On 19 November 2012 16:04, Manu <turkey...@gmail.com> wrote: > On 19 November 2012 06:19, Walter Bright <newshou...@digitalmars.com> wrote: >> >> On 11/18/2012 4:31 PM, Manu wrote: >>> >>> If I told you this is how real should be implemented, would you vote ++? >>> What >>> about double? Why? >>> Why not float for that matter? There seems like no reason for the >>> language to >>> define any floating point type at all if you consider this acceptable... >> >> >> Because they are implemented in hardware. It's pretty dang hard for a >> compiler to look at a floating point emulator and figure out "gee, I have a >> nice hardware instruction that does the same thing as this 2K of code!" > > > Right, and this is my point precisely. It's hard for GDC for instance to > hook some complex library because it happens to have hardware to do it. > >>> 'half' isn't some custom float for niche use, it's an established >>> standard, >>> implemented in vastly more hardware than implements 'real'. >> >> >> It's implemented in GPUs, sure, but it is it implemented in hardware that >> D runs on? (I do know about this: >> http://gcc.gnu.org/onlinedocs/gcc/Half_002dPrecision.html) >> >> There is no major technical difficulty in implementing it as a basic type, >> but I want to be sure we've exhausted the library approach first. > > > Well it's available in hardware on basically all mobile devices (that's a > LOT of devices (in the billions)), but even if it's just implemented in > software (x86), the values are consumed by the GPU, and the validity of the > values is no less important. It still seems like a valuable 1st class type; > why shouldn't it enjoy the same casting, assignment, literal, range checking > rules as the rest of the floats? Additionally, convenience and compatibility > with generic code would be significantly improved. > I don't see how it can be made to feel seamless with a lib... and that > sounds like an awful lot more work. > > > Anyway, I'm not desperate for this personally. I just wondered how people > felt about it in general, and if it was something that should/would be > seriously considered.
I'm neither here nor there. I'm just pointing out that you are proposing a dedicated type to be introduced that is supported on only one platform. :-) -- Iain Buclaw *(p < e ? p++ : p) = (c & 0x0f) + '0';
