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-rw-r--r--libm/s_isnan.c45
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diff --git a/libm/s_isnan.c b/libm/s_isnan.c
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+/* @(#)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"
+
+libm_hidden_proto (__isnan)
+#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);
+}
+libm_hidden_def (__isnan)
+weak_alias (__isnan, isnan)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__isnan, __isnanl)
+weak_alias (__isnan, isnanl)
+#endif