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

[Anton Afanasyev via Phabricator via llvm-commits]

anton-afanasyev marked an inline comment as done.
anton-afanasyev added inline comments.


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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()) {
----------------
fhahn wrote:
> 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?
Sure, thanks, dit it that way. Potentially this could be not NFC and improve handling of NotConstant operand, but SCCP doesn't use NotConstant state, so actually no change at all.


Repository:
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  https://reviews.llvm.org/D112721/new/

https://reviews.llvm.org/D112721