SIPUSH bytecode is not used for short integer constant #33
Description
When I compiled the simple program using janinoc with janino 3.0.7, I realized that the compiled java bytecode does not use sipush java bytecode, but it uses ldc java bytecode. While it functionally works correctly, the generated java bytecode consumes an additional constant pool entry.
When I compiled this program using javac in OpenJDK8, the generated java bytecode uses sipush.
public class CP2 {
static public void main(String[] argv) {
int i = 32767;
}
}
Classfile /home/ishizaki/Spark/PR/lsof/spark/CP2.class
Last modified Nov 24, 2017; size 263 bytes
MD5 checksum 8759300e8265dce5114c34a53ae853d0
Compiled from "CP2.java"
public class CP2
minor version: 0
major version: 49
flags: ACC_PUBLIC, ACC_SUPER
Constant pool:
#1 = Utf8 CP2
#2 = Class #1 // CP2
#3 = Utf8 java/lang/Object
#4 = Class #3 // java/lang/Object
#5 = Utf8 SourceFile
#6 = Utf8 CP2.java
#7 = Utf8 main
#8 = Utf8 ([Ljava/lang/String;)V
#9 = Integer 32767
#10 = Utf8 LineNumberTable
#11 = Utf8 Code
#12 = Utf8 <init>
#13 = Utf8 ()V
#14 = NameAndType #12:#13 // "<init>":()V
#15 = Methodref #4.#14 // java/lang/Object."<init>":()V
{
public static void main(java.lang.String[]);
descriptor: ([Ljava/lang/String;)V
flags: ACC_PUBLIC, ACC_STATIC
Code:
stack=1, locals=2, args_size=1
0: ldc #9 // int 32767
2: istore_1
3: return
LineNumberTable:
line 3: 0
line 2: 3
public CP2();
descriptor: ()V
flags: ACC_PUBLIC
Code:
stack=1, locals=1, args_size=1
0: aload_0
1: invokespecial #15 // Method java/lang/Object."<init>":()V
4: return
LineNumberTable:
line 1: 0
}