Florian Hahn 90fd99c079
Recommit "[VPlan] First step towards VPlan cost modeling. (#92555)"
This reverts commit 46080abe9b136821eda2a1a27d8a13ceac349f8c.

Extra tests have been added in 52d29eb287.

Original message:
This adds a new interface to compute the cost of recipes, VPBasicBlocks,
VPRegionBlocks and VPlan, initially falling back to the legacy cost model
for all recipes. Follow-up patches will gradually migrate recipes to
compute their own costs step-by-step.

It also adds getBestPlan function to LVP which computes the cost of all
VPlans and picks the most profitable one together with the most
profitable VF.

The VPlan selected by the VPlan cost model is executed and there is an
assert to catch cases where the VPlan cost model and the legacy cost
model disagree. Even though I checked a number of different build
configurations on AArch64 and X86, there may be some differences
that have been missed.

Additional discussions and context can be found in @arcbbb's
https://github.com/llvm/llvm-project/pull/67647 and
https://github.com/llvm/llvm-project/pull/67934 which is an earlier
version of the current PR.

PR: https://github.com/llvm/llvm-project/pull/92555
2024-06-14 12:33:48 +01:00
..
2023-09-04 09:17:18 +01:00