文字列連結の最適化の変更点

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文字列連結の最適化
!!!文字列連結の最適化

[文字列の連結が最適化されているさま。|http://www.y-adagio.com/public/standards/tr_javalang2/expressions.doc.html#40226]

 /**
  * @see JSL 15.18.1.2 Optimization of String Concatenation 
  */
 public class OptStrConcatTest {
    
   public static void main(String[] args) {
 
     String s2 = args[0] + args[1] + args[2];
   }
 }

 >javac OptStrConcatTest.java
 >javap -c SbTest > SbTest.jc

 Compiled from "OptStrConcatTest.java"
 public class OptStrConcatTest extends java.lang.Object{
 public OptStrConcatTest();
   Code:
    0:	aload_0
    1:	invokespecial	#1; //Method java/lang/Object."<init>":()V
    4:	return
 
 public static void main(java.lang.String[]);
   Code:
    0:	new	#2; //class StringBuffer
    3:	dup
    4:	invokespecial	#3; //Method java/lang/StringBuffer."<init>":()V
    7:	aload_0
    8:	iconst_0
    9:	aaload
    10:	invokevirtual	#4; //Method java/lang/StringBuffer.append:(Ljava/lang/String;)Ljava/lang/StringBuffer;
    13:	aload_0
    14:	iconst_1
    15:	aaload
    16:	invokevirtual	#4; //Method java/lang/StringBuffer.append:(Ljava/lang/String;)Ljava/lang/StringBuffer;
    19:	aload_0
    20:	iconst_2
    21:	aaload
    22:	invokevirtual	#4; //Method java/lang/StringBuffer.append:(Ljava/lang/String;)Ljava/lang/StringBuffer;
    25:	invokevirtual	#5; //Method java/lang/StringBuffer.toString:()Ljava/lang/String;
    28:	astore_1
    29:	return
 }

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