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/*
 * @test
 * @bug 8296389
 * @summary Peeling of Irreducible loop can lead to NeverBranch being visited from either side
 * @run main/othervm -Xcomp -XX:-TieredCompilation -XX:PerMethodTrapLimit=0
 *      -XX:CompileCommand=compileonly,TestPhaseCFGNeverBranchToGotoMain::test
 *      TestPhaseCFGNeverBranchToGotoMain
 */

/*
 * @test
 * @bug 8296389
 * @compile TestPhaseCFGNeverBranchToGoto.jasm
 * @summary Peeling of Irreducible loop can lead to NeverBranch being visited from either side
 * @run main/othervm -Xcomp -XX:-TieredCompilation -XX:PerMethodTrapLimit=0
 *      -XX:CompileCommand=compileonly,TestPhaseCFGNeverBranchToGoto::test
 *      TestPhaseCFGNeverBranchToGoto
 */


public class TestPhaseCFGNeverBranchToGotoMain {
    public static void main (String[] args) {
        test(false, false);
    }

    public static void test(boolean flag1, boolean flag2) {
        if (flag1) { // runtime check, avoid infinite loop
            int a = 77;
            int b = 0;
            do { // empty loop
                a--;
                b++;
            } while (a > 0);
            // a == 0, b == 77 - after first loop-opts phase
            int p = 0;
            for (int i = 0; i < 4; i++) {
                if ((i % 2) == 0) {
                    p = 1;
                }
            }
            // p == 1 - after second loop-opts phase (via unrolling)
            // in first loop-opts phase we have 2x unrolling, 4x after second
            int x = 1;
            if (flag2) {
                x = 3;
            } // have region here, so that NeverBranch does not get removed
            do { // infinite loop
                do {
                    // NeverBranch inserted here, during loop-opts 1
                    x *= 2;
                    if (p == 0) { // reason for peeling in loop-opts 1
                        // after we know that p == 1, we lose this exit
                        break;
                    }
                    // once we know that b == 77, we lose exit
            } while (b == 77);
            // after we lost both exits above, this loop gets cut off
            int y = 5;
                do {
                    y *= 3;
                } while (b == 77);
            } while (true);
        }
    }
}