__int128 and vectorization?

Revision en1, by collapse, 2021-04-28 20:49:48

Does anyone know why __int128 seems to use 64-bit operations instead of SIMD instructions?

In this demo, 64-bit instructions are used but switching __int128 with any smaller type (int, long long, etc.) enables vectorization + unrolling.

Is using 64-bit operations just faster than loading into/out of the 128-bit registers?

Tags simd, vectorization

History

 
 
 
 
Revisions
 
 
  Rev. Lang. By When Δ Comment
en1 English collapse 2021-04-28 20:49:48 391 Initial revision (published)