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+
+/* @(#)s_ldexp.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.
+ * ====================================================
+ */
+
+/*
+FUNCTION
+ <<ldexp>>, <<ldexpf>>---load exponent
+
+INDEX
+ ldexp
+INDEX
+ ldexpf
+
+ANSI_SYNOPSIS
+ #include <math.h>
+ double ldexp(double <[val]>, int <[exp]>);
+ float ldexpf(float <[val]>, int <[exp]>);
+
+TRAD_SYNOPSIS
+ #include <math.h>
+
+ double ldexp(<[val]>, <[exp]>)
+ double <[val]>;
+ int <[exp]>;
+
+ float ldexpf(<[val]>, <[exp]>)
+ float <[val]>;
+ int <[exp]>;
+
+
+DESCRIPTION
+<<ldexp>> calculates the value
+@ifinfo
+<[val]> times 2 to the power <[exp]>.
+@end ifinfo
+@tex
+$val\times 2^{exp}$.
+@end tex
+<<ldexpf>> is identical, save that it takes and returns <<float>>
+rather than <<double>> values.
+
+RETURNS
+<<ldexp>> returns the calculated value.
+
+Underflow and overflow both set <<errno>> to <<ERANGE>>.
+On underflow, <<ldexp>> and <<ldexpf>> return 0.0.
+On overflow, <<ldexp>> returns plus or minus <<HUGE_VAL>>.
+
+PORTABILITY
+<<ldexp>> is ANSI, <<ldexpf>> is an extension.
+
+*/
+
+#include "fdlibm.h"
+#include <errno.h>
+
+#ifndef _DOUBLE_IS_32BITS
+
+#ifdef __STDC__
+ double ldexp(double value, int exp)
+#else
+ double ldexp(value, exp)
+ double value; int exp;
+#endif
+{
+ if(!finite(value)||value==0.0) return value;
+ value = scalbn(value,exp);
+ if(!finite(value)||value==0.0) errno = ERANGE;
+ return value;
+}
+
+#endif /* _DOUBLE_IS_32BITS */