From bd352604153543d8527929c7671fcfd2a22acc4a Mon Sep 17 00:00:00 2001 From: Milian Wolff Date: Sun, 14 Feb 2016 16:24:13 +0100 Subject: Microoptimize QObject::activate. This patch removes temporary variables that are not used in all cases. This reduces the instruction count per iteration for the corresponding benchmark by 1 or 2. Before: ********* Start testing of QObjectBenchmark ********* Config: Using QtTest library 5.7.0, Qt 5.7.0 (x86_64-little_endian-lp64 shared (dynamic) release build; by GCC 5.3.0) PASS : QObjectBenchmark::initTestCase() PASS : QObjectBenchmark::signal_slot_benchmark(simple function) RESULT : QObjectBenchmark::signal_slot_benchmark():"simple function": 21.0065466 instructions per iteration (total: 210,065,466, iterations: 10000000) PASS : QObjectBenchmark::signal_slot_benchmark(single signal/slot) RESULT : QObjectBenchmark::signal_slot_benchmark():"single signal/slot": 405.0829559 instructions per iteration (total: 4,050,829,559, iterations: 10000000) PASS : QObjectBenchmark::signal_slot_benchmark(multi signal/slot) RESULT : QObjectBenchmark::signal_slot_benchmark():"multi signal/slot": 405.0812465 instructions per iteration (total: 4,050,812,465, iterations: 10000000) PASS : QObjectBenchmark::signal_slot_benchmark(unconnected signal) RESULT : QObjectBenchmark::signal_slot_benchmark():"unconnected signal": 104.0147348 instructions per iteration (total: 1,040,147,349, iterations: 10000000) PASS : QObjectBenchmark::signal_slot_benchmark(single signal/ptr) RESULT : QObjectBenchmark::signal_slot_benchmark():"single signal/ptr": 369.1021099 instructions per iteration (total: 3,691,021,100, iterations: 10000000) PASS : QObjectBenchmark::signal_slot_benchmark(functor) RESULT : QObjectBenchmark::signal_slot_benchmark():"functor": 370.0982862 instructions per iteration (total: 3,700,982,862, iterations: 10000000) PASS : QObjectBenchmark::cleanupTestCase() Totals: 8 passed, 0 failed, 0 skipped, 0 blacklisted, 6036ms ********* Finished testing of QObjectBenchmark ********* After: ********* Start testing of QObjectBenchmark ********* Config: Using QtTest library 5.7.0, Qt 5.7.0 (x86_64-little_endian-lp64 shared (dynamic) release build; by GCC 5.3.0) PASS : QObjectBenchmark::initTestCase() PASS : QObjectBenchmark::signal_slot_benchmark(simple function) RESULT : QObjectBenchmark::signal_slot_benchmark():"simple function": 21.0061664 instructions per iteration (total: 210,061,664, iterations: 10000000) PASS : QObjectBenchmark::signal_slot_benchmark(single signal/slot) RESULT : QObjectBenchmark::signal_slot_benchmark():"single signal/slot": 403.0829161 instructions per iteration (total: 4,030,829,162, iterations: 10000000) PASS : QObjectBenchmark::signal_slot_benchmark(multi signal/slot) RESULT : QObjectBenchmark::signal_slot_benchmark():"multi signal/slot": 403.0836305 instructions per iteration (total: 4,030,836,305, iterations: 10000000) PASS : QObjectBenchmark::signal_slot_benchmark(unconnected signal) RESULT : QObjectBenchmark::signal_slot_benchmark():"unconnected signal": 104.0150038 instructions per iteration (total: 1,040,150,039, iterations: 10000000) PASS : QObjectBenchmark::signal_slot_benchmark(single signal/ptr) RESULT : QObjectBenchmark::signal_slot_benchmark():"single signal/ptr": 368.0981987 instructions per iteration (total: 3,680,981,988, iterations: 10000000) PASS : QObjectBenchmark::signal_slot_benchmark(functor) RESULT : QObjectBenchmark::signal_slot_benchmark():"functor": 369.1179429 instructions per iteration (total: 3,691,179,429, iterations: 10000000) PASS : QObjectBenchmark::cleanupTestCase() Totals: 8 passed, 0 failed, 0 skipped, 0 blacklisted, 5975ms ********* Finished testing of QObjectBenchmark ********* Change-Id: Iba3bffbca5b58109816c8b1a7dea0796b18c8785 Reviewed-by: Olivier Goffart (Woboq GmbH) --- src/corelib/kernel/qobject.cpp | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'src/corelib/kernel') diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp index 6702f78a04..e3e536d7e1 100644 --- a/src/corelib/kernel/qobject.cpp +++ b/src/corelib/kernel/qobject.cpp @@ -3713,8 +3713,6 @@ void QMetaObject::activate(QObject *sender, int signalOffset, int local_signal_i if (receiverInSameThread) { sw.switchSender(receiver, sender, signal_index); } - const QObjectPrivate::StaticMetaCallFunction callFunction = c->callFunction; - const int method_relative = c->method_relative; if (c->isSlotObject) { c->slotObj->ref(); QScopedPointer obj(c->slotObj); @@ -3727,10 +3725,12 @@ void QMetaObject::activate(QObject *sender, int signalOffset, int local_signal_i obj.reset(); locker.relock(); - } else if (callFunction && c->method_offset <= receiver->metaObject()->methodOffset()) { + } else if (c->callFunction && c->method_offset <= receiver->metaObject()->methodOffset()) { //we compare the vtable to make sure we are not in the destructor of the object. - locker.unlock(); const int methodIndex = c->method(); + const int method_relative = c->method_relative; + const auto callFunction = c->callFunction; + locker.unlock(); if (qt_signal_spy_callback_set.slot_begin_callback != 0) qt_signal_spy_callback_set.slot_begin_callback(receiver, methodIndex, argv ? argv : empty_argv); @@ -3740,7 +3740,7 @@ void QMetaObject::activate(QObject *sender, int signalOffset, int local_signal_i qt_signal_spy_callback_set.slot_end_callback(receiver, methodIndex); locker.relock(); } else { - const int method = method_relative + c->method_offset; + const int method = c->method_relative + c->method_offset; locker.unlock(); if (qt_signal_spy_callback_set.slot_begin_callback != 0) { -- cgit v1.2.3