Inter-compiler portability of asm between gdc and ldc2 (and dmd)

[kinke]

On Wednesday, 15 July 2020 at 13:02:40 UTC, Cecil Ward wrote:
> On Wednesday, 15 July 2020 at 09:10:10 UTC, rikki cattermole 
> wrote:
>> On 15/07/2020 8:17 PM, kinke wrote:
>>> You're not up-to-date, LDC supports gdc/gcc-style inline asm 
>>> since version 1.21.
>>
>> D's wiki needs updating then. I searched for this information 
>> there and it wasn't there.
>
> I am struggling to find documentation regarding LDC. The 
> runtime library for instance. Do please forgive me if it’s just 
> me being useless. I’m on powerful drugs for pain which make me 
> very woozy. A poor excuse :-)
>
> Could someone hit me with some good urls for relevant 
> LDC-specifics.

I don't think there are any docs about druntime LDC-specifics - 
the only thing which should be of relevance for the user are some 
extra LDC modules in the `ldc` top-level 'package', in particular 
ldc.intrinsics for LLVM intrinsics, ldc.attributes for UDAs, 
ldc.llvmasm for LDC-specific __asm and __ir (inline asm and LLVM 
IR), ldc.dcompute for dcompute, and (auto-generated, depending on 
LLVM version) gccbuiltins_<arch> for GCC builtins compatibility.

https://wiki.dlang.org/LDC-specific_language_changes contains 
some infos, but the more interesting files (ldc.intrinsics, 
ldc.attributes) should be mostly self-explanatory.

We obviously try to employ any LLVM intrinsics wherever we can in 
regular druntime and Phobos (e.g., core.bitop and std.math), so 
that the user doesn't have to use them manually.