[FEATURE] multiply int64s as int32s

[DenisYaroshevskiy]

on x86 while _mm256_mullo_epi32 exists, _mm256_mullo_epi64 does not.

Clang has some scheme to do it though: https://godbolt.org/z/K8rvrroPT

We should do like clang.

(p.s. _mm256_mullo_epi64 also seems missing from our code)

If this is actually a first issue for someone

Should be fixed somewhere here https://github.com/jfalcou/eve/blob/0faa88d158427d6480ae8b53e6762de46606ec65/include/eve/module/core/regular/impl/simd/x86/mul.hpp#L61

Here is how to build https://jfalcou.github.io/eve/dev_cmake.html

Some tests https://github.com/jfalcou/eve/blob/main/test/unit/module/core/mul.cpp unit.core.mul.exe is the target

[ignorant05]

I‘d like to take this issue.

[DenisYaroshevskiy]

Awesome. Let's say you got it for a month, if you don't touch it by then - it's up for grabs again. Let me know if you need help.