# HG changeset patch
# User Samuel Iseli <samuel.iseli@gmail.com>
# Date 1328275087 -3600
# Branch 2.7
# Node ID 0bd59b0fb1065931f248760dd06ffa81e7d4ee87
# Parent  41cabdff268624c91f084ca2203668db58df0460
Issue #13889: Add _Py_SET_53BIT_PRECISION_* macros for win32

diff -r 41cabdff2686 -r 0bd59b0fb106 Include/pyport.h
--- a/Include/pyport.h	Fri Feb 03 02:39:49 2012 +0100
+++ b/Include/pyport.h	Fri Feb 03 14:18:07 2012 +0100
@@ -549,6 +549,29 @@
         _Py_set_387controlword(old_387controlword)
 #endif
 
+/* get and set x87 control word for MS VC /x86 */
+#ifdef _WIN32
+/* x87 not supported in 64bit applications */
+#ifndef _WIN64
+#define HAVE_PY_SET_53BIT_PRECISION 1
+#define _Py_SET_53BIT_PRECISION_HEADER                          \
+    unsigned int old_387controlword, new_387controlword
+/* we are using the __control87_2 function to set only the x87 controlword.
+   SSE controlword is unaffected  */
+#define _Py_SET_53BIT_PRECISION_START                                   \
+    do {                                                                \
+		__control87_2(0, 0, &old_387controlword, NULL);		\
+		new_387controlword = old_387controlword;			\
+        if ( !(old_387controlword & _PC_53) )               \
+            __control87_2(_PC_53, _MCW_PC, &new_387controlword, NULL)   \	
+    } while (0)
+#define _Py_SET_53BIT_PRECISION_END                             \
+    if (new_387controlword != old_387controlword)               \
+		__control87_2(old_387controlword, _MCW_PC, &new_387controlword, NULL)
+#endif
+#endif
+
+
 /* default definitions are empty */
 #ifndef HAVE_PY_SET_53BIT_PRECISION
 #define _Py_SET_53BIT_PRECISION_HEADER