Configuration for optimizing QtCreator compiler

Question

I'm using QtCreator in Windows 7.

I want to configure it to use third level optimization (-O3) for c++ compiler.

How can I do this to speed up my code and what changes are necessary?

**[See here](http://stackoverflow.com/a/3042278/170194)** – rubber boots Oct 08 '12 at 17:46 — rubber boots, Oct 08 '12 at 17:46

score 20 · Answer 1 · answered Oct 12 '12 at 22:30

20

Try to add next lines to your .pro file:

# remove possible other optimization flags
QMAKE_CXXFLAGS_RELEASE -= -O
QMAKE_CXXFLAGS_RELEASE -= -O1
QMAKE_CXXFLAGS_RELEASE -= -O2 

# add the desired -O3 if not present
QMAKE_CXXFLAGS_RELEASE *= -O3

answered Oct 12 '12 at 22:30

NG_

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I did it. But I can't see any improvement. Maybe I should think about rebuilding Qt with -O3 – batista cori Oct 13 '12 at 11:00

score 1 · Answer 2 · answered Nov 10 '12 at 16:52

Add these line's to your .pro file if you want a small application size

QMAKE_CXXFLAGS += -Os -mpreferred-stack-boundary=2 -finline-small-functions -momit-leaf-frame-pointer

If you want a faster application , consider using -O2 instead of -Os

refer this for more options

Configuration for optimizing QtCreator compiler

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