initial commit, 4.5 stable

thirdparty/sdl/libm/s_isnan.c

@@ -0,0 +1,31 @@
+#include "SDL_internal.h"
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+/*
+ * isnan(x) returns 1 is x is nan, else 0;
+ * no branching!
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+int __isnan(double x)
+{
+	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)
+libm_hidden_def(__isnan)