Index: llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
===================================================================
--- llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -1528,8 +1528,14 @@
   if (Value *V = SimplifyUsingDistributiveLaws(I))
     return replaceInstUsesWith(I, V);
 
-  // If this is a 'B = x-(-A)', change to B = x+A.
   Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
+  Value *X;
+  // (X | Y) - Y --> (X | Y) ^ Y
+  // (Y | X) - Y --> (Y | X) ^ Y
+  if (match(Op0, m_OneUse(m_c_Or(m_Value(X), m_Specific(Op1)))))
+    return BinaryOperator::CreateXor(Builder.CreateOr(X, Op1), Op1);
+
+  // If this is a 'B = x-(-A)', change to B = x+A.
   if (Value *V = dyn_castNegVal(Op1)) {
     BinaryOperator *Res = BinaryOperator::CreateAdd(Op0, V);
 
@@ -1554,7 +1560,7 @@
     return BinaryOperator::CreateNot(Op1);
 
   // (~X) - (~Y) --> Y - X
-  Value *X, *Y;
+  Value *Y;
   if (match(Op0, m_Not(m_Value(X))) && match(Op1, m_Not(m_Value(Y))))
     return BinaryOperator::CreateSub(Y, X);
 
Index: llvm/test/Transforms/InstCombine/sub.ll
===================================================================
--- llvm/test/Transforms/InstCombine/sub.ll
+++ llvm/test/Transforms/InstCombine/sub.ll
@@ -1267,6 +1267,38 @@
   ret <2 x i32> %res
 }
 
+define i32 @test70(i32 %A) {
+; CHECK-LABEL: @test70(
+; CHECK-NEXT: [[A:%.*]] = and i32 [[TMP1:%.*]], -124
+; CHECK-NEXT: ret i32 [[A]]
+;
+  %B = or i32 %A, 123
+  %C = sub i32 %B, 123
+  ret i32 %C
+}
+
+define i32 @test71(i32 %A, i32 %B) {
+; CHECK-LABEL: @test71(
+; CHECK-NEXT: [[A:%.*]] = xor i32 [[TMP1:%.*]], -1
+; CHECK-NEXT: [[B:%.*]] = and i32 [[A]], [[TMP2:%.*]]
+; CHECK-NEXT: ret i32 [[B]]
+;
+  %C = or i32 %A, %B
+  %D = sub i32 %C, %B
+  ret i32 %D
+}
+
+define i32 @test72(i32 %A, i32 %B) {
+; CHECK-LABEL: @test72(
+; CHECK-NEXT: [[A:%.*]] = xor i32 [[TMP1:%.*]], -1
+; CHECK-NEXT: [[B:%.*]] = and i32 [[A]], [[TMP2:%.*]]
+; CHECK-NEXT: ret i32 [[B]]
+;
+  %C = or i32 %B, %A
+  %D = sub i32 %C, %B
+  ret i32 %D
+}
+
 define i32 @nsw_inference1(i32 %x, i32 %y) {
 ; CHECK-LABEL: @nsw_inference1(
 ; CHECK-NEXT:    [[X2:%.*]] = or i32 [[X:%.*]], 1024