PaperMC/Spigot-Server-Patches/0492-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/core/BlockPosition.java b/src/main/java/net/minecraft/core/BlockPosition.java
index 1fb931d4c0720a5e496030e25c865771aea3ec70..eb67af795dd716d9f92ac32843accc1ec4efd647 100644
--- a/src/main/java/net/minecraft/core/BlockPosition.java
+++ b/src/main/java/net/minecraft/core/BlockPosition.java
@@ -31,14 +31,16 @@ public class BlockPosition extends BaseBlockPosition {
     }).stable();
     private static final Logger LOGGER = LogManager.getLogger();
     public static final BlockPosition ZERO = new BlockPosition(0, 0, 0);
-    private static final int f = 1 + MathHelper.f(MathHelper.c(30000000));
-    private static final int g = BlockPosition.f;
-    private static final int h = 64 - BlockPosition.f - BlockPosition.g;
-    private static final long i = (1L << BlockPosition.f) - 1L;
-    private static final long j = (1L << BlockPosition.h) - 1L;
-    private static final long k = (1L << BlockPosition.g) - 1L;
-    private static final int l = BlockPosition.h;
-    private static final int m = BlockPosition.h + BlockPosition.g;
+    // Paper start - static constants
+    private static final int f = 26;
+    private static final int g = 26;
+    private static final int h = 12;
+    private static final long i = 67108863;
+    private static final long j = 4095;
+    private static final long k = 67108863;
+    private static final int l = 12;
+    private static final int m = 38;
+    // Paper end
 
     public BlockPosition(int i, int j, int k) {
         super(i, j, k);
@@ -60,28 +62,29 @@ public class BlockPosition extends BaseBlockPosition {
         this(baseblockposition.getX(), baseblockposition.getY(), baseblockposition.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.m - BlockPosition.f >> 64 - BlockPosition.f);
+        return (int) (i >> 38); // Paper - simplify/inline
     }
 
     public static int c(long i) {
-        return (int) (i << 64 - BlockPosition.h >> 64 - BlockPosition.h);
+        return (int) ((i << 52) >> 52); // Paper - simplify/inline
     }
 
     public static int d(long i) {
-        return (int) (i << 64 - BlockPosition.l - BlockPosition.g >> 64 - BlockPosition.g);
+        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 long asLong() {
@@ -90,12 +93,7 @@ public class BlockPosition extends BaseBlockPosition {
 
     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.i) << BlockPosition.m;
-        l |= ((long) j & BlockPosition.j) << 0;
-        l |= ((long) k & BlockPosition.k) << BlockPosition.l;
-        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/core/SectionPosition.java b/src/main/java/net/minecraft/core/SectionPosition.java
index 97126ae5a43bb7acb04a1ab14fb7f364c8c2675f..7d9a16eb81288b74425319c60525f57c98ad3b69 100644
--- a/src/main/java/net/minecraft/core/SectionPosition.java
+++ b/src/main/java/net/minecraft/core/SectionPosition.java
@@ -19,7 +19,7 @@ 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) {
@@ -31,15 +31,23 @@ 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) {
         return a(i, enumdirection.getAdjacentX(), enumdirection.getAdjacentY(), enumdirection.getAdjacentZ());
     }
 
+    // Paper start
+    public static long getAdjacentFromBlockPos(int x, int y, int z, EnumDirection enumdirection) {
+        return (((long) ((x >> 4) + enumdirection.getAdjacentX()) & 4194303L) << 42) | (((long) ((y >> 4) + enumdirection.getAdjacentY()) & 1048575L)) | (((long) ((z >> 4) + enumdirection.getAdjacentZ()) & 4194303L) << 20);
+    }
+    public static long getAdjacentFromSectionPos(int x, int y, int z, EnumDirection enumdirection) {
+        return (((long) (x + enumdirection.getAdjacentX()) & 4194303L) << 42) | (((long) ((y) + enumdirection.getAdjacentY()) & 1048575L)) | (((long) (z + enumdirection.getAdjacentZ()) & 4194303L) << 20);
+    }
+    // Paper end
     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) {
@@ -51,11 +59,7 @@ 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 << 0);
+        return (short) ((blockposition.getX() & 15) << 8 | (blockposition.getZ() & 15) << 4 | blockposition.getY() & 15); // Paper - simplify/inline
     }
 
     public static int a(short short0) {
@@ -114,16 +118,16 @@ public class SectionPosition extends BaseBlockPosition {
         return this.getZ();
     }
 
-    public int d() {
-        return this.a() << 4;
+    public final int d() { // Paper
+        return this.getX() << 4; // Paper
     }
 
-    public int e() {
-        return this.b() << 4;
+    public final int e() { // Paper
+        return this.getY() << 4; // Paper
     }
 
-    public int f() {
-        return this.c() << 4;
+    public final int f() { // Paper
+        return this.getZ() << 4; // Paper
     }
 
     public int g() {
@@ -138,8 +142,10 @@ public class SectionPosition extends BaseBlockPosition {
         return (this.c() << 4) + 15;
     }
 
+    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) {
@@ -160,17 +166,18 @@ 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 s() {
-        return b(this.a(), this.b(), this.c());
+        return (((long) getX() & 4194303L) << 42) | (((long) getY() & 1048575L)) | (((long) getZ() & 4194303L) << 20); // Paper - Simplify to reduce instruction count
     }
 
     public Stream<BlockPosition> t() {
@@ -178,18 +185,11 @@ public class SectionPosition extends BaseBlockPosition {
     }
 
     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.getX() - i, sectionposition.getY() - i, sectionposition.getZ() - i, sectionposition.getX() + i, sectionposition.getY() + i, sectionposition.getZ() + 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) {