diff --git a/llvm/test/Instrumentation/MemorySanitizer/count-zeroes.ll b/llvm/test/Instrumentation/MemorySanitizer/count-zeroes.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Instrumentation/MemorySanitizer/count-zeroes.ll
@@ -0,0 +1,156 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt %s -S -passes=msan 2>&1 | FileCheck %s
+
+target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+declare i64 @llvm.ctlz.i64(i64, i1) nounwind readnone
+define i64 @test_ctlz_i64_zeropoison(i64 %v) #0 {
+; CHECK-LABEL: @test_ctlz_i64_zeropoison(
+; CHECK-NEXT:    [[TMP1:%.*]] = load i64, ptr @__msan_param_tls, align 8
+; CHECK-NEXT:    call void @llvm.donothing()
+; CHECK-NEXT:    [[_MSCMP:%.*]] = icmp ne i64 [[TMP1]], 0
+; CHECK-NEXT:    br i1 [[_MSCMP]], label [[TMP2:%.*]], label [[TMP3:%.*]], !prof [[PROF0:![0-9]+]]
+; CHECK:       2:
+; CHECK-NEXT:    call void @__msan_warning_noreturn() #[[ATTR4:[0-9]+]]
+; CHECK-NEXT:    unreachable
+; CHECK:       3:
+; CHECK-NEXT:    [[RES:%.*]] = call i64 @llvm.ctlz.i64(i64 [[V:%.*]], i1 true)
+; CHECK-NEXT:    store i64 0, ptr @__msan_retval_tls, align 8
+; CHECK-NEXT:    ret i64 [[RES]]
+;
+  %res = call i64 @llvm.ctlz.i64(i64 %v, i1 true) ; <<i64>> [#uses=1]
+  ret i64 %res
+}
+define i64 @test_ctlz_i64_nozeropoison(i64 %v) #0 {
+; CHECK-LABEL: @test_ctlz_i64_nozeropoison(
+; CHECK-NEXT:    [[TMP1:%.*]] = load i64, ptr @__msan_param_tls, align 8
+; CHECK-NEXT:    call void @llvm.donothing()
+; CHECK-NEXT:    [[_MSCMP:%.*]] = icmp ne i64 [[TMP1]], 0
+; CHECK-NEXT:    br i1 [[_MSCMP]], label [[TMP2:%.*]], label [[TMP3:%.*]], !prof [[PROF0]]
+; CHECK:       2:
+; CHECK-NEXT:    call void @__msan_warning_noreturn() #[[ATTR4]]
+; CHECK-NEXT:    unreachable
+; CHECK:       3:
+; CHECK-NEXT:    [[RES:%.*]] = call i64 @llvm.ctlz.i64(i64 [[V:%.*]], i1 false)
+; CHECK-NEXT:    store i64 0, ptr @__msan_retval_tls, align 8
+; CHECK-NEXT:    ret i64 [[RES]]
+;
+  %res = call i64 @llvm.ctlz.i64(i64 %v, i1 false) ; <<i64>> [#uses=1]
+  ret i64 %res
+}
+
+declare <2 x i64> @llvm.ctlz.v2i64(<2 x i64>, i1) nounwind readnone
+define <2 x i64> @test_ctlz_v2i64_zeropoison(<2 x i64> %v) #0 {
+; CHECK-LABEL: @test_ctlz_v2i64_zeropoison(
+; CHECK-NEXT:    [[TMP1:%.*]] = load <2 x i64>, ptr @__msan_param_tls, align 8
+; CHECK-NEXT:    call void @llvm.donothing()
+; CHECK-NEXT:    [[TMP2:%.*]] = bitcast <2 x i64> [[TMP1]] to i128
+; CHECK-NEXT:    [[_MSCMP:%.*]] = icmp ne i128 [[TMP2]], 0
+; CHECK-NEXT:    br i1 [[_MSCMP]], label [[TMP3:%.*]], label [[TMP4:%.*]], !prof [[PROF0]]
+; CHECK:       3:
+; CHECK-NEXT:    call void @__msan_warning_noreturn() #[[ATTR4]]
+; CHECK-NEXT:    unreachable
+; CHECK:       4:
+; CHECK-NEXT:    [[RES:%.*]] = call <2 x i64> @llvm.ctlz.v2i64(<2 x i64> [[V:%.*]], i1 true)
+; CHECK-NEXT:    store <2 x i64> zeroinitializer, ptr @__msan_retval_tls, align 8
+; CHECK-NEXT:    ret <2 x i64> [[RES]]
+;
+  %res = call <2 x i64> @llvm.ctlz.v2i64(<2 x i64> %v, i1 true) ; <<2 x i64>> [#uses=1]
+  ret <2 x i64> %res
+}
+define <2 x i64> @test_ctlz_v2i64_nozeropoison(<2 x i64> %v) #0 {
+; CHECK-LABEL: @test_ctlz_v2i64_nozeropoison(
+; CHECK-NEXT:    [[TMP1:%.*]] = load <2 x i64>, ptr @__msan_param_tls, align 8
+; CHECK-NEXT:    call void @llvm.donothing()
+; CHECK-NEXT:    [[TMP2:%.*]] = bitcast <2 x i64> [[TMP1]] to i128
+; CHECK-NEXT:    [[_MSCMP:%.*]] = icmp ne i128 [[TMP2]], 0
+; CHECK-NEXT:    br i1 [[_MSCMP]], label [[TMP3:%.*]], label [[TMP4:%.*]], !prof [[PROF0]]
+; CHECK:       3:
+; CHECK-NEXT:    call void @__msan_warning_noreturn() #[[ATTR4]]
+; CHECK-NEXT:    unreachable
+; CHECK:       4:
+; CHECK-NEXT:    [[RES:%.*]] = call <2 x i64> @llvm.ctlz.v2i64(<2 x i64> [[V:%.*]], i1 false)
+; CHECK-NEXT:    store <2 x i64> zeroinitializer, ptr @__msan_retval_tls, align 8
+; CHECK-NEXT:    ret <2 x i64> [[RES]]
+;
+  %res = call <2 x i64> @llvm.ctlz.v2i64(<2 x i64> %v, i1 false) ; <<2 x i64>> [#uses=1]
+  ret <2 x i64> %res
+}
+
+declare i64 @llvm.cttz.i64(i64, i1) nounwind readnone
+define i64 @test_cttz_i64_zeropoison(i64 %v) #0 {
+; CHECK-LABEL: @test_cttz_i64_zeropoison(
+; CHECK-NEXT:    [[TMP1:%.*]] = load i64, ptr @__msan_param_tls, align 8
+; CHECK-NEXT:    call void @llvm.donothing()
+; CHECK-NEXT:    [[_MSCMP:%.*]] = icmp ne i64 [[TMP1]], 0
+; CHECK-NEXT:    br i1 [[_MSCMP]], label [[TMP2:%.*]], label [[TMP3:%.*]], !prof [[PROF0]]
+; CHECK:       2:
+; CHECK-NEXT:    call void @__msan_warning_noreturn() #[[ATTR4]]
+; CHECK-NEXT:    unreachable
+; CHECK:       3:
+; CHECK-NEXT:    [[RES:%.*]] = call i64 @llvm.cttz.i64(i64 [[V:%.*]], i1 true)
+; CHECK-NEXT:    store i64 0, ptr @__msan_retval_tls, align 8
+; CHECK-NEXT:    ret i64 [[RES]]
+;
+  %res = call i64 @llvm.cttz.i64(i64 %v, i1 true) ; <<i64>> [#uses=1]
+  ret i64 %res
+}
+define i64 @test_cttz_i64_nozeropoison(i64 %v) #0 {
+; CHECK-LABEL: @test_cttz_i64_nozeropoison(
+; CHECK-NEXT:    [[TMP1:%.*]] = load i64, ptr @__msan_param_tls, align 8
+; CHECK-NEXT:    call void @llvm.donothing()
+; CHECK-NEXT:    [[_MSCMP:%.*]] = icmp ne i64 [[TMP1]], 0
+; CHECK-NEXT:    br i1 [[_MSCMP]], label [[TMP2:%.*]], label [[TMP3:%.*]], !prof [[PROF0]]
+; CHECK:       2:
+; CHECK-NEXT:    call void @__msan_warning_noreturn() #[[ATTR4]]
+; CHECK-NEXT:    unreachable
+; CHECK:       3:
+; CHECK-NEXT:    [[RES:%.*]] = call i64 @llvm.cttz.i64(i64 [[V:%.*]], i1 false)
+; CHECK-NEXT:    store i64 0, ptr @__msan_retval_tls, align 8
+; CHECK-NEXT:    ret i64 [[RES]]
+;
+  %res = call i64 @llvm.cttz.i64(i64 %v, i1 false) ; <<i64>> [#uses=1]
+  ret i64 %res
+}
+
+declare <2 x i64> @llvm.cttz.v2i64(<2 x i64>, i1) nounwind readnone
+define <2 x i64> @test_cttz_v2i64_zeropoison(<2 x i64> %v) #0 {
+; CHECK-LABEL: @test_cttz_v2i64_zeropoison(
+; CHECK-NEXT:    [[TMP1:%.*]] = load <2 x i64>, ptr @__msan_param_tls, align 8
+; CHECK-NEXT:    call void @llvm.donothing()
+; CHECK-NEXT:    [[TMP2:%.*]] = bitcast <2 x i64> [[TMP1]] to i128
+; CHECK-NEXT:    [[_MSCMP:%.*]] = icmp ne i128 [[TMP2]], 0
+; CHECK-NEXT:    br i1 [[_MSCMP]], label [[TMP3:%.*]], label [[TMP4:%.*]], !prof [[PROF0]]
+; CHECK:       3:
+; CHECK-NEXT:    call void @__msan_warning_noreturn() #[[ATTR4]]
+; CHECK-NEXT:    unreachable
+; CHECK:       4:
+; CHECK-NEXT:    [[RES:%.*]] = call <2 x i64> @llvm.cttz.v2i64(<2 x i64> [[V:%.*]], i1 true)
+; CHECK-NEXT:    store <2 x i64> zeroinitializer, ptr @__msan_retval_tls, align 8
+; CHECK-NEXT:    ret <2 x i64> [[RES]]
+;
+  %res = call <2 x i64> @llvm.cttz.v2i64(<2 x i64> %v, i1 true) ; <<2 x i64>> [#uses=1]
+  ret <2 x i64> %res
+}
+define <2 x i64> @test_cttz_v2i64_nozeropoison(<2 x i64> %v) #0 {
+; CHECK-LABEL: @test_cttz_v2i64_nozeropoison(
+; CHECK-NEXT:    [[TMP1:%.*]] = load <2 x i64>, ptr @__msan_param_tls, align 8
+; CHECK-NEXT:    call void @llvm.donothing()
+; CHECK-NEXT:    [[TMP2:%.*]] = bitcast <2 x i64> [[TMP1]] to i128
+; CHECK-NEXT:    [[_MSCMP:%.*]] = icmp ne i128 [[TMP2]], 0
+; CHECK-NEXT:    br i1 [[_MSCMP]], label [[TMP3:%.*]], label [[TMP4:%.*]], !prof [[PROF0]]
+; CHECK:       3:
+; CHECK-NEXT:    call void @__msan_warning_noreturn() #[[ATTR4]]
+; CHECK-NEXT:    unreachable
+; CHECK:       4:
+; CHECK-NEXT:    [[RES:%.*]] = call <2 x i64> @llvm.cttz.v2i64(<2 x i64> [[V:%.*]], i1 false)
+; CHECK-NEXT:    store <2 x i64> zeroinitializer, ptr @__msan_retval_tls, align 8
+; CHECK-NEXT:    ret <2 x i64> [[RES]]
+;
+  %res = call <2 x i64> @llvm.cttz.v2i64(<2 x i64> %v, i1 false) ; <<2 x i64>> [#uses=1]
+  ret <2 x i64> %res
+}
+
+
+attributes #0 = { sanitize_memory }