Fixup atomic msvc intrinsics

NVIDIA · Nov 19, 2020 · 78034a2 · 78034a2
1 parent 38de998
commit 78034a2
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Showing 2 changed files with 23 additions and 0 deletions.
diff --git a/libcxx/include/__config b/libcxx/include/__config
@@ -858,6 +858,11 @@ typedef __char32_t char32_t;
 #define _LIBCUDACXX_HAS_NO_LOGICAL_METAFUNCTION_ALIASES
 #endif
 
+// MSVC exposed __iso_volatile intrinsics beginning on 1924 for x86
+#if _MSC_VER < 1924
+    #define _LIBCUDACXX_HAS_NO_ISO_INTRIN
+#endif
+
 #define _LIBCUDACXX_UNDERLYING_TYPE(...) __underlying_type(__VA_ARGS__)
 #define _LIBCUDACXX_IS_CONSTRUCTIBLE(...) __is_constructible(__VA_ARGS__)
 #define _LIBCUDACXX_IS_DESTRUCTIBLE(...) __is_destructible(__VA_ARGS__)

diff --git a/libcxx/include/support/win32/atomic_msvc.h b/libcxx/include/support/win32/atomic_msvc.h
@@ -1,3 +1,4 @@
+// -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 // Part of libcu++, the C++ Standard Library for your entire system,
@@ -45,22 +46,38 @@ namespace detail {
 
 template<class _Type, detail::_enable_if_sized_as<_Type,1> = 0>
 void __atomic_load_relaxed(const volatile _Type *__ptr, _Type *__ret) {
+#ifdef _LIBCUDACXX_HAS_NO_ISO_INTRIN
+    __int8 __tmp = *(const volatile __int8 *)__ptr;
+#else
     __int8 __tmp = __iso_volatile_load8((const volatile __int8 *)__ptr);
+#endif
     *__ret = reinterpret_cast<_Type&>(__tmp);
 }
 template<class _Type, detail::_enable_if_sized_as<_Type,2> = 0>
 void __atomic_load_relaxed(const volatile _Type *__ptr, _Type *__ret) {
+#ifdef _LIBCUDACXX_HAS_NO_ISO_INTRIN
+    __int16 __tmp = *(const volatile __int8 *)__ptr;
+#else
     __int16 __tmp = __iso_volatile_load16((const volatile __int16 *)__ptr);
+#endif
     *__ret = reinterpret_cast<_Type&>(__tmp);
 }
 template<class _Type, detail::_enable_if_sized_as<_Type,4> = 0>
 void __atomic_load_relaxed(const volatile _Type *__ptr, _Type *__ret) {
+#ifdef _LIBCUDACXX_HAS_NO_ISO_INTRIN
+    __int32 __tmp = *(const volatile __int8 *)__ptr;
+#else
     __int32 __tmp = __iso_volatile_load32((const volatile __int32 *)__ptr);
+#endif
     *__ret = reinterpret_cast<_Type&>(__tmp);
 }
 template<class _Type, detail::_enable_if_sized_as<_Type,8> = 0>
 void __atomic_load_relaxed(const volatile _Type *__ptr, _Type *__ret) {
+#ifdef _LIBCUDACXX_HAS_NO_ISO_INTRIN
+    __int64 __tmp = *(const volatile __int8 *)__ptr;
+#else
     __int64 __tmp = __iso_volatile_load64((const volatile __int64 *)__ptr);
+#endif
     *__ret = reinterpret_cast<_Type&>(__tmp);
 }
 
@@ -75,6 +92,7 @@ void __atomic_load(const volatile _Type *__ptr, _Type *__ret, int __memorder) {
     }
 }
 
+
 template<class _Type, detail::_enable_if_sized_as<_Type,1> = 0>
 void __atomic_store_relaxed(const volatile _Type *__ptr, _Type *__val) {
     __int8 __tmp = reinterpret_cast<__int8&>(*__val);