On Sunday, 3 August 2014 at 19:47:27 UTC, David Bregman wrote:
4. Performance.
Q4a. What level of performance increases are expected of this
proposal, for a representative sample of D programs?
Q4b. Is there any threshold level of expected performance
required to justify this proposal? For example, if a study
determined that the average program could expect a speedup of
0.01% or less, would that still be considered a good tradeoff
against the negatives?
Q4c. Have any works or studies, empirical or otherwise, been
done to estimate the expected performance benefit? Is there any
evidence at all for a speedup sufficient to justify this
proposal?
Q4d. When evaluating the potential negative effects of the
proposal on their codebase, D users may decide it is now too
risky to compile with -release. (Even if their own code has
been constructed with the new assert semantics in mind, the
libraries they use might not). Thus the effect of the proposal
would actually be to decrease the performance of their program
instead of increase it. Has this been considered in the
evaluation of tradeoffs?
I'd like to add:
Q4e: Have other alternatives been taken into consideration that
could achieve the same performance gains, but in a safer way? I'm
particularly thinking about whole program optimization. I suspect
that WPO can prove most of what can only be assumed with asserts.
