On Wednesday, 12 December 2012 at 14:39:40 UTC, Michael wrote:
Machine/hardware have a explicitly defined register size and does know nothing about sign and data type. fastest operation is unsigned and fits to register size.
Frankly, the hardware knows nothing about classes and about virtual methods, neither.
The question is: why the DEVELOPER should know about that register size? There are many other things that the developer is unaware of (read SSE instructions) and those are optimized behind his back.
The choice to promote to the fastest type is a sweet thing for the compiler, but a burden for the developer.
OTOH, I *never* asked for compulsory promotion, just mimicking it. (in fact, I was not asking for anything, just addressed a question) The idea is to guarantee, by the compiler, that the final result of an integral arithmetic expression is AS IF all integrals there are promoted to some widest-integral type.
Actual promotion would be made only if the compiler believes that's really necessary.
In the current implementattion too, speed is lost as long as you have a long there, as you need promotion further than int.
