test/hotspot/jtreg/compiler/loopopts/TestInfiniteLoopWithUnmergedBackedges.jasm

/*
 * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

super public class TestInfiniteLoopWithUnmergedBackedges
{
    public Method "<init>":"()V"
    stack 2 locals 1
    {
        aload_0;
        invokespecial  Method java/lang/Object."<init>":"()V";
        return;
    }
    static Method test_001:"(IIIII)V"
    stack 5 locals 10
    {
        iload_0;
        ifgt LOOP;
        // below is dominated by the one above
        iload_0;
        ifle BACK;
        goto HEAD;
    HEAD:
        iload_3;
        ifeq BACK;
    BACK:
        goto HEAD;
    LOOP:
        iload_1;
        iflt LOOP;
        iload_2;
        iflt LOOP;
        return;
    }
    static Method test_002:"(IIIII)V"
    stack 5 locals 30
    {
        iload_0;
        ifgt LOOP;

        iconst_0;
        istore 9;

        goto HEAD;
    TAIL:
        iload_3;
        iload 9;
        if_icmpeq HEAD;
        iinc 9, 1;
    HEAD:
        goto TAIL;
    LOOP:
        iload_1;
        iflt LOOP;
        iload_2;
        iflt LOOP;
        return;
    }
    static Method test_003:"(IIIII)I"
    stack 5 locals 30
    {
        iload_0;
        ifgt SKIP;

        iconst_0;
        istore 9;

        goto HEAD;
    TAIL:
        iload_3;
        iload 9;
        if_icmpeq HEAD;
        iinc 9, 1;
        // Two paths lead to HEAD, so we have an inner and outer loop
        // But no SafePoint is placed here, because we go forward in bci
    HEAD:
        // SafePoint is placed here, because we go from here back in bci
        goto TAIL;

    SKIP:
        iconst_0;
        istore 8;
        iconst_0;
        istore 9;
        // loop with two backedges, which calls
        // merge_many_backedges and then recomputes
        // build_loop_tree
    LOOP:
        iinc 9, 1;
        iinc 8, -1;
        iload 9;
        ldc 7;
        irem;
        ifeq LOOP;
        iload 9;
        ldc 10001;
        if_icmple LOOP;
        iload 8;
        ireturn;
    }
    static Method test_004:"(IIIII)I"
    stack 5 locals 30
    {
        iload_0;
        ifgt SKIP;

        iconst_0;
        istore 9;

        goto HEAD;
    TAIL:
        iload_3;
        iload 9;
        if_icmpeq HEAD;
        iinc 9, 1;
        iload 9;
        ldc 10001;
        if_icmpeq HEAD; // a second one
        iinc 9, 1;
    HEAD:
        goto TAIL;

    SKIP:
        iconst_0;
        istore 8;
        iconst_0;
        istore 9;
    LOOP:
        iinc 9, 1;
        iinc 8, -1;
        iload 9;
        ldc 7;
        irem;
        ifeq LOOP;
        iload 9;
        ldc 10001;
        if_icmple LOOP;
        iload 8;
        ireturn;
    }
    static Method test_005:"(IIIII)I"
    stack 5 locals 30
    {
        iload_0;
        ifgt SKIP;

        iconst_0;
        istore 9;

        goto HEAD;
    TAIL:
        iload_3;
        iload 9;
        if_icmpeq HEAD;
        iinc 9, 1;
        iload 9;
        ldc 10001;
        if_icmpeq HEAD; // a second one
        iinc 9, 1;
    HEAD:
        goto TAIL;

    SKIP:
        iconst_0;
        istore 8;
        iconst_0;
        istore 9;
    LOOP:
        iinc 9, 1;
        iinc 8, -1;
        iload 9;
        ldc 7;
        irem;
        ifeq LOOP;
        iload 9;
        ldc 10001;
        if_icmple LOOP;
        iload 8;
        ireturn;
    }
}