[llvm] [VPlan] Handle single-scalar conds in VPWidenSelectRecipe. (PR #165506)

[via llvm-commits]

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@@ -1286,6 +1286,15 @@ static void simplifyRecipe(VPSingleDefRecipe *Def, VPTypeAnalysis &TypeInfo) {
     return;
   }
 
+  // Look through broadcast of single-scalar when used as select conditions; in
+  // that case the scalar condition can be used directly.
+  if (match(Def,
+            m_Select(m_Broadcast(m_VPValue(C)), m_VPValue(), m_VPValue())) &&
+      vputils::isSingleScalar(C)) {
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ayalz wrote:

Is this redundant (can assert instead) - if Def is a Broadcast its operand C must be a single scalar?

https://github.com/llvm/llvm-project/pull/165506