[llvm] [LLVM][TableGen][DecoderEmitter] Add wrapper class for `bit_value_t` (PR #146248)

[Rahul Joshi via llvm-commits]

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@@ -252,84 +246,86 @@ class DecoderEmitter {
   StringRef PredicateNamespace;
 };
 
-} // end anonymous namespace
-
 // The set (BIT_TRUE, BIT_FALSE, BIT_UNSET) represents a ternary logic system
 // for a bit value.
 //
 // BIT_UNFILTERED is used as the init value for a filter position.  It is used
 // only for filter processings.
-typedef enum : uint8_t {
-  BIT_FALSE,     // '0'
-  BIT_TRUE,      // '1'
-  BIT_UNSET,     // '?'
-  BIT_UNFILTERED // unfiltered
-} bit_value_t;
-
-static bool ValueSet(bit_value_t V) {
-  return (V == BIT_TRUE || V == BIT_FALSE);
-}
+class BitValue {
+public:
+  enum bit_value_t : uint8_t {
+    BIT_FALSE,     // '0'
+    BIT_TRUE,      // '1'
+    BIT_UNSET,     // '?', printed as '_'
+    BIT_UNFILTERED // unfiltered, printed as '.'
+  };
+
+  BitValue(bit_value_t V) : V(V) {}
+  BitValue(const Init *Init) {
+    if (const BitInit *Bit = dyn_cast<BitInit>(Init))
+      V = Bit->getValue() ? BIT_TRUE : BIT_FALSE;
+    else
+      V = BIT_UNSET;
+  }
+  BitValue(const BitsInit &Bits, unsigned Idx) : BitValue(Bits.getBit(Idx)) {}
+
+  bool isSet(void) const { return V == BIT_TRUE || V == BIT_FALSE; }
+  bool isUnset(void) const { return V == BIT_UNSET; }
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jurahul wrote:

Done

https://github.com/llvm/llvm-project/pull/146248