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Re: patch for merging graphite branch (before tuplification)

Roberto Bagnara wrote:

I think a little clarification is necessary.  It is not strictly true
that the PPL's interface is such that there is a unique correct output
for any input.

I will freely admit to not following all the mathematics here, but this does raise a question for Sebastian.

Sebastian, will the behavior of Graphite be deterministic, in that for a given compiler and a given input program, we can be assured of the same output? (I would assume so, but I would like to check.)

Also, given Roberto's comments about floating-point and such, are we sure that we will get the same results on multiple hosts, if generating code for the same target? It's an important design goal that this be the case, and I'm concerned that differences in floating-point (i.e., default rounding modes, precision of long double, etc.) could make a difference in behavior. I'm not sufficiently knowledgeable about floating-point architectures to know whether explicitly specifying rounding modes and such is sufficient to get the same answer on all hosts, or not.

Thanks,

--
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713

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