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
|
/*
* Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package vm.compiler.coverage.parentheses.share;
import java.util.List;
/**
* Tiny stack InstructionsExecutor. This executor verifies HotspotInstructionsExecutor
*/
public class TinyInstructionsExecutor implements InstructionsExecutor {
private int[] stack;
private int stackHead = -1;
public TinyInstructionsExecutor(int stackSize) {
stack = new int[stackSize];
}
private void putOnStack(int v) {
stack[++stackHead] = v;
}
private void exec(Instruction instruction) {
switch (instruction) {
case ICONST_M1:
putOnStack(-1);
break;
case ICONST_0:
putOnStack(0);
break;
case ICONST_1:
putOnStack(1);
break;
case ICONST_2:
putOnStack(2);
break;
case ICONST_3:
putOnStack(3);
break;
case ICONST_4:
putOnStack(4);
break;
case ICONST_5:
putOnStack(5);
break;
case DUP:
stack[stackHead + 1] = stack[stackHead];
stackHead++;
break;
case IADD:
stack[stackHead - 1] += stack[stackHead];
stackHead--;
break;
case ISUB:
stack[stackHead - 1] -= stack[stackHead];
stackHead--;
break;
case IMUL:
stack[stackHead - 1] *= stack[stackHead];
stackHead--;
break;
case IOR:
stack[stackHead - 1] |= stack[stackHead];
stackHead--;
break;
case IAND:
stack[stackHead - 1] &= stack[stackHead];
stackHead--;
break;
case IXOR:
stack[stackHead - 1] ^= stack[stackHead];
stackHead--;
break;
case ISHL:
stack[stackHead - 1] <<= stack[stackHead];
stackHead--;
break;
case ISHR:
stack[stackHead - 1] >>= stack[stackHead];
stackHead--;
break;
case SWAP: {
int t = stack[stackHead];
stack[stackHead] = stack[stackHead - 1];
stack[stackHead - 1] = t;
break;
}
case NOP:
break;
case INEG:
stack[stackHead] = -stack[stackHead];
break;
}
}
private int top() {
return stack[stackHead];
}
@Override
public int execute(List<Instruction> instructions) {
for (Instruction instruction : instructions) {
exec(instruction);
}
return top();
}
}
|
