1 files changed, 129 insertions, 0 deletions
diff --git a/ext/bcmath/libbcmath/src/sqrt.c b/ext/bcmath/libbcmath/src/sqrt.c
new file mode 100644
index 0000000..5db5113
--- /dev/null
+++ b/ext/bcmath/libbcmath/src/sqrt.c
@@ -0,0 +1,129 @@
+/* sqrt.c: bcmath library file. */
+/*
+    Copyright (C) 1991, 1992, 1993, 1994, 1997 Free Software Foundation, Inc.
+    Copyright (C) 2000 Philip A. Nelson
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.  (COPYING.LIB)
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to:
+
+      The Free Software Foundation, Inc.
+      59 Temple Place, Suite 330
+      Boston, MA 02111-1307 USA.
+
+    You may contact the author by:
+       e-mail:  philnelson@acm.org
+      us-mail:  Philip A. Nelson
+                Computer Science Department, 9062
+                Western Washington University
+                Bellingham, WA 98226-9062
+       
+*************************************************************************/
+
+#include <config.h>
+#include <stdio.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <stdarg.h>
+#include "bcmath.h"
+#include "private.h"
+
+/* Take the square root NUM and return it in NUM with SCALE digits
+   after the decimal place. */
+
+int
+bc_sqrt (bc_num *num, int scale TSRMLS_DC)
+{
+  int rscale, cmp_res, done;
+  int cscale;
+  bc_num guess, guess1, point5, diff;
+
+  /* Initial checks. */
+  cmp_res = bc_compare (*num, BCG(_zero_));
+  if (cmp_res < 0)
+    return 0;		/* error */
+  else
+    {
+      if (cmp_res == 0)
+	{
+	  bc_free_num (num);
+	  *num = bc_copy_num (BCG(_zero_));
+	  return 1;
+	}
+    }
+  cmp_res = bc_compare (*num, BCG(_one_));
+  if (cmp_res == 0)
+    {
+      bc_free_num (num);
+      *num = bc_copy_num (BCG(_one_));
+      return 1;
+    }
+
+  /* Initialize the variables. */
+  rscale = MAX (scale, (*num)->n_scale);
+  bc_init_num(&guess TSRMLS_CC);
+  bc_init_num(&guess1 TSRMLS_CC);
+  bc_init_num(&diff TSRMLS_CC);
+  point5 = bc_new_num (1,1);
+  point5->n_value[1] = 5;
+
+
+  /* Calculate the initial guess. */
+  if (cmp_res < 0)
+    {
+      /* The number is between 0 and 1.  Guess should start at 1. */
+      guess = bc_copy_num (BCG(_one_));
+      cscale = (*num)->n_scale;
+    }
+  else
+    {
+      /* The number is greater than 1.  Guess should start at 10^(exp/2). */
+      bc_int2num (&guess,10);
+
+      bc_int2num (&guess1,(*num)->n_len);
+      bc_multiply (guess1, point5, &guess1, 0 TSRMLS_CC);
+      guess1->n_scale = 0;
+      bc_raise (guess, guess1, &guess, 0 TSRMLS_CC);
+      bc_free_num (&guess1);
+      cscale = 3;
+    }
+
+  /* Find the square root using Newton's algorithm. */
+  done = FALSE;
+  while (!done)
+    {
+      bc_free_num (&guess1);
+      guess1 = bc_copy_num (guess);
+      bc_divide (*num, guess, &guess, cscale TSRMLS_CC);
+      bc_add (guess, guess1, &guess, 0);
+      bc_multiply (guess, point5, &guess, cscale TSRMLS_CC);
+      bc_sub (guess, guess1, &diff, cscale+1);
+      if (bc_is_near_zero (diff, cscale))
+	{
+	  if (cscale < rscale+1)
+	    cscale = MIN (cscale*3, rscale+1);
+	  else
+	    done = TRUE;
+	}
+    }
+
+  /* Assign the number and clean up. */
+  bc_free_num (num);
+  bc_divide (guess,BCG(_one_),num,rscale TSRMLS_CC);
+  bc_free_num (&guess);
+  bc_free_num (&guess1);
+  bc_free_num (&point5);
+  bc_free_num (&diff);
+  return 1;
+}
+