On 16 May 2016 at 06:02, Manu via Digitalmars-d <digitalmars-d@puremagic.com> wrote: > > I'm not interested in C/C++, I gave some anecdotes where it's gone > wrong for me too, but regardless; generally, they do match, and I > can't think of a single modern example where that's not true. If you > *select* fast-math, then you may generate code that doesn't match, but > that's a deliberate selection. > > If I want 'real' math (in CTFE or otherwise), I will type "real". It > is completely unreasonable to reinterpret the type that the user > specified. CTFE should execute code the same way runtime would execute > the code (without -ffast-math, and conformant ieee hardware). This is > not a big ask. > > Incidentally, I made the mistake of mentioning this thread (due to my > astonishment that CTFE ignores float types) out loud to my > colleagues... and they actually started yelling violently out loud. > One of them has now been on a 10 minute angry rant with elevated tone > and waving his arms around about how he's been shafted by this sort > behaviour so many times before. I wish I recorded it, I'd love to have > submit it as evidence.
It isn't all bad. Most the time you'll never notice. :-) I can't think of a case of the top of my head where too much precision caused a surprise. It's always when there is too little: https://issues.dlang.org/show_bug.cgi?id=16026 And I think the it's about that time of the year when I remind people of gcc bug 323, and this lovely blog post. http://blog.jwhitham.org/2015/04/gcc-bug-323-journey-to-heart-of.html
