[llvm] [VPlan] Simplify pow-of-2 (mul|udiv) -> (shl|lshr) (PR #172477)

[Luke Lau via llvm-commits]

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@@ -291,7 +291,8 @@ struct Recipe_match {
       return false;
 
     if (R->getNumOperands() != std::tuple_size<Ops_t>::value) {
-      assert(Opcode == Instruction::PHI &&
+      auto *RepR = dyn_cast<VPReplicateRecipe>(R);
+      assert((Opcode == Instruction::PHI || RepR && RepR->isPredicated()) &&
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lukel97 wrote:

How come we need this bit? Does the udiv simplification match on a predicated VPReplicateRecipe or something? 

https://github.com/llvm/llvm-project/pull/172477