1 files changed, 97 insertions, 0 deletions
diff --git a/src/libs/math/sqrt.c b/src/libs/math/sqrt.c
new file mode 100644
index 0000000..1f02cac
--- /dev/null
+++ b/src/libs/math/sqrt.c
@@ -0,0 +1,97 @@
+//Copyright Paul Reiche, Fred Ford. 1992-2002
+
+/*
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include "mthintrn.h"
+
+COUNT
+square_root (DWORD value)
+{
+	UWORD sig_word, mask;
+	COUNT result, shift;
+
+	if ((sig_word = HIWORD (value)) > 0)
+	{
+		DWORD mask_squared, result_shift;
+
+		for (mask = 1 << 15, shift = 31;
+				!(mask & sig_word); mask >>= 1, --shift)
+			;
+		shift >>= 1;
+		mask = 1 << shift;
+
+		result = mask;
+		mask_squared = result_shift = (DWORD)mask << shift;
+		value -= mask_squared;
+		while (mask >>= 1)
+		{
+			DWORD remainder;
+
+			mask_squared >>= 1;
+			mask_squared >>= 1;
+			if ((remainder = result_shift + mask_squared) > value)
+				result_shift >>= 1;
+			else
+			{
+				value -= remainder;
+
+				result_shift = (result_shift >> 1) + mask_squared;
+
+				result |= mask;
+			}
+		}
+
+		return (result);
+	}
+	else if ((sig_word = LOWORD (value)) > 0)
+	{
+		UWORD mask_squared, result_shift;
+
+		for (mask = 1 << 15, shift = 15;
+				!(mask & sig_word); mask >>= 1, --shift)
+			;
+		shift >>= 1;
+		mask = 1 << shift;
+
+		result = mask;
+		mask_squared = result_shift = mask << shift;
+		sig_word -= mask_squared;
+		while (mask >>= 1)
+		{
+			UWORD remainder;
+
+			mask_squared >>= 1;
+			mask_squared >>= 1;
+			if ((remainder = result_shift + mask_squared) > sig_word)
+				result_shift >>= 1;
+			else
+			{
+				sig_word -= remainder;
+
+				result_shift = (result_shift >> 1) + mask_squared;
+
+				result |= mask;
+			}
+		}
+
+		return (result);
+	}
+
+	return (0);
+}
+
+