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  1. IMPALA
  2. IMPALA-5980

Upgrade to LLVM 5.0.1

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Details

    • Improvement
    • Status: Resolved
    • Major
    • Resolution: Fixed
    • None
    • Impala 2.13.0
    • Backend
    • ghx-label-4

    Description

      As a part of IMPALA-5907 it was identified that the GVN optimization pass is slow for large cases, specifically when huge expression trees are passed to it.
      This slow GVN pass problem is a known issue (https://groups.google.com/forum/#!msg/llvm-dev/ozsAceDmOuA/2O_QC6EiDgAJ) that has motivated the llvm devs to develop a new GVN pass which is claimed to be faster and is available in LLVM 5.0.1
      Therefore after upgrading to LLVM 5.0.1 we should try moving to the NewGVN pass and figure out if it is helpful by doing a perf analysis.

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          Bikramjeet Vig

        Issue Links

          is depended upon by

          Improvement - An improvement or enhancement to an existing feature or task. IMPALA-6259 Remove workaround for posix_memalign in SystemAllocator after LLVM 6.0 upgrade

          • Major - Major loss of function.
          • Open

          Improvement - An improvement or enhancement to an existing feature or task. IMPALA-6304 Consider re-enabling AVX512 codegen once we have LLVM 5 + test coverage

          • Minor - Minor loss of function, or other problem where easy workaround is present.
          • Open
          is related to

          Bug - A problem which impairs or prevents the functions of the product. IMPALA-5907 Increased codegen time on specific queries in Impala 2.6

          • Critical - Crashes, loss of data, severe memory leak.
          • Closed
          relates to

          Improvement - An improvement or enhancement to an existing feature or task. IMPALA-6177 Clean up handcrafted IRs if they encounter error during creation

          • Major - Major loss of function.
          • Resolved

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              bikramjeet.vig Bikramjeet Vig
              bikramjeet.vig Bikramjeet Vig
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                Created:
                Updated:
                Resolved: