[PATCH] Added InstCombine transform for pattern "(A & B) ^ ((A ^ C) | B) -> (~A)".

[sonam kumari]

Hi David,Suyog,

Thanks David for pointing out the mistake.I have submitted the patch related to the expression you mentioned.

Thanks Suyog for this valuable information.I have attached the Z3 link for this expression.

Z3 Link : http://rise4fun.com/Z3/kOaU

Please help in reviewing the patch.

Regards,
Sonam.

http://reviews.llvm.org/D4828

Files:
  lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
  test/Transforms/InstCombine/xor2.ll

Index: lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
===================================================================
--- lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -2516,6 +2516,10 @@
     if (match(Op0I, m_Xor(m_Value(A), m_Value(B))) &&
         match(Op1I, m_And(m_Specific(A), m_Specific(B))))
       return BinaryOperator::CreateOr(A, B);
+    // (A & B) ^ ((A ^ C) | B) -> (B | C) ^ A
+    if (match(Op0I, m_And(m_Value(A), m_Value(B))) &&
+        match(Op1I, m_Or(m_Xor(m_Specific(A), m_Value(C)), m_Specific(B))))
+      return BinaryOperator::CreateXor(Builder->CreateOr(B, C), A);
   }
 
   // (A | B)^(~A) -> (A | ~B)
Index: test/Transforms/InstCombine/xor2.ll
===================================================================
--- test/Transforms/InstCombine/xor2.ll
+++ test/Transforms/InstCombine/xor2.ll
@@ -167,3 +167,15 @@
 ; CHECK-NEXT: %1 = and i32 %a, %b
 ; CHECK-NEXT: %xor = xor i32 %1, -1
 }
+
+define i32 @test15(i32 %x, i32 %y, i32 %z) {
+  %and = and i32 %x, %y
+  %xor = xor i32 %x, %z
+  %or = or i32 %xor, %y
+  %xor1 = xor i32 %and, %or
+  ret i32 %xor1
+; CHECK-LABEL: @test15(
+; CHECK-NEXT: %1 = or i32 %y, %z
+; CHECK-NEXT: %xor1 = xor i32 %1, %x
+; CHECK-NEXT: ret i32 %xor1
+}
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