test/hotspot/jtreg/compiler/floatingpoint/TestRound.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * 2 along with this work; if not, write to the Free Software Foundation,
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/**
 * @test
 * @bug 4755500
 * @summary calling Math.round(NaN) can break subsequent calls to Math.round()
 * @run main compiler.floatingpoint.TestRound
 */

package compiler.floatingpoint;

public class TestRound {
    public static void main(String[] args) {
        // Note: it's really only necessary to run this loop 8 times to
        // reproduce the bug, but the 10000-length loop causes compilation
        // of Math.round() without any other command-line flags.
        // A bug in the d2l NaN case was causing overflow of the FPU
        // stack, yielding subsequent wrong results for flds.
        for (int i = 0; i < 10_000; i++) {
            Math.round(Double.NaN);
        }
        if (Math.round(1d) != 1) {
            throw new AssertionError("TEST FAILED");
        }
        System.out.println("Test passed.");
    }
}