[llvm-branch-commits] [RISCV] Set DisableLatencyHeuristic to true (PR #115858)

[Michael Maitland via llvm-branch-commits]

michaelmaitland wrote:

I measured this patch on spec for an in-order and an out-of-order core. 

For the out-of-order core, 557.xz_r saw a regression.
For the in-order core, I see regression on 456.hmmer and 458.sjeng.

I saw no other significant improvements or regressions.

These findings, combined with the fact that latency heuristic is so low on the heuristic list (above only program order), I'm not sure that I see a strong argument to set this to true on either in-order or out-of-order by default.

https://github.com/llvm/llvm-project/pull/115858