Totally rework the math library, this time based on the MacOs X

math library (which is itself based on the math lib from FreeBSD).
 -Erik

1 files changed, 61 insertions, 0 deletions

diff --git a/libm/s_frexp.c b/libm/s_frexp.c
new file mode 100644
index 000000000..f187d8472
--- /dev/null
+++ b/libm/s_frexp.c
@@ -0,0 +1,61 @@
+#if !defined(__ppc__)
+/* @(#)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.
+ * ====================================================
+ */
+
+#if defined(LIBM_SCCS) && !defined(lint)
+static char rcsid[] = "$NetBSD: s_frexp.c,v 1.9 1995/05/10 20:47:24 jtc Exp $";
+#endif
+
+/*
+ * 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 "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+static const double
+#else
+static double
+#endif
+two54 =  1.80143985094819840000e+16; /* 0x43500000, 0x00000000 */
+
+#ifdef __STDC__
+	double frexp(double x, int *eptr)
+#else
+	double frexp(x, eptr)
+	double x; int *eptr;
+#endif
+{
+	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;
+}
+#endif /* !__ppc__ */