[llvm] [DAG] SimplifyDemandedVectorElts - add handling for INT<->FP conversions (PR #117884)

[Matt Arsenault via llvm-commits]

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@@ -3736,6 +3736,14 @@ bool TargetLowering::SimplifyDemandedVectorElts(
       KnownUndef.clearAllBits();
     }
     break;
+  case ISD::SINT_TO_FP:
+  case ISD::UINT_TO_FP:
+  case ISD::FP_TO_SINT:
+  case ISD::FP_TO_UINT:
+    if (SimplifyDemandedVectorElts(Op.getOperand(0), DemandedElts, KnownUndef,
+                                   KnownZero, TLO, Depth + 1))
+      return true;
+    break;
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arsenm wrote:

Is the fallthrough to the undef handling tested (not sure this is actually a useful path)

https://github.com/llvm/llvm-project/pull/117884