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Diffstat (limited to 'sysdeps/ieee754/dbl-64/s_isnan.c')
-rw-r--r--sysdeps/ieee754/dbl-64/s_isnan.c43
1 files changed, 43 insertions, 0 deletions
diff --git a/sysdeps/ieee754/dbl-64/s_isnan.c b/sysdeps/ieee754/dbl-64/s_isnan.c
new file mode 100644
index 0000000000..86301e1531
--- /dev/null
+++ b/sysdeps/ieee754/dbl-64/s_isnan.c
@@ -0,0 +1,43 @@
+/* @(#)s_isnan.c 5.1 93/09/24 */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+#if defined(LIBM_SCCS) && !defined(lint)
+static char rcsid[] = "$NetBSD: s_isnan.c,v 1.8 1995/05/10 20:47:36 jtc Exp $";
+#endif
+
+/*
+ * isnan(x) returns 1 is x is nan, else 0;
+ * no branching!
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+	int __isnan(double x)
+#else
+	int __isnan(x)
+	double x;
+#endif
+{
+	int32_t hx,lx;
+	EXTRACT_WORDS(hx,lx,x);
+	hx &= 0x7fffffff;
+	hx |= (u_int32_t)(lx|(-lx))>>31;
+	hx = 0x7ff00000 - hx;
+	return (int)(((u_int32_t)hx)>>31);
+}
+weak_alias (__isnan, isnan)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__isnan, __isnanl)
+weak_alias (__isnan, isnanl)
+#endif