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 // Portions of code courtesy of Clifford Click
  26 
  27 // Optimization - Graph Style
  28 
  29 #include "incls/_precompiled.incl"
  30 #include "incls/_subnode.cpp.incl"
  31 #include "math.h"
  32 
  33 //=============================================================================
  34 //------------------------------Identity---------------------------------------
  35 // If right input is a constant 0, return the left input.
  36 Node *SubNode::Identity( PhaseTransform *phase ) {
  37   assert(in(1) != this, "Must already have called Value");
  38   assert(in(2) != this, "Must already have called Value");
  39 
  40   // Remove double negation
  41   const Type *zero = add_id();
  42   if( phase->type( in(1) )->higher_equal( zero ) &&
  43       in(2)->Opcode() == Opcode() &&
  44       phase->type( in(2)->in(1) )->higher_equal( zero ) ) {
  45     return in(2)->in(2);
  46   }
  47 
  48   // Convert "(X+Y) - Y" into X and "(X+Y) - X" into Y
  49   if( in(1)->Opcode() == Op_AddI ) {
  50     if( phase->eqv(in(1)->in(2),in(2)) )

   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 "compiler/compileLog.hpp"
  27 #include "memory/allocation.inline.hpp"
  28 #include "opto/addnode.hpp"
  29 #include "opto/callnode.hpp"
  30 #include "opto/cfgnode.hpp"
  31 #include "opto/connode.hpp"
  32 #include "opto/loopnode.hpp"
  33 #include "opto/matcher.hpp"
  34 #include "opto/mulnode.hpp"
  35 #include "opto/opcodes.hpp"
  36 #include "opto/phaseX.hpp"
  37 #include "opto/subnode.hpp"
  38 #include "runtime/sharedRuntime.hpp"
  39 
  40 // Portions of code courtesy of Clifford Click
  41 
  42 // Optimization - Graph Style
  43 


  44 #include "math.h"
  45 
  46 //=============================================================================
  47 //------------------------------Identity---------------------------------------
  48 // If right input is a constant 0, return the left input.
  49 Node *SubNode::Identity( PhaseTransform *phase ) {
  50   assert(in(1) != this, "Must already have called Value");
  51   assert(in(2) != this, "Must already have called Value");
  52 
  53   // Remove double negation
  54   const Type *zero = add_id();
  55   if( phase->type( in(1) )->higher_equal( zero ) &&
  56       in(2)->Opcode() == Opcode() &&
  57       phase->type( in(2)->in(1) )->higher_equal( zero ) ) {
  58     return in(2)->in(2);
  59   }
  60 
  61   // Convert "(X+Y) - Y" into X and "(X+Y) - X" into Y
  62   if( in(1)->Opcode() == Op_AddI ) {
  63     if( phase->eqv(in(1)->in(2),in(2)) )