diff --git a/library/stdarch/crates/core_arch/src/x86/avx512f.rs b/library/stdarch/crates/core_arch/src/x86/avx512f.rs
index 2e71cf296a60..46357c82ffa3 100644
--- a/library/stdarch/crates/core_arch/src/x86/avx512f.rs
+++ b/library/stdarch/crates/core_arch/src/x86/avx512f.rs
@@ -104,6 +104,17 @@ pub unsafe fn _mm512_cmplt_epu64_mask(a: __m512i, b: __m512i) -> __mmask8 {
     simd_bitmask::<__m512i, _>(simd_lt(a.as_u64x8(), b.as_u64x8()))
 }
 
+///Compare packed unsigned 64-bit integers in a and b for less-than, and store the results in a mask vector k
+/// using zeromask m (elements are zeroed out when the corresponding mask bit is not set).
+///
+/// [Intel's documentation](https://software.intel.com/sites/landingpage/IntrinsicsGuide/#expand=727,1063,4909,1062,1062,1063&text=_mm512_mask_cmplt_epu64)
+#[inline]
+#[target_feature(enable = "avx512f")]
+#[cfg_attr(test, assert_instr(vpcmp))]
+pub unsafe fn _mm512_mask_cmplt_epu64_mask(m: __mmask8, a: __m512i, b: __m512i) -> __mmask8 {
+    _mm512_cmplt_epu64_mask(a, b) & m
+}
+
 #[cfg(test)]
 mod tests {
     use std;
diff --git a/library/stdarch/crates/core_arch/src/x86_64/avx512f.rs b/library/stdarch/crates/core_arch/src/x86_64/avx512f.rs
index c5ab3af52557..22cd159bd925 100644
--- a/library/stdarch/crates/core_arch/src/x86_64/avx512f.rs
+++ b/library/stdarch/crates/core_arch/src/x86_64/avx512f.rs
@@ -57,6 +57,15 @@ mod tests {
         assert_eq!(m, 0b11001111);
     }
 
+    #[simd_test(enable = "avx512f")]
+    unsafe fn test_mm512_mask_cmplt_epu64_mask() {
+        let a = _mm512_set_epi64(0, 1, -1, u64::MAX as i64, i64::MAX, i64::MIN, 100, -100);
+        let b = _mm512_set1_epi64(-1);
+        let mask = 0b01111010;
+        let r = _mm512_mask_cmplt_epu64_mask(mask, a, b);
+        assert_eq!(r, 0b01001010);
+    }
+
     #[simd_test(enable = "avx512f")]
     unsafe fn test_mm512_set_epi64() {
         let r = _mm512_setr_epi64(0, 1, 2, 3, 4, 5, 6, 7);