[libcxx] Fix std::align by using __builtin_align_up()

CTSRD-CHERI · Jul 1, 2019 · dd01245 · dd01245
1 parent d9531f5
commit dd01245
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/libcxx/src/memory.cpp b/libcxx/src/memory.cpp
@@ -222,7 +222,11 @@ align(size_t alignment, size_t size, void*& ptr, size_t& space)
     if (size <= space)
     {
         char* p1 = static_cast<char*>(ptr);
+#if __has_builtin(__builtin_align_up)
+        char* p2 = __builtin_align_up(p1, alignment);
+#else
         char* p2 = reinterpret_cast<char*>(reinterpret_cast<size_t>(p1 + (alignment - 1)) & -alignment);
+#endif
         size_t d = static_cast<size_t>(p2 - p1);
         if (d <= space - size)
         {