diff --git a/llvm/test/Transforms/InstSimplify/call.ll b/llvm/test/Transforms/InstSimplify/call.ll
index 99a4a96d33b1..c7a2ba3faa12 100644
--- a/llvm/test/Transforms/InstSimplify/call.ll
+++ b/llvm/test/Transforms/InstSimplify/call.ll
@@ -1291,7 +1291,7 @@ declare float @fmaxf(float, float)
 
 define float @nobuiltin_fmax() {
 ; CHECK-LABEL: @nobuiltin_fmax(
-; CHECK-NEXT:    [[M:%.*]] = call float @fmaxf(float 0.000000e+00, float 1.000000e+00) #[[ATTR3:[0-9]+]]
+; CHECK-NEXT:    [[M:%.*]] = call float @fmaxf(float 0.000000e+00, float 1.000000e+00) #[[ATTR4:[0-9]+]]
 ; CHECK-NEXT:    [[R:%.*]] = call float @llvm.fabs.f32(float [[M]])
 ; CHECK-NEXT:    ret float [[R]]
 ;
@@ -1304,6 +1304,7 @@ define float @nobuiltin_fmax() {
 declare i32 @llvm.ctpop.i32(i32)
 declare <3 x i33> @llvm.ctpop.v3i33(<3 x i33>)
 declare i1 @llvm.ctpop.i1(i1)
+declare void @llvm.assume(i1)
 
 define i32 @ctpop_lowbit(i32 %x) {
 ; CHECK-LABEL: @ctpop_lowbit(
@@ -1464,4 +1465,78 @@ define <3 x i33> @ctlz_ashr_sign_bit_vec(<3 x i33> %x) {
   ret <3 x i33> %r
 }
 
+define i32 @ctlz_sext_negative_zero_undef(i16 %x) {
+; CHECK-LABEL: @ctlz_sext_negative_zero_undef(
+; CHECK-NEXT:    [[ASSUME:%.*]] = icmp slt i16 [[X:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[ASSUME]])
+; CHECK-NEXT:    [[S:%.*]] = sext i16 [[X]] to i32
+; CHECK-NEXT:    [[C:%.*]] = call i32 @llvm.ctlz.i32(i32 [[S]], i1 true)
+; CHECK-NEXT:    ret i32 [[C]]
+;
+  %assume = icmp slt i16 %x, 0
+  call void @llvm.assume(i1 %assume)
+  %s = sext i16 %x to i32
+  %c = call i32 @llvm.ctlz.i32(i32 %s, i1 true)
+  ret i32 %c
+}
+
+define i32 @ctlz_negative_zero_undef(i32 %x) {
+; CHECK-LABEL: @ctlz_negative_zero_undef(
+; CHECK-NEXT:    [[ASSUME:%.*]] = icmp slt i32 [[X:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[ASSUME]])
+; CHECK-NEXT:    [[C:%.*]] = call i32 @llvm.ctlz.i32(i32 [[X]], i1 true)
+; CHECK-NEXT:    ret i32 [[C]]
+;
+  %assume = icmp slt i32 %x, 0
+  call void @llvm.assume(i1 %assume)
+  %c = call i32 @llvm.ctlz.i32(i32 %x, i1 true)
+  ret i32 %c
+}
+
+define i32 @ctlz_negative_zero_def(i32 %x) {
+; CHECK-LABEL: @ctlz_negative_zero_def(
+; CHECK-NEXT:    [[ASSUME:%.*]] = icmp slt i32 [[X:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[ASSUME]])
+; CHECK-NEXT:    [[C:%.*]] = call i32 @llvm.ctlz.i32(i32 [[X]], i1 false)
+; CHECK-NEXT:    ret i32 [[C]]
+;
+  %assume = icmp slt i32 %x, 0
+  call void @llvm.assume(i1 %assume)
+  %c = call i32 @llvm.ctlz.i32(i32 %x, i1 false)
+  ret i32 %c
+}
+
+define i32 @ctlz_sext_negative_zero_def(i16 %x) {
+; CHECK-LABEL: @ctlz_sext_negative_zero_def(
+; CHECK-NEXT:    [[ASSUME:%.*]] = icmp slt i16 [[X:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[ASSUME]])
+; CHECK-NEXT:    [[S:%.*]] = sext i16 [[X]] to i32
+; CHECK-NEXT:    [[C:%.*]] = call i32 @llvm.ctlz.i32(i32 [[S]], i1 false)
+; CHECK-NEXT:    ret i32 [[C]]
+;
+  %assume = icmp slt i16 %x, 0
+  call void @llvm.assume(i1 %assume)
+  %s = sext i16 %x to i32
+  %c = call i32 @llvm.ctlz.i32(i32 %s, i1 false)
+  ret i32 %c
+}
+
+declare void @use(i32)
+define i32 @ctlz_sext_negative_zero_undef_extra_use(i16 %x) {
+; CHECK-LABEL: @ctlz_sext_negative_zero_undef_extra_use(
+; CHECK-NEXT:    [[ASSUME:%.*]] = icmp slt i16 [[X:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[ASSUME]])
+; CHECK-NEXT:    [[S:%.*]] = sext i16 [[X]] to i32
+; CHECK-NEXT:    call void @use(i32 [[S]])
+; CHECK-NEXT:    [[C:%.*]] = call i32 @llvm.ctlz.i32(i32 [[S]], i1 true)
+; CHECK-NEXT:    ret i32 [[C]]
+;
+  %assume = icmp slt i16 %x, 0
+  call void @llvm.assume(i1 %assume)
+  %s = sext i16 %x to i32
+  call void @use(i32 %s)
+  %c = call i32 @llvm.ctlz.i32(i32 %s, i1 true)
+  ret i32 %c
+}
+
 attributes #0 = { nobuiltin readnone }