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  1. JDK
  2. JDK-8313672

C2: PhaseCCP does not correctly track analysis dependencies involving shift, convert, and mask

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    • b24

    Description

      ### Failure analysis ###
      The failure appears because `PhaseCCP::push_and` does not capture all patterns from `MulNode::AndIL_shift_and_mask_is_always_zero` (called from `AndLNode::Value`). As a consequence, some nodes which need re-analysis in `PhaseCCP` are not re-added to the worklist.

      ### Original report ###
      The attached fuzzer test fails with the following assertion since the assert was added in JDK-8257197 (most likely also affects earlier version where the assert is missing):

      To reproduce:
      $ java -XX:CompileCommand=RepeatCompilation,Test::mainTest,1000 -XX:-TieredCompilation -XX:+StressIGVN -Xcomp -XX:CompileOnly=Test::* Test.java
      $ java -XX:RepeatCompilation=1000 -XX:-TieredCompilation -XX:+StressIGVN -Xcomp -XX:CompileCommand=compileonly,Reduced::test Reduced.java

      #
      # A fatal error has been detected by the Java Runtime Environment:
      #
      # Internal Error (/opt/mach5/mesos/work_dir/slaves/cd627e65-f015-4fb1-a1d2-b6c9b8127f98-S107234/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/3f6d0df7-2217-4a65-bfa3-1294b5554df9/runs/b8ed7f9d-165b-4b78-86e8-e4c923096d65/workspace/open/src/hotspot/share/opto/phaseX.cpp:1826), pid=472204, tid=472226
      # assert(!failure) failed: Missed optimization opportunity in PhaseCCP
      #
      # JRE version: Java(TM) SE Runtime Environment (21.0+1) (fastdebug build 21-galahadeestaging+1-LTS-60)
      # Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 21-galahadeestaging+1-LTS-60, compiled mode, sharing, compressed oops, compressed class ptrs, g1 gc, linux-aarch64)
      # Problematic frame:
      # V [libjvm.so+0x13d4610] PhaseCCP::analyze()+0x6e0
      .........
      Command Line: -XX:-TieredCompilation -XX:+IgnoreUnrecognizedVMOptions -XX:+UnlockDiagnosticVMOptions -XX:+StressLCM -XX:+StressGCM -XX:+StressIGVN -XX:+StressCCP -XX:StressSeed=1464539141 -Xmx1G -Xcomp -Xbatch -XX:CompileOnly=Test -XX:CompileCommand=quiet -XX:MaxRAMPercentage=6.25 -Dtest.boot.jdk=/opt/mach5/mesos/work_dir/jib-master/install/jdk/20/36/bundles/linux-aarch64/jdk-20_linux-aarch64_bin.tar.gz/jdk-20 -Djava.io.tmpdir=/opt/mach5/mesos/work_dir/slaves/cd627e65-f015-4fb1-a1d2-b6c9b8127f98-S119357/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/4ce1ae21-d8a4-4dd7-bc28-ae5d04951013/runs/ee39a676-757e-4f39-8eb7-2849b60f23a9/testoutput/test-support/jtreg_closed_test_hotspot_jtreg_applications_javafuzzer_BigTest_java/tmp Test
      .........
      Current CompileTask:
      C2: 500 71 b Test::mainTest (562 bytes)

      Stack: [0x0000ffff9ad8e000,0x0000ffff9af8c000], sp=0x0000ffff9af86e80, free space=2019k
      Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
      V [libjvm.so+0x13d4610] PhaseCCP::analyze()+0x6e0 (phaseX.cpp:1826)
      V [libjvm.so+0x907494] Compile::Optimize()+0x490 (compile.cpp:2364)
      V [libjvm.so+0x9095b4] Compile::Compile(ciEnv*, ciMethod*, int, Options, DirectiveSet*)+0x14e4 (compile.cpp:842)
      V [libjvm.so+0x7600d8] C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x328 (c2compiler.cpp:118)
      V [libjvm.so+0x9156e4] CompileBroker::invoke_compiler_on_method(CompileTask*)+0x8e4 (compileBroker.cpp:2276)
      V [libjvm.so+0x916114] CompileBroker::compiler_thread_loop()+0x594 (compileBroker.cpp:1944)
      V [libjvm.so+0xda8dcc] JavaThread::thread_main_inner()+0xec (javaThread.cpp:719)
      V [libjvm.so+0x15f7b24] Thread::call_run()+0xb0 (thread.cpp:217)
      V [libjvm.so+0x13537e0] thread_native_entry(Thread*)+0x130 (os_linux.cpp:778)
      C [libpthread.so.0+0x7908] start_thread+0x188

      Attachments

        1. FuzzerUtils.java
          13 kB
          Christian Hagedorn
        2. hs_err_pid472204.log
          116 kB
          Christian Hagedorn
        3. Reduced.java
          0.4 kB
          Christian Hagedorn
        4. Test.java
          7 kB
          Christian Hagedorn

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              dlunden Daniel Lunden
              chagedorn Christian Hagedorn
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                Created:
                Updated:
                Resolved: