[PATCH] D114996: Add logic `or` fold

[Mehrnoosh Heidarpour via Phabricator via llvm-commits]

MehrHeidar created this revision.
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Add logic `or` fold:    `(A ^ B) | (~A | B) --> -1`

https://alive2.llvm.org/ce/z/PMtdYB

Test cases with base results are added in D114992 <https://reviews.llvm.org/D114992>


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D114996

Files:
  llvm/lib/Analysis/InstructionSimplify.cpp


Index: llvm/lib/Analysis/InstructionSimplify.cpp
===================================================================
--- llvm/lib/Analysis/InstructionSimplify.cpp
+++ llvm/lib/Analysis/InstructionSimplify.cpp
@@ -2226,6 +2226,12 @@
       match(Y, m_c_Or(m_Specific(A), m_Specific(B))))
     return ConstantInt::getAllOnesValue(Ty);
 
+  // (A ^ B) | (~A | B) --> -1
+  // (A ^ B) | (~B | A) --> -1
+  if (match(X, m_c_Or(m_Not(m_Value(A)), m_Value(B))) &&
+      match(Y, m_c_Xor(m_Specific(A), m_Specific(B))))
+    return ConstantInt::getAllOnesValue(Ty);
+
   return nullptr;
 }
 


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