[llvm] [LV] Reduce register usage for scaled reductions (PR #133090)

[Florian Hahn via llvm-commits]

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@@ -71,6 +71,11 @@ raw_ostream &llvm::operator<<(raw_ostream &OS, const VPValue &V) {
   V.print(OS, SlotTracker);
   return OS;
 }
+raw_ostream &llvm::operator<<(raw_ostream &OS, const VPRecipeBase &R) {
+  VPSlotTracker SlotTracker(R.getParent()->getPlan());
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fhahn wrote:

`Parent` may be nullptr if the recipe hasn't been added to a plan yet. Would be good to account for that in the general util

https://github.com/llvm/llvm-project/pull/133090