On 4/8/2013 9:24 AM, Kenneth Zadeck wrote:
So then how does a language like ada work in gcc? My assumption is that most of what you describe here is done in the front end and by the time you get to the middle end of the compiler, you have chosen types for which you are comfortable to have any remaining math done in along with explicit checks for overflow where the programmer asked for them.
That's right, the front end does all the promotion of types
Otherwise, how could ada have ever worked with gcc?
Sometimes we do have to make changes to gcc to accomodate Ada specific requirements, but this was not one of those cases. Of course the back end would do a better job of the range analysis to remove some unnecessary use of infinite precision, but the front end in practice does a good enough job.
