Index: llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
===================================================================
--- llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -892,6 +892,15 @@
   if (!match(Op1, m_APInt(C)))
     return nullptr;
 
+  // (X | C2) + C --> (X | C2) ^ C2
+  // (C2 | X) + C --> (C2 | X) ^ C2
+  // iff (C2 == -C)
+  const APInt *C2;
+  if (match(Op0, m_c_Or(m_Value(), m_APInt(C2))) &&
+      *C2 == -*C)
+    return BinaryOperator::CreateXor(Op0,
+                                     ConstantInt::get(Add.getType(), *C2));
+
   if (C->isSignMask()) {
     // If wrapping is not allowed, then the addition must set the sign bit:
     // X + (signmask) --> X | signmask
@@ -906,7 +915,6 @@
   // Is this add the last step in a convoluted sext?
   // add(zext(xor i16 X, -32768), -32768) --> sext X
   Type *Ty = Add.getType();
-  const APInt *C2;
   if (match(Op0, m_ZExt(m_Xor(m_Value(X), m_APInt(C2)))) &&
       C2->isMinSignedValue() && C2->sext(Ty->getScalarSizeInBits()) == *C)
     return CastInst::Create(Instruction::SExt, X, Ty);
Index: llvm/test/Transforms/InstCombine/add.ll
===================================================================
--- llvm/test/Transforms/InstCombine/add.ll
+++ llvm/test/Transforms/InstCombine/add.ll
@@ -978,3 +978,34 @@
   %E = add i32 %D, 1
   ret i32 %E
 }
+
+; (X | C1) + C2 --> (X | C1) ^ C1 iff (C1 == -C2)
+define i32 @test44(i32 %A) {
+; CHECK-LABEL: @test44(
+; CHECK-NEXT:    [[TMP1:%.*]] = and i32 [[A:%.*]], -124
+; CHECK-NEXT:    ret i32 [[TMP1]]
+;
+  %B = or i32 %A, 123
+  %C = add i32 %B, -123
+  ret i32 %C
+}
+
+define i32 @test44_commuted(i32 %A) {
+; CHECK-LABEL: @test44_commuted(
+; CHECK-NEXT:    [[TMP1:%.*]] = and i32 [[A:%.*]], -124
+; CHECK-NEXT:    ret i32 [[TMP1]]
+;
+  %B = or i32 123, %A
+  %C = add i32 %B, -123
+  ret i32 %C
+}
+
+define <2 x i32> @test44_vec(<2 x i32> %A) {
+; CHECK-LABEL: @test44_vec(
+; CHECK-NEXT:    [[TMP1:%.*]] = and <2 x i32> [[A:%.*]], <i32 -124, i32 -124>
+; CHECK-NEXT:    ret <2 x i32> [[TMP1]]
+;
+  %B = or <2 x i32> %A, <i32 123, i32 123>
+  %C = add <2 x i32> %B, <i32 -123, i32 -123>
+  ret <2 x i32> %C
+}
Index: llvm/test/Transforms/InstCombine/sub.ll
===================================================================
--- llvm/test/Transforms/InstCombine/sub.ll
+++ llvm/test/Transforms/InstCombine/sub.ll
@@ -1267,6 +1267,55 @@
   ret <2 x i32> %res
 }
 
+; Check (X | Y) - Y --> X & ~Y when Y is a constant
+define i32 @test70(i32 %A) {
+; CHECK-LABEL: @test70(
+; CHECK-NEXT:    [[TMP1:%.*]] = and i32 [[A:%.*]], -124
+; CHECK-NEXT:    ret i32 [[TMP1]]
+;
+  %B = or i32 %A, 123
+  %C = sub i32 %B, 123
+  ret i32 %C
+}
+
+; Check (X | Y) - Y --> (X | Y) ^ Y doesn't happen where (X | Y) has multiple uses
+define i32 @test71(i32 %A, i32 %B) {
+; CHECK-LABEL: @test71(
+; CHECK-NEXT:    [[C:%.*]] = or i32 [[A:%.*]], [[B:%.*]]
+; CHECK-NEXT:    [[D:%.*]] = sub i32 [[C]], [[B]]
+; CHECK-NEXT:    [[E:%.*]] = mul i32 [[C]], [[D]]
+; CHECK-NEXT:    ret i32 [[E]]
+;
+  %C = or i32 %A, %B
+  %D = sub i32 %C, %B
+  %E = mul i32 %C, %D
+  ret i32 %E
+}
+
+; Check (X | Y) - Y --> X & ~Y where X and Y are vectors
+define <2 x i32> @test72(<2 x i32> %A, <2 x i32> %B) {
+; CHECK-LABEL: @test72(
+; CHECK-NEXT:    [[B_NOT:%.*]] = xor <2 x i32> [[B:%.*]], <i32 -1, i32 -1>
+; CHECK-NEXT:    [[D:%.*]] = and <2 x i32> [[B_NOT]], [[A:%.*]]
+; CHECK-NEXT:    ret <2 x i32> [[D]]
+;
+  %C = or <2 x i32> %A, %B
+  %D = sub <2 x i32> %C, %B
+  ret <2 x i32> %D
+}
+
+; Check reversing sub operands won't trigger (X | Y) - Y --> X & ~Y
+define i32 @test73(i32 %A, i32 %B) {
+; CHECK-LABEL: @test73(
+; CHECK-NEXT:    [[C:%.*]] = or i32 [[A:%.*]], [[B:%.*]]
+; CHECK-NEXT:    [[D:%.*]] = sub i32 [[B]], [[C]]
+; CHECK-NEXT:    ret i32 [[D]]
+;
+  %C = or i32 %A, %B
+  %D = sub i32 %B, %C
+  ret i32 %D
+}
+
 define i32 @nsw_inference1(i32 %x, i32 %y) {
 ; CHECK-LABEL: @nsw_inference1(
 ; CHECK-NEXT:    [[X2:%.*]] = or i32 [[X:%.*]], 1024