[PATCH] D112721: [SCCP] Tune cast instruction handling for overdefined operand

[Florian Hahn via Phabricator via llvm-commits]

fhahn added a comment.

Thanks for the update! I think with the latest changes applied, I noticed another potential simplification.



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Comment at: llvm/lib/Transforms/Utils/SCCPSolver.cpp:818
     markConstant(&I, C);
-  } else if (OpSt.isConstantRange() && I.getDestTy()->isIntegerTy()) {
+  } else if ((OpSt.isConstantRange() || OpSt.isOverdefined()) &&
+             I.getDestTy()->isIntegerTy()) {
----------------
IIUC we need to check for range or overdefined here explicitly because we implicitly do not do anything for under or overdefined.

Could we instead add an early bail out on undeforunknown, only check for integer types here (and not constant range and overdefined) and drop the markOverdefined in the else of below?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D112721/new/

https://reviews.llvm.org/D112721