1 /*
  2  * Copyright (c) 2014, 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 "opto/narrowptrnode.hpp"
 27 #include "opto/phaseX.hpp"
 28 
 29 Node* DecodeNNode::Identity(PhaseGVN* phase) {
 30   const Type *t = phase->type( in(1) );
 31   if( t == Type::TOP ) return in(1);
 32 
 33   if (in(1)->is_EncodeP()) {
 34     // (DecodeN (EncodeP p)) -> p
 35     return in(1)->in(1);
 36   }
 37   return this;
 38 }
 39 
 40 const Type* DecodeNNode::Value(PhaseGVN* phase) const {
 41   const Type *t = phase->type( in(1) );
 42   if (t == Type::TOP) return Type::TOP;
 43   if (t == TypeNarrowOop::NULL_PTR) return TypePtr::NULL_PTR;
 44 
 45   assert(t->isa_narrowoop(), "only narrowoop here");
 46   return t->make_ptr();
 47 }
 48 
 49 Node* EncodePNode::Identity(PhaseGVN* phase) {
 50   const Type *t = phase->type( in(1) );
 51   if( t == Type::TOP ) return in(1);
 52 
 53   if (in(1)->is_DecodeN()) {
 54     // (EncodeP (DecodeN p)) -> p
 55     return in(1)->in(1);
 56   }
 57   return this;
 58 }
 59 
 60 const Type* EncodePNode::Value(PhaseGVN* phase) const {
 61   const Type *t = phase->type( in(1) );
 62   if (t == Type::TOP) return Type::TOP;
 63   if (t == TypePtr::NULL_PTR) return TypeNarrowOop::NULL_PTR;
 64 
 65   assert(t->isa_oop_ptr(), "only oopptr here");
 66   return t->make_narrowoop();
 67 }
 68 
 69 
 70 Node* DecodeNKlassNode::Identity(PhaseGVN* phase) {
 71   const Type *t = phase->type( in(1) );
 72   if( t == Type::TOP ) return in(1);
 73 
 74   if (in(1)->is_EncodePKlass()) {
 75     // (DecodeNKlass (EncodePKlass p)) -> p
 76     return in(1)->in(1);
 77   }
 78   return this;
 79 }
 80 
 81 const Type* DecodeNKlassNode::Value(PhaseGVN* phase) const {
 82   const Type *t = phase->type( in(1) );
 83   if (t == Type::TOP) return Type::TOP;
 84   assert(t != TypeNarrowKlass::NULL_PTR, "null klass?");
 85 
 86   assert(t->isa_narrowklass(), "only narrow klass ptr here");
 87   return t->make_ptr();
 88 }
 89 
 90 Node* EncodePKlassNode::Identity(PhaseGVN* phase) {
 91   const Type *t = phase->type( in(1) );
 92   if( t == Type::TOP ) return in(1);
 93 
 94   if (in(1)->is_DecodeNKlass()) {
 95     // (EncodePKlass (DecodeNKlass p)) -> p
 96     return in(1)->in(1);
 97   }
 98   return this;
 99 }
100 
101 const Type* EncodePKlassNode::Value(PhaseGVN* phase) const {
102   const Type *t = phase->type( in(1) );
103   if (t == Type::TOP) return Type::TOP;
104   assert (t != TypePtr::NULL_PTR, "null klass?");
105 
106   assert(UseCompressedClassPointers && t->isa_klassptr(), "only klass ptr here");
107   return t->make_narrowklass();
108 }
109