--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/genericopenlibs/cstdlib/LMATH/S_FREXP.C Tue Feb 02 02:01:42 2010 +0200
@@ -0,0 +1,117 @@
+/* S_FREXP.C
+ *
+ * Portions Copyright (c) 1993-2005 Nokia Corporation and/or its subsidiary(-ies).
+ * All rights reserved.
+ */
+
+
+/* @(#)s_frexp.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
+ <<frexp>>, <<frexpf>>---split floating-point number
+INDEX
+ frexp
+INDEX
+ frexpf
+
+ANSI_SYNOPSIS
+ #include <math.h>
+ double frexp(double <[val]>, int *<[exp]>);
+ float frexpf(float <[val]>, int *<[exp]>);
+
+TRAD_SYNOPSIS
+ #include <math.h>
+ double frexp(<[val]>, <[exp]>)
+ double <[val]>;
+ int *<[exp]>;
+
+ float frexpf(<[val]>, <[exp]>)
+ float <[val]>;
+ int *<[exp]>;
+
+
+DESCRIPTION
+ All non zero, normal numbers can be described as <[m]> * 2**<[p]>.
+ <<frexp>> represents the double <[val]> as a mantissa <[m]>
+ and a power of two <[p]>. The resulting mantissa will always
+ be greater than or equal to <<0.5>>, and less than <<1.0>> (as
+ long as <[val]> is nonzero). The power of two will be stored
+ in <<*>><[exp]>.
+
+@ifinfo
+<[m]> and <[p]> are calculated so that
+<[val]> is <[m]> times <<2>> to the power <[p]>.
+@end ifinfo
+@tex
+<[m]> and <[p]> are calculated so that
+$ val = m \times 2^p $.
+@end tex
+
+<<frexpf>> is identical, other than taking and returning
+floats rather than doubles.
+
+RETURNS
+<<frexp>> returns the mantissa <[m]>. If <[val]> is <<0>>, infinity,
+or Nan, <<frexp>> will set <<*>><[exp]> to <<0>> and return <[val]>.
+
+PORTABILITY
+<<frexp>> is ANSI.
+<<frexpf>> is an extension.
+
+
+*/
+
+/*
+ * for non-zero x
+ * x = frexp(arg,&exp);
+ * return a double fp quantity x such that 0.5 <= |x| <1.0
+ * and the corresponding binary exponent "exp". That is
+ * arg = x*2^exp.
+ * If arg is inf, 0.0, or NaN, then frexp(arg,&exp) returns arg
+ * with *exp=0.
+ */
+
+#include "FDLIBM.H"
+
+static const double
+two54 = 1.80143985094819840000e+16; /* 0x43500000, 0x00000000 */
+
+/**
+Get mantissa and exponent of floating-point value.
+Calculates mantissa (a floating-point value between 0.5 and 1)
+and exponent (an integer value) where x is parameter x,
+mantissa is the value returned by the function and exponent
+is set by the function at location pointed by eptr.
+@return Mantissa.
+@param x Floating point value
+@param eptr Location where to exponent will be received.
+*/
+EXPORT_C double frexp(double x, int *eptr) __SOFTFP
+{
+ __int32_t hx, ix, lx;
+ EXTRACT_WORDS(hx,lx,x);
+ ix = 0x7fffffff&hx;
+ *eptr = 0;
+ if(ix>=0x7ff00000||((ix|lx)==0)) return x; /* 0,inf,nan */
+ if (ix<0x00100000) { /* subnormal */
+ x *= two54;
+ GET_HIGH_WORD(hx,x);
+ ix = hx&0x7fffffff;
+ *eptr = -54;
+ }
+ *eptr += (ix>>20)-1022;
+ hx = (hx&0x800fffff)|0x3fe00000;
+ SET_HIGH_WORD(x,hx);
+ return x;
+}