--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/support/fdlibm/s_logb.c Thu Nov 15 22:10:02 2012 +0000
@@ -0,0 +1,38 @@
+
+/* @(#)s_logb.c 1.3 95/01/18 */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunSoft, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+/*
+ * double logb(x)
+ * IEEE 754 logb. Included to pass IEEE test suite. Not recommend.
+ * Use ilogb instead.
+ */
+
+#include "fdlibm.h"
+
+#ifdef __STDC__
+ double logb(double x)
+#else
+ double logb(x)
+ double x;
+#endif
+{
+ int lx,ix;
+ ix = (__HI(x))&0x7fffffff; /* high |x| */
+ lx = __LO(x); /* low x */
+ if((ix|lx)==0) return -1.0/fabs(x);
+ if(ix>=0x7ff00000) return x*x;
+ if((ix>>=20)==0) /* IEEE 754 logb */
+ return -1022.0;
+ else
+ return (double) (ix-1023);
+}