[llvm] [DAG] canCreateUndefOrPoison - remove isGuaranteedNotToBeUndefOrPoison check for shift nodes (PR #146502)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-selectiondag

Author: Simon Pilgrim (RKSimon)

<details>
<summary>Changes</summary>

No longer necessary now that #<!-- -->146490 has landed - we still have the test coverage from #<!-- -->94145 that covers this.

---
Full diff: https://github.com/llvm/llvm-project/pull/146502.diff


1 Files Affected:

- (modified) llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (+1-3) 


``````````diff
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index ad941a1964683..4ec6be534e278 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -5616,9 +5616,7 @@ bool SelectionDAG::canCreateUndefOrPoison(SDValue Op, const APInt &DemandedElts,
   case ISD::SRA:
     // If the max shift amount isn't in range, then the shift can
     // create poison.
-    return !isGuaranteedNotToBeUndefOrPoison(Op.getOperand(1), DemandedElts,
-                                             PoisonOnly, Depth + 1) ||
-           !getValidMaximumShiftAmount(Op, DemandedElts, Depth + 1);
+    return !getValidMaximumShiftAmount(Op, DemandedElts, Depth + 1);
 
   case ISD::SCALAR_TO_VECTOR:
     // Check if we demand any upper (undef) elements.

``````````

</details>


https://github.com/llvm/llvm-project/pull/146502