GCC builtins in LDC - compiler interoperability

[David Nadlinger]

On 16 Jul 2020, at 0:31, Cecil Ward via digitalmars-d-ldc wrote:
> Oh, shame. There’s no __builtin_unreachable in ldc? I wonder if I 
> could work around this with LDC then.

As a general note, LLVM tends not to provide intrinsics with semantics 
that can also be cleanly modelled in the regular LLVM IR. Clang 
implements virtually all GCC intrinsics in the respective header files, 
but does so by providing equivalent implementations manually for many of 
them.

As pointed out in the other response, you can easily access the 
functionality from LDC through inline IR still. A project to write an 
automatic converter to provide full GCC compatibility by building on 
Clang's implementation might be interesting, though.

  — David