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Re: Questions on data transfer and non-arithmetic handling rules



On Sat, 30 Apr 2011 14:26:33 -0600 Charles Stevens wrote:

1)  I do not find any rule offhand in IEEE Std 754-2008 
   Clause 5.4.2 or elsewhere that says what happens when 
   the "source" item is exactly the same format (and encoding) 
   as the "sink" item.  My personal assumption is that this 
   would be a "bit-for-bit" transfer, with no reformatting at 
   all, and that's what the COBOL rules specify.   

QUESTION:  Is there a rule that specifies this?  

A very similar question:
Must "conversion" to same type of a signaling NaN trigger? 

IEEE allows either way.
    Signal required logic:
    5.1 Overview:  General-computational operations -- might signal
    5.4 formatOf general-computational operations
    5.4.2 convertFormat() -- is one "conversion" operator
    7.2 Invalid operation -- a) any general-computational ... operation
        on a sNaN

    No signal allowed logic:
    5.1 Overview:  Quiet-computational operations -- do not signal
    5.5 Quiet-computational operations
    5.5.1 Sign bit operations -- ... signal no exception.
        copy(x) -- is the other "conversion" operator

---
Fred J. Tydeman        Tydeman Consulting
tydeman@xxxxxxxxx      Testing, numerics, programming
+1 (775) 358-9748      Vice-chair of PL22.11 (ANSI "C")
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