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754R refractory unresolved issues



I think the most refractory unresolved issues in 754R have common
elements:

1) one way is better for performance on existing implementations
2) an incompatible different way is better on implementations 
   designed from scratch for even better performance
3) the "obvious" technical solution of allowing an implementation choice 
   between the old way and the new way satisfies everybody except our
   nominal target audience of software developers, who generally prefer
   fewer choices and would regard 754R's failure to choose to be a 
   shirking of responsibilities

In my view, that encapsulates the issues of decimal interchange formats
and of global state (modes and flags).    No clever wording can avoid
the reality that any of these choices has profound implications for
somebody, either in performance or complexity.

With Turing machines, none of these choices are actually impossible
to implement, 
at some price in performance and complexity depending on the hardware.
It's the performance and complexity  that we are arguing about.

I hope that Thursday's attendees will voice some ideas about how to proceed
with these technical matters, as well as with the procedural changes mandated
by the IEEE.

For those who have recently tuned in for the first time, the specifics are

1) better for performance on existing implementations:
   a) decimal interchange format optimized for software implementation
      such as BID or BCD 
   b) in the absence of an explicit declaration otherwise, 
      the modes are propagated dynamically and implicitly 
      from a caller to a callee,
      and the flags are propagated dynamically and implicitly 
      from the callee to the caller (no work required to implement 
      with global state registers)

2) better for performance on new implementations:
   a) decimal interchange format optimized for hardware implementation
      such as DPD
   b) in the absence of an explicit declaration otherwise,
      the modes are not propagated from caller to callee,
      so default modes are in effect,
      and the flags are not propagated from callee to caller

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