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