Author Topic: How serios is Aliasing? Is there any tools?  (Read 639 times)

Offline Botsareus

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How serios is Aliasing? Is there any tools?
« on: September 15, 2013, 01:02:58 PM »
Numsgil, I am pretty sure db2 does not use aliasing, but just in case it does:

1.) If I set "assume no aliasing" to true, can it cause runtime errors 6 or div/0?
2.) Are there any tools out there to tell if at any line in the vb6 db2 code uses aliasing? I looked for such a tool, did not find any.
« Last Edit: September 15, 2013, 01:07:44 PM by Botsareus »

Offline Numsgil

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Re: How serios is Aliasing? Is there any tools?
« Reply #1 on: September 16, 2013, 02:19:15 AM »
I doubt you'd see much of a performance improvement enabling it.  And it's possible there's some variables aliased somewhere.  So it's probably not worth the effort to play with it.

To give some perspective, aliasing is an issue in C++ as well, and even in highly performant C++ code like you'd find in a video game engine no one is really messing with the aliasing issues, except possibly in the case of some really low level operations around vectors and matrices.  It's just not worth the mental effort to think about.

Offline Botsareus

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Re: How serios is Aliasing? Is there any tools?
« Reply #2 on: September 16, 2013, 03:25:43 PM »
It was initially enabled.
In-fact, when I got control of the source code, all unsecure compiler options where enabled.
 :P

I'll disable them all on my next mod.

edit: I have not seen much performance change, so, unless you think otherwise, it should be a safe bet.
« Last Edit: September 16, 2013, 03:30:02 PM by Botsareus »

Offline Botsareus

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Re: How serios is Aliasing? Is there any tools?
« Reply #3 on: September 18, 2013, 10:19:35 AM »
That's cool then. I am disabling all unsecure compile options on my next revision as no one seems to be against it.