[builtins] emutls cleanup: determine header size using sizeof
Summary: Also add a few post-#else/#endif comments
Reviewers: echristo, srhines
Subscribers: chh, delcypher, llvm-commits, #sanitizers
@@ -96,7 +96,7 @@ static __inline emutls_address_array* emutls_getspecific() {
return (emutls_address_array*) pthread_getspecific(emutls_pthread_key);
}
-#else
+#else /* _WIN32 */
#include <windows.h>
#include <malloc.h>
@@ -222,11 +222,11 @@ static __inline void __atomic_store_n(void *ptr, uintptr_t val, unsigned type) {
InterlockedExchangePointer((void *volatile *)ptr, (void *)val);
}
-#endif
+#endif /* __ATOMIC_RELEASE */
#pragma warning (pop)
-#endif
+#endif /* _WIN32 */
static size_t emutls_num_object = 0; /* number of allocated TLS objects */
@@ -314,11 +314,12 @@ static __inline void emutls_check_array_set_size(emutls_address_array *array,
* which must be no smaller than the given index.
*/
static __inline uintptr_t emutls_new_data_array_size(uintptr_t index) {
- /* Need to allocate emutls_address_array with one extra slot
- * to store the data array size.
+ /* Need to allocate emutls_address_array with extra slots
+ * to store the header.
* Round up the emutls_address_array size to multiple of 16.
*/
- return ((index + 1 + 15) & ~((uintptr_t)15)) - 1;
+ uintptr_t header_words = sizeof(emutls_address_array) / sizeof(void *);
+ return ((index + header_words + 15) & ~((uintptr_t)15)) - header_words;
}
/* Returns the size in bytes required for an emutls_address_array with
