JDK-8362972 : C2 fails with unexpected node in SuperWord truncation: IsFiniteF, IsFiniteD
  • Type: Bug
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 25
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • CPU: riscv
  • Submitted: 2025-07-22
  • Updated: 2025-07-25
  • Resolved: 2025-07-23
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JDK 26
26 b08Fixed
Related Reports
Causes :  
JDK-8350177 - C2 SuperWord: Integer.numberOfLeadingZeros, numberOfTrailingZeros, reverse and bitCount have input types wrongly truncated for byte and short
Relates :  
JDK-8294198 - Implement isFinite intrinsic for RISC-V
Description
After JDK-8350177, we hit the following assert in C2:

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  Internal Error (/home/jenkins-slave/jdk/src/hotspot/share/opto/superword.cpp:2606), pid=3789547, tid=3789567
#  assert(false) failed: Unexpected node in SuperWord truncation: IsFiniteD
#
# JRE version: OpenJDK Runtime Environment (26.0) (fastdebug build 26-internal-jenkins-slave-20250718001030-jdk-ls-fc4f8f3d054)
# Java VM: OpenJDK 64-Bit Server VM (fastdebug 26-internal-jenkins-slave-20250718001030-jdk-ls-fc4f8f3d054, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, linux-loongarch64)
# Problematic frame:
# V  [libjvm.so+0x1a93bb8]  VLoopTypes::compute_vector_element_type()+0x8d0
#
# Core dump will be written. Default location: Core dumps may be processed with "/usr/libexec/abrt-hook-ccpp %s %c %p %u %g %t %P %I %h %e" (or dumping to /home/jenkins-slave/jdk/build/linux-loongarch64-server-fastdebug/test-support/jtreg_test_hotspot_jtreg_tier1/scratch/0/core.3789547)
#
Unsupported internal testing APIs have been used.
Comments
Changeset: 9f796da3 Branch: master Author: Wang Haomin <wanghaomin@openjdk.org> Committer: Jasmine Karthikeyan <jkarthikeyan@openjdk.org> Date: 2025-07-23 08:08:05 +0000 URL: https://git.openjdk.org/jdk/commit/9f796da3774b2e2f92dca178fdccd93989919256
23-07-2025
ILW = Assert during C2 compilation (harmless, only affects debug), with VM changes only on RISCV, disable superword or compilation of affected method = MLM = P4
22-07-2025
[~jkarthikeyan] FYI
22-07-2025
A pull request was submitted for review. Branch: master URL: https://git.openjdk.org/jdk/pull/26423 Date: 2025-07-22 07:21:15 +0000
22-07-2025