RFR: 8261137: Optimization of Box nodes in uncommon_trap [v6]

[Wang Huang]

On Thu, 4 Mar 2021 01:30:02 GMT, Wang Huang <whuang at openjdk.org> wrote:

> Got failure during testing `applications/ctw/modules/java_desktop.java` on linux-aarch64.
> With additional flags `-ea -esa -XX:CompileThreshold=100 -XX:+UnlockExperimentalVMOptions -server -XX:-TieredCompilation -Djava.awt.headless=true`
> 
> ```
> #  Internal Error (/workspace/open/src/hotspot/share/opto/loopTransform.cpp:3711), pid=305808, tid=305821
> #  assert(use == polladr) failed: the use should be a safepoint polling
> #
> 
> Current CompileTask:
> C2:  66678 5846   !b        com.sun.media.sound.RealTimeSequencer$DataPump::makeDisabledArray (183 bytes)
> 
> Stack: [0x0000ffff53c00000,0x0000ffff53e00000],  sp=0x0000ffff53df9c50,  free space=2023k
> Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
> V  [libjvm.so+0x11d7090]  PhaseIdealLoop::match_fill_loop(IdealLoopTree*, Node*&, Node*&, Node*&, Node*&)+0xbe0
> V  [libjvm.so+0x11d7388]  PhaseIdealLoop::intrinsify_fill(IdealLoopTree*) [clone .part.0]+0xa4
> V  [libjvm.so+0x11d81e8]  PhaseIdealLoop::do_intrinsify_fill()+0x218
> V  [libjvm.so+0x120afb8]  PhaseIdealLoop::build_and_optimize(LoopOptsMode)+0xec8
> V  [libjvm.so+0x98027c]  PhaseIdealLoop::optimize(PhaseIterGVN&, LoopOptsMode)+0x28c
> V  [libjvm.so+0x97d9bc]  Compile::Optimize()+0xf3c
> V  [libjvm.so+0x97ed20]  Compile::Compile(ciEnv*, ciMethod*, int, bool, bool, bool, bool, DirectiveSet*)+0xf50
> ```

Does this error reproduct every time? I tested this case in my aarch64 machine for many times （> 300） and failed to encounter this error. 

Can you give me some more info about this error? For example, crash log ? 

PS: 
I used `make run-test CONF=slowdebug JTREG="JAVA_OPTIONS=-ea -esa -XX:CompileThreshold=100 -XX:+UnlockExperimentalVMOptions -server -XX:-TieredCompilation -Djava.awt.headless=true" TEST="applications/ctw/modules/java_desktop.java"` to run this case.

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PR: https://git.openjdk.java.net/jdk/pull/2401