new version from Kahan and Zliu; AT&T free, add Berkeley header

[unix-history] / usr / src / lib / libm / ieee / cbrt.c

diff --git a/usr/src/lib/libm/ieee/cbrt.c b/usr/src/lib/libm/ieee/cbrt.c
index d307f9c..9bab38b 100644 (file)
--- a/usr/src/lib/libm/ieee/cbrt.c
+++ b/usr/src/lib/libm/ieee/cbrt.c
@@ -1,20 +1,23 @@
-/* 
+/*

  * Copyright (c) 1985 Regents of the University of California.
  * Copyright (c) 1985 Regents of the University of California.

- * 
- * Use and reproduction of this software are granted  in  accordance  with
- * the terms and conditions specified in  the  Berkeley  Software  License
- * Agreement (in particular, this entails acknowledgement of the programs'
- * source, and inclusion of this notice) with the additional understanding
- * that  all  recipients  should regard themselves as participants  in  an
- * ongoing  research  project and hence should  feel  obligated  to report
- * their  experiences (good or bad) with these elementary function  codes,
- * using "sendbug 4bsd-bugs@BERKELEY", to the authors.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that this notice is preserved and that due credit is given
+ * to the University of California at Berkeley. The name of the University
+ * may not be used to endorse or promote products derived from this
+ * software without specific prior written permission. This software
+ * is provided ``as is'' without express or implied warranty.
+ *
+ * All recipients should regard themselves as participants in an ongoing
+ * research project and hence should feel obligated to report their
+ * experiences (good or bad) with these elementary function codes, using
+ * the sendbug(8) program, to the authors.

  */
 
 #ifndef lint
  */
 
 #ifndef lint

-static char sccsid[] =
-"@(#)cbrt.c    1.1 (Berkeley) 5/23/85; 5.1 (ucb.elefunt) %G%";
-#endif /* not lint */
+static char sccsid[] = "@(#)cbrt.c     5.3 (Berkeley) %G%";
+#endif /* not lint */

 
 /* kahan's cube root (53 bits IEEE double precision)
  * for IEEE machines only
 
 /* kahan's cube root (53 bits IEEE double precision)
  * for IEEE machines only


@@ -87,7 +90,7 @@ double x;
        s=t*t;          /* t*t is exact */
        r=x/s;
        w=t+t;
        s=t*t;          /* t*t is exact */
        r=x/s;
        w=t+t;

-       r=(r-t)/(w+r);  /* r-s is exact */
+       r=(r-t)/(w+r);  /* r-t is exact */

        t=t+t*r;
 
 
        t=t+t*r;