1 files changed, 20 insertions, 0 deletions
diff --git a/winsup/mingw/mingwex/fpclassify.c b/winsup/mingw/mingwex/fpclassify.c
new file mode 100644
index 000000000..f8cd8cb44
--- /dev/null
+++ b/winsup/mingw/mingwex/fpclassify.c
@@ -0,0 +1,20 @@
+#include <math.h>
+
+/* 'fxam' sets FPU flags C3,C2,C0   'fstsw' stores: 
+ FP_NAN			001		0x0100
+ FP_NORMAL		010		0x0400
+ FP_INFINITE		011		0x0500
+ FP_ZERO		100		0x4000
+ FP_SUBNORMAL		110		0x4400
+
+and sets C1 flag (signbit) if neg */
+
+int __fpclassify (double _x){
+  unsigned short sw;
+  __asm__ (
+	"fxam; fstsw %%ax;"
+	: "=a" (sw)
+	: "t" (_x)
+	);
+  return sw & (FP_NAN | FP_NORMAL | FP_ZERO );
+}