[llvm] [Instructions] cache computed shufflevector properties (PR #115536)

[Nikita Popov via llvm-commits]

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@@ -1903,6 +1917,27 @@ class ShuffleVectorInst : public Instruction {
 
   SmallVector<int, 4> ShuffleMask;
   Constant *ShuffleMaskForBitcode;
+  ShuffleMaskAttrs ShuffleAttrs;
+
+  // (Re)compute the shuffle mask attributes.
+  void computeShuffleAttrs() {
+    ShuffleAttrs = {}; // reset
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nikic wrote:

Not needed, as you're reassigning all members anyway.

https://github.com/llvm/llvm-project/pull/115536