From: Suyog Sarda <suyog.sarda@samsung.com>
Date: Fri, 1 Aug 2014 04:50:31 +0000 (+0000)
Subject: This patch implements transform for pattern "( A & (~B)) | (A ^ B) -> (A ^ B)"
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=d05b6c6f2c242d061bf67a134495541adc398f9c;p=oota-llvm.git

This patch implements transform for pattern "( A & (~B)) | (A ^ B) -> (A ^ B)"

Differential Revision: http://reviews.llvm.org/D4652



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214477 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index 60e81ebfd0c..add2f29b341 100644
--- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -2010,6 +2010,16 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
       match(Op1, m_Not(m_Specific(A))))
     return BinaryOperator::CreateOr(Builder->CreateNot(A), B);
 
+  // (A & (~B)) | (A ^ B) -> (A ^ B)
+  if (match(Op0, m_And(m_Value(A), m_Not(m_Value(B)))) &&
+      match(Op1, m_Xor(m_Specific(A), m_Specific(B))))
+    return BinaryOperator::CreateXor(A, B);
+
+  // (A ^ B) | ( A & (~B)) -> (A ^ B)
+  if (match(Op0, m_Xor(m_Value(A), m_Value(B))) &&
+      match(Op1, m_And(m_Specific(A), m_Not(m_Specific(B)))))
+    return BinaryOperator::CreateXor(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 8e2e6ad9677..2fcdfa5f8ce 100644
--- a/test/Transforms/InstCombine/or.ll
+++ b/test/Transforms/InstCombine/or.ll
@@ -449,3 +449,23 @@ define i32 @test42(i32 %a, i32 %b) {
  %or = or i32 %xor, %and
  ret i32 %or
 }
+
+define i32 @test43(i32 %a, i32 %b) {
+; CHECK-LABEL: test43(
+; CHECK-NEXT: %or = xor i32 %a, %b
+ %neg = xor i32 %b, -1
+ %and = and i32 %a, %neg
+ %xor = xor i32 %a, %b
+ %or = or i32 %and, %xor
+ ret i32 %or
+}
+
+define i32 @test44(i32 %a, i32 %b) {
+; CHECK-LABEL: test44(
+; CHECK-NEXT: %or = xor i32 %a, %b
+ %xor = xor i32 %a, %b
+ %neg = xor i32 %b, -1
+ %and = and i32 %a, %neg
+ %or = or i32 %xor, %and
+ ret i32 %or
+}