Author: mark.dickinson
Date: Mon Apr 13 18:25:29 2009
New Revision: 71577
Log:
Add functions to get and set the x87 FPU control word, where applicable
Modified:
python/branches/py3k-short-float-repr/Include/pymath.h
python/branches/py3k-short-float-repr/Python/pymath.c
Modified: python/branches/py3k-short-float-repr/Include/pymath.h
==============================================================================
--- python/branches/py3k-short-float-repr/Include/pymath.h (original)
+++ python/branches/py3k-short-float-repr/Include/pymath.h Mon Apr 13 18:25:29 2009
@@ -92,6 +92,11 @@
# endif
#endif
+#ifdef HAVE_GCC_ASM_FOR_X87
+PyAPI_FUNC(unsigned short) _Py_get_387controlword(void);
+PyAPI_FUNC(void) _Py_set_387controlword(unsigned short);
+#endif
+
/* Py_IS_NAN(X)
* Return 1 if float or double arg is a NaN, else 0.
* Caution:
Modified: python/branches/py3k-short-float-repr/Python/pymath.c
==============================================================================
--- python/branches/py3k-short-float-repr/Python/pymath.c (original)
+++ python/branches/py3k-short-float-repr/Python/pymath.c Mon Apr 13 18:25:29 2009
@@ -13,6 +13,28 @@
}
#endif
+#ifdef USING_X87_FPU
+# ifdef HAVE_GCC_ASM_FOR_X87
+
+/* inline assembly for getting and setting the 387 FPU control word on
+ gcc/x86 */
+
+unsigned short _Py_get_387controlword(void) {
+ unsigned short cw;
+ __asm__ __volatile__ ("fnstcw %0" : "=m" (cw));
+ return cw;
+}
+
+void _Py_set_387controlword(unsigned short cw) {
+ __asm__ __volatile__ ("fldcw %0" : : "m" (cw));
+}
+
+# else
+# error "Unable to get and set x87 control word"
+# endif
+#endif
+
+
#ifndef HAVE_HYPOT
double hypot(double x, double y)
{