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 1997-2007 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.
*
*/
#include "incls/_precompiled.incl"
#include "incls/_stubRoutines_sparc.cpp.incl"
// Implementation of the platform-specific part of StubRoutines - for
// a description of how to extend it, see the stubRoutines.hpp file.
extern "C" {
address _flush_reg_windows(); // in .s file.
// Flush registers to stack. In case of error we will need to stack walk.
address bootstrap_flush_windows(void) {
Thread* thread = ThreadLocalStorage::get_thread_slow();
// Very early in process there is no thread.
if (thread != NULL) {
guarantee(thread->is_Java_thread(), "Not a Java thread.");
JavaThread* jt = (JavaThread*)thread;
guarantee(!jt->has_last_Java_frame(), "Must be able to flush registers!");
}
return (address)_flush_reg_windows();
};
};
address StubRoutines::Sparc::_test_stop_entry = NULL;
address StubRoutines::Sparc::_stop_subroutine_entry = NULL;
address StubRoutines::Sparc::_flush_callers_register_windows_entry = CAST_FROM_FN_PTR(address, bootstrap_flush_windows);
address StubRoutines::Sparc::_partial_subtype_check = NULL;
int StubRoutines::Sparc::_atomic_memory_operation_lock = StubRoutines::Sparc::unlocked;
int StubRoutines::Sparc::_v8_oop_lock_cache[StubRoutines::Sparc::nof_v8_oop_lock_cache_entries];