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Speed up tst_QGraphicsView::mapToScene test 

This test is doing a brute-force mapping. Coupled with changes to
QCOMPARE last year, this now allocates and deallocates a lot of memory
per iteration. On my Sandybridge, it takes two minutes to run:

     111136.781153 task-clock                #    0.999 CPUs utilized
   371,692,633,238 cycles                    #    3.344 GHz
   182,641,818,708 stalled-cycles-frontend   #   49.14% frontend cycles idle
    57,951,552,830 stalled-cycles-backend    #   15.59% backend  cycles idle
   477,216,332,971 instructions              #    1.28  insns per cycle
                                             #    0.38  stalled cycles per insn
    86,959,637,669 branches                  #  782.456 M/sec
       309,185,237 branch-misses             #    0.36% of all branches

     111.264868818 seconds time elapsed

Changing the iteration step from 1 to 5 reduces the runtime to about 5
seconds.

Change-Id: I9cad6f85f535f472319da7cd6c4aa28e12ddf1b7
Reviewed-by: Jason McDonald <jason.mcdonald@nokia.com>
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>
bb10
Thiago Macieira 2012-08-13 00:24:27 +02:00 committed by Qt by Nokia
parent 4b73950cc8
commit b1fd9a93b9
1 changed files with 1 additions and 1 deletions
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2
tests/auto/widgets/graphicsview/qgraphicsview/tst_qgraphicsview.cpp
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@ -1720,7 +1720,7 @@ void tst_QGraphicsView::mapToScene()
#ifdef Q_PROCESSOR_ARM
const int step = 20;
#else
const int step = 1;
const int step = 5;
#endif
for (int x = 0; x < view.width(); x += step) {