test/hotspot/jtreg/compiler/loopopts/TestLoopLimitSubtractionsCollapse.java

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/*
 * @test
 * @bug 8303466
 * @summary Verify that AddL->MaxL->AddL->MaxL chains of unroll limit adjustments collapse.
 *          If it did not collapse, we would have about 10 MaxL/MinL. With the collapse, it
 *          is now one or two.
 * @library /test/lib /
 * @requires vm.compiler2.enabled
 * @run driver compiler.loopopts.TestLoopLimitSubtractionsCollapse
 */

package compiler.loopopts;
import compiler.lib.ir_framework.*;

public class TestLoopLimitSubtractionsCollapse {
    static int START = 0;
    static int FINISH = 512;
    static int RANGE = 512;

    static byte[] data1 = new byte[RANGE];
    static byte[] data2 = new byte[RANGE];

    public static void main(String[] args) {
        TestFramework.run();
    }

    @Test
    @Warmup(0)
    @IR(counts = {IRNode.MAX_L, "> 0", IRNode.MAX_L, "<= 2"},
        phase = CompilePhase.PHASEIDEALLOOP_ITERATIONS)
    public static void test1() {
        for (int j = START; j < FINISH; j++) {
            data1[j] = (byte)(data1[j] * 11);
        }
    }

    @Test
    @Warmup(0)
    @IR(counts = {IRNode.MIN_L, "> 0", IRNode.MIN_L, "<= 2"},
        phase = CompilePhase.PHASEIDEALLOOP_ITERATIONS)
    public static void test2() {
        for (int j = FINISH-1; j >= START; j--) {
            data2[j] = (byte)(data2[j] * 11);
        }
    }
}