Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly
Appearance settings

Latest commit

 

History

History
History
189 lines (173 loc) · 6.81 KB
/

ForLoop.java

File metadata and controls

189 lines (173 loc) · 6.81 KB
Copy raw file
Download raw file
Open symbols panel
Edit and raw actions
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
package symjava.bytecode.bcel;
import static com.sun.org.apache.bcel.internal.Constants.ACC_PUBLIC;
import static com.sun.org.apache.bcel.internal.Constants.ACC_SUPER;
import symjava.bytecode.BytecodeFunc;
import symjava.symbolic.utils.FuncClassLoader;
import com.sun.org.apache.bcel.internal.generic.ALOAD;
import com.sun.org.apache.bcel.internal.generic.ArrayType;
import com.sun.org.apache.bcel.internal.generic.ClassGen;
import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.DADD;
import com.sun.org.apache.bcel.internal.generic.DALOAD;
import com.sun.org.apache.bcel.internal.generic.DLOAD;
import com.sun.org.apache.bcel.internal.generic.DSTORE;
import com.sun.org.apache.bcel.internal.generic.GOTO;
import com.sun.org.apache.bcel.internal.generic.IF_ICMPLT;
import com.sun.org.apache.bcel.internal.generic.IINC;
import com.sun.org.apache.bcel.internal.generic.ILOAD;
import com.sun.org.apache.bcel.internal.generic.ISTORE;
import com.sun.org.apache.bcel.internal.generic.InstructionConstants;
import com.sun.org.apache.bcel.internal.generic.InstructionFactory;
import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.LocalVariableGen;
import com.sun.org.apache.bcel.internal.generic.MethodGen;
import com.sun.org.apache.bcel.internal.generic.PUSH;
import com.sun.org.apache.bcel.internal.generic.Type;
public class ForLoop {
public static void main(String[] args) {
String packageName = "symjava.bytecode";
String clsName = "TestForLoop";
String fullClsName = packageName+"."+clsName;
ClassGen cg = new ClassGen(fullClsName, "java.lang.Object",
"<generated>", ACC_PUBLIC | ACC_SUPER, new String[]{"symjava.bytecode.BytecodeFunc"});
ConstantPoolGen cp = cg.getConstantPool(); // cg creates constant pool
InstructionList il = new InstructionList();
InstructionFactory factory = new InstructionFactory(cg);
short acc_flags = ACC_PUBLIC;
MethodGen mg = new MethodGen(acc_flags, // access flags
Type.DOUBLE, // return type
new Type[] { // argument types
new ArrayType(Type.DOUBLE, 1)
},
new String[] { "args" }, // arg names
"apply", fullClsName, // method, class
il, cp);
//double sum = 0;
LocalVariableGen lg;
lg = mg.addLocalVariable("sum",
Type.DOUBLE, null, null);
int idxSum = lg.getIndex();
il.append(InstructionConstants.DCONST_0);
lg.setStart(il.append(new DSTORE(idxSum))); // "sum" valid from here
//////////////////////////////////////////////////////////////
// for(int i=0; i<10; i++) {
// sum += args[i];
// }
/////////////////////////////////////////////////////////////
//int i = 0;
lg = mg.addLocalVariable("i",
Type.INT, null, null);
int idxI = lg.getIndex();
il.append(InstructionConstants.ICONST_0);
lg.setStart(il.append(new ISTORE(idxI))); // "i" valid from here
//Loop body: sum = sum + args[i]
InstructionHandle loopStart = il.append(new ALOAD(1));
il.append(new ILOAD(idxI));
il.append(new DALOAD());
il.append(new DLOAD(idxSum));
il.append(new DADD());
il.append(new DSTORE(idxSum));
//i++
il.append(new IINC(idxI, 1));
//Compare: i < 10
InstructionHandle loopCmp = il.append(new ILOAD(idxI));
il.append(new PUSH(cp, 10));
il.append(new IF_ICMPLT(loopStart));
il.insert(loopStart, new GOTO(loopCmp));
/////////////////////////////////////////////////////////////
il.append(new DLOAD(idxSum));
il.append(InstructionConstants.DRETURN);
mg.setMaxStack();
cg.addMethod(mg.getMethod());
il.dispose(); // Allow instruction handles to be reused
cg.addEmptyConstructor(ACC_PUBLIC);
FuncClassLoader<BytecodeFunc> fcl = new FuncClassLoader<BytecodeFunc>();
BytecodeFunc fun = fcl.newInstance(cg);
double[] params = new double[10];
for(int i=0; i<params.length; i++)
params[i] = i;
System.out.println(fun.apply(params));
try {
cg.getJavaClass().dump("bin/symjava/bytecode/"+clsName+".class");
} catch (java.io.IOException e) {
System.err.println(e);
}
}
}
/**
$ javap -verbose TestForLoop.class
Classfile /home/yliu/workspace_java/SymJava/bin/symjava/bytecode/TestForLoop.class
Last modified Apr 9, 2015; size 441 bytes
MD5 checksum 0c83fefac38f7c2a4f3ac482d6219cde
Compiled from "<generated>"
public class symjava.bytecode.TestForLoop implements symjava.bytecode.BytecodeFunc
SourceFile: "<generated>"
minor version: 3
major version: 45
flags: ACC_PUBLIC, ACC_SUPER
Constant pool:
#1 = Utf8 SourceFile
#2 = Utf8 <generated>
#3 = Utf8 symjava/bytecode/TestForLoop
#4 = Class #3 // symjava/bytecode/TestForLoop
#5 = Utf8 java/lang/Object
#6 = Class #5 // java/lang/Object
#7 = Utf8 apply
#8 = Utf8 ([D)D
#9 = Utf8 this
#10 = Utf8 Lsymjava/bytecode/TestForLoop;
#11 = Utf8 args
#12 = Utf8 [D
#13 = Utf8 sum
#14 = Utf8 D
#15 = Utf8 i
#16 = Utf8 I
#17 = Utf8 LocalVariableTable
#18 = Utf8 Code
#19 = Utf8 <init>
#20 = Utf8 ()V
#21 = NameAndType #19:#20 // "<init>":()V
#22 = Methodref #6.#21 // java/lang/Object."<init>":()V
#23 = Utf8 symjava/bytecode/BytecodeFunc
#24 = Class #23 // symjava/bytecode/BytecodeFunc
{
public double apply(double[]);
flags: ACC_PUBLIC
Code:
stack=4, locals=5, args_size=2
0: dconst_0
1: dstore_2 //sum=0
2: iconst_0
3: istore 4 //i=0
5: goto 18
8: aload_1
9: iload 4
11: daload //args[i]
12: dload_2 //sum
13: dadd //args[i]+sum
14: dstore_2 //sum = args[i]+sum
15: iinc 4, 1 //i++
18: iload 4
20: bipush 10
22: if_icmplt 8 //i<10
25: dload_2
26: dreturn //return sum
LocalVariableTable:
Start Length Slot Name Signature
0 27 0 this Lsymjava/bytecode/TestForLoop;
0 27 1 args [D
1 26 2 sum D
3 24 4 i I
public symjava.bytecode.TestForLoop();
flags: ACC_PUBLIC
Code:
stack=1, locals=1, args_size=1
0: aload_0
1: invokespecial #22 // Method java/lang/Object."<init>":()V
4: return
LocalVariableTable:
Start Length Slot Name Signature
0 5 0 this Lsymjava/bytecode/TestForLoop;
}
*/
Morty Proxy This is a proxified and sanitized view of the page, visit original site.