-O0 nearly twice as fast to build as -O2

Dan Kegel dank at kegel.com
Fri Jun 13 06:27:51 CDT 2008

On Thu, Jun 12, 2008 at 10:43 PM, Pavel Troller <patrol at sinus.cz> wrote:
>  Yes, you are right, turning optimization off speeds up the compilation
> substantially.
>  HOWEVER, it changes the generated code and due to various features of the
> compiler (like inlining or another) being present/absent, the code can,
> in rare cases, behave differently. I have many experiences that for example
> a program was repeatedly crashing, when compiled by default way, i.e. with
> optimalization, and when I compiled it without optimalization and with -g
> for debugging, it never crashed and worked perfectly under the debugger.

Indeed.  I think I've had a case where it worked properly
with optimization, but crashed with -O0, too.
Every once in a while we should make sure that Wine
passes its tests when compiled without optimization.

(Incidentally, Valgrind gives somewhat better info with -O0, and it
catches some of the problems you're describing.)

But the main point of my post was to suggest a way to
speed up regression testing.  I've add a note about it
to http://wiki.winehq.org/RegressionTesting
- Dan

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