[llvm] [SelectionDAG]: Deduce known bits from SMIN and SMAX (PR #85722)

[Craig Topper via llvm-commits]

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@@ -4017,6 +4015,16 @@ KnownBits SelectionDAG::computeKnownBits(SDValue Op, const APInt &DemandedElts,
       }
     }
 
+    // For SMIN, if CstHigh is negative we know the result will be
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topperc wrote:

> smin_known_zero_2
> 
> it mirrors smax's logic

I don't see how that test could test something that uses ComputeNumSignBits.

https://github.com/llvm/llvm-project/pull/85722