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

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/*
 * @test
 * @bug 8298176
 * @summary Must remove OpaqueZeroTripGuardPostLoop after main loop disappears else
 *          the zero-trip-guard of the post loop cannot die and leaves an inconsistent
 *          graph behind.
 * @run main/othervm -Xcomp -XX:-TieredCompilation
 *      -XX:CompileCommand=compileonly,TestOpaqueZeroTripGuardPostLoopRemoval::test*
 *      -XX:CompileCommand=dontinline,TestOpaqueZeroTripGuardPostLoopRemoval::*
 *      TestOpaqueZeroTripGuardPostLoopRemoval
 */

public class TestOpaqueZeroTripGuardPostLoopRemoval {
    static long x;

    public static void main(String[] strArr) {
        test_001();
        test_002();
        try {
            test_003();
        } catch (Exception e) {
            // Expected
        }
        test_004();
        test_005();
    }

    static void test_001() {
        int b = 6;
        for (long l = 1; l < 9; l++) {
            b++;
        }
        for (int i = 1; i < 1000; i*=2) {
            for (int j = 1; j < 2; j++) {
                x = b + 1;
            }
        }
    }

    static void test_002() {
        int b = 6;
        for (long l = 60; l < 3000; l+=3) {
            // bounds of loop: no work for post loop
            b += 33; // any multiple of iv step
        }
        for (int i = 1; i < 1000; i*=2) {
            for (int j = 1; j < 2; j++) {
                x = b + 1;
            }
        }
    }

    static void dontInline() {
        throw new RuntimeException();
    }

    static int test_003() {
        int y = 3;
        for (int i = 0; i < 9; ) {
            for (long l = 1; l < 5; l++) {
                y *= 2;
            }
            while (true) {
                dontInline();
            }
        }
        return y;
    }

    static void test_004() {
        for (int i2 = 4; i2 < 13; i2++) {
            double d = 56;
            for (long l = 1; l < 5; l++) {
                d = d + 3;
            }
            for (int i = 0; i < 10; i++) {
                for (int d2 = i2; d2 < 2; d2 = 3) {
                }
            }
        }
    }

    public static int test_005() {
        long arr[]=new long[400];
        for (int i = 3; i < 177; i++) {
            for (int j = 0; j < 10; j++){}
        }
        int y = 0;
        for (int i = 15; i < 356; i++) {
            // Inner loop prevents strip-mining of outer loop
            // later, inner loop is removed, so outer does pre-main-post without strip-mining
            for (int j = 0; j < 10; j++){
                y |= 1;
            }
        }
        return y;
    }
}