jdk-24/test/hotspot/jtreg/compiler/c2/irTests/loopOpts/LoopIdealizationTests.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package compiler.c2.irTests.loopOpts;

import compiler.lib.ir_framework.*;

/*
 * @test
 * @bug 8267265
 * @summary Test that Ideal transformations of CountedLoopNode* are being performed as expected.
 * @library /test/lib /
 * @run driver compiler.c2.irTests.loopOpts.LoopIdealizationTests
 */
public class LoopIdealizationTests {
    public static void main(String[] args) {
        TestFramework.run();
    }

    @DontInline
    private void blackhole() { }

    @Test
    @IR(failOn = {IRNode.MUL, IRNode.DIV, IRNode.ADD, IRNode.LOOP, IRNode.COUNTED_LOOP, IRNode.COUNTED_LOOP_MAIN, IRNode.CALL})
    // Checks that a for loop with 0 iterations is removed
    public void zeroIterForLoop() {
        for (int i = 0; i < 0; i++) {
            System.out.println(13 / 17 * 23 + 1);
        }
    }

    @Test
    @IR(failOn = {IRNode.ADD, IRNode.LOOP, IRNode.COUNTED_LOOP, IRNode.COUNTED_LOOP_MAIN, IRNode.CALL})
    // Checks that a for loop with 1 iteration doesn't have CountedLoop nodes
    public void iterOneBreakForLoop() {
        for (int i = 0; i < 500; i++) {
            break;
        }
    }

    @Test
    @IR(failOn = {IRNode.ADD, IRNode.LOOP, IRNode.COUNTED_LOOP, IRNode.COUNTED_LOOP_MAIN, IRNode.TRAP})
    @IR(counts = {IRNode.CALL, "1"})
    // Checks that a for loop with 1 iteration is simplified to straight code
    public void oneIterForLoop() {
        for (int i = 0; i < 1; i++) {
            this.blackhole();
        }
    }

    @Test
    @IR(failOn = {IRNode.ADD, IRNode.LOOP, IRNode.COUNTED_LOOP, IRNode.COUNTED_LOOP_MAIN, IRNode.TRAP})
    @IR(counts = {IRNode.CALL, "1"})
    // Checks that a for loop with 1 iteration is simplified to straight code
    public void oneIterForLoop1() {
        for (int i = 0; i < 500; i++) {
            this.blackhole();
            break;
        }
    }

    @Test
    @IR(failOn = {IRNode.ADD, IRNode.LOOP, IRNode.COUNTED_LOOP, IRNode.COUNTED_LOOP_MAIN, IRNode.TRAP})
    @IR(counts = {IRNode.CALL, "1"})
    // Checks that a for loop with 1 iteration is simplified to straight code
    public void oneIterForLoop2() {
        for (int i = 0; i < 500; i++) {
            this.blackhole();
            if (i == 0) {
                break;
            }
            else {
               this.blackhole();
               i++;
            }
        }
    }

    @Test
    @IR(failOn = {IRNode.LOOP, IRNode.TRAP})
    @IR(counts = {IRNode.CALL, "1"})
    // Checks that a while loop with 1 iteration is simplified to straight code
    public void oneIterWhileLoop() {
        while (true) {
            this.blackhole();
            break;
        }
    }

    @Test
    @IR(failOn = {IRNode.ADD, IRNode.LOOP, IRNode.COUNTED_LOOP, IRNode.COUNTED_LOOP_MAIN, IRNode.TRAP})
    @IR(counts = {IRNode.CALL, "1"})
    // Checks that a while loop with 1 iteration is simplified to straight code
    public void oneIterWhileLoop1() {
        int i = 0;
        while (i < 1) {
            this.blackhole();
            i++;
        }
    }

    @Test
    @IR(failOn = {IRNode.ADD, IRNode.LOOP, IRNode.COUNTED_LOOP, IRNode.COUNTED_LOOP_MAIN, IRNode.TRAP})
    @IR(counts = {IRNode.CALL, "1"})
    // Checks that a while loop with 1 iteration is simplified to straight code
    public void oneIterWhileLoop2() {
        int i = 0;
        while (i < 500) {
            this.blackhole();
            if (i == 0) {
                 break;
            }
            else {
                this.blackhole();
                i++;
            }
        }
    }

    @Test
    @IR(failOn = {IRNode.LOOP, IRNode.TRAP})
    @IR(counts = {IRNode.CALL, "1"})
    // Checks that a while loop with 1 iteration is simplified to straight code
    public void oneIterDoWhileLoop() {
        do {
            this.blackhole();
            break;
        } while (true);
    }

    @Test
    @IR(failOn = {IRNode.LOOP, IRNode.TRAP})
    @IR(counts = {IRNode.CALL, "1"})
    // Checks that a while loop with 1 iteration is simplified to straight code
    public void oneIterDoWhileLoop1() {
        do {
            this.blackhole();
        } while (false);
    }

    @Test
    @IR(failOn = {IRNode.ADD, IRNode.LOOP, IRNode.TRAP})
    @IR(counts = {IRNode.CALL, "1"})
    // Checks that a while loop with 1 iteration is simplified to straight code
    public void oneIterDoWhileLoop2() {
        int i = 0;
        do {
            this.blackhole();
            i++;
        } while (i == -1);
    }
}