1 /*
2 * Copyright (c) 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
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24 */
25 package oracle.code.samples;
26
27 import jdk.incubator.code.Block;
28 import jdk.incubator.code.Reflect;
29 import jdk.incubator.code.Op;
30 import jdk.incubator.code.bytecode.BytecodeGenerator;
31 import jdk.incubator.code.dialect.core.CoreOp;
32 import jdk.incubator.code.dialect.core.CoreType;
33 import jdk.incubator.code.dialect.core.Inliner;
34 import jdk.incubator.code.dialect.java.JavaType;
35
36 import java.lang.invoke.MethodHandle;
37 import java.lang.invoke.MethodHandles;
38 import java.lang.reflect.Method;
39 import java.util.List;
40 import java.util.Optional;
41 import java.util.stream.Stream;
42
43 /**
44 * Example of inlining based on one of the example from the code-reflection unit-tests.
45 * This example illustrates how to embed a value into a function and propagate that
46 * change in the code model.
47 *
48 * <p>
49 * How to run from the terminal?
50 * <code>
51 * java --add-modules jdk.incubator.code -cp target/crsamples-1.0-SNAPSHOT.jar oracle.code.samples.InlineExample
52 * </code>
53 * </p>
54 */
55 public class InlineExample {
56
57 // We are going to inline this function and specialize one of the parameters
58 // (e.g., parameter b) to a constant value.
59 // The new function will contain two parameters to perform a * CONSTANT + c
60 @Reflect
61 private static float fma(float a, float b, float c) {
62 return a * b + c;
63 }
64
65 // Utility for building a code model from a given method from a class.
66 private static CoreOp.FuncOp buildCodeModelForMethod(Class<?> klass, String methodName) {
67 Optional<Method> function = Stream.of(klass.getDeclaredMethods())
68 .filter(m -> m.getName().equals(methodName))
69 .findFirst();
70 Method method = function.get();
71 CoreOp.FuncOp funcOp = Op.ofMethod(method).get();
72 return funcOp;
73 }
74
75 static void main() {
76
77 // 1. Build the code model for the fma static method of this class.
78 CoreOp.FuncOp fmaCodeModel = buildCodeModelForMethod(InlineExample.class, "fma");
79
80 // 2. Builds a new FuncOp with the copy of the fmaCodeModel and with the specialized values
81 // This example is useful, for example, to apply partial evaluation of expression at runtime,
82 CoreOp.FuncOp f = CoreOp.func("myFunction",
83 CoreType.functionType(JavaType.FLOAT, // return type
84 JavaType.FLOAT, // param 1
85 JavaType.FLOAT // param 2 (the new function has 2 params
86 ))
87 .body(blockBuilder -> {
88 // Get parameters for the new function
89 Block.Parameter parameter1 = blockBuilder.parameters().get(0);
90 Block.Parameter parameter2 = blockBuilder.parameters().get(1);
91
92 // Build a new op with a pre-defined constant. We will place this constant
93 // as one of the parameters of the function and then inline with the new values.
94 Op.Result myConstantValue = blockBuilder.add(CoreOp.ConstantOp.constant(JavaType.FLOAT, 50.f));
95
96 // Inline the function with the new values
97 Inliner.inline(blockBuilder,
98 fmaCodeModel, // inline the fmaCodeModel
99 List.of(parameter1, myConstantValue, parameter2), // apply the 3 parameters to the function to inline
100 Inliner.INLINE_RETURN);
101 });
102
103 // 3. Print the resulting code model
104 IO.println(f.toText());
105
106 // 4. Generate bytecodes from the code model.
107 MethodHandle methodHandle = BytecodeGenerator.generate(MethodHandles.lookup(), f);
108 try {
109 var res = methodHandle.invoke(10.f, 20.f);
110 IO.println("Result from bytecode generation: " + res);
111 } catch (Throwable e) {
112 throw new RuntimeException(e);
113 }
114 }
115 }