--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/cpu/arm/vm/frame_arm.cpp Mon Dec 19 12:39:01 2016 -0500
@@ -0,0 +1,655 @@
+/*
+ * Copyright (c) 2008, 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "interpreter/interpreter.hpp"
+#include "memory/resourceArea.hpp"
+#include "oops/markOop.hpp"
+#include "oops/method.hpp"
+#include "oops/oop.inline.hpp"
+#include "runtime/frame.inline.hpp"
+#include "runtime/handles.inline.hpp"
+#include "runtime/javaCalls.hpp"
+#include "runtime/monitorChunk.hpp"
+#include "runtime/signature.hpp"
+#include "runtime/stubCodeGenerator.hpp"
+#include "runtime/stubRoutines.hpp"
+#include "vmreg_arm.inline.hpp"
+#ifdef COMPILER1
+#include "c1/c1_Runtime1.hpp"
+#include "runtime/vframeArray.hpp"
+#endif
+#include "prims/methodHandles.hpp"
+
+#ifdef ASSERT
+void RegisterMap::check_location_valid() {
+}
+#endif
+
+
+// Profiling/safepoint support
+
+bool frame::safe_for_sender(JavaThread *thread) {
+ address sp = (address)_sp;
+ address fp = (address)_fp;
+ address unextended_sp = (address)_unextended_sp;
+
+ static size_t stack_guard_size = os::uses_stack_guard_pages() ?
+ (JavaThread::stack_red_zone_size() + JavaThread::stack_yellow_zone_size()) : 0;
+ size_t usable_stack_size = thread->stack_size() - stack_guard_size;
+
+ // sp must be within the usable part of the stack (not in guards)
+ bool sp_safe = (sp != NULL &&
+ (sp <= thread->stack_base()) &&
+ (sp >= thread->stack_base() - usable_stack_size));
+
+ if (!sp_safe) {
+ return false;
+ }
+
+ bool unextended_sp_safe = (unextended_sp != NULL &&
+ (unextended_sp <= thread->stack_base()) &&
+ (unextended_sp >= sp));
+ if (!unextended_sp_safe) {
+ return false;
+ }
+
+ // We know sp/unextended_sp are safe. Only fp is questionable here.
+
+ bool fp_safe = (fp != NULL &&
+ (fp <= thread->stack_base()) &&
+ fp >= sp);
+
+ if (_cb != NULL ) {
+
+ // First check if frame is complete and tester is reliable
+ // Unfortunately we can only check frame complete for runtime stubs and nmethod
+ // other generic buffer blobs are more problematic so we just assume they are
+ // ok. adapter blobs never have a frame complete and are never ok.
+
+ if (!_cb->is_frame_complete_at(_pc)) {
+ if (_cb->is_compiled() || _cb->is_adapter_blob() || _cb->is_runtime_stub()) {
+ return false;
+ }
+ }
+
+ // Could just be some random pointer within the codeBlob
+ if (!_cb->code_contains(_pc)) {
+ return false;
+ }
+
+ // Entry frame checks
+ if (is_entry_frame()) {
+ // an entry frame must have a valid fp.
+ return fp_safe && is_entry_frame_valid(thread);
+ }
+
+ intptr_t* sender_sp = NULL;
+ address sender_pc = NULL;
+
+ if (is_interpreted_frame()) {
+ // fp must be safe
+ if (!fp_safe) {
+ return false;
+ }
+
+ sender_pc = (address) this->fp()[return_addr_offset];
+ sender_sp = (intptr_t*) addr_at(sender_sp_offset);
+
+ } else {
+ // must be some sort of compiled/runtime frame
+ // fp does not have to be safe (although it could be check for c1?)
+
+ sender_sp = _unextended_sp + _cb->frame_size();
+ // Is sender_sp safe?
+ if ((address)sender_sp >= thread->stack_base()) {
+ return false;
+ }
+ // With our calling conventions, the return_address should
+ // end up being the word on the stack
+ sender_pc = (address) *(sender_sp - sender_sp_offset + return_addr_offset);
+ }
+
+ // We must always be able to find a recognizable pc
+ CodeBlob* sender_blob = CodeCache::find_blob_unsafe(sender_pc);
+ if (sender_pc == NULL || sender_blob == NULL) {
+ return false;
+ }
+
+
+ // If the potential sender is the interpreter then we can do some more checking
+ if (Interpreter::contains(sender_pc)) {
+
+ // FP is always saved in a recognizable place in any code we generate. However
+ // only if the sender is interpreted/call_stub (c1 too?) are we certain that the saved FP
+ // is really a frame pointer.
+
+ intptr_t *saved_fp = (intptr_t*)*(sender_sp - frame::sender_sp_offset + link_offset);
+ bool saved_fp_safe = ((address)saved_fp <= thread->stack_base()) && (saved_fp > sender_sp);
+
+ if (!saved_fp_safe) {
+ return false;
+ }
+
+ // construct the potential sender
+
+ frame sender(sender_sp, saved_fp, sender_pc);
+
+ return sender.is_interpreted_frame_valid(thread);
+ }
+
+ if (sender_blob->is_zombie() || sender_blob->is_unloaded()) {
+ return false;
+ }
+
+ // Could just be some random pointer within the codeBlob
+ if (!sender_blob->code_contains(sender_pc)) {
+ return false;
+ }
+
+ // We should never be able to see an adapter if the current frame is something from code cache
+ if (sender_blob->is_adapter_blob()) {
+ return false;
+ }
+
+ // Could be the call_stub
+ if (StubRoutines::returns_to_call_stub(sender_pc)) {
+ intptr_t *saved_fp = (intptr_t*)*(sender_sp - frame::sender_sp_offset + link_offset);
+ bool saved_fp_safe = ((address)saved_fp <= thread->stack_base()) && (saved_fp >= sender_sp);
+
+ if (!saved_fp_safe) {
+ return false;
+ }
+
+ // construct the potential sender
+
+ frame sender(sender_sp, saved_fp, sender_pc);
+
+ // Validate the JavaCallWrapper an entry frame must have
+ address jcw = (address)sender.entry_frame_call_wrapper();
+
+ bool jcw_safe = (jcw <= thread->stack_base()) && (jcw > (address)sender.fp());
+
+ return jcw_safe;
+ }
+
+ // If the frame size is 0 something (or less) is bad because every nmethod has a non-zero frame size
+ // because the return address counts against the callee's frame.
+
+ if (sender_blob->frame_size() <= 0) {
+ assert(!sender_blob->is_compiled(), "should count return address at least");
+ return false;
+ }
+
+ // We should never be able to see anything here except an nmethod. If something in the
+ // code cache (current frame) is called by an entity within the code cache that entity
+ // should not be anything but the call stub (already covered), the interpreter (already covered)
+ // or an nmethod.
+
+ if (!sender_blob->is_compiled()) {
+ return false;
+ }
+
+ // Could put some more validation for the potential non-interpreted sender
+ // frame we'd create by calling sender if I could think of any. Wait for next crash in forte...
+
+ // One idea is seeing if the sender_pc we have is one that we'd expect to call to current cb
+
+ // We've validated the potential sender that would be created
+ return true;
+ }
+
+ // Must be native-compiled frame. Since sender will try and use fp to find
+ // linkages it must be safe
+
+ if (!fp_safe) {
+ return false;
+ }
+
+ // Will the pc we fetch be non-zero (which we'll find at the oldest frame)
+
+ if ((address) this->fp()[return_addr_offset] == NULL) return false;
+
+
+ // could try and do some more potential verification of native frame if we could think of some...
+
+ return true;
+}
+
+
+void frame::patch_pc(Thread* thread, address pc) {
+ address* pc_addr = &((address *)sp())[-sender_sp_offset+return_addr_offset];
+ if (TracePcPatching) {
+ tty->print_cr("patch_pc at address" INTPTR_FORMAT " [" INTPTR_FORMAT " -> " INTPTR_FORMAT "] ",
+ p2i(pc_addr), p2i(*pc_addr), p2i(pc));
+ }
+ *pc_addr = pc;
+ _cb = CodeCache::find_blob(pc);
+ address original_pc = CompiledMethod::get_deopt_original_pc(this);
+ if (original_pc != NULL) {
+ assert(original_pc == _pc, "expected original PC to be stored before patching");
+ _deopt_state = is_deoptimized;
+ // leave _pc as is
+ } else {
+ _deopt_state = not_deoptimized;
+ _pc = pc;
+ }
+}
+
+bool frame::is_interpreted_frame() const {
+ return Interpreter::contains(pc());
+}
+
+int frame::frame_size(RegisterMap* map) const {
+ frame sender = this->sender(map);
+ return sender.sp() - sp();
+}
+
+intptr_t* frame::entry_frame_argument_at(int offset) const {
+ assert(is_entry_frame(), "entry frame expected");
+ // convert offset to index to deal with tsi
+ int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
+ // Entry frame's arguments are always in relation to unextended_sp()
+ return &unextended_sp()[index];
+}
+
+// sender_sp
+intptr_t* frame::interpreter_frame_sender_sp() const {
+ assert(is_interpreted_frame(), "interpreted frame expected");
+ return (intptr_t*) at(interpreter_frame_sender_sp_offset);
+}
+
+void frame::set_interpreter_frame_sender_sp(intptr_t* sender_sp) {
+ assert(is_interpreted_frame(), "interpreted frame expected");
+ ptr_at_put(interpreter_frame_sender_sp_offset, (intptr_t) sender_sp);
+}
+
+
+// monitor elements
+
+BasicObjectLock* frame::interpreter_frame_monitor_begin() const {
+ return (BasicObjectLock*) addr_at(interpreter_frame_monitor_block_bottom_offset);
+}
+
+BasicObjectLock* frame::interpreter_frame_monitor_end() const {
+ BasicObjectLock* result = (BasicObjectLock*) *addr_at(interpreter_frame_monitor_block_top_offset);
+ // make sure the pointer points inside the frame
+ assert((intptr_t) fp() > (intptr_t) result, "result must < than frame pointer");
+ assert((intptr_t) sp() <= (intptr_t) result, "result must >= than stack pointer");
+ return result;
+}
+
+void frame::interpreter_frame_set_monitor_end(BasicObjectLock* value) {
+ *((BasicObjectLock**)addr_at(interpreter_frame_monitor_block_top_offset)) = value;
+}
+
+#ifdef AARCH64
+
+// Used by template based interpreter deoptimization
+void frame::interpreter_frame_set_stack_top(intptr_t* stack_top) {
+ *((intptr_t**)addr_at(interpreter_frame_stack_top_offset)) = stack_top;
+}
+
+// Used by template based interpreter deoptimization
+void frame::interpreter_frame_set_extended_sp(intptr_t* sp) {
+ *((intptr_t**)addr_at(interpreter_frame_extended_sp_offset)) = sp;
+}
+
+#else
+
+// Used by template based interpreter deoptimization
+void frame::interpreter_frame_set_last_sp(intptr_t* sp) {
+ *((intptr_t**)addr_at(interpreter_frame_last_sp_offset)) = sp;
+}
+
+#endif // AARCH64
+
+frame frame::sender_for_entry_frame(RegisterMap* map) const {
+ assert(map != NULL, "map must be set");
+ // Java frame called from C; skip all C frames and return top C
+ // frame of that chunk as the sender
+ JavaFrameAnchor* jfa = entry_frame_call_wrapper()->anchor();
+ assert(!entry_frame_is_first(), "next Java fp must be non zero");
+ assert(jfa->last_Java_sp() > sp(), "must be above this frame on stack");
+ map->clear();
+ assert(map->include_argument_oops(), "should be set by clear");
+#ifdef AARCH64
+ assert (jfa->last_Java_pc() != NULL, "pc should be stored");
+ frame fr(jfa->last_Java_sp(), jfa->last_Java_fp(), jfa->last_Java_pc());
+ return fr;
+#else
+ if (jfa->last_Java_pc() != NULL) {
+ frame fr(jfa->last_Java_sp(), jfa->last_Java_fp(), jfa->last_Java_pc());
+ return fr;
+ }
+ frame fr(jfa->last_Java_sp(), jfa->last_Java_fp());
+ return fr;
+#endif // AARCH64
+}
+
+//------------------------------------------------------------------------------
+// frame::verify_deopt_original_pc
+//
+// Verifies the calculated original PC of a deoptimization PC for the
+// given unextended SP. The unextended SP might also be the saved SP
+// for MethodHandle call sites.
+#ifdef ASSERT
+void frame::verify_deopt_original_pc(CompiledMethod* nm, intptr_t* unextended_sp, bool is_method_handle_return) {
+ frame fr;
+
+ // This is ugly but it's better than to change {get,set}_original_pc
+ // to take an SP value as argument. And it's only a debugging
+ // method anyway.
+ fr._unextended_sp = unextended_sp;
+
+ address original_pc = nm->get_original_pc(&fr);
+ assert(nm->insts_contains(original_pc), "original PC must be in nmethod");
+ assert(nm->is_method_handle_return(original_pc) == is_method_handle_return, "must be");
+}
+#endif
+
+//------------------------------------------------------------------------------
+// frame::adjust_unextended_sp
+void frame::adjust_unextended_sp() {
+ // same as on x86
+
+ // If we are returning to a compiled MethodHandle call site, the
+ // saved_fp will in fact be a saved value of the unextended SP. The
+ // simplest way to tell whether we are returning to such a call site
+ // is as follows:
+
+ CompiledMethod* sender_cm = (_cb == NULL) ? NULL : _cb->as_compiled_method_or_null();
+ if (sender_cm != NULL) {
+ // If the sender PC is a deoptimization point, get the original
+ // PC. For MethodHandle call site the unextended_sp is stored in
+ // saved_fp.
+ if (sender_cm->is_deopt_mh_entry(_pc)) {
+ DEBUG_ONLY(verify_deopt_mh_original_pc(sender_cm, _fp));
+ _unextended_sp = _fp;
+ }
+ else if (sender_cm->is_deopt_entry(_pc)) {
+ DEBUG_ONLY(verify_deopt_original_pc(sender_cm, _unextended_sp));
+ }
+ else if (sender_cm->is_method_handle_return(_pc)) {
+ _unextended_sp = _fp;
+ }
+ }
+}
+
+//------------------------------------------------------------------------------
+// frame::update_map_with_saved_link
+void frame::update_map_with_saved_link(RegisterMap* map, intptr_t** link_addr) {
+ // see x86 for comments
+ map->set_location(FP->as_VMReg(), (address) link_addr);
+#ifdef AARCH64
+ // also adjust a high part of register
+ map->set_location(FP->as_VMReg()->next(), (address) link_addr);
+#endif // AARCH64
+}
+
+frame frame::sender_for_interpreter_frame(RegisterMap* map) const {
+ // SP is the raw SP from the sender after adapter or interpreter
+ // extension.
+ intptr_t* sender_sp = this->sender_sp();
+
+ // This is the sp before any possible extension (adapter/locals).
+ intptr_t* unextended_sp = interpreter_frame_sender_sp();
+
+#ifdef COMPILER2
+ if (map->update_map()) {
+ update_map_with_saved_link(map, (intptr_t**) addr_at(link_offset));
+ }
+#endif // COMPILER2
+
+ return frame(sender_sp, unextended_sp, link(), sender_pc());
+}
+
+frame frame::sender_for_compiled_frame(RegisterMap* map) const {
+ assert(map != NULL, "map must be set");
+
+ // frame owned by optimizing compiler
+ assert(_cb->frame_size() >= 0, "must have non-zero frame size");
+ intptr_t* sender_sp = unextended_sp() + _cb->frame_size();
+ intptr_t* unextended_sp = sender_sp;
+
+ address sender_pc = (address) *(sender_sp - sender_sp_offset + return_addr_offset);
+
+ // This is the saved value of FP which may or may not really be an FP.
+ // It is only an FP if the sender is an interpreter frame (or C1?).
+ intptr_t** saved_fp_addr = (intptr_t**) (sender_sp - sender_sp_offset + link_offset);
+
+ if (map->update_map()) {
+ // Tell GC to use argument oopmaps for some runtime stubs that need it.
+ // For C1, the runtime stub might not have oop maps, so set this flag
+ // outside of update_register_map.
+ map->set_include_argument_oops(_cb->caller_must_gc_arguments(map->thread()));
+ if (_cb->oop_maps() != NULL) {
+ OopMapSet::update_register_map(this, map);
+ }
+
+ // Since the prolog does the save and restore of FP there is no oopmap
+ // for it so we must fill in its location as if there was an oopmap entry
+ // since if our caller was compiled code there could be live jvm state in it.
+ update_map_with_saved_link(map, saved_fp_addr);
+ }
+
+ assert(sender_sp != sp(), "must have changed");
+ return frame(sender_sp, unextended_sp, *saved_fp_addr, sender_pc);
+}
+
+frame frame::sender(RegisterMap* map) const {
+ // Default is we done have to follow them. The sender_for_xxx will
+ // update it accordingly
+ map->set_include_argument_oops(false);
+
+ if (is_entry_frame()) return sender_for_entry_frame(map);
+ if (is_interpreted_frame()) return sender_for_interpreter_frame(map);
+ assert(_cb == CodeCache::find_blob(pc()),"Must be the same");
+
+ if (_cb != NULL) {
+ return sender_for_compiled_frame(map);
+ }
+
+ assert(false, "should not be called for a C frame");
+ return frame();
+}
+
+bool frame::is_interpreted_frame_valid(JavaThread* thread) const {
+ assert(is_interpreted_frame(), "Not an interpreted frame");
+ // These are reasonable sanity checks
+ if (fp() == 0 || (intptr_t(fp()) & (wordSize-1)) != 0) {
+ return false;
+ }
+ if (sp() == 0 || (intptr_t(sp()) & (wordSize-1)) != 0) {
+ return false;
+ }
+ if (fp() + interpreter_frame_initial_sp_offset < sp()) {
+ return false;
+ }
+ // These are hacks to keep us out of trouble.
+ // The problem with these is that they mask other problems
+ if (fp() <= sp()) { // this attempts to deal with unsigned comparison above
+ return false;
+ }
+ // do some validation of frame elements
+
+ // first the method
+
+ Method* m = *interpreter_frame_method_addr();
+
+ // validate the method we'd find in this potential sender
+ if (!m->is_valid_method()) return false;
+
+ // stack frames shouldn't be much larger than max_stack elements
+
+ if (fp() - sp() > 1024 + m->max_stack()*Interpreter::stackElementSize) {
+ return false;
+ }
+
+ // validate bci/bcp
+
+ address bcp = interpreter_frame_bcp();
+ if (m->validate_bci_from_bcp(bcp) < 0) {
+ return false;
+ }
+
+ // validate ConstantPoolCache*
+ ConstantPoolCache* cp = *interpreter_frame_cache_addr();
+ if (cp == NULL || !cp->is_metaspace_object()) return false;
+
+ // validate locals
+
+ address locals = (address) *interpreter_frame_locals_addr();
+
+ if (locals > thread->stack_base() || locals < (address) fp()) return false;
+
+ // We'd have to be pretty unlucky to be mislead at this point
+
+ return true;
+}
+
+BasicType frame::interpreter_frame_result(oop* oop_result, jvalue* value_result) {
+ assert(is_interpreted_frame(), "interpreted frame expected");
+ Method* method = interpreter_frame_method();
+ BasicType type = method->result_type();
+
+ intptr_t* res_addr;
+ if (method->is_native()) {
+ // Prior to calling into the runtime to report the method_exit both of
+ // the possible return value registers are saved.
+#ifdef AARCH64
+ // Return value registers are saved into the frame
+ if (type == T_FLOAT || type == T_DOUBLE) {
+ res_addr = addr_at(interpreter_frame_fp_saved_result_offset);
+ } else {
+ res_addr = addr_at(interpreter_frame_gp_saved_result_offset);
+ }
+#else
+ // Return value registers are pushed to the native stack
+ res_addr = (intptr_t*)sp();
+#ifdef __ABI_HARD__
+ // FP result is pushed onto a stack along with integer result registers
+ if (type == T_FLOAT || type == T_DOUBLE) {
+ res_addr += 2;
+ }
+#endif // __ABI_HARD__
+#endif // AARCH64
+ } else {
+ res_addr = (intptr_t*)interpreter_frame_tos_address();
+ }
+
+ switch (type) {
+ case T_OBJECT :
+ case T_ARRAY : {
+ oop obj;
+ if (method->is_native()) {
+ obj = cast_to_oop(at(interpreter_frame_oop_temp_offset));
+ } else {
+ obj = *(oop*)res_addr;
+ }
+ assert(obj == NULL || Universe::heap()->is_in(obj), "sanity check");
+ *oop_result = obj;
+ break;
+ }
+ case T_BOOLEAN : value_result->z = *(jboolean*)res_addr; break;
+ case T_BYTE : value_result->b = *(jbyte*)res_addr; break;
+ case T_CHAR : value_result->c = *(jchar*)res_addr; break;
+ case T_SHORT : value_result->s = *(jshort*)res_addr; break;
+ case T_INT : value_result->i = *(jint*)res_addr; break;
+ case T_LONG : value_result->j = *(jlong*)res_addr; break;
+ case T_FLOAT : value_result->f = *(jfloat*)res_addr; break;
+ case T_DOUBLE : value_result->d = *(jdouble*)res_addr; break;
+ case T_VOID : /* Nothing to do */ break;
+ default : ShouldNotReachHere();
+ }
+
+ return type;
+}
+
+
+intptr_t* frame::interpreter_frame_tos_at(jint offset) const {
+ int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
+ return &interpreter_frame_tos_address()[index];
+}
+
+#ifndef PRODUCT
+
+#define DESCRIBE_FP_OFFSET(name) \
+ values.describe(frame_no, fp() + frame::name##_offset, #name)
+
+void frame::describe_pd(FrameValues& values, int frame_no) {
+ if (is_interpreted_frame()) {
+ DESCRIBE_FP_OFFSET(interpreter_frame_sender_sp);
+#ifdef AARCH64
+ DESCRIBE_FP_OFFSET(interpreter_frame_stack_top);
+ DESCRIBE_FP_OFFSET(interpreter_frame_extended_sp);
+#else
+ DESCRIBE_FP_OFFSET(interpreter_frame_last_sp);
+#endif // AARCH64
+ DESCRIBE_FP_OFFSET(interpreter_frame_method);
+ DESCRIBE_FP_OFFSET(interpreter_frame_mdp);
+ DESCRIBE_FP_OFFSET(interpreter_frame_cache);
+ DESCRIBE_FP_OFFSET(interpreter_frame_locals);
+ DESCRIBE_FP_OFFSET(interpreter_frame_bcp);
+ DESCRIBE_FP_OFFSET(interpreter_frame_initial_sp);
+ }
+}
+
+// This is a generic constructor which is only used by pns() in debug.cpp.
+frame::frame(void* sp, void* fp, void* pc) {
+ init((intptr_t*)sp, (intptr_t*)fp, (address)pc);
+}
+#endif
+
+intptr_t *frame::initial_deoptimization_info() {
+ // used to reset the saved FP
+ return fp();
+}
+
+intptr_t* frame::real_fp() const {
+#ifndef AARCH64
+ if (is_entry_frame()) {
+ // Work-around: FP (currently) does not conform to the ABI for entry
+ // frames (see generate_call_stub). Might be worth fixing as another CR.
+ // Following code assumes (and asserts) this has not yet been fixed.
+ assert(frame::entry_frame_call_wrapper_offset == 0, "adjust this code");
+ intptr_t* new_fp = fp();
+ new_fp += 5; // saved R0,R1,R2,R4,R10
+#ifndef __SOFTFP__
+ new_fp += 8*2; // saved D8..D15
+#endif
+ return new_fp;
+ }
+#endif // !AARCH64
+ if (_cb != NULL) {
+ // use the frame size if valid
+ int size = _cb->frame_size();
+ if (size > 0) {
+ return unextended_sp() + size;
+ }
+ }
+ // else rely on fp()
+ assert(! is_compiled_frame(), "unknown compiled frame size");
+ return fp();
+}