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  1. Qt
  2. QTBUG-137540

[Reg 6.5.0 -> 6.5.5] Compilation blog post example doesn't work anymore

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    • c36360eb1 (6.9), 9bfcc36f2 (tqtc/lts-6.8), 9bc25cd53 (tqtc/lts-6.8), dfc56c205 (tqtc/lts-6.8), 564d2eb26 (tqtc/lts-6.8), b9974d82c (dev), 6bd483038 (6.10), 9383c7c05 (6.9), bc8ebb88d (tqtc/lts-6.8), f3a593235 (tqtc/lts-6.5), 81e8b11ad (tqtc/lts-6.5)

      The example from https://www.qt.io/blog/compiling-qml-to-c-a-4x-speedup doesn't compile to C++ anymore. You instead get:

      Categorizer.qml:24: warning: Could not compile binding for numbers: Cannot generate efficient code for storing an array in a non-sequence type [compiler]
Categorizer.qml:39: warning: Could not compile function sum: Cannot generate efficient code for LoadElement on a sequence potentially affected by side effects [compiler]
Categorizer.qml:59: warning: Could not compile binding for onCompleted: Cannot generate efficient code for LoadElement on a sequence potentially affected by side effects [compiler]

      There's no obvious reason for this. The array shouldn't have to be stored in anything but list<double> and the numbers in sum() are not actually affected by any side effects.

      In onCompleted it probably assumes console.log() has side effects. We could deal with that by starting to mark specific functions as pure. However, onCompleted is not the hot code path here.

        For Gerrit Dashboard: QTBUG-137540
        # Subject Branch Project Status CR V
        653739,7 QmlCompiler: Restore support for writing to temporary arrays dev qt/qtdeclarative Status: MERGED +2 0
        654062,1 QtQml: Do not use redundant stack slots for array member expressions dev qt/qtdeclarative Status: ABANDONED 0 0
        654063,3 QJSEngine: Optimize conversions between double and int dev qt/qtdeclarative Status: MERGED +2 0
        654534,5 QmlCompiler: Simplify register allocation dev qt/qtdeclarative Status: MERGED +2 0
        654663,2 QJSEngine: Optimize conversions between double and int 6.10 qt/qtdeclarative Status: MERGED +2 0
        654707,5 QmlCompiler: Sharpen side effect detection dev qt/qtdeclarative Status: MERGED +2 0
        654710,5 QmlCompiler: Discern between different kinds of side effects dev qt/qtdeclarative Status: MERGED +2 0
        654908,2 QJSEngine: Optimize conversions between double and int 6.9 qt/qtdeclarative Status: MERGED +2 0
        655174,2 QJSEngine: Optimize conversions between double and int tqtc/lts-6.8 qt/tqtc-qtdeclarative Status: MERGED +2 0
        655180,2 QmlCompiler: Simplify register allocation 6.10 qt/qtdeclarative Status: MERGED +2 0
        655181,2 QmlCompiler: Restore support for writing to temporary arrays 6.10 qt/qtdeclarative Status: MERGED +2 0
        655258,2 QJSEngine: Optimize conversions between double and int tqtc/lts-6.5 qt/tqtc-qtdeclarative Status: MERGED +2 0
        655275,2 QmlCompiler: Sharpen side effect detection 6.10 qt/qtdeclarative Status: MERGED +2 0
        655276,2 QmlCompiler: Discern between different kinds of side effects 6.10 qt/qtdeclarative Status: MERGED +2 0
        655285,3 QmlCompiler: Simplify register allocation 6.9 qt/qtdeclarative Status: MERGED +2 0
        655286,3 QmlCompiler: Restore support for writing to temporary arrays 6.9 qt/qtdeclarative Status: MERGED +2 0
        655642,3 QmlCompiler: Sharpen side effect detection 6.9 qt/qtdeclarative Status: MERGED +2 0
        655645,3 QmlCompiler: Discern between different kinds of side effects 6.9 qt/qtdeclarative Status: MERGED +2 0
        655650,3 QmlCompiler: Simplify register allocation tqtc/lts-6.8 qt/tqtc-qtdeclarative Status: MERGED +2 0
        655651,3 QmlCompiler: Restore support for writing to temporary arrays tqtc/lts-6.8 qt/tqtc-qtdeclarative Status: MERGED +2 0
        655920,3 QmlCompiler: Sharpen side effect detection tqtc/lts-6.8 qt/tqtc-qtdeclarative Status: MERGED +2 0
        655921,3 QmlCompiler: Discern between different kinds of side effects tqtc/lts-6.8 qt/tqtc-qtdeclarative Status: MERGED +2 0
        656259,3 WIP: QmlCompiler: Simplify register allocation tqtc/lts-6.5 qt/tqtc-qtdeclarative Status: ABANDONED -2 0
        656260,1 QmlCompiler: Restore support for writing to temporary arrays tqtc/lts-6.5 qt/tqtc-qtdeclarative Status: ABANDONED 0 0
        656261,1 QmlCompiler: Sharpen side effect detection tqtc/lts-6.5 qt/tqtc-qtdeclarative Status: ABANDONED 0 0
        656262,6 QmlCompiler: Discern between different kinds of side effects tqtc/lts-6.5 qt/tqtc-qtdeclarative Status: MERGED +2 0
        656445,1 WIP: Preserve external side effects across jumps tqtc/lts-6.5 qt/tqtc-qtdeclarative Status: ABANDONED -2 0
        656450,5 QmlCompiler: Preserve external side effects across jumps dev qt/qtdeclarative Status: MERGED +2 0
        657052,2 QmlCompiler: Preserve external side effects across jumps 6.10 qt/qtdeclarative Status: MERGED +2 0
        657104,2 QmlCompiler: Preserve external side effects across jumps 6.9 qt/qtdeclarative Status: MERGED +2 0
        657133,3 QmlCompiler: Preserve external side effects across jumps tqtc/lts-6.8 qt/tqtc-qtdeclarative Status: MERGED +2 0
        657270,3 QmlCompiler: Preserve external side effects across jumps tqtc/lts-6.5 qt/tqtc-qtdeclarative Status: MERGED +2 0

            ulherman Ulf Hermann
            ulherman Ulf Hermann
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              Created:
              Updated:
              Resolved:

                There are no open Gerrit changes