[llvm] [TableGen][DecoderEmitter] Fix decoder reading bytes past instruction (PR #154916)

[Rahul Joshi via llvm-commits]

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@@ -501,28 +516,47 @@ class FilterChooser {
   };
 
 public:
+  /// Constructs a top-level filter chooser.
   FilterChooser(ArrayRef<InstructionEncoding> Encodings,
-                ArrayRef<unsigned> EncodingIDs, unsigned BW,
+                ArrayRef<unsigned> EncodingIDs, unsigned MaxFilterWidth,
                 const DecoderEmitter *E)
-      : Encodings(Encodings), EncodingIDs(EncodingIDs), FilterBits(BW),
-        Parent(nullptr), BitWidth(BW), Emitter(E) {
+      : Encodings(Encodings), EncodingIDs(EncodingIDs), Parent(nullptr),
+        MaxFilterWidth(MaxFilterWidth), Emitter(E) {
+    // Sort encoding IDs once.
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jurahul wrote:

Sounds good. I am approving. I think this and https://github.com/llvm/llvm-project/pull/154934 are mostly independent.

https://github.com/llvm/llvm-project/pull/154916