[PATCH] D86967: [PassManager] Move load/store motion pass after DSE in LTO pipeline.

[Alina Sbirlea via Phabricator via llvm-commits]

asbirlea added a comment.

The idea to have all passes in sequence preserved and use MemorySSA is great. I'm wondering if changing the pass order affects run time (due to potential missed optimizations).
On the other hand, this only affects the LPM, so it may not be as critical due to the plan to switch to the NPM.

The NPM has the passes that take advantage of MSSA combined as DSE+LICM (https://github.com/llvm-mirror/llvm/blob/master/lib/Passes/PassBuilder.cpp#L525) and GVN+MemCpyOpt (https://github.com/llvm-mirror/llvm/blob/master/lib/Passes/PassBuilder.cpp#L504), and GVN+MemCpyOpt+DSE for LTO (https://github.com/llvm-mirror/llvm/blob/master/lib/Passes/PassBuilder.cpp#L1303)
So all cases should be covered by the other "preserve MSSA" patches.

I'll follow up on the llvmdev@ thread regarding testing for the NPM.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D86967/new/

https://reviews.llvm.org/D86967