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-rw-r--r--lib/msun/src/s_modf.c92
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diff --git a/lib/msun/src/s_modf.c b/lib/msun/src/s_modf.c
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+/* @(#)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;
+ }
+ }
+}