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  1. Qt
  2. QTBUG-58446

[REG 5.7→5.8] Illegal instruction POPCNT

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Details

    • Bug
    • Resolution: Done
    • P1: Critical
    • 5.9.0 Beta 2
    • 5.8.0
    • Core: Containers and Algorithms
    • None
    • Assistant.exe and Designer.exe falls at settings window
    • 72f49ef46a3426471b3c2102566d7d04390217d2

    Description

      Qt5Gui.dll and Qt5Guid.dll uses intrisic instruction __popcnt64
      But processor Intel Core 2 DUO E8500 do not have this.
      See file qalgorithms.h at string 653- 659

      #if Q_PROCESSOR_WORDSIZE == 8
/#define QALGORITHMS_USE_BUILTIN_POPCOUNTLL
Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_popcountll(quint64 v) Q_DECL_NOTHROW
{
    return __popcnt64(v); // <-ILLEGAL instrucrion this!!
}

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          duplicates

          Bug - A problem which impairs or prevents the functions of the product. QTBUG-58647 qPopulationCount uses unchecked SSE4 instructions with MSVC

          • P1: Critical - Urgent and Important, will STOP the release if matched with set FixVersion field. This includes regressions from the last version that are not edge cases; Data loss; Build issues; All but the most unlikely crashes/lockups/hanging; Serious usability issues and embarrassing bugs & Bugs critical to a deliverable. This is the highest possible priority for requirements.
          • Closed
          relates to

          Bug - A problem which impairs or prevents the functions of the product. QTBUG-58647 qPopulationCount uses unchecked SSE4 instructions with MSVC

          • P1: Critical - Urgent and Important, will STOP the release if matched with set FixVersion field. This includes regressions from the last version that are not edge cases; Data loss; Build issues; All but the most unlikely crashes/lockups/hanging; Serious usability issues and embarrassing bugs & Bugs critical to a deliverable. This is the highest possible priority for requirements.
          • Closed
          For Gerrit Dashboard: QTBUG-58446
          # Subject Branch Project Status CR V
          183633,3 MSVC: Fix use of POPCNT instruction without CPU check 5.8 qt/qtbase Status: MERGED +2 0

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              thiago Thiago Macieira
              nickb53 Nickolay Bychkov
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              Dates

                Created:
                Updated:
                Resolved:

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