Re: Other Quesa concerns/suggestions

[Sean M. <se...@ro...>]

On 4/24/09 8:47 AM, James W. Walker said:

>> 1) In Quesa-common.xcconfig we have:
>>  GCC_FAST_MATH = YES
>>
>> From my understanding, this option is not generally recommended.  Is  
>> it
>> really needed?
>
>Can you give me any references?  I googled it, and couldn't find any  
>recommendations one way or another.  But to me, the word "fast" is a  
>recommendation.

Xcode's 'Research Assistant' has this to say: 

"Enables some floating point optimizations that are not IEEE754-
compliant, but which usually work. Programs which require strict IEEE
compliance may not work with this option. [GCC_FAST_MATH, -ffast-math]"

gcc's man page says:

"-ffast-math
Sets -fno-math-errno, -funsafe-math-optimizations, -fno-trapping-math, -
ffinite-math-only, -fno-rounding-math, -fno-signaling-nans and fcx-
limited-range.
This option causes the preprocessor macro "__FAST_MATH__" to be defined.

This option should never be turned on by any -O option since it can
result in incorrect output for programs which depend on an exact
implementation of IEEE or ISO rules/specifications for math functions."

I agree 'fast' sounds like a recommendation, they probably should have
called it GCC_BROKEN_MATH. :)

>> 2) In Quesa.h we have:
>>  #pragma options align=power
>>
>> Is this really needed?  Can we wrap it in #if TARGET_RT_MAC_CFM so  
>> that
>> it only applies to Mac OS 9?
>
>It probably is a relic of QD3D.  I expect that as long as the  
>alignment of the header agrees with the alignment used to build Quesa,  
>then it shouldn't matter.  So I think we can wrap it as you suggest.

Great.

>> 3) In Debug, the static library is named libQuesaD.a and in Release it
>> is libQuesa.a.  Why is this?  For CodeWarrior this would be handy, but
>> for Xcode it is annoying because Xcode does not allow different
>> libraries to be used in different configurations.  The only way to do
>> that with Xcode is to pass -libQuesa as a linker flag and change  
>> library
>> search paths between Debug and Release.  This requires the libs to  
>> have
>> the same name.
>
>
>I don't know why, and wouldn't object to changing it.  (I always use  
>Quesa as a framework.)  However, I don't think it's exactly true that  
>Xcode doesn't allow different libraries to be used in different  
>configurations.  You can use a trick of putting symbolic links in the  
>build product Release and Debug folders, and then putting one of those  
>links in the project with a Build Product-relative path.

Up to you of course, it's not a big bother for my version to be 1
character off the standard version. :)

-- 
____________________________________________________________
Sean McBride, B. Eng                 se...@ro...
Rogue Research                        www.rogue-research.com 
Mac Software Developer              Montréal, Québec, Canada