[3.7] Revert "align PyGC_Head to alignof(long double) (GH-13335)" (GH-13569)

This reverts commit ea2b76bdc5f97f49701213d105b8ec2387ea2fa5.
See the bug for discussion.

https://bugs.python.org/issue27987

diff --git a/Include/objimpl.h b/Include/objimpl.h
index 0436ba7899d9a8a3769ff4d228982439707254b0..057bb50cbda9e22da6600807a7be091cc19f0fea 100644 (file)
--- a/Include/objimpl.h
+++ b/Include/objimpl.h
@@ -255,11 +255,7 @@ typedef union _gc_head {
         union _gc_head *gc_prev;
         Py_ssize_t gc_refs;
     } gc;
-    long double dummy;  /* force worst-case alignment */
-    // malloc returns memory block aligned for any built-in types and
-    // long double is the largest standard C type.
-    // On amd64 linux, long double requires 16 byte alignment.
-    // See bpo-27987 for more discussion.
+    double dummy;  /* force worst-case alignment */
 } PyGC_Head;
 
 extern PyGC_Head *_PyGC_generation0;

diff --git a/Misc/NEWS.d/next/Core and Builtins/2019-05-15-18-28-43.bpo-27987.FaxuLy.rst b/Misc/NEWS.d/next/Core and Builtins/2019-05-15-18-28-43.bpo-27987.FaxuLy.rst
deleted file mode 100644 (file)
index 97ca37b..0000000
--- a/Misc/NEWS.d/next/Core and Builtins/2019-05-15-18-28-43.bpo-27987.FaxuLy.rst
+++ /dev/null
@@ -1,2 +0,0 @@
-``PyGC_Head`` structure is aligned to ``long double``.  This is needed to
-GC-ed objects are aligned properly.  Patch by Inada Naoki.