[PATCH] D126896: [DAGCombiner][RISCV] Improve computeKnownBits for (smax X, C) where C is non-negative.

[Jay Foad via Phabricator via llvm-commits]

foad added inline comments.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:3709
+        Known.Zero.setHighBits(std::min(SignBits, ValueLow.getNumSignBits()));
+        break;
+      }
----------------
If you break here you don't call smin/smax below, which could compute known low order bits in the result. Wouldn't it be better to add this new code after the calls to smin/smax below, to improve the result that they calculate?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D126896/new/

https://reviews.llvm.org/D126896