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src/hotspot/share/runtime/stackValue.cpp

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  1 /*
  2  * Copyright (c) 1997, 2025, 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 "code/debugInfo.hpp"
 26 #include "oops/access.hpp"
 27 #include "oops/compressedOops.inline.hpp"
 28 #include "oops/oop.hpp"
 29 #include "runtime/frame.inline.hpp"
 30 #include "runtime/globals.hpp"
 31 #include "runtime/handles.inline.hpp"
 32 #include "runtime/stackValue.hpp"
 33 #if INCLUDE_SHENANDOAHGC
 34 #include "gc/shenandoah/shenandoahBarrierSet.inline.hpp"
 35 #endif
 36 
 37 class RegisterMap;
 38 class SmallRegisterMap;
 39 
 40 template StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv);
 41 template StackValue* StackValue::create_stack_value(const frame* fr, const SmallRegisterMapNoArgs* reg_map, ScopeValue* sv);
 42 
 43 template<typename RegisterMapT>
 44 StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMapT* reg_map, ScopeValue* sv) {
 45   return create_stack_value(sv, stack_value_address(fr, reg_map, sv), reg_map);
 46 }
 47 
 48 static oop oop_from_oop_location(stackChunkOop chunk, void* addr) {
 49   if (addr == nullptr) {
 50     return nullptr;
 51   }
 52 
 53   if (UseCompressedOops) {
 54     // When compressed oops is enabled, an oop location may
 55     // contain narrow oop values - we deal with that here
 56 
 57     if (chunk != nullptr && chunk->has_bitmap()) {
 58       // Transformed stack chunk with narrow oops
 59       return chunk->load_oop((narrowOop*)addr);
 60     }
 61 
 62 #ifdef _LP64
 63     if (CompressedOops::is_base(*(void**)addr)) {
 64       // Compiled code may produce decoded oop = narrow_oop_base
 65       // when a narrow oop implicit null check is used.
 66       // The narrow_oop_base could be null or be the address

127 
128   return val;
129 }
130 
131 StackValue* StackValue::create_stack_value_from_oop_location(stackChunkOop chunk, void* addr) {
132   oop val = oop_from_oop_location(chunk, addr);
133   assert(oopDesc::is_oop_or_null(val), "bad oop found at " INTPTR_FORMAT " in_cont: %d compressed: %d",
134          p2i(addr), chunk != nullptr, chunk != nullptr && chunk->has_bitmap() && UseCompressedOops);
135   Handle h(Thread::current(), val); // Wrap a handle around the oop
136   return new StackValue(h);
137 }
138 
139 StackValue* StackValue::create_stack_value_from_narrowOop_location(stackChunkOop chunk, void* addr, bool is_register) {
140   oop val = oop_from_narrowOop_location(chunk, addr, is_register);
141   assert(oopDesc::is_oop_or_null(val), "bad oop found at " INTPTR_FORMAT " in_cont: %d compressed: %d",
142          p2i(addr), chunk != nullptr, chunk != nullptr && chunk->has_bitmap() && UseCompressedOops);
143   Handle h(Thread::current(), val); // Wrap a handle around the oop
144   return new StackValue(h);
145 }
146 



147 template<typename RegisterMapT>
148 StackValue* StackValue::create_stack_value(ScopeValue* sv, address value_addr, const RegisterMapT* reg_map) {

149   stackChunkOop chunk = reg_map->stack_chunk()();
150   if (sv->is_location()) {
151     // Stack or register value
152     Location loc = ((LocationValue *)sv)->location();
153 
154     // Then package it right depending on type
155     // Note: the transfer of the data is thru a union that contains
156     // an intptr_t. This is because an interpreter stack slot is
157     // really an intptr_t. The use of a union containing an intptr_t
158     // ensures that on a 64 bit platform we have proper alignment
159     // and that we store the value where the interpreter will expect
160     // to find it (i.e. proper endian). Similarly on a 32bit platform
161     // using the intptr_t ensures that when a value is larger than
162     // a stack slot (jlong/jdouble) that we capture the proper part
163     // of the value for the stack slot in question.
164     //
165     switch( loc.type() ) {
166     case Location::float_in_dbl: { // Holds a float in a double register?
167       // The callee has no clue whether the register holds a float,
168       // double or is unused.  He always saves a double.  Here we know

229   } else if (sv->is_constant_oop()) {
230     // constant oop
231     return new StackValue(sv->as_ConstantOopReadValue()->value());
232 #ifdef _LP64
233   } else if (sv->is_constant_double()) {
234     // Constant double in a single stack slot
235     union { intptr_t p; double d; } value;
236     value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
237     value.d = ((ConstantDoubleValue *)sv)->value();
238     return new StackValue(value.p);
239   } else if (sv->is_constant_long()) {
240     // Constant long in a single stack slot
241     union { intptr_t p; jlong jl; } value;
242     value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
243     value.jl = ((ConstantLongValue *)sv)->value();
244     return new StackValue(value.p);
245 #endif
246   } else if (sv->is_object()) { // Scalar replaced object in compiled frame
247     ObjectValue* ov = (ObjectValue *)sv;
248     Handle hdl = ov->value();
249     return new StackValue(hdl, hdl.is_null() && ov->is_scalar_replaced() ? 1 : 0);









250   } else if (sv->is_marker()) {
251     // Should never need to directly construct a marker.
252     ShouldNotReachHere();
253   }
254   // Unknown ScopeValue type
255   ShouldNotReachHere();
256   return new StackValue((intptr_t) 0);   // dummy
257 }
258 
259 template address StackValue::stack_value_address(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv);
260 template address StackValue::stack_value_address(const frame* fr, const SmallRegisterMapNoArgs* reg_map, ScopeValue* sv);
261 
262 template<typename RegisterMapT>
263 address StackValue::stack_value_address(const frame* fr, const RegisterMapT* reg_map, ScopeValue* sv) {
264   if (!sv->is_location()) {
265     return nullptr;
266   }
267   Location loc = ((LocationValue *)sv)->location();
268   if (loc.type() == Location::invalid) {
269     return nullptr;

  1 /*
  2  * Copyright (c) 1997, 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 "code/debugInfo.hpp"
 26 #include "oops/access.hpp"
 27 #include "oops/compressedOops.inline.hpp"
 28 #include "oops/oop.hpp"
 29 #include "runtime/frame.inline.hpp"
 30 #include "runtime/globals.hpp"
 31 #include "runtime/handles.inline.hpp"
 32 #include "runtime/stackValue.hpp"
 33 #if INCLUDE_SHENANDOAHGC
 34 #include "gc/shenandoah/shenandoahBarrierSet.inline.hpp"
 35 #endif
 36 
 37 class RegisterMap;
 38 class SmallRegisterMap;
 39 







 40 
 41 static oop oop_from_oop_location(stackChunkOop chunk, void* addr) {
 42   if (addr == nullptr) {
 43     return nullptr;
 44   }
 45 
 46   if (UseCompressedOops) {
 47     // When compressed oops is enabled, an oop location may
 48     // contain narrow oop values - we deal with that here
 49 
 50     if (chunk != nullptr && chunk->has_bitmap()) {
 51       // Transformed stack chunk with narrow oops
 52       return chunk->load_oop((narrowOop*)addr);
 53     }
 54 
 55 #ifdef _LP64
 56     if (CompressedOops::is_base(*(void**)addr)) {
 57       // Compiled code may produce decoded oop = narrow_oop_base
 58       // when a narrow oop implicit null check is used.
 59       // The narrow_oop_base could be null or be the address

120 
121   return val;
122 }
123 
124 StackValue* StackValue::create_stack_value_from_oop_location(stackChunkOop chunk, void* addr) {
125   oop val = oop_from_oop_location(chunk, addr);
126   assert(oopDesc::is_oop_or_null(val), "bad oop found at " INTPTR_FORMAT " in_cont: %d compressed: %d",
127          p2i(addr), chunk != nullptr, chunk != nullptr && chunk->has_bitmap() && UseCompressedOops);
128   Handle h(Thread::current(), val); // Wrap a handle around the oop
129   return new StackValue(h);
130 }
131 
132 StackValue* StackValue::create_stack_value_from_narrowOop_location(stackChunkOop chunk, void* addr, bool is_register) {
133   oop val = oop_from_narrowOop_location(chunk, addr, is_register);
134   assert(oopDesc::is_oop_or_null(val), "bad oop found at " INTPTR_FORMAT " in_cont: %d compressed: %d",
135          p2i(addr), chunk != nullptr, chunk != nullptr && chunk->has_bitmap() && UseCompressedOops);
136   Handle h(Thread::current(), val); // Wrap a handle around the oop
137   return new StackValue(h);
138 }
139 
140 template StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv);
141 template StackValue* StackValue::create_stack_value(const frame* fr, const SmallRegisterMapNoArgs* reg_map, ScopeValue* sv);
142 
143 template<typename RegisterMapT>
144 StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMapT* reg_map, ScopeValue* sv) {
145   address value_addr = stack_value_address(fr, reg_map, sv);
146   stackChunkOop chunk = reg_map->stack_chunk()();
147   if (sv->is_location()) {
148     // Stack or register value
149     Location loc = ((LocationValue *)sv)->location();
150 
151     // Then package it right depending on type
152     // Note: the transfer of the data is thru a union that contains
153     // an intptr_t. This is because an interpreter stack slot is
154     // really an intptr_t. The use of a union containing an intptr_t
155     // ensures that on a 64 bit platform we have proper alignment
156     // and that we store the value where the interpreter will expect
157     // to find it (i.e. proper endian). Similarly on a 32bit platform
158     // using the intptr_t ensures that when a value is larger than
159     // a stack slot (jlong/jdouble) that we capture the proper part
160     // of the value for the stack slot in question.
161     //
162     switch( loc.type() ) {
163     case Location::float_in_dbl: { // Holds a float in a double register?
164       // The callee has no clue whether the register holds a float,
165       // double or is unused.  He always saves a double.  Here we know

226   } else if (sv->is_constant_oop()) {
227     // constant oop
228     return new StackValue(sv->as_ConstantOopReadValue()->value());
229 #ifdef _LP64
230   } else if (sv->is_constant_double()) {
231     // Constant double in a single stack slot
232     union { intptr_t p; double d; } value;
233     value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
234     value.d = ((ConstantDoubleValue *)sv)->value();
235     return new StackValue(value.p);
236   } else if (sv->is_constant_long()) {
237     // Constant long in a single stack slot
238     union { intptr_t p; jlong jl; } value;
239     value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
240     value.jl = ((ConstantLongValue *)sv)->value();
241     return new StackValue(value.p);
242 #endif
243   } else if (sv->is_object()) { // Scalar replaced object in compiled frame
244     ObjectValue* ov = (ObjectValue *)sv;
245     Handle hdl = ov->value();
246     bool scalar_replaced = hdl.is_null() && ov->is_scalar_replaced();
247     if (ov->has_properties()) {
248       Klass* k = java_lang_Class::as_Klass(ov->klass()->as_ConstantOopReadValue()->value()());
249       if (!k->is_array_klass()) {
250         // Don't treat inline type as scalar replaced if it is null
251         jint null_marker = StackValue::create_stack_value(fr, reg_map, ov->properties())->get_jint();
252         scalar_replaced &= (null_marker != 0);
253       }
254     }
255     return new StackValue(hdl, scalar_replaced ? 1 : 0);
256   } else if (sv->is_marker()) {
257     // Should never need to directly construct a marker.
258     ShouldNotReachHere();
259   }
260   // Unknown ScopeValue type
261   ShouldNotReachHere();
262   return new StackValue((intptr_t) 0);   // dummy
263 }
264 
265 template address StackValue::stack_value_address(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv);
266 template address StackValue::stack_value_address(const frame* fr, const SmallRegisterMapNoArgs* reg_map, ScopeValue* sv);
267 
268 template<typename RegisterMapT>
269 address StackValue::stack_value_address(const frame* fr, const RegisterMapT* reg_map, ScopeValue* sv) {
270   if (!sv->is_location()) {
271     return nullptr;
272   }
273   Location loc = ((LocationValue *)sv)->location();
274   if (loc.type() == Location::invalid) {
275     return nullptr;
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