[PATCH] D94355: [Passes] Add relative lookup table converter pass

Wed Mar 31 23:31:31 PDT 2021

aeubanks added inline comments.

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Comment at: llvm/test/Other/opt-O3-pipeline-enable-matrix.ll:322-323
 ; CHECK-NEXT:       Simplify the CFG
+; CHECK-NEXT:     Relative Lookup Table Converter
+; CHECK-NEXT:     FunctionPass Manager
 ; CHECK-NEXT:       Annotation Remarks
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aeubanks wrote:
> rnk wrote:
> > Putting a ModulePass in the middle of the CodeGen pass pipeline creates a "pass barrier": now instead of applying every pass to each function in turn, the old pass manager will stop, run this whole-module pass, and then run subseqeunt passes in the next function pass manager on each function in turn. This isn't ideal. @aeubanks, can you follow-up to make sure this is addressed?
> > 
> > We had the same issues with the SymbolRewriter pass, which if you grep for "Rewrite Symbols" you can see has the same issue. I remember writing a patch to fix it, but I guess I never landed it.
> I see "Rewrite Symbols" in the codegen pipeline and yeah it's splitting the function pass manager.
> 
> For this patch, can we just not add the pass to the legacy PM pipeline? It's deprecated and the new PM is already the default for the optimization pipeline.
(https://reviews.llvm.org/D99707 for anybody interested)

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D94355/new/

https://reviews.llvm.org/D94355