[PATCH] D115016: [CostModel][X86] Add i64 mul cost for avx as 1cy

[Haohai, Wen via Phabricator via llvm-commits]

HaohaiWen added a comment.

Can we first fix imul i64 cost for avx512 before merging D46276 <https://reviews.llvm.org/D46276>? It's 1 cy for all avx512 target.

> A more critical feature would be to 'add' costs correctly for throughput cost kinds - depending on pipe usage etc. - instead of just numerically adding the costs together, which only makes sense for latency / size cost kinds.

We may need to fix resource_cycles for many x86 schedmodels (e.g. SKL, SKX) to get a correct throughput. Most instructions set resource_cycles to 1 for each uop which gets wrong throughput.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D115016/new/

https://reviews.llvm.org/D115016