[PATCH] D155600: [AIX][TLS] Produce a faster local-exec access sequence with -maix-small-local-exec-tls (And optimize when load/store offsets are 0)

Mon Jul 24 05:41:40 PDT 2023

hubert.reinterpretcast added inline comments.

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Comment at: llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp:7621-7622
       // For these cases, the immediate may not be divisible by 4, in
       // which case the fold is illegal for DS-form instructions.  (The
       // other cases provide aligned addresses and are always safe.)
+      if (RequiresMod4Offset && !HasAIXSmallLocalExecTLS &&
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The comment is out-of-date given the number of `RequiresMod4Offset` checks in the function. It seems the comment is bolstering the legitimacy of outdated code. The check on `dyn_cast<ConstantSDNode>(ImmOpnd)` further below seems to be a better version of the code here. Perhaps the code here should just be removed?

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Comment at: llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp:7697
       //     requirements.
       if (auto *C = dyn_cast<ConstantSDNode>(ImmOpnd)) {
         Offset += C->getSExtValue();
----------------
Note: Looks like better version of the code is here.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D155600/new/

https://reviews.llvm.org/D155600