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/*
 * @test
 * @bug 8343944
 * @summary Test that _widen is set correctly in MinL::add_ring() to prevent an endless widening in CCP.
 * @run main/othervm -Xcomp -XX:CompileCommand=compileonly,compiler.ccp.TestWrongMinLWiden::*
 *                   compiler.ccp.TestWrongMinLWiden
 */

package compiler.ccp;

public class TestWrongMinLWiden {
    static long lFld;
    static short sFld;

    public static void main(String[] strArr) {
        Math.min(3,3); // Make sure Math class is loaded.
        test();
        testWithMathMin();
    }


    static long test() {
        long x = 50398;
        for (int i = 1; i < 100; i++) {
            long xMinus1 = x - 1; // x is a phi with type #long
            // Long comparison:
            //     ConvI2L(sFld) <= xMinus1
            // First converted to
            //     CMoveL(sFld <= xMinus1, sFld, xMinus1)
            //     CMoveL(ConvI2L(sFld) <= long_phi, ConvI2L(sFld), long_phi)
            // with types
            //     CMoveL(#short <= #long, #short, #long)
            // And then converted in CMoveNode::Ideal() to
            //     MinL(sFld, xMinus1)
            //     MinL(ConvI2L(sFld), long_phi)
            //
            // We wrongly set the _widen of the new type for MinL in MinL::add_ring() to the minimum of both types which
            // is always 0 because the _widen of sFld is 0. As a result, we will endlessly widen the involved types
            // because the new type for MinL keeps resetting _widen to 0.
            // Instead, we should choose the maximum of both _widen fields for the new type for MinL which will then
            // select the _widen of xMinus1 which will grow each time we set a new type for the long_phi. Eventually,
            // we will saturate the type of long_phi to min_long to avoid an endless widening.
            x = sFld <= xMinus1 ? sFld : xMinus1;
        }
        return x;
    }

    // Same as test() but with Math.min() which internally uses x <= y ? x : y which allows the CMoveL pattern to be
    // replaced with MinL.
    static long testWithMathMin() {
        long x = 50398;
        for (int i = 1; i < 100; i++) {
            x = Math.min(sFld, x - 1);
        }
        return x;
    }
}