ARM first & default LDC

[Iain Buclaw]

On Monday, 14 December 2020 at 10:48:43 UTC, IGotD- wrote:
>
> There is one thing that worries me. GCC and LLVM contains 
> primitives for optimizations and help for certain features. 
> These primitives are often complicated and takes time to 
> duplicate in the DMD backend. The result is that D will not use 
> the helpful primitives in LLVM and therefore skip certain 
> features that would otherwise be simpler to implement.
>

I think your feelings are misguided, a primitive does not mean it 
must be implemented in the compiler.  Take core.bitop.rol() and 
ror() as one example, these are implemented as a function in 
druntime for DMD and LDC, but are primitives to GDC (LROTATE_EXPR 
and RROTATE_EXPR respectively).  Same also applies to the entire 
core.checkedint module, or the core.varargs module, both of which 
are treated as primitives for GDC as well.

> The DMD backend might be Walter's darling but what if he could 
> move to LLVM, discover all the helpful primitives which perhaps 
> increase the productivity and new ideas might emerge. It's a 
> selling point.

Moving main development to LDC will be the death of D.