diff --git a/llvm/lib/Analysis/CmpInstAnalysis.cpp b/llvm/lib/Analysis/CmpInstAnalysis.cpp
--- a/llvm/lib/Analysis/CmpInstAnalysis.cpp
+++ b/llvm/lib/Analysis/CmpInstAnalysis.cpp
@@ -79,7 +79,7 @@
   using namespace PatternMatch;
 
   const APInt *C;
-  if (!match(RHS, m_APInt(C)))
+  if (!match(RHS, m_APIntAllowUndef(C)))
     return false;
 
   switch (Pred) {
diff --git a/llvm/test/Transforms/InstCombine/icmp-logical.ll b/llvm/test/Transforms/InstCombine/icmp-logical.ll
--- a/llvm/test/Transforms/InstCombine/icmp-logical.ll
+++ b/llvm/test/Transforms/InstCombine/icmp-logical.ll
@@ -378,11 +378,8 @@
 }
 
 define <2 x i1> @nomask_splat_and_B_allones(<2 x i32> %A) {
-; CHECK-LABEL: @nomask_and_B_allones_splat(
-; CHECK-NEXT:    [[TST1:%.*]] = icmp slt <2 x i32> [[A:%.*]], <i32 0, i32 undef>
-; CHECK-NEXT:    [[MASK2:%.*]] = and <2 x i32> [[A]], <i32 1879048192, i32 1879048192>
-; CHECK-NEXT:    [[TST2:%.*]] = icmp eq <2 x i32> [[MASK2]], <i32 1879048192, i32 1879048192>
-; CHECK-NEXT:    [[RES:%.*]] = and <2 x i1> [[TST1]], [[TST2]]
+; CHECK-LABEL: @nomask_splat_and_B_allones(
+; CHECK-NEXT:    [[RES:%.*]] = icmp ugt <2 x i32> [[A:%.*]], <i32 -268435457, i32 -268435457>
 ; CHECK-NEXT:    ret <2 x i1> [[RES]]
 ;
   %tst1 = icmp slt <2 x i32> %A, <i32 0, i32 undef>
@@ -393,11 +390,9 @@
 }
 
 define <2 x i1> @nomask_splat_and_B_mixed(<2 x i32> %A) {
-; CHECK-LABEL: @nomask_and_B_mixed_splat(
-; CHECK-NEXT:    [[TST1:%.*]] = icmp sgt <2 x i32> [[A:%.*]], <i32 -1, i32 undef>
-; CHECK-NEXT:    [[MASK2:%.*]] = and <2 x i32> [[A]], <i32 1879048192, i32 1879048192>
-; CHECK-NEXT:    [[TST2:%.*]] = icmp eq <2 x i32> [[MASK2]], <i32 1879048192, i32 1879048192>
-; CHECK-NEXT:    [[RES:%.*]] = and <2 x i1> [[TST1]], [[TST2]]
+; CHECK-LABEL: @nomask_splat_and_B_mixed(
+; CHECK-NEXT:    [[TMP1:%.*]] = and <2 x i32> [[A:%.*]], <i32 -268435456, i32 -268435456>
+; CHECK-NEXT:    [[RES:%.*]] = icmp eq <2 x i32> [[TMP1]], <i32 1879048192, i32 1879048192>
 ; CHECK-NEXT:    ret <2 x i1> [[RES]]
 ;
   %tst1 = icmp sgt <2 x i32> %A, <i32 -1, i32 undef>
diff --git a/llvm/test/Transforms/InstCombine/signed-truncation-check.ll b/llvm/test/Transforms/InstCombine/signed-truncation-check.ll
--- a/llvm/test/Transforms/InstCombine/signed-truncation-check.ll
+++ b/llvm/test/Transforms/InstCombine/signed-truncation-check.ll
@@ -200,11 +200,8 @@
 
 define <3 x i1> @positive_vec_undef0(<3 x i32> %arg) {
 ; CHECK-LABEL: @positive_vec_undef0(
-; CHECK-NEXT:    [[T1:%.*]] = icmp sgt <3 x i32> [[ARG:%.*]], <i32 -1, i32 undef, i32 -1>
-; CHECK-NEXT:    [[T2:%.*]] = add <3 x i32> [[ARG]], <i32 128, i32 128, i32 128>
-; CHECK-NEXT:    [[T3:%.*]] = icmp ult <3 x i32> [[T2]], <i32 256, i32 256, i32 256>
-; CHECK-NEXT:    [[T4:%.*]] = and <3 x i1> [[T1]], [[T3]]
-; CHECK-NEXT:    ret <3 x i1> [[T4]]
+; CHECK-NEXT:    [[T4_SIMPLIFIED:%.*]] = icmp ult <3 x i32> [[ARG:%.*]], <i32 128, i32 128, i32 128>
+; CHECK-NEXT:    ret <3 x i1> [[T4_SIMPLIFIED]]
 ;
   %t1 = icmp sgt <3 x i32> %arg, <i32 -1, i32 undef, i32 -1>
   %t2 = add <3 x i32> %arg, <i32 128, i32 128, i32 128>