Re: RMCL 5.2 on Snow Leopard: floating point issues

The problem manifests itself with returning every float value as 0.0  
which is a likely source of causing division by zero float error.

I still do not know what causes this problem. There is no obvious CL  
code that could explain this. However, there is good news, or at least  
good enough news. I can now replicate the bug. Tracking the bug in a  
large code base finally turned up this unlikely culprit:

Welcome to Macintosh Common Lisp Version 5.2!
? 3.3
3.3
? (choose-directory-dialog)
#P"Double Ristretto:Users:alex:Desktop:RMCL 5.2:level-1:"
? 3.3
0.0
?

OS X 10.6.1, Core 2 Duo, 2.6 Ghz MacBook Pro with a fresh copy of RMCL  
from Google Code.

time to sleep...

Alex



On Oct 15, 2009, at 9:30 PM, Chun Tian wrote:

> Hi again,
>
>> (this is in a Listerner 1 process "initial" breaking after the error
>> occurring for the first time resulting in float /0 errors)
>
> What does above mean? I try to eval something like (/ 1.0 0.0) first,
> but the rest of those float tests are still keep the same.
>
> --binghe
>
> 在 2009-10-16，11:26， Chun Tian 写道：
>
>> Hi, Alexander
>>
>> Hmmm ... I'm also in Snow Leopard using RMCL 5.2, but your tests are
>> all fine here:
>>
>> Welcome to Macintosh Common Lisp Version 5.2!
>> ? 3
>> 3
>> ? 3.0
>> 3.0
>> ? *read-default-float-format*
>> SINGLE-FLOAT
>> ? (setq *read-default-float-format* 'short-float)
>> SHORT-FLOAT
>> ? 3
>> 3
>> ? 3.3
>> 3.3
>> ? (float 3)
>> 3.0
>> ? (+ 4.5 5.5)
>> 10.0
>> ?
>>
>> This is Mac OS X 10.6.1 on Intel Core 2 Duo 2.66GHz (MacBookPro5,2).
>> I just want to clarify that not everyone met the same issue as you
>> (I'm sorry for that).
>>
>> Regards,
>>
>> Chun Tian (binghe)
>>
>> 在 2009-10-16，4:38， Alexander Repenning 写道：
>>
>>> getting closer to WHAT is happening but not WHY. Keep in mind this
>>> worked on Leopard but not Snow Leopard. I would assume this is has
>>> something to do with the new version of Rosetta. Here are some
>>> stunning listener interactions (this is in a Listerner 1 process
>>> "initial" breaking after the error occurring for the first time
>>> resulting in float /0 errors):
>>>
>>> 1 > 3
>>> 3
>>> ;; OK
>>> 1 > 3.0
>>> 1.06099791E-315
>>> ;; HUH!!!
>>>
>>> 1 > (setq *read-default-float-format* 'short-float)
>>> SHORT-FLOAT
>>> 1 > 3
>>> 3
>>> 1 > 3.3
>>> 0.0
>>> 1 > (float 3)
>>> 0.0
>>> 1 > (+ 4.5 5.5)
>>> 0.0
>>>
>>> Looks as if ANY kind of float returned is a 0.0
>>>
>>> Meanwhile, in the regular listerner things are still working as
>>> expected.
>>>
>>> I am stumped at the moment and would appreciate any pointer or even
>>> wild guesses on how RMCL could possibly enter this state.
>>>
>>> So far I have only seen the problem in process initial but I am not
>>> sure if this is relevant.
>>>
>>> all the best,  Alex
>>>
>>>
>>>
>>>
>>>
>>>
>>> On Oct 14, 2009, at 2:57 PM, Terje Norderhaug wrote:
>>>
>>>> On Oct 14, 2009, at 9:15 AM, Alexander Repenning wrote:
>>>>> What kinds of  issues do people have out there with RMCL 5.2 and
>>>>> Snow Leopard (OS X, 10.6.1)?
>>>>>
>>>>> Things almost work here but there are some strange floating point
>>>>> issues (with shorts).
>>>>>
>>>>> At least we get further, ironically, with RCML 5.2 than CCL 1.3
>>>>> which immediately quits. What is the version of CCL one should use
>>>>> to work under OS X 10.6.1?
>>>>
>>>> Are these the same as the problems discussed in issue 8 at
>>>> mcl.googlecode.com?
>>>>
>>>> http://code.google.com/p/mcl/issues/detail?id=8
>>>>
>>>> Gary made some changes to the floating point functionality, but  
>>>> come
>>>> to think about it, these changes may not have been propagated into
>>>> the distribution yet:
>>>>
>>>> http://code.google.com/p/mcl/source/detail?
>>>> r=ff3f7eb878e5d61e1a8e83f6d19b3a3ea86de346
>>>>
>>>> -- Terje
>>>> _______________________________________________
>>>> info-mcl mailing list
>>>> [email protected]
>>>> http://clozure.com/mailman/listinfo/info-mcl
>>>
>>> Prof. Alexander Repenning
>>>
>>> University of Colorado
>>> Computer Science Department
>>> Boulder, CO 80309-430
>>>
>>> vCard: http://www.cs.colorado.edu/~ralex/AlexanderRepenning.vcf
>>>
>>>
>>> _______________________________________________
>>> info-mcl mailing list
>>> [email protected]
>>> http://clozure.com/mailman/listinfo/info-mcl
>>
>
> _______________________________________________
> info-mcl mailing list
> [email protected]
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Prof. Alexander Repenning

University of Colorado
Computer Science Department
Boulder, CO 80309-430

vCard: http://www.cs.colorado.edu/~ralex/AlexanderRepenning.vcf

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