!!!Please add intrinsics module for DMD DRuntime!!!

[rikki cattermole via Digitalmars-d]

On 23/11/2016 1:46 PM, Walter Bright wrote:
> On 11/22/2016 5:31 AM, Ilya Yaroshenko wrote:
>> Please add a module (core.intrinsics ?) which will contain all DMD
>> intrinsics
>> similar to ldc.intrinsics. After each DMD release it is not clear what is
>> intrinsics and what is not. I need BSF intrinsics for Better C library
>> Mir
>> Random [1], which should work without linking with DRuntime and
>> Phobos. I can
>> use ldc.intrinsics for LDC, but have no idea about DMD. I want BSR and
>> BSF
>> instructions to be generated instead of current _software_
>> implementation in
>> core.bitop.
>>
>> ==================
>> Philosophical Questions:
>>
>> 1. Why hight level stuff like BitRange is in core.bitop, but not in
>> std.bitmanip? If it should be in core, why it is public?
>>
>> 2. Why bsf and bsr do NOT use hardware instructions anymore?
>> ==================
>>
>> Please ping me for Phobos and DRuntime PRs if they are related to math
>> and
>> numeric issues.
>
>
> The definitive list of dmd intrinsics is here:
>
>   https://github.com/dlang/dmd/blob/master/src/toir.d#L349
>
> It is definitive in the sense that it is what dmd actually does, rather
> than what any documentation says it does :-)
>
> There reason there isn't a specific core.intrinsics module is that
> essentially any function in the library could be made an intrinsic by an
> implementation, and it is up to the implementation to make such choices.
> Therefore, making a function an intrinsic should not necessitate moving
> its location.
>
> The bodies of 'intrinsic' functions exist to:
>
> 1. provide a reference implementation that documents what it does
>
> 2. provide a fallback if some implementation decides to not make it an
> intrinsic. Such decisions are left up to the implementation.
>
> 3. the bodies are needed if the address of an intrinsic function is taken.
>
> If an implementation does decide to make a certain function an
> intrinsic, the function is not referenced from the object file and the
> library does not need to be linked to.
>
> bsr and bsf are dmd intrinsics. It's easy enough to verify by running
> obj2asm on a dmd generated object file, and then grepping it for bsr/bsf
> instruction mnemonics.

Most of those intrinsics are in std.math.
These things are why I failed to split std.math up.

Pretty please can we get them moved out?