bpo-35758: Fix building on ARM + MSVC (gh-11531)
* Disable x87 control word for non-x86 targets
On msvc, x87 control word is only available on x86 target. Need to disable it for other targets to prevent compiling problems.
* Include immintrin.h on x86 and x64 only
Immintrin.h is only available on x86 and x64. Need to disable it for other targets to prevent compiling problems.
diff --git a/Include/internal/pycore_atomic.h b/Include/internal/pycore_atomic.h
index f430a5c..5669f71 100644
--- a/Include/internal/pycore_atomic.h
+++ b/Include/internal/pycore_atomic.h
@@ -19,7 +19,9 @@
#if defined(_MSC_VER)
#include <intrin.h>
-#include <immintrin.h>
+#if defined(_M_IX86) || defined(_M_X64)
+# include <immintrin.h>
+#endif
#endif
/* This is modeled after the atomics interface from C1x, according to
diff --git a/Include/pyport.h b/Include/pyport.h
index 7f88c4f..4971a49 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -406,7 +406,7 @@
#endif
/* get and set x87 control word for VisualStudio/x86 */
-#if defined(_MSC_VER) && !defined(_WIN64) /* x87 not supported in 64-bit */
+#if defined(_MSC_VER) && defined(_M_IX86) /* x87 only supported in x86 */
#define HAVE_PY_SET_53BIT_PRECISION 1
#define _Py_SET_53BIT_PRECISION_HEADER \
unsigned int old_387controlword, new_387controlword, out_387controlword
diff --git a/Misc/NEWS.d/next/Windows/2019-01-21-05-18-14.bpo-35758.8LsY3l.rst b/Misc/NEWS.d/next/Windows/2019-01-21-05-18-14.bpo-35758.8LsY3l.rst
new file mode 100644
index 0000000..c1e19d4
--- /dev/null
+++ b/Misc/NEWS.d/next/Windows/2019-01-21-05-18-14.bpo-35758.8LsY3l.rst
@@ -0,0 +1 @@
+Allow building on ARM with MSVC.