[llvm] [SLP] Check for extracts, being replaced by original scalars, for user nodes (PR #149572)

[Craig Topper via llvm-commits]

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@@ -13784,7 +13929,8 @@ BoUpSLP::getEntryCost(const TreeEntry *E, ArrayRef<Value *> VectorizedVals,
   case Instruction::Trunc:
   case Instruction::FPTrunc:
   case Instruction::BitCast: {
-    auto SrcIt = MinBWs.find(getOperandEntry(E, 0));
+    auto SrcIt =
+        MinBWs.empty() ? MinBWs.end() : MinBWs.find(getOperandEntry(E, 0));
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topperc wrote:

Why do we need to check empty? Won't find return MinBWs.end() if it is empty?

https://github.com/llvm/llvm-project/pull/149572