6800154: Add comments to long_by_long_mulhi() for better understandability
Summary: This patch adds a comment pointing to the Hacker's Delight version of the algorithm plus a verbatim copy of it. Furthermore it adds inline comments.
Reviewed-by: kvn, jrose
/*
* Copyright 1997-2008 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/
// machine-dependent parts of class relocInfo
private:
enum {
// Since SPARC instructions are whole words,
// the two low-order offset bits can always be discarded.
offset_unit = 4,
// There is no need for format bits; the instructions are
// sufficiently self-identifying.
#ifndef _LP64
format_width = 0
#else
// Except narrow oops in 64-bits VM.
format_width = 1
#endif
};
//Reconciliation History
// 1.3 97/10/15 15:38:36 relocInfo_i486.hpp
// 1.4 97/12/08 16:01:06 relocInfo_i486.hpp
// 1.5 98/01/23 01:34:55 relocInfo_i486.hpp
// 1.6 98/02/27 15:44:53 relocInfo_i486.hpp
// 1.6 98/03/12 14:47:13 relocInfo_i486.hpp
// 1.8 99/06/22 16:37:50 relocInfo_i486.hpp
// 1.9 99/07/16 11:12:11 relocInfo_i486.hpp
//End