From f2595c038ed7bfd182d9d05d83786106ebd02ca0 Mon Sep 17 00:00:00 2001
From: Lawrence D'Anna <64555057+lawrence-danna-apple@users.noreply.github.com>
Date: Tue, 30 Jun 2020 02:15:46 -0700
Subject: [PATCH] bpo-41100: fix _decimal for arm64 Mac OS (GH-21228)

Patch by Lawrence Danna.
---
 .../Core and Builtins/2020-06-30-04-44-29.bpo-41100.PJwA6F.rst | 1 +
 Modules/_decimal/libmpdec/mpdecimal.h                          | 3 +++
 2 files changed, 4 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Core and Builtins/2020-06-30-04-44-29.bpo-41100.PJwA6F.rst

diff --git a/Misc/NEWS.d/next/Core and Builtins/2020-06-30-04-44-29.bpo-41100.PJwA6F.rst b/Misc/NEWS.d/next/Core and Builtins/2020-06-30-04-44-29.bpo-41100.PJwA6F.rst
new file mode 100644
index 0000000000..d6176d69f0
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2020-06-30-04-44-29.bpo-41100.PJwA6F.rst	
@@ -0,0 +1 @@
+add arm64 to the allowable Mac OS arches in mpdecimal.h
\ No newline at end of file
diff --git a/Modules/_decimal/libmpdec/mpdecimal.h b/Modules/_decimal/libmpdec/mpdecimal.h
index a67dd9bc12..3e9c8185c3 100644
--- a/Modules/_decimal/libmpdec/mpdecimal.h
+++ b/Modules/_decimal/libmpdec/mpdecimal.h
@@ -135,6 +135,9 @@ const char *mpd_version(void);
   #elif defined(__x86_64__)
     #define CONFIG_64
     #define ASM
+  #elif defined(__arm64__)
+    #define CONFIG_64
+    #define ANSI
   #else
     #error "unknown architecture for universal build."
   #endif
-- 
2.37.3

