[llvm] [VPlan] Speed up VPSlotTracker by using ModuleSlotTracker (PR #139881)

[Florian Hahn via llvm-commits]

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@@ -1441,7 +1441,23 @@ void VPSlotTracker::assignName(const VPValue *V) {
   std::string Name;
   if (UV) {
     raw_string_ostream S(Name);
-    UV->printAsOperand(S, false);
+    if (MST) {
+      UV->printAsOperand(S, false, *MST);
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fhahn wrote:

Might be worth pulling out the code that gets the name for a VPValue, can simplify have an early exit for the cases where no ModuleSlotTracker is needed and then create it if needed and use it.

https://github.com/llvm/llvm-project/pull/139881