Added InstCombine Transform for patterns:

"((~A & B) | A) -> (A | B)" and "((A & B) | ~A) -> (~A | B)"

Original Patch credit to Ankit Jain !!

Differential Revision: http://reviews.llvm.org/D4591

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213676 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index 431f7323511332cd57bc31953c3e9acd0ae669a7..ef6a848357e16e47288030487f6b6491d9506958 100644 (file)
--- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -1988,6 +1988,16 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
     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))) &&

diff --git a/test/Transforms/InstCombine/or.ll b/test/Transforms/InstCombine/or.ll
index 1cd897ee90c6b77926277cf07bd054e7137f87ba..1a493df6153fb23cd3a91ab59e8d69860d6bea70 100644 (file)
--- a/test/Transforms/InstCombine/or.ll
+++ b/test/Transforms/InstCombine/or.ll
@@ -408,3 +408,22 @@ define i32 @test38(i32* %xp, i32 %y) {
   %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
+}