It's the width of the instruction that matters, not the ISA extension it came from. So if you use a fancy AVX-512 instruction but only with xmm (128-bit) regs, it behaves the same as any other SSE 128-bit instructions. So you can get a lot of benefit from the new AVX-512 instructions and features like included masking and broadcasting even if you don't use the full width instructions because you want to avoid the slowdown.
I helped write this article: https://lemire.me/blog/2018/09/07/avx-512-when-and-how-to-use-these-new-instructions/ which answers some of the other questions such as if a single instruction causes a frequency shift. -- You received this message because you are subscribed to the Google Groups "mechanical-sympathy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
