diff --git a/src/hotspot/os_cpu/bsd_zero/atomic_bsd_zero.hpp b/src/hotspot/os_cpu/bsd_zero/atomic_bsd_zero.hpp
index b39f03fd0d2..4d5d97fddcd 100644
--- a/src/hotspot/os_cpu/bsd_zero/atomic_bsd_zero.hpp
+++ b/src/hotspot/os_cpu/bsd_zero/atomic_bsd_zero.hpp
@@ -286,31 +286,19 @@ inline T Atomic::PlatformCmpxchg<8>::operator()(T volatile* dest,
 }
 
 // Atomically copy 64 bits of data
-static void atomic_copy64(const volatile void *src, volatile void *dst) {
-#if defined(PPC32)
-  double tmp;
-  asm volatile ("lfd  %0, 0(%1)\n"
-                "stfd %0, 0(%2)\n"
-                : "=f"(tmp)
-                : "b"(src), "b"(dst));
-#elif defined(S390) && !defined(_LP64)
-  double tmp;
-  asm volatile ("ld  %0, 0(%1)\n"
-                "std %0, 0(%2)\n"
-                : "=r"(tmp)
-                : "a"(src), "a"(dst));
-#else
-  *(jlong *) dst = *(const jlong *) src;
-#endif
+inline void atomic_copy64(const volatile void *src, volatile void *dst) {
+  int64_t tmp;
+  __atomic_load(reinterpret_cast<const volatile int64_t*>(src), &tmp, __ATOMIC_RELAXED);
+  __atomic_store(reinterpret_cast<volatile int64_t*>(dst), &tmp, __ATOMIC_RELAXED);
 }
 
 template<>
 template<typename T>
 inline T Atomic::PlatformLoad<8>::operator()(T const volatile* src) const {
   STATIC_ASSERT(8 == sizeof(T));
-  volatile int64_t dest;
-  atomic_copy64(reinterpret_cast<const volatile int64_t*>(src), reinterpret_cast<volatile int64_t*>(&dest));
-  return PrimitiveConversions::cast<T>(dest);
+  T dest;
+  __atomic_load(const_cast<T*>(src), &dest, __ATOMIC_RELAXED);
+  return dest;
 }
 
 template<>
@@ -318,7 +306,7 @@ template<typename T>
 inline void Atomic::PlatformStore<8>::operator()(T volatile* dest,
                                                  T store_value) const {
   STATIC_ASSERT(8 == sizeof(T));
-  atomic_copy64(reinterpret_cast<const volatile int64_t*>(&store_value), reinterpret_cast<volatile int64_t*>(dest));
+  __atomic_store(dest, &store_value, __ATOMIC_RELAXED);
 }
 
 #endif // OS_CPU_BSD_ZERO_ATOMIC_BSD_ZERO_HPP
diff --git a/src/hotspot/os_cpu/linux_zero/atomic_linux_zero.hpp b/src/hotspot/os_cpu/linux_zero/atomic_linux_zero.hpp
index eefa8d5d062..7b7beba6565 100644
--- a/src/hotspot/os_cpu/linux_zero/atomic_linux_zero.hpp
+++ b/src/hotspot/os_cpu/linux_zero/atomic_linux_zero.hpp
@@ -134,54 +134,18 @@ inline T Atomic::PlatformCmpxchg<8>::operator()(T volatile* dest,
 
 // Atomically copy 64 bits of data
 inline void atomic_copy64(const volatile void *src, volatile void *dst) {
-#if defined(PPC32) && !defined(__SPE__)
-  double tmp;
-  asm volatile ("lfd  %0, %2\n"
-                "stfd %0, %1\n"
-                : "=&f"(tmp), "=Q"(*(volatile double*)dst)
-                : "Q"(*(volatile double*)src));
-#elif defined(PPC32) && defined(__SPE__)
-  long tmp;
-  asm volatile ("evldd  %0, %2\n"
-                "evstdd %0, %1\n"
-                : "=&r"(tmp), "=Q"(*(volatile long*)dst)
-                : "Q"(*(volatile long*)src));
-#elif defined(S390) && !defined(_LP64)
-  double tmp;
-  asm volatile ("ld  %0, %2\n"
-                "std %0, %1\n"
-                : "=&f"(tmp), "=Q"(*(volatile double*)dst)
-                : "Q"(*(volatile double*)src));
-#elif defined(__ARM_ARCH_7A__)
-  // The only way to perform the atomic 64-bit load/store
-  // is to use ldrexd/strexd for both reads and writes.
-  // For store, we need to have the matching (fake) load first.
-  // Put clrex between exclusive ops on src and dst for clarity.
-  uint64_t tmp_r, tmp_w;
-  uint32_t flag_w;
-  asm volatile ("ldrexd %[tmp_r], [%[src]]\n"
-                "clrex\n"
-                "1:\n"
-                "ldrexd %[tmp_w], [%[dst]]\n"
-                "strexd %[flag_w], %[tmp_r], [%[dst]]\n"
-                "cmp    %[flag_w], 0\n"
-                "bne    1b\n"
-                : [tmp_r] "=&r" (tmp_r), [tmp_w] "=&r" (tmp_w),
-                  [flag_w] "=&r" (flag_w)
-                : [src] "r" (src), [dst] "r" (dst)
-                : "cc", "memory");
-#else
-  *(jlong *) dst = *(const jlong *) src;
-#endif
+  int64_t tmp;
+  __atomic_load(reinterpret_cast<const volatile int64_t*>(src), &tmp, __ATOMIC_RELAXED);
+  __atomic_store(reinterpret_cast<volatile int64_t*>(dst), &tmp, __ATOMIC_RELAXED);
 }
 
 template<>
 template<typename T>
 inline T Atomic::PlatformLoad<8>::operator()(T const volatile* src) const {
   STATIC_ASSERT(8 == sizeof(T));
-  volatile int64_t dest;
-  atomic_copy64(reinterpret_cast<const volatile int64_t*>(src), reinterpret_cast<volatile int64_t*>(&dest));
-  return PrimitiveConversions::cast<T>(dest);
+  T dest;
+  __atomic_load(const_cast<T*>(src), &dest, __ATOMIC_RELAXED);
+  return dest;
 }
 
 template<>
@@ -189,7 +153,7 @@ template<typename T>
 inline void Atomic::PlatformStore<8>::operator()(T volatile* dest,
                                                  T store_value) const {
   STATIC_ASSERT(8 == sizeof(T));
-  atomic_copy64(reinterpret_cast<const volatile int64_t*>(&store_value), reinterpret_cast<volatile int64_t*>(dest));
+  __atomic_store(dest, &store_value, __ATOMIC_RELAXED);
 }
 
 #endif // OS_CPU_LINUX_ZERO_ATOMIC_LINUX_ZERO_HPP