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 *

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/*

 * @test

 * @bug 8054307

 * @summary Validates StringCoding.hasNegatives intrinsic with a small range of tests.

 * @library /compiler/patches

 *

 * @build java.base/java.lang.Helper

 * @run main compiler.intrinsics.string.TestHasNegatives

 */

package compiler.intrinsics.string;

/*

 * @summary Validates StringCoding.hasNegatives intrinsic with a small

 *          range of tests.

 */

public class TestHasNegatives {

    private static byte[] tBa = new byte[4096 + 16];

    /**

     * Completely initialize the test array, preparing it for tests of the

     * StringCoding.hasNegatives method with a given array segment offset,

     * length, and number of negative bytes.

     */

    public static void initialize(int off, int len, int neg) {

        assert (len + off <= tBa.length);

        // insert "canary" (negative) values before offset

        for (int i = 0; i < off; ++i) {

            tBa[i] = (byte) (((i + 15) & 0x7F) | 0x80);

        }

        // fill the array segment

        for (int i = off; i < len + off; ++i) {

            tBa[i] = (byte) (((i - off + 15) & 0x7F));

        }

        if (neg != 0) {

            // modify a number (neg) disparate array bytes inside

            // segment to be negative.

            int div = (neg > 1) ? (len - 1) / (neg - 1) : 0;

            int idx;

            for (int i = 0; i < neg; ++i) {

                idx = off + (len - 1) - div * i;

                tBa[idx] = (byte) (0x80 | tBa[idx]);

            }

        }

        // insert "canary" negative values after array segment

        for (int i = len + off; i < tBa.length; ++i) {

            tBa[i] = (byte) (((i + 15) & 0x7F) | 0x80);

        }

    }

    /** Sizes of array segments to test. */

    private static int sizes[] = { 1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 13, 17, 19, 23, 37, 61, 131,

            4099 };

    /**

     * Test different array segment sizes, offsets, and number of negative

     * bytes.

     */

    public static void test_hasNegatives() throws Exception {

        int len, off;

        int ng;

        boolean r;

        for (ng = 0; ng < 57; ++ng) { // number of negatives in array segment

            for (off = 0; off < 8; ++off) { // starting offset of array segment

                for (int i = 0; i < sizes.length; ++i) { // array segment size

                                                         // choice

                    len = sizes[i];

                    if (len + off > tBa.length)

                        continue;

                    initialize(off, len, ng);

                    r = Helper.StringCodingHasNegatives(tBa, off, len);

                    if (r ^ ((ng == 0) ? false : true)) {

                        throw new Exception("Failed test hasNegatives " + "offset: " + off + " "

                                + "length: " + len + " " + "return: " + r + " " + "negatives: "

                                + ng);

                    }

                }

            }

        }

    }

    public void run() throws Exception {

        // iterate to eventually get intrinsic inlined

        for (int j = 0; j < 1000; ++j) {

            test_hasNegatives();

        }

    }

    public static void main(String[] args) throws Exception {

        (new TestHasNegatives()).run();

        System.out.println("hasNegatives validated");

    }

}