8301630: C2: 8297933 broke type speculation in some cases #12368

rwestrel · 2023-02-01T16:55:01Z

With 8297933, a TypeAryPtr is a lot more likely to have a null _klass
and that breaks TypePtr::speculative_type().

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JDK-8301630: C2: 8297933 broke type speculation in some cases

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Christian Hagedorn (@chhagedorn - Reviewer)
Tobias Hartmann (@TobiHartmann - Reviewer)

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bridgekeeper · 2023-02-01T16:55:50Z

👋 Welcome back roland! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

openjdk · 2023-02-01T16:57:52Z

@rwestrel The following label will be automatically applied to this pull request:

hotspot-compiler

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mlbridge · 2023-02-02T08:35:19Z

Webrevs

01: Full - Incremental (34c17a1d)
00: Full (266692b9)

chhagedorn

Looks good!

openjdk · 2023-02-02T08:50:40Z

@rwestrel This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8301630: C2: 8297933 broke type speculation in some cases

Reviewed-by: chagedorn, thartmann

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 345 new commits pushed to the master branch:

1bab93b: 8303073: (bf) Temporarily reinstate private DirectByteBuffer(long, int) constructor
221f346: 8303047: avoid NULL after 8301661
23e9d9d: 8302811: NMT.random_reallocs_vm fails if NMT is off
fcaf871: 8302028: Port fdlibm atan2 to Java
07e976a: 8303081: Serial: Remove unused VM_MarkSweep
8de841d: 8302667: Improve message format when failing to load symbols or libraries
f893d23: 8303024: (fs) WindowsFileSystem.supportedFileAttributeViews can use Set.of
d7ada66: 8303084: G1 Heap region liveness verification has inverted return value
5d7e7e2: 8302760: Improve liveness/remembered set verification for G1
b0e0f37: 8303067: G1: Remove unimplemented G1FullGCScope::heap_transition
... and 335 more: https://git.openjdk.org/jdk/compare/cae577a7102e97278f3f6880e529a68c1f7b71ab...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

TobiHartmann · 2023-02-02T14:07:40Z

compiler/intrinsics/unsafe/AllocateUninitializedArray.java fails with -XX:TypeProfileLevel=222

# A fatal error has been detected by the Java Runtime Environment:
#
#  Internal Error (/workspace/open/src/hotspot/share/opto/type.hpp:1202), pid=57805, tid=23299
#  Error: assert(k != __null || maybe_null) failed


Current CompileTask:
C2:   7286  312       4       compiler.intrinsics.unsafe.AllocateUninitializedArray$$Lambda$38/0x0000000801006c70::call (4 bytes)

Stack: [0x0000700009549000,0x0000700009649000],  sp=0x00007000096466b0,  free space=1013k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [libjvm.dylib+0x1284c09]  VMError::report_and_die(int, char const*, char const*, __va_list_tag*, Thread*, unsigned char*, void*, void*, char const*, int, unsigned long)+0x739  (type.hpp:1202)
V  [libjvm.dylib+0x128526b]  VMError::report_and_die(Thread*, void*, char const*, int, char const*, char const*, __va_list_tag*)+0x3b
V  [libjvm.dylib+0x6cfcfd]  report_vm_error(char const*, int, char const*, char const*, ...)+0xdd
V  [libjvm.dylib+0x11ee54a]  TypePtr::speculative_type() const+0x14a
V  [libjvm.dylib+0x11f2d70]  TypeOopPtr::would_improve_type(ciKlass*, int) const+0x40
V  [libjvm.dylib+0x932263]  GraphKit::record_profile_for_speculation(Node*, ciKlass*, ProfilePtrKind)+0xb3
V  [libjvm.dylib+0x932d6d]  GraphKit::record_profiled_return_for_speculation()+0xed
V  [libjvm.dylib+0x78aca3]  Parse::do_call()+0x1303
V  [libjvm.dylib+0xf95d22]  Parse::do_one_bytecode()+0x232
V  [libjvm.dylib+0xf8642c]  Parse::do_one_block()+0x43c
V  [libjvm.dylib+0xf844c9]  Parse::do_all_blocks()+0x3a9
V  [libjvm.dylib+0xf8047b]  Parse::Parse(JVMState*, ciMethod*, float)+0xc1b
V  [libjvm.dylib+0x51b3fa]  ParseGenerator::generate(JVMState*)+0xaa
V  [libjvm.dylib+0x636556]  Compile::Compile(ciEnv*, ciMethod*, int, Options, DirectiveSet*)+0x15b6
V  [libjvm.dylib+0x5190e7]  C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x167
V  [libjvm.dylib+0x654fab]  CompileBroker::invoke_compiler_on_method(CompileTask*)+0x63b
V  [libjvm.dylib+0x654768]  CompileBroker::compiler_thread_loop()+0x288
V  [libjvm.dylib+0xa1673f]  JavaThread::thread_main_inner()+0x1ff
V  [libjvm.dylib+0x11cd647]  Thread::call_run()+0x177
V  [libjvm.dylib+0xf4e4bf]  thread_native_entry(Thread*)+0x14f
C  [libsystem_pthread.dylib+0x6109]  _pthread_start+0x94
C  [libsystem_pthread.dylib+0x1b8b]  thread_start+0xf

rwestrel · 2023-02-06T14:02:03Z

compiler/intrinsics/unsafe/AllocateUninitializedArray.java fails with -XX:TypeProfileLevel=222

The reason for that failure is that speculation sees an array type that is exact but of element type top which makes little sense. I added a test case. That happens when an array of some integer type is casted to some other integer type (int[] and short[] in the test case). The result should not be an exact array. I propose fixing TypePtr::meet_aryptr() to address that issue: I tweaked the "Integral array element types" so it follows the "Non integral arrays."

TobiHartmann

Looks good to me. I'll re-run testing and report back.

TobiHartmann · 2023-02-10T12:10:39Z

All tests passed.

rwestrel · 2023-02-20T13:47:20Z

@TobiHartmann thanks for the review and tests. @chhagedorn 's review was on the previous version of this fix so I'd like another review. Anyone?

chhagedorn

The update looks good to me, too!

rwestrel · 2023-03-01T09:33:47Z

@chhagedorn thanks for the review.

rwestrel · 2023-03-01T09:34:20Z

/integrate

openjdk · 2023-03-01T09:36:33Z

Going to push as commit 6b07243.
Since your change was applied there have been 404 commits pushed to the master branch:

3aeefbf: 8303421: [BACKOUT] 8303133: Update ProcessTools.startProcess(...) to exit early if process exit before linePredicate is printed.
1fdaf25: 8303133: Update ProcessTools.startProcess(...) to exit early if process exit before linePredicate is printed.
65da2c5: 8303412: Update linux_x64-to-linux_aarch64 cross compilation devkit at Oracle
7e47d51: 8282319: java.util.Locale method to stream available Locales
8815175: 8303216: Prefer ArrayList to LinkedList in sun.net.httpserver.ServerImpl
a10d5ac: 8303130: Document required Accessibility permissions on macOS
50dc041: 8303227: JniObjWithEnv should be NullablePointer compliant
61e8867: 8302040: Port fdlibm sqrt to Java
6423065: 8303261: JFR: jdk/jfr/api/consumer/streaming/TestJVMCrash.java doesn't retry
dc5ea6a: 8303350: Fix mistyped {@code}
... and 394 more: https://git.openjdk.org/jdk/compare/cae577a7102e97278f3f6880e529a68c1f7b71ab...master

Your commit was automatically rebased without conflicts.

openjdk · 2023-03-01T09:36:46Z

@rwestrel Pushed as commit 6b07243.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.

test & fix

91e60bc

openjdk bot added the hotspot-compiler hotspot-compiler-dev@openjdk.org label Feb 1, 2023

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openjdk bot added the rfr Pull request is ready for review label Feb 2, 2023

chhagedorn approved these changes Feb 2, 2023

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openjdk bot added the ready Pull request is ready to be integrated label Feb 2, 2023

type system fix & test

34c17a1

TobiHartmann approved these changes Feb 8, 2023

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chhagedorn approved these changes Feb 23, 2023

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openjdk bot added the integrated Pull request has been integrated label Mar 1, 2023

openjdk bot closed this Mar 1, 2023

openjdk bot removed ready Pull request is ready to be integrated rfr Pull request is ready for review labels Mar 1, 2023

8301630: C2: 8297933 broke type speculation in some cases #12368

8301630: C2: 8297933 broke type speculation in some cases #12368

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