1 /*
   2  * Copyright (c) 1998, 2009, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "incls/_precompiled.incl"
  26 #include "incls/_postaloc.cpp.incl"


  27 
  28 // see if this register kind does not requires two registers
  29 static bool is_single_register(uint x) {
  30 #ifdef _LP64
  31   return (x != Op_RegD && x != Op_RegL && x != Op_RegP);
  32 #else
  33   return (x != Op_RegD && x != Op_RegL);
  34 #endif
  35 }
  36 
  37 //---------------------------may_be_copy_of_callee-----------------------------
  38 // Check to see if we can possibly be a copy of a callee-save value.
  39 bool PhaseChaitin::may_be_copy_of_callee( Node *def ) const {
  40   // Short circuit if there are no callee save registers
  41   if (_matcher.number_of_saved_registers() == 0) return false;
  42 
  43   // Expect only a spill-down and reload on exit for callee-save spills.
  44   // Chains of copies cannot be deep.
  45   // 5008997 - This is wishful thinking. Register allocator seems to
  46   // be splitting live ranges for callee save registers to such

   1 /*
   2  * Copyright (c) 1998, 2010, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "memory/allocation.inline.hpp"
  27 #include "opto/chaitin.hpp"
  28 #include "opto/machnode.hpp"
  29 
  30 // see if this register kind does not requires two registers
  31 static bool is_single_register(uint x) {
  32 #ifdef _LP64
  33   return (x != Op_RegD && x != Op_RegL && x != Op_RegP);
  34 #else
  35   return (x != Op_RegD && x != Op_RegL);
  36 #endif
  37 }
  38 
  39 //---------------------------may_be_copy_of_callee-----------------------------
  40 // Check to see if we can possibly be a copy of a callee-save value.
  41 bool PhaseChaitin::may_be_copy_of_callee( Node *def ) const {
  42   // Short circuit if there are no callee save registers
  43   if (_matcher.number_of_saved_registers() == 0) return false;
  44 
  45   // Expect only a spill-down and reload on exit for callee-save spills.
  46   // Chains of copies cannot be deep.
  47   // 5008997 - This is wishful thinking. Register allocator seems to
  48   // be splitting live ranges for callee save registers to such