box and val (c2 crash)
forax at univ-mlv.fr
forax at univ-mlv.fr
Mon Jan 7 13:16:47 UTC 2019
Hi Tobias,
it solves the second issue i've reported but not the first one,
(the issue in TypePtr::xmeet_helper(Type const*)),
so it still crashes.
with 12-valhalla+0-09d9f9085910:
Current CompileTask:
C2: 325 120 fr.umlv.valuetype.perf.TupleLoopBenchMark::sum (46 bytes)
Stack: [0x00007f53541cd000,0x00007f53542ce000], sp=0x00007f53542ca700, free space=1013k
Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0xe1a0a6] VMError::report_and_die(int, char const*, char const*, __va_list_tag*, Thread*, unsigned char*, void*, void*, char const*, int, unsigned long)+0x186
V [libjvm.so+0xe1ae57] VMError::report_and_die(Thread*, void*, char const*, int, char const*, char const*, __va_list_tag*)+0x47
V [libjvm.so+0x67a7fe] report_vm_error(char const*, int, char const*, char const*, ...) [clone .constprop.51]+0xee
V [libjvm.so+0xdbc50e] TypePtr::xmeet_helper(Type const*) const+0x5e
V [libjvm.so+0xdb8250] TypePtr::xmeet(Type const*) const+0x10
V [libjvm.so+0x556611] PhiNode::Value(PhaseGVN*) const+0x131
V [libjvm.so+0xc38af6] PhaseGVN::transform_no_reclaim(Node*)+0x86
V [libjvm.so+0xc00d9d] Parse::do_exits()+0x4bd
V [libjvm.so+0xc05d86] Parse::Parse(JVMState*, ciMethod*, float)+0xab6
V [libjvm.so+0x53db98] ParseGenerator::generate(JVMState*)+0x88
V [libjvm.so+0x70f9ed] Parse::do_call()+0x2dd
V [libjvm.so+0xc15b08] Parse::do_one_bytecode()+0x32e8
V [libjvm.so+0xc031e7] Parse::do_one_block()+0x197
V [libjvm.so+0xc03652] Parse::do_all_blocks()+0x102
V [libjvm.so+0xc05d40] Parse::Parse(JVMState*, ciMethod*, float)+0xa70
V [libjvm.so+0x53db98] ParseGenerator::generate(JVMState*)+0x88
V [libjvm.so+0x61bc28] Compile::Compile(ciEnv*, C2Compiler*, ciMethod*, int, bool, bool, bool, DirectiveSet*)+0xe98
V [libjvm.so+0x53d096] C2Compiler::compile_method(ciEnv*, ciMethod*, int, DirectiveSet*)+0xe6
V [libjvm.so+0x6242f2] CompileBroker::invoke_compiler_on_method(CompileTask*)+0x3a2
V [libjvm.so+0x625738] CompileBroker::compiler_thread_loop()+0x608
V [libjvm.so+0xda4468] JavaThread::thread_main_inner()+0xf8
V [libjvm.so+0xda1131] Thread::call_run()+0x171
V [libjvm.so+0xbd5708] thread_native_entry(Thread*)+0xf8
cheers,
Rémi
----- Mail original -----
> De: "Tobias Hartmann" <tobias.hartmann at oracle.com>
> À: "Remi Forax" <forax at univ-mlv.fr>, "valhalla-dev" <valhalla-dev at openjdk.java.net>
> Envoyé: Lundi 7 Janvier 2019 10:55:51
> Objet: Re: box and val (c2 crash)
> Hi Remi,
>
> I fixed the issue with JDK-8216260:
> http://hg.openjdk.java.net/valhalla/valhalla/rev/09d9f9085910
>
> The problem was that we tried to scalarize a boxed value type return which
> obviously fails if null
> is returned. Could you please verify that the fix solves the crashes you were
> seeing?
>
> Thanks,
> Tobias
>
> On 04.01.19 15:25, Tobias Hartmann wrote:
>> Hi Remi,
>>
>> thanks a lot for reporting these issues. I'll have a look!
>>
>> Best regards,
>> Tobias
>>
>>
>> On 04.01.19 15:14, Remi Forax wrote:
>>> I believe the crash comes from the method "next()" (or indexedElements() because
>>> it the same kind of code),
>>>
>>> Cursor.box next() {
>>> if (index + 1 == array.length) {
>>> return null;
>>> }
>>> return new Cursor(array, index + 1);
>>> }
>>>
>>> There is a merge of either null or a Cursor (which is a value type) into a
>>> register typed Cursor.box.
>>>
>>> Trying to insert a local variable in between result in a crash in a different
>>> methods
>>> Cursor.box next() {
>>> Cursor.box box;
>>> if (index + 1 == array.length) {
>>> box = null;
>>> } else {
>>> box = new Cursor(array, index + 1);
>>> }
>>> return box;
>>> }
>>>
>>> Current CompileTask:
>>> C2: 308 117
>>> fr.umlv.valuetype.perf.TupleLoopBenchMark$Cursor::next (38 bytes)
>>>
>>> Stack: [0x00007fb3b253c000,0x00007fb3b263d000], sp=0x00007fb3b2639d00, free
>>> space=1015k
>>> Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted,
>>> Vv=VM code, C=native code)
>>> V [libjvm.so+0xde246f] ValueTypeNode::make_from_oop(GraphKit*, Node*,
>>> ciValueKlass*)+0x9f
>>> V [libjvm.so+0xc06567] Parse::return_current(Node*)+0x8d7
>>> V [libjvm.so+0xc14dc4] Parse::do_one_bytecode()+0x2714
>>> V [libjvm.so+0xc03077] Parse::do_one_block()+0x197
>>> V [libjvm.so+0xc034e2] Parse::do_all_blocks()+0x102
>>> V [libjvm.so+0xc05bd0] Parse::Parse(JVMState*, ciMethod*, float)+0xa70
>>> V [libjvm.so+0x53da48] ParseGenerator::generate(JVMState*)+0x88
>>> V [libjvm.so+0x61bab8] Compile::Compile(ciEnv*, C2Compiler*, ciMethod*, int,
>>> bool, bool, bool, DirectiveSet*)+0xe98
>>> V [libjvm.so+0x53cf46] C2Compiler::compile_method(ciEnv*, ciMethod*, int,
>>> DirectiveSet*)+0xe6
>>> V [libjvm.so+0x624182]
>>> CompileBroker::invoke_compiler_on_method(CompileTask*)+0x3a2
>>> V [libjvm.so+0x6255c8] CompileBroker::compiler_thread_loop()+0x608
>>> V [libjvm.so+0xda42f8] JavaThread::thread_main_inner()+0xf8
>>> V [libjvm.so+0xda0fc1] Thread::call_run()+0x171
>>> V [libjvm.so+0xbd5598] thread_native_entry(Thread*)+0xf8
>>>
>>> Rémi
>>>
>>> ----- Mail original -----
>>>> De: "Remi Forax" <forax at univ-mlv.fr>
>>>> À: "valhalla-dev" <valhalla-dev at openjdk.java.net>
>>>> Envoyé: Jeudi 3 Janvier 2019 16:14:22
>>>> Objet: box and val (c2 crash)
>>>
>>>> Now, i've tried to play with the .box/.val trying to implement the clojure
>>>> Cursor protocol,
>>>> which iterate like it's an abstract linked list, so at each step either you
>>>> return a new Cursor (a value type) or null at the end (which seems to be a good
>>>> test for a nullable value type).
>>>>
>>>> The following code compiles !
>>>> I had to had the fix method because the compier refuse to find any methods on
>>>> Cursor.box and
>>>> Cursor.box boxed = ...
>>>> ((Cursor)boxed).next
>>>> doesn't compile too.
>>>>
>>>> If you try to execute the code, it crashes the VM (in the C2 compiler thread it
>>>> seems)
>>>>
>>>> Current CompileTask:
>>>> C2: 338 119 fr.umlv.valuetype.perf.TupleLoopBenchMark::sum (46
>>>> bytes)
>>>>
>>>> Stack: [0x00007ff4c0a37000,0x00007ff4c0b38000], sp=0x00007ff4c0b34700, free
>>>> space=1013k
>>>> Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted,
>>>> Vv=VM code, C=native code)
>>>> V [libjvm.so+0xe19ed6] VMError::report_and_die(int, char const*, char const*,
>>>> __va_list_tag*, Thread*, unsigned char*, void*, void*, char const*, int,
>>>> unsigned long)+0x186
>>>> V [libjvm.so+0xe1ac87] VMError::report_and_die(Thread*, void*, char const*,
>>>> int, char const*, char const*, __va_list_tag*)+0x47
>>>> V [libjvm.so+0x67a68e] report_vm_error(char const*, int, char const*, char
>>>> const*, ...) [clone .constprop.51]+0xee
>>>> V [libjvm.so+0xdbc39e] TypePtr::xmeet_helper(Type const*) const+0x5e
>>>> V [libjvm.so+0xdb80e0] TypePtr::xmeet(Type const*) const+0x10
>>>> V [libjvm.so+0x5564c1] PhiNode::Value(PhaseGVN*) const+0x131
>>>> V [libjvm.so+0xc38986] PhaseGVN::transform_no_reclaim(Node*)+0x86
>>>> V [libjvm.so+0xc00c2d] Parse::do_exits()+0x4bd
>>>> V [libjvm.so+0xc05c16] Parse::Parse(JVMState*, ciMethod*, float)+0xab6
>>>> V [libjvm.so+0x53da48] ParseGenerator::generate(JVMState*)+0x88
>>>> V [libjvm.so+0x70f87d] Parse::do_call()+0x2dd
>>>> V [libjvm.so+0xc15998] Parse::do_one_bytecode()+0x32e8
>>>> V [libjvm.so+0xc03077] Parse::do_one_block()+0x197
>>>> V [libjvm.so+0xc034e2] Parse::do_all_blocks()+0x102
>>>> V [libjvm.so+0xc05bd0] Parse::Parse(JVMState*, ciMethod*, float)+0xa70
>>>> V [libjvm.so+0x53da48] ParseGenerator::generate(JVMState*)+0x88
>>>> V [libjvm.so+0x61bab8] Compile::Compile(ciEnv*, C2Compiler*, ciMethod*, int,
>>>> bool, bool, bool, DirectiveSet*)+0xe98
>>>> V [libjvm.so+0x53cf46] C2Compiler::compile_method(ciEnv*, ciMethod*, int,
>>>> DirectiveSet*)+0xe6
>>>> V [libjvm.so+0x624182]
>>>> CompileBroker::invoke_compiler_on_method(CompileTask*)+0x3a2
>>>> V [libjvm.so+0x6255c8] CompileBroker::compiler_thread_loop()+0x608
>>>> V [libjvm.so+0xda42f8] JavaThread::thread_main_inner()+0xf8
>>>> V [libjvm.so+0xda0fc1] Thread::call_run()+0x171
>>>> V [libjvm.so+0xbd5598] thread_native_entry(Thread*)+0xf8
>>>>
>>>>
>>>> Rémi
>>>>
>>>> ---
>>>> static value class Tuple {
>>>> private final int index;
>>>> private final int element;
>>>>
>>>>
>>>> private Tuple(int index, int element) {
>>>> this.index = index;
>>>> this.element = element;
>>>> }
>>>> }
>>>>
>>>> static value class Cursor {
>>>> private final int[] array;
>>>> private final int index;
>>>>
>>>> private Cursor(int[] array, int index) {
>>>> this.array = array;
>>>> this.index = index;
>>>> }
>>>>
>>>> Tuple current() {
>>>> return new Tuple(index, array[index]);
>>>> }
>>>>
>>>> Cursor.box next() {
>>>> if (index + 1 == array.length) {
>>>> return null;
>>>> }
>>>> return new Cursor(array, index + 1);
>>>> }
>>>> }
>>>>
>>>> private static Cursor.box indexedElements(int[] array) {
>>>> if (array.length == 0) {
>>>> return null;
>>>> }
>>>> return new Cursor(array, 0);
>>>> }
>>>>
>>>> private static Cursor fix(Cursor.box cursor) {
>>>> return cursor;
>>>> }
>>>>
>>>> @Benchmark
>>>> public int sum() {
>>>> int sum = 0;
>>>> for(Cursor.box cursor = indexedElements(ARRAY); cursor != null; cursor =
>>>> fix(cursor).next()) {
>>>> Tuple tuple = fix(cursor).current();
>>>> sum += tuple.index + tuple.element;
>>>> }
>>>> return sum;
> >>> }
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