JDK-8275326 : C2: assert(no_dead_loop) failed: dead loop detected
  • Type: Bug
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 11,17,18
  • Priority: P3
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2021-10-15
  • Updated: 2022-01-20
  • Resolved: 2021-12-01
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JDK 11 JDK 17 JDK 18
11.0.15-oracleFixed 17.0.3-oracleFixed 18 b26Fixed
Related Reports
Relates :  
JDK-8273612 - Fix for JDK-8272873 causes timeout in running some tests with -Xcomp
Relates :  
JDK-8280126 - Dead loop assert with -Xcomp
Description
(synopsis is provisional, feel free to change it or close as duplicate of known bug)

Attached Fuzzer test fails like this:

$ ./build/linux-x86_64-server-fastdebug/images/jdk/bin/java -XX:+StressIGVN -XX:StressSeed=77325781 -Xcomp -XX:CompileOnly=Test Test
...
#  Internal Error (/home/shade/trunks/jdk/src/hotspot/share/opto/phaseX.cpp:945), pid=2711484, tid=2711497
#  assert(no_dead_loop) failed: dead loop detected

Bisection shows it started with JDK-8273612, but that might only be because the profiling info had changed a bit.
Comments
A pull request was submitted for review. URL: https://git.openjdk.java.net/jdk11u-dev/pull/772 Date: 2022-01-18 12:40:14 +0000
18-01-2022
Fix request [11u] I backport this for parity with 11.0.15-oracle. Clean backport. SAP nightly tests passed.
18-01-2022
Fix request [17u] I backport this for parity with 11.0.15-oracle. As it is in 11, I think it should also go to 17. Typical risk of changing C2. Clean backport. SAP nightly tests passed. Pre-submit tests passed in PR 43.
29-12-2021
A pull request was submitted for review. URL: https://git.openjdk.java.net/jdk17u-dev/pull/43 Date: 2021-12-29 17:11:27 +0000
29-12-2021
A pull request was submitted for review. URL: https://git.openjdk.java.net/jdk17u-dev/pull/31 Date: 2021-12-22 16:18:38 +0000
22-12-2021
Changeset: 70d5dffb Author: Christian Hagedorn <chagedorn@openjdk.org> Date: 2021-12-01 08:24:59 +0000 URL: https://git.openjdk.java.net/jdk/commit/70d5dffb4e7110902b59b56efaef31614916148c
01-12-2021
Could only reproduce this with the attached replay file with latest JDK even after repeated runs with StressIGVN + RepeatCompilation. Added label noreg-hard accordingly.
08-11-2021
ILW = C2 assertion during IGVN due to dead data loop, only fails with single Java Fuzzer test, disable compilation of affected method = HLM = P3
29-10-2021
This dead loop assertion failure involves a MergeMemNode replacing a phi node which results in a dead data loop. This failure is unrelated to JDK-8271056 which creates a dead data loop with cmoving identity. I therefore reopen and retriage this bug for 18.
29-10-2021
Might be related to JDK-8271056. I found some dead loop fails with the Java Fuzzer which I'm currently looking into. I propose to close this as a dup of it and reopen this one if the fix for JDK-8271056 is unrelated.
15-10-2021