[llvm] [Xtensa][NFC] Use compact enum for CPUNames/features (PR #206954)

[Fangrui Song via llvm-commits]

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@@ -19,28 +20,21 @@ namespace llvm {
 
 namespace Xtensa {
 struct CPUInfo {
-  StringLiteral Name;
   CPUKind Kind;
   uint64_t Features;
 };
 
-struct FeatureName {
-  uint64_t ID;
-  const char *NameCStr;
-  size_t NameLength;
-
-  StringRef getName() const { return StringRef(NameCStr, NameLength); }
-};
-
-const FeatureName XtensaFeatureNames[] = {
-#define XTENSA_FEATURE(ID, NAME) {ID, "+" NAME, sizeof(NAME)},
+constexpr EnumStringDef<uint64_t> FeatureNameDefs[] = {
+#define XTENSA_FEATURE(ID, NAME) {{NAME}, ID},
 #include "llvm/TargetParser/XtensaTargetParser.def"
 };
+static constexpr auto FeatureNames = BUILD_ENUM_STRINGS(FeatureNameDefs);
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MaskRay wrote:

static is redundant: non-volatile const (implied by constexpr) has the internal linkage

https://github.com/llvm/llvm-project/pull/206954