[llvm] X86: Add pattern for optimized BLSIC IR form (PR #209814)

[Simon Pilgrim via llvm-commits]

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@@ -125,6 +125,11 @@ let Predicates = [HasTBM] in {
   def : Pat<(or GR64:$src, (add GR64:$src, -1)),
             (BLSFILL64rr GR64:$src)>;
 
+  def : Pat<(xor (and GR32:$src, (sub 0, GR32:$src)), -1),
+            (BLSIC32rr GR32:$src)>;
+  def : Pat<(xor (and GR64:$src, (sub 0, GR64:$src)), -1),
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RKSimon wrote:

replace sub 0, x with ineg x

https://github.com/llvm/llvm-project/pull/209814