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[Octave-bug-tracker] [bug #53293] uint64 are truncated


From: jpap
Subject: [Octave-bug-tracker] [bug #53293] uint64 are truncated
Date: Tue, 6 Mar 2018 02:32:54 -0500 (EST)
User-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_3) AppleWebKit/604.5.6 (KHTML, like Gecko) Version/11.0.3 Safari/604.5.6

URL:
  <http://savannah.gnu.org/bugs/?53293>

                 Summary: uint64 are truncated
                 Project: GNU Octave
            Submitted by: jpap
            Submitted on: Mon 05 Mar 2018 11:32:53 PM PST
                Category: Interpreter
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Incorrect Result
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 4.2.1
        Operating System: Mac OS

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Details:

It looks like Octave is truncating the lower 8-bits of a large uint64 number. 
As a result I can't do any simple int64 mathematical operations reliably, nor
can I even define an accurate uint64 constant using the `uint64(...)` syntax.


octave:1> uint64(7189901176607676539) - uint64(7189901176607676416)
ans = 0
octave:2> intmax('uint64')
ans = 18446744073709551615
octave:3> uint64(18446744073709551615) - uint64(18446744073709551600)
ans = 0
octave:4> format hex
octave:5> uint64(18446744073709551615)
ans = ffffffffffffffff
octave:6> uint64(18446744073709551600)
ans = ffffffffffffffff
octave:7> uint64(0x63c7a906c1dd187b)
ans = 63c7a9 6c1dd18 0
octave:8> uint64(0x63c7a906c1dd1800)
ans = 63c7a9 6c1dd18 0
octave:9> uint64(0x63c7a906c1dd1000)
ans = 63c7a9 6c1dd10 0






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  <http://savannah.gnu.org/bugs/?53293>

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