Optimisation consistency

[elliotwoods]

Continuation of http://forum.openframeworks.cc/index.php/topic,9095.msg42378.html#new

NOTE: Things may have changed as the projects I'm using are all created using the older creation tools.
Can somebody up to date please check?

Currently XCode's default project setting is /O2 for debug projects
whilst Visual Studio's is /O0

/O0 generally makes the most sense for debug mode as it allows for effective program flow and variable tracking (because with /O2, lines of code and variables are commonly optimised away).

If we are worried that this will leave default users in a default 'slower state' then perhaps we could make release the default? Then people could be aware that they are selecting debug when they want to actually do some debugging?
But this may have other issues (such as some libraries might not perform as many checks as otherwise?)

it might be worth making users more aware of the 2 options anyway, and then start using them consistently

[damian0815]

this is a big topic.. i'd suggest making debug the default option, but with O2 optimisations. i rarely notice the O2 debug setting when doing most debugging, and if i really need it i can set it back to O0 by hand (i figure anyone who knows how to use a debugger knows how to do this anyway!)

[elliotwoods]

@DamianNZ - that is the current default in osx
but not in VS
but in VS, you can't debug at all at /O2

we could also consider oF code debug at /O2 but users project at /O0

[damian0815]

oF code debug at O2 and user's project at O0 sounds good to me, just as long as the users know that they can make it faster if they choose to.

i'd still steer clear of defaulting to O0 on Xcode. perhaps consistency isn't as big a problem as you're suggesting, since GCC's optimiser works differently to VC's anyway.

[kylemcdonald]

i would also suggest avoiding O0 as a default. which one of these are you more likely to hear?

• why is my code so slow?
• why are my variables being optimized away?

it is strange that VS acts so different in O2.

[elliotwoods]

yep.
it almost makes sense how it is now
most optimisation whilst preserving basic debugging capability
but it makes me think the default compile option on vs should maybe be Release
so that users don't indeed complain 'why is my code so slow', especially compared to osx

[ofTheo]

@elliotwoods agreed!
what about O1 for VS - does that allow debugging?

[elliotwoods]

i'm not 100%, but am pretty sure that /O1 also blocks debugging
(otherwise i'd be using /O1)

[colormotor]

I would vote for using /O0 with Debug mode and perhaps use Release by default.
Debugging with optimization is quite frustrating.
Also it can give some satisfaction to see code running twice as fast when compiling in release mode :)

[ofTheo]

so the suggestion would be /O0 for debug but we would make Release the default so people don't complain about code slowdown?

@ofZach @arturoc how does that sound?

or we could have debug/ reallyDebug/ and Release/ ;)

[colormotor]

yes.
I also think that right now it might be hard for a novice user trying to debug, to figure out why the debugger is not functioning correctly, since debugging is pretty straight forward while compiler options may be a bit more misterious.
maybe make a debugOptimized mode?

[armadillu]

I agree with colormotor. More than actively trying to debug him/herself, a novice will quite likely get crashes. With the optimizations enabled by default, it will be even even more difficult to find out where / why the program crashed.

[elliotwoods]

update :
actually it is possible to debug in vs2010 with optimisations (including /O2)
you just have to turn off a bunch of other things (e.g. edit and continue)
suggesting DebugOptimized as default

sorry for missing this before

[memoakten]

re-igniting this thread. in xcode the default for the debug openframeworks project is Os which makes it undebuggable - and it's a shared project obviously, so you can't change it per project. To have optimizations which prevent debugging in a debug build I find a bit crazy to be honest! If people don't want to debug and prefer performance, they should run in release mode! that's what's for!

[bilderbuchi]

hm, wasn't this fixed recently in master? I remember someone (@arturoc? @ofTheo?) noticing this a couple of days back.