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23 
24 
25 package org.graalvm.compiler.replacements.test;
26 
27 import org.graalvm.compiler.core.test.GraalCompilerTest;
28 import org.graalvm.compiler.nodes.ConstantNode;
29 import org.graalvm.compiler.nodes.FixedNode;
30 import org.graalvm.compiler.nodes.ReturnNode;
31 import org.graalvm.compiler.nodes.StructuredGraph;
32 import org.graalvm.compiler.nodes.ValueNode;
33 import jdk.vm.ci.meta.JavaConstant;
34 import org.junit.Test;
35 
36 import jdk.vm.ci.meta.ResolvedJavaMethod;
37 import static org.hamcrest.CoreMatchers.instanceOf;
38 import org.junit.Assert;
39 
40 /**
41  * Tests constant folding of {@link String#hashCode()}.
42  */
43 public class StringHashConstantTest extends GraalCompilerTest {
44 
45     private static final String A_CONSTANT_STRING = "a constant string";
46 
asConstant(StructuredGraph graph, String str)47     private ValueNode asConstant(StructuredGraph graph, String str) {
48         return ConstantNode.forConstant(getSnippetReflection().forObject(str), getMetaAccess(), graph);
49     }
50 
51     @Test
test1()52     public void test1() {
53         ResolvedJavaMethod method = getResolvedJavaMethod("parameterizedHashCode");
54         StructuredGraph graph = parseForCompile(method);
55 
56         String s = "some string";
57         int expected = s.hashCode();
58         graph.getParameter(0).replaceAndDelete(asConstant(graph, s));
59 
60         compile(method, graph);
61 
62         FixedNode firstFixed = graph.start().next();
63         Assert.assertThat(firstFixed, instanceOf(ReturnNode.class));
64 
65         ReturnNode ret = (ReturnNode) firstFixed;
66         JavaConstant result = ret.result().asJavaConstant();
67         if (result == null) {
68             Assert.fail("result not constant: " + ret.result());
69         } else {
70             Assert.assertEquals("result", expected, result.asInt());
71         }
72     }
73 
parameterizedHashCode(String value)74     public static int parameterizedHashCode(String value) {
75         return value.hashCode();
76     }
77 
78     @Test
test2()79     public void test2() {
80         ResolvedJavaMethod method = getResolvedJavaMethod("constantHashCode");
81         StructuredGraph graph = parseForCompile(method);
82 
83         FixedNode firstFixed = graph.start().next();
84         Assert.assertThat(firstFixed, instanceOf(ReturnNode.class));
85 
86         ReturnNode ret = (ReturnNode) firstFixed;
87         JavaConstant result = ret.result().asJavaConstant();
88         if (result == null) {
89             Assert.fail("result not constant: " + ret.result());
90         } else {
91             int expected = A_CONSTANT_STRING.hashCode();
92             Assert.assertEquals("result", expected, result.asInt());
93         }
94     }
95 
constantHashCode()96     public static int constantHashCode() {
97         return A_CONSTANT_STRING.hashCode();
98     }
99 }
100