[clang] [llvm] [LV][NFC] Rename PreferPredicateOverEpilogue to PreferTailFolding (PR #191803)

[Luke Lau via cfe-commits]

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@@ -205,36 +205,34 @@ static cl::opt<bool> ForceTargetSupportsMaskedMemoryOps(
     cl::desc("Assume the target supports masked memory operations (used for "
              "testing)."));
 
-// Option prefer-predicate-over-epilogue indicates that an epilogue is undesired,
-// that predication is preferred, and this lists all options. I.e., the
-// vectorizer will try to fold the tail-loop (epilogue) into the vector body
-// and predicate the instructions accordingly. If tail-folding fails, there are
-// different fallback strategies depending on these values:
-namespace PreferPredicateTy {
-  enum Option {
-    ScalarEpilogue = 0,
-    PredicateElseScalarEpilogue,
-    PredicateOrDontVectorize
-  };
-} // namespace PreferPredicateTy
+// Option prefer-tail-folding indicates that an epilogue is undesired, that
+// tail folding is preferred, and this lists all options. I.e., the vectorizer
+// will try to fold the tail-loop (epilogue) into the vector body and the
+// instructions accordingly. If tail-folding fails, there are different fallback
+// strategies depending on these values:
+namespace PreferTailFoldingTy {
+enum Option {
+  PreferEpilogue = 0,
+  FoldTailElseEpilogue,
+  FoldTailOrDontVectorize
+};
+} // namespace PreferTailFoldingTy
 
-static cl::opt<PreferPredicateTy::Option> PreferPredicateOverEpilogue(
-    "prefer-predicate-over-epilogue",
-    cl::init(PreferPredicateTy::ScalarEpilogue),
+static cl::opt<PreferTailFoldingTy::Option> PreferTailFolding(
+    "prefer-tail-folding", cl::init(PreferTailFoldingTy::PreferEpilogue),
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lukel97 wrote:

Whilst we're here I think it would make sense to name the flag something like `tail-folding-policy`, since some of these options aren't "preferences" but hard rules that disable tail folding etc.

https://github.com/llvm/llvm-project/pull/191803