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
@@ -1847,6 +1847,21 @@
                   foldCmpLoadFromIndexedGlobal(LI, GEP, GV, Cmp, C2))
             return Res;
 
+  // icmp slt (and -X, X), 0 --> icmp eq (X, MinSignedC)
+  // icmp sgt (and -X, X), -1 --> icmp ne (X, MinSignedC)
+  {
+    Value* X;
+    if (match(And, m_OneUse(m_c_And(m_Neg(m_Value(X)), m_Deferred(X))))) {
+      Constant *MinSignedC = ConstantInt::get(
+          X->getType(),
+          APInt::getSignedMinValue(X->getType()->getScalarSizeInBits()));
+      if (Pred == ICmpInst::ICMP_SLT && C.isZero())
+        return new ICmpInst(ICmpInst::ICMP_EQ, X, MinSignedC);
+      if (Pred == ICmpInst::ICMP_SGT && C.isAllOnes())
+        return new ICmpInst(ICmpInst::ICMP_NE, X, MinSignedC);
+    }
+  }
+
   if (!Cmp.isEquality())
     return nullptr;
 
diff --git a/llvm/test/Transforms/InstCombine/fold-signbit-test-power2.ll b/llvm/test/Transforms/InstCombine/fold-signbit-test-power2.ll
--- a/llvm/test/Transforms/InstCombine/fold-signbit-test-power2.ll
+++ b/llvm/test/Transforms/InstCombine/fold-signbit-test-power2.ll
@@ -4,9 +4,7 @@
 ; icmp slt (and X, -X), 0 --> icmp eq (X, MinSignC)
 define i1 @pow2_or_zero1(i8 %x) {
 ; CHECK-LABEL: @pow2_or_zero1(
-; CHECK-NEXT:    [[NEG:%.*]] = sub i8 0, [[X:%.*]]
-; CHECK-NEXT:    [[POW2_OR_ZERO:%.*]] = and i8 [[NEG]], [[X]]
-; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i8 [[POW2_OR_ZERO]], 0
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[X:%.*]], -128
 ; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %neg = sub i8 0, %x
@@ -18,13 +16,11 @@
 ; icmp slt (and -X, X), 0 --> icmp eq (X, MinSignC)
 define i1 @pow2_or_zero1_commute(i8 %A) {
 ; CHECK-LABEL: @pow2_or_zero1_commute(
-; CHECK-NEXT:    [[X:%.*]] = sdiv i8 42, [[A:%.*]]
-; CHECK-NEXT:    [[NEG:%.*]] = sub nsw i8 0, [[X]]
-; CHECK-NEXT:    [[POW2_OR_ZERO:%.*]] = and i8 [[X]], [[NEG]]
-; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i8 [[POW2_OR_ZERO]], 0
+; CHECK-NEXT:    [[X:%.*]] = mul i8 [[A:%.*]], 42
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[X]], -128
 ; CHECK-NEXT:    ret i1 [[CMP]]
 ;
-  %x = sdiv i8 42, %A ; thwart complexity-based canonicalization
+  %x = mul i8 42, %A ; thwart complexity-based canonicalization
   %neg = sub i8 0, %x
   %pow2_or_zero = and i8 %neg, %x
   %cmp = icmp slt i8 %pow2_or_zero, 0
@@ -33,9 +29,7 @@
 
 define <2 x i1> @pow2_or_zero1_vec(<2 x i8> %x) {
 ; CHECK-LABEL: @pow2_or_zero1_vec(
-; CHECK-NEXT:    [[NEG:%.*]] = sub <2 x i8> zeroinitializer, [[X:%.*]]
-; CHECK-NEXT:    [[POW2_OR_ZERO:%.*]] = and <2 x i8> [[NEG]], [[X]]
-; CHECK-NEXT:    [[CMP:%.*]] = icmp slt <2 x i8> [[POW2_OR_ZERO]], zeroinitializer
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq <2 x i8> [[X:%.*]], <i8 -128, i8 -128>
 ; CHECK-NEXT:    ret <2 x i1> [[CMP]]
 ;
   %neg = sub <2 x i8> <i8 0, i8 0>, %x
@@ -48,9 +42,7 @@
 define <2 x i1> @pow2_or_zero1_vec_commute(<2 x i8> %A) {
 ; CHECK-LABEL: @pow2_or_zero1_vec_commute(
 ; CHECK-NEXT:    [[X:%.*]] = mul <2 x i8> [[A:%.*]], <i8 42, i8 42>
-; CHECK-NEXT:    [[NEG:%.*]] = sub <2 x i8> zeroinitializer, [[X]]
-; CHECK-NEXT:    [[POW2_OR_ZERO:%.*]] = and <2 x i8> [[X]], [[NEG]]
-; CHECK-NEXT:    [[CMP:%.*]] = icmp slt <2 x i8> [[POW2_OR_ZERO]], zeroinitializer
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq <2 x i8> [[X]], <i8 -128, i8 -128>
 ; CHECK-NEXT:    ret <2 x i1> [[CMP]]
 ;
   %x = mul <2 x i8> <i8 42, i8 42>, %A ; thwart complexity-based canonicalization
@@ -63,9 +55,7 @@
 ; icmp sgt (and X, -X), -1 --> icmp ne (X, MinSignC)
 define i1 @pow2_or_zero2(i8 %x) {
 ; CHECK-LABEL: @pow2_or_zero2(
-; CHECK-NEXT:    [[NEG:%.*]] = sub i8 0, [[X:%.*]]
-; CHECK-NEXT:    [[POW2_OR_ZERO:%.*]] = and i8 [[NEG]], [[X]]
-; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[POW2_OR_ZERO]], -1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i8 [[X:%.*]], -128
 ; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %neg = sub i8 0, %x
@@ -78,9 +68,7 @@
 define i1 @pow2_or_zero2_commute(i8 %A) {
 ; CHECK-LABEL: @pow2_or_zero2_commute(
 ; CHECK-NEXT:    [[X:%.*]] = mul i8 [[A:%.*]], 42
-; CHECK-NEXT:    [[NEG:%.*]] = sub i8 0, [[X]]
-; CHECK-NEXT:    [[POW2_OR_ZERO:%.*]] = and i8 [[X]], [[NEG]]
-; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[POW2_OR_ZERO]], -1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i8 [[X]], -128
 ; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %x = mul i8 42, %A ; thwart complexity-based canonicalization
@@ -92,9 +80,7 @@
 
 define <2 x i1> @pow2_or_zero2_vec(<2 x i8> %x) {
 ; CHECK-LABEL: @pow2_or_zero2_vec(
-; CHECK-NEXT:    [[NEG:%.*]] = sub <2 x i8> zeroinitializer, [[X:%.*]]
-; CHECK-NEXT:    [[POW2_OR_ZERO:%.*]] = and <2 x i8> [[NEG]], [[X]]
-; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt <2 x i8> [[POW2_OR_ZERO]], <i8 -1, i8 -1>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne <2 x i8> [[X:%.*]], <i8 -128, i8 -128>
 ; CHECK-NEXT:    ret <2 x i1> [[CMP]]
 ;
   %neg = sub <2 x i8> <i8 0, i8 0>, %x
@@ -106,9 +92,7 @@
 define <2 x i1> @pow2_or_zero2_vec_commute(<2 x i8> %A) {
 ; CHECK-LABEL: @pow2_or_zero2_vec_commute(
 ; CHECK-NEXT:    [[X:%.*]] = mul <2 x i8> [[A:%.*]], <i8 42, i8 42>
-; CHECK-NEXT:    [[NEG:%.*]] = sub <2 x i8> zeroinitializer, [[X]]
-; CHECK-NEXT:    [[POW2_OR_ZERO:%.*]] = and <2 x i8> [[X]], [[NEG]]
-; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt <2 x i8> [[POW2_OR_ZERO]], <i8 -1, i8 -1>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne <2 x i8> [[X]], <i8 -128, i8 -128>
 ; CHECK-NEXT:    ret <2 x i1> [[CMP]]
 ;
   %x = mul <2 x i8> <i8 42, i8 42>, %A ; thwart complexity-based canonicalization
diff --git a/llvm/test/Transforms/InstCombine/minmax-of-xor-x.ll b/llvm/test/Transforms/InstCombine/minmax-of-xor-x.ll
--- a/llvm/test/Transforms/InstCombine/minmax-of-xor-x.ll
+++ b/llvm/test/Transforms/InstCombine/minmax-of-xor-x.ll
@@ -134,9 +134,7 @@
 
 define i8 @smax_xor_pow2_neg(i8 %x, i8 %y) {
 ; CHECK-LABEL: @smax_xor_pow2_neg(
-; CHECK-NEXT:    [[NY:%.*]] = sub i8 0, [[Y:%.*]]
-; CHECK-NEXT:    [[YP2:%.*]] = and i8 [[NY]], [[Y]]
-; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i8 [[YP2]], 0
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[Y:%.*]], -128
 ; CHECK-NEXT:    br i1 [[CMP]], label [[NEG:%.*]], label [[POS:%.*]]
 ; CHECK:       neg:
 ; CHECK-NEXT:    [[R:%.*]] = and i8 [[X:%.*]], 127