From 15797a79516ef8aa100e5a06363cd8224d3537a9 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Sun, 20 Sep 2015 19:17:15 -0600
Subject: [PATCH] Windows: use same TLS strategy for both VC and MinGW in
 64-bit mode

---
 racket/src/racket/include/schthread.h | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/racket/src/racket/include/schthread.h b/racket/src/racket/include/schthread.h
index e60de86483..db10d94214 100644
--- a/racket/src/racket/include/schthread.h
+++ b/racket/src/racket/include/schthread.h
@@ -28,8 +28,12 @@ extern "C" {
 #if defined(MZ_USE_PLACES) || defined(MZ_USE_FUTURES)
 # define USE_THREAD_LOCAL
 # ifdef _WIN32
-#  if defined(_WIN64) && !defined(__MINGW32__)
-#   define THREAD_LOCAL __declspec(thread)
+#  if defined(_WIN64)
+#   if defined(__MINGW32__)
+#     define THREAD_LOCAL __thread
+#   else
+#     define THREAD_LOCAL __declspec(thread)
+#   endif
 #   define MZ_THREAD_EXTERN extern
 #   define IMPLEMENT_THREAD_LOCAL_EXTERNALLY_VIA_PROC
 #  else