[Openmcl-devel] = fails for integers with the same printed representation on 32bit CCL

[Ron Garret]

It seems to be a regression.  I can’t reproduce this on 1.10.

On Jan 9, 2017, at 9:28 PM, R. Matthew Emerson <rme at clozure.com> wrote:

> Filed as http://trac.clozure.com/ccl/ticket/1403
> 
> I don't think = is the problem.  It seems more likely to me that cl:random is returning a bignum with too many bignum digits.
> 
> Thanks for the report.
> 
> 
>> On Jan 8, 2017, at 7:51 PM, Anton Vodonosov <avodonosov at gmail.com> wrote:
>> 
>> Hello,
>> 
>> I reduced the use case to the following
>> 
>>    (defparameter *rnd-state* (make-random-state t))
>> 
>>    (dotimes (i 300000)
>>      (let* ((rand-val (random #.(1- (expt 2 64)) *rnd-state*))
>>             (read-val (read-from-string (with-output-to-string (o)
>>                                           (pprint rand-val o)))))
>>        (assert (= rand-val read-val)
>>                nil
>>                "rand-val: ~S, read-val: ~S" rand-val read-val)))
>> 
>> 
>>   ;; it doesn't fail from the first time, try 2-3 times more
>> 
>> At some point assert fails and the message is:
>> 
>>    rand-val: 1037244565857250958, read-val: 1037244565857250958
>>       [Condition of type SIMPLE-ERROR]
>> 
>> Inspecting the variables in SLIME debuggers shows this:
>> 
>> 
>> RAND-VAL:
>> 
>> #<(INTEGER 536870912) #xE65086FE5202E8E>
>> --------------------
>> Value: 1037244565857250958 = #xE65086FE5202E8E = #o71450206774510027216 = #b1110 01100101 00001000 01101111 11100101 00100000 00101110 10001110 = 1.0260616E+19
>> Integer-length: 64
>> 
>> 
>> 
>> READ-VAL:
>> 
>> #<(INTEGER 536870912) #xE65086FE5202E8E>
>> --------------------
>> Value: 1037244565857250958 = #xE65086FE5202E8E = #o71450206774510027216 = #b1110 01100101 00001000 01101111 11100101 00100000 00101110 10001110 = 1.0372446E+18
>> Integer-length: 60
>> 
>> 
>> As you see, it prints the same binary representation, but Integer-length: 64 vs Integer-length: 60
>> 
>> 
>> Is it a CCL bug?
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