llvm-project

e23ab733 - [VPlan] Don't convert widen recipes to VP intrinsics in EVL transform (#127180)

[VPlan] Don't convert widen recipes to VP intrinsics in EVL transform (#127180) This is a copy of #126177, since it was automatically and permanently closed because I messed up the source branch on my remote This patch proposes to avoid converting widening recipes to VP intrinsics during the EVL transform. IIUC we initially did this to avoid `vl` toggles on RISC-V. However we now have the RISCVVLOptimizer pass which mostly makes this redundant. Emitting regular IR instead of VP intrinsics allows more generic optimisations, both in the middle end and DAGCombiner, and we generally have better patterns in the RISC-V backend for non-VP nodes. Sticking to regular IR instructions is likely a lot less work than reimplementing all of these optimisations for VP intrinsics, and on SPEC CPU 2017 we get noticeably better code generation.