[PATCH] Added InstCombine Transform for pattern "((~A & B) | A) -> (A | B)"

suyog suyog.sarda at samsung.com
Tue Jul 22 11:18:28 PDT 2014


Closed by commit rL213676 (authored by @suyog).

REPOSITORY
  rL LLVM

http://reviews.llvm.org/D4591

Files:
  llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
  llvm/trunk/test/Transforms/InstCombine/or.ll

Index: llvm/trunk/test/Transforms/InstCombine/or.ll
===================================================================
--- llvm/trunk/test/Transforms/InstCombine/or.ll
+++ llvm/trunk/test/Transforms/InstCombine/or.ll
@@ -408,3 +408,22 @@
   %or = or i32 %x, %sext
   ret i32 %or
 }
+
+define i32 @test39(i32 %a, i32 %b) {
+; CHECK-LABEL: test39(
+; CHECK-NEXT: %or = or i32 %a, %b
+ %xor = xor i32 %a, -1
+ %and = and i32 %xor, %b
+ %or = or i32 %and, %a
+ ret i32 %or
+}
+
+define i32 @test40(i32 %a, i32 %b) {
+; CHECK-LABEL: test40(
+; CHECK-NEXT:   %1 = xor i32 %a, -1 
+; CHECK-NEXT: %or = or i32 %1, %b
+ %and = and i32 %a, %b
+ %xor = xor i32 %a, -1
+ %or = or i32 %and, %xor
+ ret i32 %or
+}
Index: llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
===================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -1988,6 +1988,16 @@
     return BinaryOperator::CreateXor(NOr, C1);
   }
 
+  // ((~A & B) | A) -> (A | B)
+  if (match(Op0, m_And(m_Not(m_Value(A)), m_Value(B))) &&
+      match(Op1, m_Specific(A)))
+    return BinaryOperator::CreateOr(A, B);
+
+  // ((A & B) | ~A) -> (~A | B)
+  if (match(Op0, m_And(m_Value(A), m_Value(B))) &&
+      match(Op1, m_Not(m_Specific(A))))
+    return BinaryOperator::CreateOr(Builder->CreateNot(A), B);
+
   // (A & C)|(B & D)
   Value *C = nullptr, *D = nullptr;
   if (match(Op0, m_And(m_Value(A), m_Value(C))) &&
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