diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -4085,15 +4085,34 @@
                           Constant::getNullValue(X->getType()), I.getName());
 }
 
+static std::optional<bool>
+getKnownSign(Value *Op, Instruction *CxtI, const DataLayout &DL,
+             AssumptionCache *AC, const DominatorTree *DT, KnownBits &Known) {
+  Known = computeKnownBits(Op, DL, 0, AC, CxtI, DT);
+  if (Known.isNonNegative())
+    return false;
+  if (Known.isNegative())
+    return true;
+
+  Value *X, *Y;
+  if (match(Op, m_NSWSub(m_Value(X), m_Value(Y))))
+    return isImpliedByDomCondition(ICmpInst::ICMP_SLT, X, Y, CxtI, DL);
+
+  return isImpliedByDomCondition(
+      ICmpInst::ICMP_SLT, Op, Constant::getNullValue(Op->getType()), CxtI, DL);
+}
+
 static Instruction *foldICmpXorXX(ICmpInst &I, const SimplifyQuery &Q,
                                   InstCombinerImpl &IC) {
   Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1), *A;
+
   // Normalize xor operand as operand 0.
   CmpInst::Predicate Pred = I.getPredicate();
   if (match(Op1, m_c_Xor(m_Specific(Op0), m_Value()))) {
     std::swap(Op0, Op1);
     Pred = ICmpInst::getSwappedPredicate(Pred);
   }
+
   if (!match(Op0, m_c_Xor(m_Specific(Op1), m_Value(A))))
     return nullptr;
 
@@ -4106,6 +4125,75 @@
       isKnownNonZero(A, Q.DL, /*Depth=*/0, Q.AC, Q.CxtI, Q.DT))
     return new ICmpInst(PredOut, Op0, Op1);
 
+  // icmp (X ^ Y) u> X --> X & MSB(Y) == 0
+  // icmp (X ^ Y) u< X --> X & MSB(Y) != 0
+  // icmp (X ^ Pos_Y) s> X --> X & MSB(Pow2_Y) == 0
+  // icmp (X ^ Pos_Y) s< X --> X & MSB(Pow2_Y) != 0
+  switch (Pred) {
+  case ICmpInst::ICMP_UGT:
+  case ICmpInst::ICMP_SGT:
+    PredOut = ICmpInst::ICMP_EQ;
+    break;
+  case ICmpInst::ICMP_ULT:
+  case ICmpInst::ICMP_SLT:
+    PredOut = ICmpInst::ICMP_NE;
+    break;
+  default:
+    break;
+  }
+
+  if (PredOut == Pred)
+    return nullptr;
+
+  bool Usable = true;
+  std::optional<KnownBits> KnownOpt;
+  // If signed version we need extra for negative / positive.
+  if (Pred == ICmpInst::ICMP_SGT || Pred == ICmpInst::ICMP_SLT) {
+    KnownBits Known;
+    auto KnownSign = getKnownSign(A, &I, Q.DL, Q.AC, Q.DT, Known);
+    KnownOpt = Known;
+    Usable = false;
+    if (KnownSign != std::nullopt) {
+      // icmp (X ^ Neg_Y) s> X --> X s< 0
+      // icmp (X ^ Neg_Y) s< X --> X s>= 0
+      if (*KnownSign /* true is Signed. */) {
+        // Negative power of 2 must be IntMin so this just a sign
+        // comparison.
+        if (Pred == ICmpInst::ICMP_SGT)
+          PredOut = ICmpInst::ICMP_SLT;
+        if (Pred == ICmpInst::ICMP_SLT)
+          PredOut = ICmpInst::ICMP_SGE;
+        return new ICmpInst(PredOut, Op1,
+                            Constant::getNullValue(Op0->getType()));
+      }
+      Usable = !*KnownSign;
+    }
+  }
+
+  if (Usable && Op0->hasOneUse()) {
+    // If known power of 2, then MSB == A.
+    if (IC.isKnownToBeAPowerOfTwo(A, /*OrZero*/ true, 0, &I))
+      return new ICmpInst(PredOut, IC.Builder.CreateAnd(Op1, A),
+                          Constant::getNullValue(Op0->getType()));
+
+    // Otherwise try and find known MSB.
+    if (KnownOpt == std::nullopt)
+      KnownOpt = IC.computeKnownBits(A, 0, &I);
+
+    unsigned MSBPos = KnownOpt->countMaxLeadingZeros();
+    unsigned BitWidth = KnownOpt->getBitWidth();
+    if (MSBPos == 0 ||
+        (MSBPos != BitWidth && MSBPos == KnownOpt->countMinLeadingZeros())) {
+      Type *Ty = Op0->getType();
+      return new ICmpInst(
+          PredOut,
+          IC.Builder.CreateAnd(
+              Op1, ConstantInt::get(Ty, APInt::getOneBitSet(
+                                            BitWidth, BitWidth - MSBPos - 1))),
+          Constant::getNullValue(Ty));
+    }
+  }
+
   return nullptr;
 }
 
diff --git a/llvm/test/Transforms/InstCombine/icmp-of-xor-x.ll b/llvm/test/Transforms/InstCombine/icmp-of-xor-x.ll
--- a/llvm/test/Transforms/InstCombine/icmp-of-xor-x.ll
+++ b/llvm/test/Transforms/InstCombine/icmp-of-xor-x.ll
@@ -62,9 +62,7 @@
 
 define i1 @xor_sge(i8 %x, i8 %yy) {
 ; CHECK-LABEL: @xor_sge(
-; CHECK-NEXT:    [[Y:%.*]] = or i8 [[YY:%.*]], -128
-; CHECK-NEXT:    [[XOR:%.*]] = xor i8 [[Y]], [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = icmp sgt i8 [[XOR]], [[X]]
+; CHECK-NEXT:    [[R:%.*]] = icmp slt i8 [[X:%.*]], 0
 ; CHECK-NEXT:    ret i1 [[R]]
 ;
   %y = or i8 %yy, 128
@@ -76,10 +74,8 @@
 define i1 @xor_ugt_2(i8 %xx, i8 %y, i8 %z) {
 ; CHECK-LABEL: @xor_ugt_2(
 ; CHECK-NEXT:    [[X:%.*]] = add i8 [[XX:%.*]], [[Z:%.*]]
-; CHECK-NEXT:    [[YZ:%.*]] = and i8 [[Y:%.*]], 63
-; CHECK-NEXT:    [[Y1:%.*]] = or i8 [[YZ]], 64
-; CHECK-NEXT:    [[XOR:%.*]] = xor i8 [[X]], [[Y1]]
-; CHECK-NEXT:    [[R:%.*]] = icmp ugt i8 [[X]], [[XOR]]
+; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X]], 64
+; CHECK-NEXT:    [[R:%.*]] = icmp ne i8 [[TMP1]], 0
 ; CHECK-NEXT:    ret i1 [[R]]
 ;
   %x = add i8 %xx, %z
@@ -92,8 +88,8 @@
 
 define i1 @xor_ult(i8 %x) {
 ; CHECK-LABEL: @xor_ult(
-; CHECK-NEXT:    [[XOR:%.*]] = xor i8 [[X:%.*]], 123
-; CHECK-NEXT:    [[R:%.*]] = icmp ult i8 [[XOR]], [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X:%.*]], 64
+; CHECK-NEXT:    [[R:%.*]] = icmp ne i8 [[TMP1]], 0
 ; CHECK-NEXT:    ret i1 [[R]]
 ;
   %xor = xor i8 %x, 123
@@ -103,10 +99,8 @@
 
 define <2 x i1> @xor_sgt(<2 x i8> %x, <2 x i8> %y) {
 ; CHECK-LABEL: @xor_sgt(
-; CHECK-NEXT:    [[YZ:%.*]] = and <2 x i8> [[Y:%.*]], <i8 31, i8 31>
-; CHECK-NEXT:    [[Y1:%.*]] = or <2 x i8> [[YZ]], <i8 64, i8 64>
-; CHECK-NEXT:    [[XOR:%.*]] = xor <2 x i8> [[Y1]], [[X:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = icmp sgt <2 x i8> [[XOR]], [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = and <2 x i8> [[X:%.*]], <i8 64, i8 64>
+; CHECK-NEXT:    [[R:%.*]] = icmp eq <2 x i8> [[TMP1]], zeroinitializer
 ; CHECK-NEXT:    ret <2 x i1> [[R]]
 ;
   %yz = and <2 x i8> %y, <i8 31, i8 31>
@@ -133,8 +127,8 @@
 
 define i1 @xor_slt_2(i8 %x, i8 %y, i8 %z) {
 ; CHECK-LABEL: @xor_slt_2(
-; CHECK-NEXT:    [[XOR:%.*]] = xor i8 [[X:%.*]], 88
-; CHECK-NEXT:    [[R:%.*]] = icmp sgt i8 [[XOR]], [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X:%.*]], 64
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[TMP1]], 0
 ; CHECK-NEXT:    ret i1 [[R]]
 ;
   %xor = xor i8 %x, 88
@@ -145,9 +139,7 @@
 define <2 x i1> @xor_sgt_intmin_2(<2 x i8> %xx, <2 x i8> %yy, <2 x i8> %z) {
 ; CHECK-LABEL: @xor_sgt_intmin_2(
 ; CHECK-NEXT:    [[X:%.*]] = add <2 x i8> [[XX:%.*]], [[Z:%.*]]
-; CHECK-NEXT:    [[Y:%.*]] = or <2 x i8> [[YY:%.*]], <i8 -128, i8 -128>
-; CHECK-NEXT:    [[XOR:%.*]] = xor <2 x i8> [[X]], [[Y]]
-; CHECK-NEXT:    [[R:%.*]] = icmp sgt <2 x i8> [[X]], [[XOR]]
+; CHECK-NEXT:    [[R:%.*]] = icmp sgt <2 x i8> [[X]], <i8 -1, i8 -1>
 ; CHECK-NEXT:    ret <2 x i1> [[R]]
 ;
   %x = add <2 x i8> %xx, %z
@@ -165,8 +157,7 @@
 ; CHECK-NEXT:    [[COMMON_RET_OP:%.*]] = phi i1 [ [[R:%.*]], [[NEG]] ], [ false, [[POS]] ]
 ; CHECK-NEXT:    ret i1 [[COMMON_RET_OP]]
 ; CHECK:       neg:
-; CHECK-NEXT:    [[XOR:%.*]] = xor i8 [[C]], [[X:%.*]]
-; CHECK-NEXT:    [[R]] = icmp slt i8 [[XOR]], [[X]]
+; CHECK-NEXT:    [[R]] = icmp sgt i8 [[X:%.*]], -1
 ; CHECK-NEXT:    br label [[COMMON_RET:%.*]]
 ; CHECK:       pos:
 ; CHECK-NEXT:    tail call void @barrier()