Any usable SIMD implementation?

[Manu via Digitalmars-d]

On 5 April 2016 at 20:30, Walter Bright via Digitalmars-d
<digitalmars-d at puremagic.com> wrote:
> On 4/5/2016 2:39 AM, 9il wrote:
>>
>> On Tuesday, 5 April 2016 at 08:34:32 UTC, Walter Bright wrote:
>>>
>>> On 4/4/2016 11:10 PM, 9il wrote:
>>> I still don't understand why you cannot just set '-version=xxx' on the
>>> command
>>> line and then switch off that version in your custom code.
>>
>>
>> I can do it, however I would like to get this information from compiler.
>> Why?
>>
>> 1. This would help to eliminate configuration bugs.
>> 2. This would reduce work for users and simplified user experience.
>> 3. This is possible and not very hard to implement if I am not wrong.
>
>
>
> Where does the compiler get the information that it should compile for, say,
> AFX?

I would add that GDC and LDC have such compiler flags and it's
possible that they could pass the state of those flags through as
versions, but all compilers need to agree on the set of versions that
will be defined for this purpose. If DMD users express them as
-version=[STANDARD_VERSION_NAME], that's fine, I guess, but a proper
flag would help avoid the situation where people get the version names
wrong, and it feels a little bit more deliberate.
Setting a version this way might lead them to presume that it's just
an arbitrary setting by the author of the build script, and not
actually an agreed standard name that GDC and LDC also produce from
their compiler flags.

But at very least, the important detail is that the version ID's are
standardised and shared among all compilers.