[PATCH] D123803: [WIP][llvm] A Unified LTO Bitcode Frontend

Fri May 19 17:04:43 PDT 2023

ormris added inline comments.

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Comment at: llvm/lib/Passes/PassBuilder.cpp:1146
+      else
+        MPM.addPass(buildLTOPreLinkDefaultPipeline(L));
     } else if (Matches[1] == "lto-pre-link") {
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tejohnson wrote:
> It is a bit odd to see that under unified LTO the regular LTO "pre-link" pipeline is used during the post link phase. I don't remember the reasons for this, maybe it is in the RFC, but it at least needs a clear comment.
After looking into this, it appears that this was added for testing purposes a while back, but is no longer in use. The correct pipelines are setup by the various frontends. While it's technically not a necessary part of this patch, I'd like to make sure that `opt --passes="thinlto-pre-link<O1>" --unified-lto` does the right thing, so moving it to the prelink condition seems best.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D123803/new/

https://reviews.llvm.org/D123803