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8222852: Reduce String concat combinator tree shapes by folding constants into prependers

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Co-authored-by: Peter Levart <peter.levart@gmail.com>
Reviewed-by: shade, plevart, forax
This commit is contained in:
Claes Redestad 2019-04-30 12:54:07 +02:00
parent e3aa6f7907
commit e7a6cbbd38
5 changed files with 293 additions and 100 deletions
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24
test/micro/org/openjdk/bench/java/lang/StringConcat.java
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@ -26,6 +26,7 @@ import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Param;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.State;
@ -42,7 +43,8 @@ import java.util.concurrent.TimeUnit;
@State(Scope.Thread)
public class StringConcat {
public int intValue = 4711;
@Param("4711")
public int intValue;
public String stringValue = String.valueOf(intValue);
@ -77,11 +79,26 @@ public class StringConcat {
return "string" + stringValue + "string" + intValue;
}
@Benchmark
public String concatMix4String() {
// Investigate "profile pollution" between shared LFs that might eliminate some JIT optimizations
String s1 = "string" + stringValue + stringValue + stringValue + stringValue;
String s2 = "string" + stringValue + "string" + stringValue + stringValue + stringValue;
String s3 = stringValue + stringValue + "string" + stringValue + "string" + stringValue + "string";
String s4 = "string" + stringValue + "string" + stringValue + "string" + stringValue + "string" + stringValue + "string";
return s1 + s2 + s3 + s4;
}
@Benchmark
public String concatConst4String() {
return "string" + stringValue + stringValue + stringValue + stringValue;
}
@Benchmark
public String concat4String() {
return stringValue + stringValue + stringValue + stringValue;
}
@Benchmark
public String concatConst2String() {
return "string" + stringValue + stringValue;
@ -97,6 +114,11 @@ public class StringConcat {
return "string" + stringValue + stringValue + stringValue + stringValue + stringValue + stringValue;
}
@Benchmark
public String concat6String() {
return stringValue + stringValue + stringValue + stringValue + stringValue + stringValue;
}
@Benchmark
public String concatConst6Object() {
return "string" + objectValue + objectValue + objectValue + objectValue + objectValue + objectValue;