The attached fuzzer test starts to fail after JDK-8256655 with the following assertion:
To reproduce:
java -Xcomp -XX:CompileOnly=Test Test.java
java -Xcomp -XX:CompileOnly=Reduced Reduced.java
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/opt/mach5/mesos/work_dir/slaves/983c483a-6907-44e0-ad29-98c7183575e2-S14911/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/d51c104c-7fa8-4fef-9dfd-5ff4ef404833/runs/00bb43bd-2184-4fd6-8bd8-12a85acffb92/workspace/open/src/hotspot/share/opto/loopnode.cpp:1748), pid=5239, tid=5252
# assert(inner->is_valid_counted_loop(T_INT) && inner->is_strip_mined()) failed: OuterStripMinedLoop should have been removed
#
# JRE version: Java(TM) SE Runtime Environment (16.0+35) (fastdebug build 16+35-2229)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 16+35-2229, compiled mode, sharing, tiered, compressed oops, g1 gc, linux-amd64)
# Problematic frame:
# V [libjvm.so+0x131c17b] LoopNode::verify_strip_mined(int) const+0xcb
............
Command Line: -Xmx1G -Xcomp -Xbatch -XX:CompileOnly=Test -XX:CompileCommand=quiet Test
............
Current thread (0x00007f465c4948b0): JavaThread "C2 CompilerThread0" daemon [_thread_in_native, id=5252, stack(0x00007f46403e9000,0x00007f46404ea000)]
Current CompileTask:
C2: 908 65 b 4 Test::mainTest (499 bytes)
Stack: [0x00007f46403e9000,0x00007f46404ea000], sp=0x00007f46404e3cd0, free space=1003k
Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0x131c17b] LoopNode::verify_strip_mined(int) const+0xcb
V [libjvm.so+0x12f686d] PathFrequency::to(Node*)+0x125d
V [libjvm.so+0x12f1804] PhaseIdealLoop::loop_predication_follow_branches(Node*, IdealLoopTree*, float, PathFrequency&, Node_Stack&, VectorSet&, Node_List&)+0x514
V [libjvm.so+0x12f2bda] PhaseIdealLoop::loop_predication_impl(IdealLoopTree*) [clone .part.0]+0x118a
V [libjvm.so+0x12f3169] IdealLoopTree::loop_predication(PhaseIdealLoop*)+0x109
V [libjvm.so+0x12f30a5] IdealLoopTree::loop_predication(PhaseIdealLoop*)+0x45
V [libjvm.so+0x12f30a5] IdealLoopTree::loop_predication(PhaseIdealLoop*)+0x45
V [libjvm.so+0x12f30a5] IdealLoopTree::loop_predication(PhaseIdealLoop*)+0x45
V [libjvm.so+0x133bb59] PhaseIdealLoop::build_and_optimize(LoopOptsMode)+0x1229
V [libjvm.so+0xa1ab1b] PhaseIdealLoop::optimize(PhaseIterGVN&, LoopOptsMode)+0x32b
V [libjvm.so+0xa17d23] Compile::Optimize()+0x14c3
V [libjvm.so+0xa19a98] Compile::Compile(ciEnv*, ciMethod*, int, bool, bool, bool, bool, DirectiveSet*)+0x1838
V [libjvm.so+0x849c2c] C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x1dc
V [libjvm.so+0xa298e8] CompileBroker::invoke_compiler_on_method(CompileTask*)+0xe88
V [libjvm.so+0xa2a538] CompileBroker::compiler_thread_loop()+0x5a8
V [libjvm.so+0x18bb2c6] JavaThread::thread_main_inner()+0x256
V [libjvm.so+0x18c1c40] Thread::call_run()+0x100
V [libjvm.so+0x15a3966] thread_native_entry(Thread*)+0x116