[Boost-commit] svn:boost r64338 - sandbox/SOC/2010/bits_and_ints/boost/integer

Subject: [Boost-commit] svn:boost r64338 - sandbox/SOC/2010/bits_and_ints/boost/integer
From: muriloufg_at_[hidden]
Date: 2010-07-25 13:47:32

Author: murilov
Date: 2010-07-25 13:47:32 EDT (Sun, 25 Jul 2010)
New Revision: 64338
URL: http://svn.boost.org/trac/boost/changeset/64338

Log:
Added isqrt() functions wich calculate the saquare root of integers
Added:
   sandbox/SOC/2010/bits_and_ints/boost/integer/isqrt.hpp   (contents, props changed)

Added: sandbox/SOC/2010/bits_and_ints/boost/integer/isqrt.hpp
==============================================================================
--- (empty file)
+++ sandbox/SOC/2010/bits_and_ints/boost/integer/isqrt.hpp	2010-07-25 13:47:32 EDT (Sun, 25 Jul 2010)
@@ -0,0 +1,114 @@
+//  Boost integer/isqrt.hpp header file  ------------------------------//
+
+//  (C) Copyright Murilo Adriano Vasconcelos 2010.
+//  Distributed under the Boost Software License, Version 1.0. (See
+//  accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt
+
+//  See http://www.boost.org for updates, documentation, and revision history. 
+
+#ifndef BOOST_ISQRT_INCLUDED
+#define BOOST_ISQRT_INCLUDED
+
+#include <boost/cstdint.hpp>
+
+namespace boost {
+	
+/*	
+ *	These functions calculates the floor of square 
+ *		root of integral values.
+ */
+
+int isqrt(uint8_t value)
+{
+	uint8_t mask, result, aux;
+	
+	mask = 0x40;
+	result = 0;
+	
+	while (mask != 0) {
+		aux = result | mask;
+		result >>= 1;
+		
+		if (value >= aux) {
+			value -= aux;
+			result |= mask;
+		}
+		
+		mask >>= 2;
+	}
+	
+	return result;	
+}
+	
+int isqrt(uint16_t value)
+{
+	uint16_t mask, result, aux;
+	
+	mask = 0x4000;
+	result = 0;
+	
+	while (mask != 0) {
+		aux = result | mask;
+		result >>= 1;
+		
+		if (value >= aux) {
+			value -= aux;
+			result |= mask;
+		}
+		
+		mask >>= 2;
+	}
+	
+	return result;	
+}
+
+int isqrt(uint32_t value)
+{
+	uint32_t mask, result, aux;
+	
+	mask = 0x40000000;
+	result = 0;
+	
+	while (mask != 0) {
+		aux = result | mask;
+		result >>= 1;
+		
+		if (value >= aux) {
+			value -= aux;
+			result |= mask;
+		}
+		
+		mask >>= 2;
+	}
+	
+	return result;	
+}
+
+/*#ifndef BOOST_HAS_NO_INT64_T
+int64_t isqrt(uint64_t value)
+{
+	uint64_t mask, result, aux;
+	
+	mask = 0x4000000000000000ULL;
+	result = 0;
+	
+	while (mask != 0) {
+		aux = result | mask;
+		result >>= 1;
+		
+		if (value >= aux) {
+			value -= aux;
+			result |= mask;
+		}
+		
+		mask >>= 2;
+	}
+	
+	return result;	
+}
+#endif*/
+
+}
+
+#endif