From 2e8656779ac3eee8567ce2bf8eda233f4c5e3620 Mon Sep 17 00:00:00 2001 From: Andrei Golubev Date: Wed, 28 Oct 2020 18:14:21 +0100 Subject: Introduce QADP::reallocateGrow() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Added realloc() code path to QMovableArrayOps Implemented fast realloc() based growing for QADP and used it in QList::emplaceBack. This gives quite a bit of speedup and shows better results than 5.15 at 100k+ iterations of "list.append(elem)", meanwhile also closing a gap between movable types Task-number: QTBUG-87330 Change-Id: I42fc182ecd93c85600dac622385152fc57735da8 Reviewed-by: Mårten Nordheim Reviewed-by: Thiago Macieira --- src/corelib/tools/qarraydata.cpp | 3 +++ 1 file changed, 3 insertions(+) (limited to 'src/corelib/tools/qarraydata.cpp') diff --git a/src/corelib/tools/qarraydata.cpp b/src/corelib/tools/qarraydata.cpp index 3217e87cc8..2bf3e9bacc 100644 --- a/src/corelib/tools/qarraydata.cpp +++ b/src/corelib/tools/qarraydata.cpp @@ -236,6 +236,7 @@ QArrayData::reallocateUnaligned(QArrayData *data, void *dataPointer, qsizetype headerSize = sizeof(QArrayData); qsizetype allocSize = calculateBlockSize(capacity, objectSize, headerSize, option); qptrdiff offset = dataPointer ? reinterpret_cast(dataPointer) - reinterpret_cast(data) : headerSize; + Q_ASSERT(offset > 0); allocSize = reserveExtraBytes(allocSize); if (Q_UNLIKELY(allocSize < 0)) // handle overflow. cannot reallocate reliably @@ -245,6 +246,8 @@ QArrayData::reallocateUnaligned(QArrayData *data, void *dataPointer, if (header) { header->alloc = uint(capacity); dataPointer = reinterpret_cast(header) + offset; + } else { + dataPointer = nullptr; } return qMakePair(static_cast(header), dataPointer); } -- cgit v1.2.3