PaperMC/Spigot-Server-Patches/0081-Optimize-DataBits.patch
Aikar 0eaffd0082
Micro Optimize DataBits
There was 2 unnecessary lines of code in a core method used for DataBits
that repeatedly calculated a static value.

We now just precalculate that in the constructor and reuse the value instead.

This is a micro optimization, but this is some of the hottest code in the server so
it should provide some minor gains as well as improve inlining.

Additionally, to further help inlining, mark the DataBits methods as final.
2020-12-30 14:02:44 -05:00

84 lines
3.5 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Tue, 5 Apr 2016 21:38:58 -0400
Subject: [PATCH] Optimize DataBits
Remove Debug checks as these are super hot and causing noticeable hits
Before: http://i.imgur.com/nQsMzAE.png
After: http://i.imgur.com/nJ46crB.png
Optimize redundant converting of static fields into an unsigned long each call by precomputing it in ctor
diff --git a/src/main/java/net/minecraft/server/DataBits.java b/src/main/java/net/minecraft/server/DataBits.java
index 53e7bac2f7a99238f509bb0f871ebed103fda568..2a01a48ad347fb123492218a60404b034cfcfbc5 100644
--- a/src/main/java/net/minecraft/server/DataBits.java
+++ b/src/main/java/net/minecraft/server/DataBits.java
@@ -12,8 +12,8 @@ public class DataBits {
private final long d;
private final int e;
private final int f;
- private final int g;
- private final int h;
+ private final int g;private final long g_unsigned; // Paper - referenced in b(int) with 2 Integer.toUnsignedLong calls
+ private final int h;private final long h_unsigned; // Paper
private final int i;
public DataBits(int i, int j) {
@@ -28,8 +28,8 @@ public class DataBits {
this.f = (char) (64 / i);
int k = 3 * (this.f - 1);
- this.g = DataBits.a[k + 0];
- this.h = DataBits.a[k + 1];
+ this.g = DataBits.a[k + 0]; this.g_unsigned = Integer.toUnsignedLong(this.g); // Paper
+ this.h = DataBits.a[k + 1]; this.h_unsigned = Integer.toUnsignedLong(this.h); // Paper
this.i = DataBits.a[k + 2];
int l = (j + this.f - 1) / this.f;
@@ -46,15 +46,15 @@ public class DataBits {
}
private int b(int i) {
- long j = Integer.toUnsignedLong(this.g);
- long k = Integer.toUnsignedLong(this.h);
+ //long j = Integer.toUnsignedLong(this.g); // Paper
+ //long k = Integer.toUnsignedLong(this.h); // Paper
- return (int) ((long) i * j + k >> 32 >> this.i);
+ return (int) ((long) i * this.g_unsigned + this.h_unsigned >> 32 >> this.i); // Paper
}
- public int a(int i, int j) {
- Validate.inclusiveBetween(0L, (long) (this.e - 1), (long) i);
- Validate.inclusiveBetween(0L, this.d, (long) j);
+ public final int a(int i, int j) { // Paper - make final for inline
+ //Validate.inclusiveBetween(0L, (long) (this.e - 1), (long) i); // Paper
+ //Validate.inclusiveBetween(0L, this.d, (long) j); // Paper
int k = this.b(i);
long l = this.b[k];
int i1 = (i - k * this.f) * this.c;
@@ -64,9 +64,9 @@ public class DataBits {
return j1;
}
- public void b(int i, int j) {
- Validate.inclusiveBetween(0L, (long) (this.e - 1), (long) i);
- Validate.inclusiveBetween(0L, this.d, (long) j);
+ public final void b(int i, int j) { // Paper - make final for inline
+ //Validate.inclusiveBetween(0L, (long) (this.e - 1), (long) i); // Paper
+ //Validate.inclusiveBetween(0L, this.d, (long) j); // Paper
int k = this.b(i);
long l = this.b[k];
int i1 = (i - k * this.f) * this.c;
@@ -74,8 +74,8 @@ public class DataBits {
this.b[k] = l & ~(this.d << i1) | ((long) j & this.d) << i1;
}
- public int a(int i) {
- Validate.inclusiveBetween(0L, (long) (this.e - 1), (long) i);
+ public final int a(int i) { // Paper - make final for inline
+ //Validate.inclusiveBetween(0L, (long) (this.e - 1), (long) i); // Paper
int j = this.b(i);
long k = this.b[j];
int l = (i - j * this.f) * this.c;