[PATCH] D88072: [X86] Improve demanded bits for X86ISD::BEXTR.

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


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Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:38341
+      if (Length == 0) {
+        Known.setAllZero();
+        return false;
----------------
Return a new zero constant if we manage to get here?


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Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:38352
+        Known = Known.zextOrTrunc(BitWidth);
+        return false;
+      }
----------------
craig.topper wrote:
> RKSimon wrote:
> > Maybe just call computeKnownBits to avoid code duplication?
> Won’t that be more costly for compile time?
Yeah - probably not worth it


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D88072/new/

https://reviews.llvm.org/D88072