1 files changed, 92 insertions, 0 deletions
diff --git a/lib/msun/src/s_modf.c b/lib/msun/src/s_modf.c
new file mode 100644
index 000000000000..0dd0d50e5912
--- /dev/null
+++ b/lib/msun/src/s_modf.c
@@ -0,0 +1,92 @@
+/* @(#)s_modf.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.
+ * ====================================================
+ */
+
+#ifndef lint
+static char rcsid[] = "$Id: s_modf.c,v 1.1.1.1 1994/05/06 00:20:06 gclarkii Exp $";
+#endif
+
+/*
+ * modf(double x, double *iptr) 
+ * return fraction part of x, and return x's integral part in *iptr.
+ * Method:
+ *	Bit twiddling.
+ *
+ * Exception:
+ *	No exception.
+ */
+
+#include "math.h"
+#include <machine/endian.h>
+
+#if BYTE_ORDER == LITTLE_ENDIAN
+#define n0	1
+#define n1	0
+#else
+#define n0	0
+#define n1	1
+#endif
+
+#ifdef __STDC__
+static const double one = 1.0;
+#else
+static double one = 1.0;
+#endif
+
+#ifdef __STDC__
+	double modf(double x, double *iptr)
+#else
+	double modf(x, iptr)
+	double x,*iptr;
+#endif
+{
+	int i0,i1,j0;
+	unsigned i;
+	i0 =  *(n0+(int*)&x);		/* high x */
+	i1 =  *(n1+(int*)&x);		/* low  x */
+	j0 = ((i0>>20)&0x7ff)-0x3ff;	/* exponent of x */
+	if(j0<20) {			/* integer part in high x */
+	    if(j0<0) {			/* |x|<1 */
+		*(n0+(int*)iptr) = i0&0x80000000;
+		*(n1+(int*)iptr) = 0;		/* *iptr = +-0 */
+		return x;
+	    } else {
+		i = (0x000fffff)>>j0;
+		if(((i0&i)|i1)==0) {		/* x is integral */
+		    *iptr = x;
+		    *(n0+(int*)&x) &= 0x80000000;
+		    *(n1+(int*)&x)  = 0;	/* return +-0 */
+		    return x;
+		} else {
+		    *(n0+(int*)iptr) = i0&(~i);
+		    *(n1+(int*)iptr) = 0;
+		    return x - *iptr;
+		}
+	    }
+	} else if (j0>51) {		/* no fraction part */
+	    *iptr = x*one;
+	    *(n0+(int*)&x) &= 0x80000000;
+	    *(n1+(int*)&x)  = 0;	/* return +-0 */
+	    return x;
+	} else {			/* fraction part in low x */
+	    i = ((unsigned)(0xffffffff))>>(j0-20);
+	    if((i1&i)==0) { 		/* x is integral */
+		*iptr = x;
+		*(n0+(int*)&x) &= 0x80000000;
+		*(n1+(int*)&x)  = 0;	/* return +-0 */
+		return x;
+	    } else {
+		*(n0+(int*)iptr) = i0;
+		*(n1+(int*)iptr) = i1&(~i);
+		return x - *iptr;
+	    }
+	}
+}