[llvm] [SLP] Loop aware cost model/tree building (PR #150450)

[Ryan Buchner via llvm-commits]

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@@ -15211,6 +15290,62 @@ TTI::CastContextHint BoUpSLP::getCastContextHint(const TreeEntry &TE) const {
   return TTI::CastContextHint::None;
 }
 
+/// Get the assumed loop trip count for the loop \p L.
+static unsigned getLoopTripCount(const Loop *L, ScalarEvolution &SE) {
+  if (LoopAwareTripCount == 0)
+    return 1;
+  if (unsigned Scale = SE.getSmallConstantTripCount(L)) {
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bababuck wrote:

Is there a way to test PGO in LIT tests?

https://github.com/llvm/llvm-project/pull/150450