return this.getY();
+    public final int b() { // Paper
+        return y; // Paper
     }
 
-    public int c() {
-        return this.getZ();
+    public final int c() { // Paper
+        return z; // Paper
     }
 
-    public int d() {
-        return this.a() << 4;
+    public final int d() { // Paper
+        return x << 4; // Paper
     }
 
-    public int e() {
-        return this.b() << 4;
+    public final int e() { // Paper
+        return y << 4; // Paper
     }
 
-    public int f() {
-        return this.c() << 4;
+    public final int f() { // Paper
+        return z << 4; // Paper
     }
 
-    public int g() {
-        return (this.a() << 4) + 15;
+    public final int g() { // Paper
+        return (x << 4) + 15; // Paper
     }
 
-    public int h() {
-        return (this.b() << 4) + 15;
+    public final int h() { // Paper
+        return (y << 4) + 15; // Paper
     }
 
-    public int r() {
-        return (this.c() << 4) + 15;
+    public final int r() { // Paper
+        return (z << 4) + 15; // Paper
     }
 
+    public static long blockToSection(long i) { return e(i); } // Paper - OBFHELPER
     public static long e(long i) {
-        return b(a(BlockPosition.b(i)), a(BlockPosition.c(i)), a(BlockPosition.d(i)));
+        // b(a(BlockPosition.b(i)), a(BlockPosition.c(i)), a(BlockPosition.d(i)));
+        return (((long) (int) (i >> 42) & 4194303L) << 42) | (((long) (int) ((i << 52) >> 56) & 1048575L)) | (((long) (int) ((i << 26) >> 42) & 4194303L) << 20); // Simplify to reduce instruction count
     }
 
     public static long f(long i) {
@@ -116,7 +114,7 @@ public class SectionPosition extends BaseBlockPosition {
     }
 
     public BlockPosition s() {
-        return new BlockPosition(c(this.a()), c(this.b()), c(this.c()));
+        return new BlockPosition(x << 4, y << 4, z << 4); // Paper
     }
 
     public BlockPosition t() {
@@ -129,36 +127,30 @@ public class SectionPosition extends BaseBlockPosition {
         return new ChunkCoordIntPair(this.a(), this.c());
     }
 
+    // Paper start
+    public static long blockPosAsSectionLong(int i, int j, int k) {
+        return (((long) (i >> 4) & 4194303L) << 42) | (((long) (j >> 4) & 1048575L)) | (((long) (k >> 4) & 4194303L) << 20);
+    }
+    // Paper end
+    public static long asLong(int i, int j, int k) { return b(i, j, k); } // Paper - OBFHELPER
     public static long b(int i, int j, int k) {
-        long l = 0L;
-
-        l |= ((long) i & 4194303L) << 42;
-        l |= ((long) j & 1048575L) << 0;
-        l |= ((long) k & 4194303L) << 20;
-        return l;
+        return (((long) i & 4194303L) << 42) | (((long) j & 1048575L)) | (((long) k & 4194303L) << 20); // Paper - Simplify to reduce instruction count
     }
 
     public long v() {
-        return b(this.a(), this.b(), this.c());
+        return (((long) x & 4194303L) << 42) | (((long) y & 1048575L)) | (((long) z & 4194303L) << 20); // Paper - Simplify to reduce instruction count
     }
 
     public Stream<BlockPosition> w() {
-        return BlockPosition.a(this.d(), this.e(), this.f(), this.g(), this.h(), this.r());
+        return BlockPosition.a(x << 4, y << 4, z << 4, (x << 4) + 15, (y << 4) + 15, (z << 4) + 15); // Paper - simplify/inline
     }
 
     public static Stream<SectionPosition> a(SectionPosition sectionposition, int i) {
-        int j = sectionposition.a();
-        int k = sectionposition.b();
-        int l = sectionposition.c();
-
-        return a(j - i, k - i, l - i, j + i, k + i, l + i);
+        return a(sectionposition.x - i, sectionposition.y - i, sectionposition.z - i, sectionposition.x + i, sectionposition.y + i, sectionposition.z + i); // Paper - simplify/inline
     }
 
     public static Stream<SectionPosition> b(ChunkCoordIntPair chunkcoordintpair, int i) {
-        int j = chunkcoordintpair.x;
-        int k = chunkcoordintpair.z;
-
-        return a(j - i, 0, k - i, j + i, 15, k + i);
+        return a(chunkcoordintpair.x - i, 0, chunkcoordintpair.z - i, chunkcoordintpair.x + i, 15, chunkcoordintpair.z + i); // Paper - simplify/inline
     }
 
     public static Stream<SectionPosition> a(final int i, final int j, final int k, final int l, final int i1, final int j1) {