Re: 64-bit unsigned integer?

["Dan'l Miller" <optikos@verizon.net>]

If anyone really needed the processor-overflow-bit-based implementation for speed efficiency, then the presence of Dmitry's IF comparisons for the powers-of-2 corresponding to the unconstrained integer type could conceivably be checked easily as a new local optimization peephole (i.e., use the processor's check-the-overflow-bit test-instruction instead of using the processor's subtraction-based comparison instructions).

If open-source Ada compiler, you could add it yourself (or turn on for Ada that optimization that might exist for C already), and submit it for merge into the repository.  If closed-source Ada compiler, you could pay your vendor to add it.  Either way it is more of an optimizer issue than a language-definition issue.  Either open-source or closer-source way, if you want it badly enough (e.g., because you have hard performance-analysis data to show management), you can expend some money and/or time and make it happen yourself using Dmitry's approach plus overflow-bit-test optimization to make Dmitry's software if statements be a few differences in generated instructions, analogous to multiplying/dividing by powers of 2 being instead generated as shift left/right instructions.  Leveraging the libraries-are-preferred-henceforth view, new optimizer enhancements go hand-in-hand henceforth with each new oft-utilized high-performance-required snippet of source code in a library.  And thus the effort & your audience focus shifts from 1) language architects on the very front end to 2) compiler-backend developers.