1 /*
  2  * Copyright (c) 1999, 2026, 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 "ci/ciArray.hpp"
 26 #include "ci/ciArrayKlass.hpp"
 27 #include "ci/ciConstant.hpp"
 28 #include "ci/ciKlass.hpp"
 29 #include "ci/ciUtilities.inline.hpp"
 30 #include "oops/flatArrayKlass.hpp"
 31 #include "oops/layoutKind.hpp"
 32 #include "oops/objArrayOop.inline.hpp"
 33 #include "oops/oop.inline.hpp"
 34 #include "oops/oopCast.inline.hpp"
 35 #include "oops/typeArrayOop.inline.hpp"
 36 #include "utilities/powerOfTwo.hpp"
 37 
 38 // ciArray
 39 //
 40 // This class represents an arrayOop in the HotSpot virtual
 41 // machine.
 42 static BasicType fixup_element_type(BasicType bt) {
 43   if (bt == T_FLAT_ELEMENT) return T_OBJECT;
 44   if (is_reference_type(bt))  return T_OBJECT;
 45   if (bt == T_BOOLEAN)  return T_BYTE;
 46   return bt;
 47 }
 48 
 49 ciConstant ciArray::element_value_impl(BasicType elembt,
 50                                        arrayOop ary,
 51                                        int index) {
 52   if (ary == nullptr)
 53     return ciConstant();
 54   assert(ary->is_array(), "");
 55   if (index < 0 || index >= ary->length())
 56     return ciConstant();
 57   ArrayKlass* ak = (ArrayKlass*) ary->klass();
 58   BasicType abt = ak->element_type();
 59   if (fixup_element_type(elembt) !=
 60       fixup_element_type(abt))
 61     return ciConstant();
 62   switch (elembt) {
 63   case T_ARRAY:
 64   case T_OBJECT:
 65     {
 66       if (ary->is_refArray()) {
 67         refArrayOop refary = oop_cast<refArrayOop>(ary);
 68         oop elem = refary->obj_at(index);
 69         return ciConstant(elembt, CURRENT_ENV->get_object(elem));
 70       } else {
 71         assert(ary->is_flatArray(), "");
 72         flatArrayOop flatary = oop_cast<flatArrayOop>(ary);
 73         assert(CompilerThread::current()->thread_state() == _thread_in_vm, "");
 74         JavaThread* THREAD = CompilerThread::current();
 75         oop elem = flatary->obj_at(index, THREAD);
 76         if (HAS_PENDING_EXCEPTION) {
 77           CLEAR_PENDING_EXCEPTION;
 78           return ciConstant();
 79         }
 80         return ciConstant(elembt, CURRENT_ENV->get_object(elem));
 81       }
 82     }
 83   default:
 84     break;
 85   }
 86   assert(ary->is_typeArray(), "");
 87   typeArrayOop tary = (typeArrayOop) ary;
 88   jint value = 0;
 89   switch (elembt) {
 90   case T_LONG:          return ciConstant(tary->long_at(index));
 91   case T_FLOAT:         return ciConstant(tary->float_at(index));
 92   case T_DOUBLE:        return ciConstant(tary->double_at(index));
 93   default:              return ciConstant();
 94   case T_BYTE:          value = tary->byte_at(index);           break;
 95   case T_BOOLEAN:       value = tary->byte_at(index) & 1;       break;
 96   case T_SHORT:         value = tary->short_at(index);          break;
 97   case T_CHAR:          value = tary->char_at(index);           break;
 98   case T_INT:           value = tary->int_at(index);            break;
 99   }
100   return ciConstant(elembt, value);
101 }
102 
103 // ------------------------------------------------------------------
104 // ciArray::element_value
105 //
106 // Current value of an element.
107 // Returns T_ILLEGAL if there is no element at the given index.
108 ciConstant ciArray::element_value(int index) {
109   BasicType elembt = element_basic_type();
110   ciConstant value = check_constant_value_cache(index, elembt);
111   if (value.is_valid()) {
112     return value;
113   }
114   GUARDED_VM_ENTRY(
115     value = element_value_impl(elembt, get_arrayOop(), index);
116   )
117   add_to_constant_value_cache(index, value);
118   return value;
119 }
120 
121 // ------------------------------------------------------------------
122 // ciArray::element_value_by_offset
123 //
124 // Current value of an element at the specified offset.
125 // Returns T_ILLEGAL if there is no element at the given offset.
126 ciConstant ciArray::element_value_by_offset(intptr_t element_offset) {
127   BasicType elembt = element_basic_type();
128   intptr_t shift  = exact_log2(type2aelembytes(elembt));
129   intptr_t header = arrayOopDesc::base_offset_in_bytes(elembt);
130   intptr_t index = (element_offset - header) >> shift;
131   intptr_t offset = header + ((intptr_t)index << shift);
132   if (offset != element_offset || index != (jint)index || index < 0 || index >= length()) {
133     return ciConstant();
134   }
135   return element_value((jint) index);
136 }
137 
138 bool ciArray::is_null_free() {
139   VM_ENTRY_MARK;
140   return get_oop()->is_null_free_array();
141 }
142 
143 bool ciArray::is_atomic() {
144   VM_ENTRY_MARK;
145   arrayOop oop = get_arrayOop();
146   return !oop->is_flatArray() || LayoutKindHelper::is_atomic_flat(FlatArrayKlass::cast(oop->klass())->layout_kind());
147 }
148 
149 // ------------------------------------------------------------------
150 // ciArray::print_impl
151 //
152 // Implementation of the print method.
153 void ciArray::print_impl(outputStream* st) {
154   st->print(" length=%d type=", length());
155   klass()->print(st);
156 }