1 files changed, 29 insertions, 0 deletions
diff --git a/newlib/libm/common/s_isinf.c b/newlib/libm/common/s_isinf.c
new file mode 100644
index 000000000..db8e8f82b
--- /dev/null
+++ b/newlib/libm/common/s_isinf.c
@@ -0,0 +1,29 @@
+/*
+ * isinf(x) returns 1 if x is infinity, else 0;
+ * no branching!
+ *
+ * isinf is a <math.h> macro in the C99 standard.  It was previously
+ * implemented as a function by newlib and is declared as such in
+ * <ieeefp.h>.  Newlib supplies it here as a function if the user
+ * chooses to use <ieeefp.h> or needs to link older code compiled with the
+ * previous <math.h> declaration.
+ */
+
+#include "fdlibm.h"
+#include <ieeefp.h>
+
+#ifndef _DOUBLE_IS_32BITS
+
+int
+_DEFUN (isinf, (x),
+	double x)
+{
+	__int32_t hx,lx;
+	EXTRACT_WORDS(hx,lx,x);
+	hx &= 0x7fffffff;
+	hx |= (__uint32_t)(lx|(-lx))>>31;	
+	hx = 0x7ff00000 - hx;
+	return 1 - (int)((__uint32_t)(hx|(-hx))>>31);
+}
+
+#endif /* _DOUBLE_IS_32BITS */