[fpc-devel] The new XMM intrinsics
florian at freepascal.org
Sat Jan 18 19:17:48 CET 2020
Am 18.01.20 um 18:52 schrieb J. Gareth Moreton:
> I think more than anything I would like to see a degree of "ease of use"
> for the SIMD intrinsics, since modifying __m128 data in C/C++ is not
> that straightforward.
... because there exist in general no instructions to do so, e.g. you
cannot access a xmm register indexed with sse. Those intrinsics provide
only what the CPU can do directly.
> Just as a straightforward example, what might be
> the best way to ensure these following record types are compatible with
> the __m128 data types?
> *type *TVector4 = *record*
> X, Y, Z, W: Single;
> *end*; // compatible with __m128f
> *type *TComplex = *record*
> Re, Im: Double;
> *end*; // compatible with __m128d
> Programmers on their own projects, whether it be a game or a
> mathematical program, would much rather work with those constructs if it
> can be helped... or at least I would.
This is another level of abstraction, the intrinsics aim really at a
direct usage of the sse/avx instructions. No more, no less.
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