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* Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
25
#include "precompiled.hpp"
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#include "asm/codeBuffer.hpp"
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#include "code/compiledIC.hpp"
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#include "code/oopRecorder.inline.hpp"
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#include "compiler/disassembler.hpp"
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#include "logging/log.hpp"
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#include "oops/klass.inline.hpp"
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#include "oops/methodData.hpp"
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#include "oops/oop.inline.hpp"
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#include "runtime/icache.hpp"
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#include "runtime/safepointVerifiers.hpp"
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#include "utilities/align.hpp"
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#include "utilities/copy.hpp"
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#include "utilities/powerOfTwo.hpp"
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#include "utilities/xmlstream.hpp"
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// The structure of a CodeSection:
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// _start -> +----------------+
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// _end -> |----------------|
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// _locs_start -> +----------------+
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// The _end (resp. _limit) pointer refers to the first
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// unused (resp. unallocated) byte.
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// The structure of the CodeBuffer while code is being accumulated:
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// _consts._start -> +----------------+
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// _insts._start -> |----------------|
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// _stubs._start -> |----------------|
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// | Stubs | (also handlers for deopt/exception)
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// + _total_size -> | |
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// When the code and relocations are copied to the code cache,
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// the empty parts of each section are removed, and everything
86
// is copied into contiguous locations.
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typedef CodeBuffer::csize_t csize_t; // file-local definition
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// External buffer, in a predefined CodeBlob.
91
// Important: The code_start must be taken exactly, and not realigned.
92
CodeBuffer::CodeBuffer(CodeBlob* blob) DEBUG_ONLY(: Scrubber(this, sizeof(*this))) {
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// Provide code buffer with meaningful name
94
initialize_misc(blob->name());
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initialize(blob->content_begin(), blob->content_size());
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debug_only(verify_section_allocation();)
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void CodeBuffer::initialize(csize_t code_size, csize_t locs_size) {
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// Always allow for empty slop around each section.
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int slop = (int) CodeSection::end_slop();
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assert(SECT_LIMIT == 3, "total_size explicitly lists all section alignments");
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int total_size = code_size + _consts.alignment() + _insts.alignment() + _stubs.alignment() + SECT_LIMIT * slop;
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assert(blob() == nullptr, "only once");
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set_blob(BufferBlob::create(_name, total_size));
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if (blob() == nullptr) {
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// The assembler constructor will throw a fatal on an empty CodeBuffer.
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return; // caller must test this
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// Set up various pointers into the blob.
114
initialize(_total_start, _total_size);
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assert((uintptr_t)insts_begin() % CodeEntryAlignment == 0, "instruction start not code entry aligned");
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if (locs_size != 0) {
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_insts.initialize_locs(locs_size / sizeof(relocInfo));
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debug_only(verify_section_allocation();)
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CodeBuffer::~CodeBuffer() {
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verify_section_allocation();
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// If we allocated our code buffer from the CodeCache via a BufferBlob, and
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// it's not permanent, then free the BufferBlob. The rest of the memory
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// will be freed when the ResourceObj is released.
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for (CodeBuffer* cb = this; cb != nullptr; cb = cb->before_expand()) {
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// Previous incarnations of this buffer are held live, so that internal
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// addresses constructed before expansions will not be confused.
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if (_overflow_arena != nullptr) {
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// free any overflow storage
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delete _overflow_arena;
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if (_shared_trampoline_requests != nullptr) {
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delete _shared_trampoline_requests;
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NOT_PRODUCT(clear_strings());
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void CodeBuffer::initialize_oop_recorder(OopRecorder* r) {
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assert(_oop_recorder == &_default_oop_recorder && _default_oop_recorder.is_unused(), "do this once");
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DEBUG_ONLY(_default_oop_recorder.freeze()); // force unused OR to be frozen
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void CodeBuffer::initialize_section_size(CodeSection* cs, csize_t size) {
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assert(cs != &_insts, "insts is the memory provider, not the consumer");
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csize_t slop = CodeSection::end_slop(); // margin between sections
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int align = cs->alignment();
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assert(is_power_of_2(align), "sanity");
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address start = _insts._start;
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address limit = _insts._limit;
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address middle = limit - size;
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middle -= (intptr_t)middle & (align-1); // align the division point downward
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guarantee(middle - slop > start, "need enough space to divide up");
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_insts._limit = middle - slop; // subtract desired space, plus slop
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cs->initialize(middle, limit - middle);
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assert(cs->start() == middle, "sanity");
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assert(cs->limit() == limit, "sanity");
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// give it some relocations to start with, if the main section has them
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if (_insts.has_locs()) cs->initialize_locs(1);
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void CodeBuffer::set_blob(BufferBlob* blob) {
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if (blob != nullptr) {
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address start = blob->content_begin();
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address end = blob->content_end();
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// Round up the starting address.
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int align = _insts.alignment();
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start += (-(intptr_t)start) & (align-1);
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_total_start = start;
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_total_size = end - start;
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// Clean out dangling pointers.
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_total_start = badAddress;
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_consts._start = _consts._end = badAddress;
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_insts._start = _insts._end = badAddress;
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_stubs._start = _stubs._end = badAddress;
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void CodeBuffer::free_blob() {
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if (_blob != nullptr) {
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BufferBlob::free(_blob);
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const char* CodeBuffer::code_section_name(int n) {
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case SECT_CONSTS: return "consts";
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case SECT_INSTS: return "insts";
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case SECT_STUBS: return "stubs";
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default: return nullptr;
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int CodeBuffer::section_index_of(address addr) const {
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for (int n = 0; n < (int)SECT_LIMIT; n++) {
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const CodeSection* cs = code_section(n);
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if (cs->allocates(addr)) return n;
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int CodeBuffer::locator(address addr) const {
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for (int n = 0; n < (int)SECT_LIMIT; n++) {
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const CodeSection* cs = code_section(n);
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if (cs->allocates(addr)) {
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return locator(addr - cs->start(), n);
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bool CodeBuffer::is_backward_branch(Label& L) {
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return L.is_bound() && insts_end() <= locator_address(L.loc());
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address CodeBuffer::decode_begin() {
240
address begin = _insts.start();
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if (_decode_begin != nullptr && _decode_begin > begin)
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begin = _decode_begin;
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GrowableArray<int>* CodeBuffer::create_patch_overflow() {
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if (_overflow_arena == nullptr) {
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_overflow_arena = new (mtCode) Arena(mtCode);
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return new (_overflow_arena) GrowableArray<int>(_overflow_arena, 8, 0, 0);
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// Helper function for managing labels and their target addresses.
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// Returns a sensible address, and if it is not the label's final
257
// address, notes the dependency (at 'branch_pc') on the label.
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address CodeSection::target(Label& L, address branch_pc) {
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if (index() == CodeBuffer::locator_sect(loc)) {
262
return start() + CodeBuffer::locator_pos(loc);
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return outer()->locator_address(loc);
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assert(allocates2(branch_pc), "sanity");
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address base = start();
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int patch_loc = CodeBuffer::locator(branch_pc - base, index());
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L.add_patch_at(outer(), patch_loc);
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// Need to return a pc, doesn't matter what it is since it will be
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// replaced during resolution later.
274
// Don't return null or badAddress, since branches shouldn't overflow.
275
// Don't return base either because that could overflow displacements
276
// for shorter branches. It will get checked when bound.
281
void CodeSection::relocate(address at, relocInfo::relocType rtype, int format, jint method_index) {
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case relocInfo::none: return;
285
case relocInfo::opt_virtual_call_type: {
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rh = opt_virtual_call_Relocation::spec(method_index);
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case relocInfo::static_call_type: {
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rh = static_call_Relocation::spec(method_index);
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case relocInfo::virtual_call_type: {
294
assert(method_index == 0, "resolved method overriding is not supported");
295
rh = Relocation::spec_simple(rtype);
299
rh = Relocation::spec_simple(rtype);
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relocate(at, rh, format);
306
void CodeSection::relocate(address at, RelocationHolder const& spec, int format) {
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// Do not relocate in scratch buffers.
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if (scratch_emit()) { return; }
309
Relocation* reloc = spec.reloc();
310
relocInfo::relocType rtype = (relocInfo::relocType) reloc->type();
311
if (rtype == relocInfo::none) return;
313
// The assertion below has been adjusted, to also work for
314
// relocation for fixup. Sometimes we want to put relocation
315
// information for the next instruction, since it will be patched
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assert(start() <= at && at <= end()+1,
318
"cannot relocate data outside code boundaries");
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// no space for relocation information provided => code cannot be
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// relocated. Make sure that relocate is only called with rtypes
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// that can be ignored for this kind of code.
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assert(rtype == relocInfo::none ||
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rtype == relocInfo::runtime_call_type ||
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rtype == relocInfo::internal_word_type||
327
rtype == relocInfo::section_word_type ||
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rtype == relocInfo::external_word_type||
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rtype == relocInfo::barrier_type,
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"code needs relocation information");
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// leave behind an indication that we attempted a relocation
332
DEBUG_ONLY(_locs_start = _locs_limit = (relocInfo*)badAddress);
336
// Advance the point, noting the offset we'll have to record.
337
csize_t offset = at - locs_point();
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// Test for a couple of overflow conditions; maybe expand the buffer.
341
relocInfo* end = locs_end();
342
relocInfo* req = end + relocInfo::length_limit;
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// Check for (potential) overflow
344
if (req >= locs_limit() || offset >= relocInfo::offset_limit()) {
345
req += (uint)offset / (uint)relocInfo::offset_limit();
346
if (req >= locs_limit()) {
347
// Allocate or reallocate.
348
expand_locs(locs_count() + (req - end));
354
// If the offset is giant, emit filler relocs, of type 'none', but
355
// each carrying the largest possible offset, to advance the locs_point.
356
while (offset >= relocInfo::offset_limit()) {
357
assert(end < locs_limit(), "adjust previous paragraph of code");
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*end++ = relocInfo::filler_info();
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offset -= relocInfo::filler_info().addr_offset();
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// If it's a simple reloc with no data, we'll just write (rtype | offset).
363
(*end) = relocInfo(rtype, offset, format);
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// If it has data, insert the prefix, as (data_prefix_tag | data1), data2.
366
end->initialize(this, reloc);
369
void CodeSection::initialize_locs(int locs_capacity) {
370
assert(_locs_start == nullptr, "only one locs init step, please");
371
// Apply a priori lower limits to relocation size:
372
csize_t min_locs = MAX2(size() / 16, (csize_t)4);
373
if (locs_capacity < min_locs) locs_capacity = min_locs;
374
relocInfo* locs_start = NEW_RESOURCE_ARRAY(relocInfo, locs_capacity);
375
_locs_start = locs_start;
376
_locs_end = locs_start;
377
_locs_limit = locs_start + locs_capacity;
381
void CodeSection::initialize_shared_locs(relocInfo* buf, int length) {
382
assert(_locs_start == nullptr, "do this before locs are allocated");
383
// Internal invariant: locs buf must be fully aligned.
384
// See copy_relocations_to() below.
385
while ((uintptr_t)buf % HeapWordSize != 0 && length > 0) {
391
_locs_limit = buf + length;
396
void CodeSection::initialize_locs_from(const CodeSection* source_cs) {
397
int lcount = source_cs->locs_count();
399
initialize_shared_locs(source_cs->locs_start(), lcount);
400
_locs_end = _locs_limit = _locs_start + lcount;
401
assert(is_allocated(), "must have copied code already");
402
set_locs_point(start() + source_cs->locs_point_off());
404
assert(this->locs_count() == source_cs->locs_count(), "sanity");
407
void CodeSection::expand_locs(int new_capacity) {
408
if (_locs_start == nullptr) {
409
initialize_locs(new_capacity);
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int old_count = locs_count();
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int old_capacity = locs_capacity();
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if (new_capacity < old_capacity * 2)
415
new_capacity = old_capacity * 2;
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relocInfo* locs_start;
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locs_start = REALLOC_RESOURCE_ARRAY(relocInfo, _locs_start, old_capacity, new_capacity);
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locs_start = NEW_RESOURCE_ARRAY(relocInfo, new_capacity);
421
Copy::conjoint_jbytes(_locs_start, locs_start, old_capacity * sizeof(relocInfo));
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_locs_start = locs_start;
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_locs_end = locs_start + old_count;
426
_locs_limit = locs_start + new_capacity;
430
int CodeSection::alignment() const {
431
if (_index == CodeBuffer::SECT_CONSTS) {
432
// CodeBuffer controls the alignment of the constants section
433
return _outer->_const_section_alignment;
435
if (_index == CodeBuffer::SECT_INSTS) {
436
return (int) CodeEntryAlignment;
438
if (_index == CodeBuffer::SECT_STUBS) {
439
// CodeBuffer installer expects sections to be HeapWordSize aligned
442
ShouldNotReachHere();
446
/// Support for emitting the code to its final location.
447
/// The pattern is the same for all functions.
448
/// We iterate over all the sections, padding each to alignment.
450
csize_t CodeBuffer::total_content_size() const {
451
csize_t size_so_far = 0;
452
for (int n = 0; n < (int)SECT_LIMIT; n++) {
453
const CodeSection* cs = code_section(n);
454
if (cs->is_empty()) continue; // skip trivial section
455
size_so_far = cs->align_at_start(size_so_far);
456
size_so_far += cs->size();
461
void CodeBuffer::compute_final_layout(CodeBuffer* dest) const {
462
address buf = dest->_total_start;
463
csize_t buf_offset = 0;
464
assert(dest->_total_size >= total_content_size(), "must be big enough");
465
assert(!_finalize_stubs, "non-finalized stubs");
468
// not sure why this is here, but why not...
469
int alignSize = MAX2((intx) sizeof(jdouble), CodeEntryAlignment);
470
assert( (dest->_total_start - _insts.start()) % alignSize == 0, "copy must preserve alignment");
473
const CodeSection* prev_cs = nullptr;
474
CodeSection* prev_dest_cs = nullptr;
476
for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
477
// figure compact layout of each section
478
const CodeSection* cs = code_section(n);
479
csize_t csize = cs->size();
481
CodeSection* dest_cs = dest->code_section(n);
482
if (!cs->is_empty()) {
483
// Compute initial padding; assign it to the previous non-empty guy.
484
// Cf. figure_expanded_capacities.
485
csize_t padding = cs->align_at_start(buf_offset) - buf_offset;
486
if (prev_dest_cs != nullptr) {
488
buf_offset += padding;
489
prev_dest_cs->_limit += padding;
492
guarantee(padding == 0, "In first iteration no padding should be needed.");
494
prev_dest_cs = dest_cs;
498
debug_only(dest_cs->_start = nullptr); // defeat double-initialization assert
499
dest_cs->initialize(buf+buf_offset, csize);
500
dest_cs->set_end(buf+buf_offset+csize);
501
assert(dest_cs->is_allocated(), "must always be allocated");
502
assert(cs->is_empty() == dest_cs->is_empty(), "sanity");
507
// Done calculating sections; did it come out to the right end?
508
assert(buf_offset == total_content_size(), "sanity");
509
debug_only(dest->verify_section_allocation();)
512
// Append an oop reference that keeps the class alive.
513
static void append_oop_references(GrowableArray<oop>* oops, Klass* k) {
514
oop cl = k->klass_holder();
515
if (cl != nullptr && !oops->contains(cl)) {
520
void CodeBuffer::finalize_oop_references(const methodHandle& mh) {
521
NoSafepointVerifier nsv;
523
GrowableArray<oop> oops;
525
// Make sure that immediate metadata records something in the OopRecorder
526
for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
527
// pull code out of each section
528
CodeSection* cs = code_section(n);
529
if (cs->is_empty() || (cs->locs_count() == 0)) continue; // skip trivial section
530
RelocIterator iter(cs);
531
while (iter.next()) {
532
if (iter.type() == relocInfo::metadata_type) {
533
metadata_Relocation* md = iter.metadata_reloc();
534
if (md->metadata_is_immediate()) {
535
Metadata* m = md->metadata_value();
536
if (oop_recorder()->is_real(m)) {
537
if (m->is_methodData()) {
538
m = ((MethodData*)m)->method();
540
if (m->is_method()) {
541
m = ((Method*)m)->method_holder();
544
append_oop_references(&oops, (Klass*)m);
546
// XXX This will currently occur for MDO which don't
547
// have a backpointer. This has to be fixed later.
549
ShouldNotReachHere();
557
if (!oop_recorder()->is_unused()) {
558
for (int i = 0; i < oop_recorder()->metadata_count(); i++) {
559
Metadata* m = oop_recorder()->metadata_at(i);
560
if (oop_recorder()->is_real(m)) {
561
if (m->is_methodData()) {
562
m = ((MethodData*)m)->method();
564
if (m->is_method()) {
565
m = ((Method*)m)->method_holder();
568
append_oop_references(&oops, (Klass*)m);
571
ShouldNotReachHere();
578
// Add the class loader of Method* for the nmethod itself
579
append_oop_references(&oops, mh->method_holder());
581
// Add any oops that we've found
582
Thread* thread = Thread::current();
583
for (int i = 0; i < oops.length(); i++) {
584
oop_recorder()->find_index((jobject)thread->handle_area()->allocate_handle(oops.at(i)));
590
csize_t CodeBuffer::total_offset_of(const CodeSection* cs) const {
591
csize_t size_so_far = 0;
592
for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
593
const CodeSection* cur_cs = code_section(n);
594
if (!cur_cs->is_empty()) {
595
size_so_far = cur_cs->align_at_start(size_so_far);
597
if (cur_cs->index() == cs->index()) {
600
size_so_far += cur_cs->size();
602
ShouldNotReachHere();
606
int CodeBuffer::total_skipped_instructions_size() const {
607
int total_skipped_size = 0;
608
for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
609
const CodeSection* cur_cs = code_section(n);
610
if (!cur_cs->is_empty()) {
611
total_skipped_size += cur_cs->_skipped_instructions_size;
614
return total_skipped_size;
617
csize_t CodeBuffer::total_relocation_size() const {
618
csize_t total = copy_relocations_to(nullptr); // dry run only
619
return (csize_t) align_up(total, HeapWordSize);
622
csize_t CodeBuffer::copy_relocations_to(address buf, csize_t buf_limit, bool only_inst) const {
623
csize_t buf_offset = 0;
624
csize_t code_end_so_far = 0;
625
csize_t code_point_so_far = 0;
627
assert((uintptr_t)buf % HeapWordSize == 0, "buf must be fully aligned");
628
assert(buf_limit % HeapWordSize == 0, "buf must be evenly sized");
630
for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) {
631
if (only_inst && (n != (int)SECT_INSTS)) {
632
// Need only relocation info for code.
635
// pull relocs out of each section
636
const CodeSection* cs = code_section(n);
637
assert(!(cs->is_empty() && cs->locs_count() > 0), "sanity");
638
if (cs->is_empty()) continue; // skip trivial section
639
relocInfo* lstart = cs->locs_start();
640
relocInfo* lend = cs->locs_end();
641
csize_t lsize = (csize_t)( (address)lend - (address)lstart );
642
csize_t csize = cs->size();
643
code_end_so_far = cs->align_at_start(code_end_so_far);
646
// Figure out how to advance the combined relocation point
647
// first to the beginning of this section.
648
// We'll insert one or more filler relocs to span that gap.
649
// (Don't bother to improve this by editing the first reloc's offset.)
650
csize_t new_code_point = code_end_so_far;
652
code_point_so_far < new_code_point;
653
code_point_so_far += jump) {
654
jump = new_code_point - code_point_so_far;
655
relocInfo filler = relocInfo::filler_info();
656
if (jump >= filler.addr_offset()) {
657
jump = filler.addr_offset();
658
} else { // else shrink the filler to fit
659
filler = relocInfo(relocInfo::none, jump);
661
if (buf != nullptr) {
662
assert(buf_offset + (csize_t)sizeof(filler) <= buf_limit, "filler in bounds");
663
*(relocInfo*)(buf+buf_offset) = filler;
665
buf_offset += sizeof(filler);
668
// Update code point and end to skip past this section:
669
csize_t last_code_point = code_end_so_far + cs->locs_point_off();
670
assert(code_point_so_far <= last_code_point, "sanity");
671
code_point_so_far = last_code_point; // advance past this guy's relocs
673
code_end_so_far += csize; // advance past this guy's instructions too
675
// Done with filler; emit the real relocations:
676
if (buf != nullptr && lsize != 0) {
677
assert(buf_offset + lsize <= buf_limit, "target in bounds");
678
assert((uintptr_t)lstart % HeapWordSize == 0, "sane start");
679
if (buf_offset % HeapWordSize == 0) {
680
// Use wordwise copies if possible:
681
Copy::disjoint_words((HeapWord*)lstart,
682
(HeapWord*)(buf+buf_offset),
683
(lsize + HeapWordSize-1) / HeapWordSize);
685
Copy::conjoint_jbytes(lstart, buf+buf_offset, lsize);
691
// Align end of relocation info in target.
692
while (buf_offset % HeapWordSize != 0) {
693
if (buf != nullptr) {
694
relocInfo padding = relocInfo(relocInfo::none, 0);
695
assert(buf_offset + (csize_t)sizeof(padding) <= buf_limit, "padding in bounds");
696
*(relocInfo*)(buf+buf_offset) = padding;
698
buf_offset += sizeof(relocInfo);
701
assert(only_inst || code_end_so_far == total_content_size(), "sanity");
706
csize_t CodeBuffer::copy_relocations_to(CodeBlob* dest) const {
707
address buf = nullptr;
708
csize_t buf_offset = 0;
709
csize_t buf_limit = 0;
711
if (dest != nullptr) {
712
buf = (address)dest->relocation_begin();
713
buf_limit = (address)dest->relocation_end() - buf;
715
// if dest is null, this is just the sizing pass
717
buf_offset = copy_relocations_to(buf, buf_limit, false);
722
void CodeBuffer::copy_code_to(CodeBlob* dest_blob) {
724
if (PrintNMethods && (WizardMode || Verbose)) {
725
tty->print("done with CodeBuffer:");
726
((CodeBuffer*)this)->print();
730
CodeBuffer dest(dest_blob);
731
assert(dest_blob->content_size() >= total_content_size(), "good sizing");
732
this->compute_final_layout(&dest);
734
// Set beginning of constant table before relocating.
735
dest_blob->set_ctable_begin(dest.consts()->start());
737
relocate_code_to(&dest);
739
// Share assembly remarks and debug strings with the blob.
740
NOT_PRODUCT(dest_blob->use_remarks(_asm_remarks));
741
NOT_PRODUCT(dest_blob->use_strings(_dbg_strings));
743
// Done moving code bytes; were they the right size?
744
assert((int)align_up(dest.total_content_size(), oopSize) == dest_blob->content_size(), "sanity");
746
// Flush generated code
747
ICache::invalidate_range(dest_blob->code_begin(), dest_blob->code_size());
750
// Move all my code into another code buffer. Consult applicable
751
// relocs to repair embedded addresses. The layout in the destination
752
// CodeBuffer is different to the source CodeBuffer: the destination
753
// CodeBuffer gets the final layout (consts, insts, stubs in order of
754
// ascending address).
755
void CodeBuffer::relocate_code_to(CodeBuffer* dest) const {
756
address dest_end = dest->_total_start + dest->_total_size;
757
address dest_filled = nullptr;
758
for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
759
// pull code out of each section
760
const CodeSection* cs = code_section(n);
761
if (cs->is_empty()) continue; // skip trivial section
762
CodeSection* dest_cs = dest->code_section(n);
763
assert(cs->size() == dest_cs->size(), "sanity");
764
csize_t usize = dest_cs->size();
765
csize_t wsize = align_up(usize, HeapWordSize);
766
assert(dest_cs->start() + wsize <= dest_end, "no overflow");
767
// Copy the code as aligned machine words.
768
// This may also include an uninitialized partial word at the end.
769
Copy::disjoint_words((HeapWord*)cs->start(),
770
(HeapWord*)dest_cs->start(),
771
wsize / HeapWordSize);
773
if (dest->blob() == nullptr) {
774
// Destination is a final resting place, not just another buffer.
775
// Normalize uninitialized bytes in the final padding.
776
Copy::fill_to_bytes(dest_cs->end(), dest_cs->remaining(),
777
Assembler::code_fill_byte());
779
// Keep track of the highest filled address
780
dest_filled = MAX2(dest_filled, dest_cs->end() + dest_cs->remaining());
782
assert(cs->locs_start() != (relocInfo*)badAddress,
783
"this section carries no reloc storage, but reloc was attempted");
785
// Make the new code copy use the old copy's relocations:
786
dest_cs->initialize_locs_from(cs);
789
// Do relocation after all sections are copied.
790
// This is necessary if the code uses constants in stubs, which are
791
// relocated when the corresponding instruction in the code (e.g., a
792
// call) is relocated. Stubs are placed behind the main code
793
// section, so that section has to be copied before relocating.
794
for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) {
795
CodeSection* dest_cs = dest->code_section(n);
796
if (dest_cs->is_empty() || (dest_cs->locs_count() == 0)) continue; // skip trivial section
797
{ // Repair the pc relative information in the code after the move
798
RelocIterator iter(dest_cs);
799
while (iter.next()) {
800
iter.reloc()->fix_relocation_after_move(this, dest);
805
if (dest->blob() == nullptr && dest_filled != nullptr) {
806
// Destination is a final resting place, not just another buffer.
807
// Normalize uninitialized bytes in the final padding.
808
Copy::fill_to_bytes(dest_filled, dest_end - dest_filled,
809
Assembler::code_fill_byte());
814
csize_t CodeBuffer::figure_expanded_capacities(CodeSection* which_cs,
816
csize_t* new_capacity) {
817
csize_t new_total_cap = 0;
819
for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
820
const CodeSection* sect = code_section(n);
822
if (!sect->is_empty()) {
823
// Compute initial padding; assign it to the previous section,
824
// even if it's empty (e.g. consts section can be empty).
825
// Cf. compute_final_layout
826
csize_t padding = sect->align_at_start(new_total_cap) - new_total_cap;
828
new_total_cap += padding;
829
assert(n - 1 >= SECT_FIRST, "sanity");
830
new_capacity[n - 1] += padding;
834
csize_t exp = sect->size(); // 100% increase
835
if ((uint)exp < 4*K) exp = 4*K; // minimum initial increase
836
if (sect == which_cs) {
837
if (exp < amount) exp = amount;
838
if (StressCodeBuffers) exp = amount; // expand only slightly
839
} else if (n == SECT_INSTS) {
840
// scale down inst increases to a more modest 25%
841
exp = 4*K + ((exp - 4*K) >> 2);
842
if (StressCodeBuffers) exp = amount / 2; // expand only slightly
843
} else if (sect->is_empty()) {
844
// do not grow an empty secondary section
847
// Allow for inter-section slop:
848
exp += CodeSection::end_slop();
849
csize_t new_cap = sect->size() + exp;
850
if (new_cap < sect->capacity()) {
851
// No need to expand after all.
852
new_cap = sect->capacity();
854
new_capacity[n] = new_cap;
855
new_total_cap += new_cap;
858
return new_total_cap;
861
void CodeBuffer::expand(CodeSection* which_cs, csize_t amount) {
863
if (PrintNMethods && (WizardMode || Verbose)) {
864
tty->print("expanding CodeBuffer:");
868
if (StressCodeBuffers && blob() != nullptr) {
869
static int expand_count = 0;
870
if (expand_count >= 0) expand_count += 1;
871
if (expand_count > 100 && is_power_of_2(expand_count)) {
872
tty->print_cr("StressCodeBuffers: have expanded %d times", expand_count);
873
// simulate an occasional allocation failure:
879
// Resizing must be allowed
881
if (blob() == nullptr) return; // caller must check if blob is null
884
// Figure new capacity for each section.
885
csize_t new_capacity[SECT_LIMIT];
886
memset(new_capacity, 0, sizeof(csize_t) * SECT_LIMIT);
887
csize_t new_total_cap
888
= figure_expanded_capacities(which_cs, amount, new_capacity);
890
// Create a new (temporary) code buffer to hold all the new data
891
CodeBuffer cb(name(), new_total_cap, 0);
892
if (cb.blob() == nullptr) {
893
// Failed to allocate in code cache.
898
// Create an old code buffer to remember which addresses used to go where.
899
// This will be useful when we do final assembly into the code cache,
900
// because we will need to know how to warp any internal address that
901
// has been created at any time in this CodeBuffer's past.
902
CodeBuffer* bxp = new CodeBuffer(_total_start, _total_size);
903
bxp->take_over_code_from(this); // remember the old undersized blob
904
DEBUG_ONLY(this->_blob = nullptr); // silence a later assert
905
bxp->_before_expand = this->_before_expand;
906
this->_before_expand = bxp;
908
// Give each section its required (expanded) capacity.
909
for (int n = (int)SECT_LIMIT-1; n >= SECT_FIRST; n--) {
910
CodeSection* cb_sect = cb.code_section(n);
911
CodeSection* this_sect = code_section(n);
912
if (new_capacity[n] == 0) continue; // already nulled out
913
if (n != SECT_INSTS) {
914
cb.initialize_section_size(cb_sect, new_capacity[n]);
916
assert(cb_sect->capacity() >= new_capacity[n], "big enough");
917
address cb_start = cb_sect->start();
918
cb_sect->set_end(cb_start + this_sect->size());
919
if (this_sect->mark() == nullptr) {
920
cb_sect->clear_mark();
922
cb_sect->set_mark(cb_start + this_sect->mark_off());
926
// Needs to be initialized when calling fix_relocation_after_move.
927
cb.blob()->set_ctable_begin(cb.consts()->start());
929
// Move all the code and relocations to the new blob:
930
relocate_code_to(&cb);
932
// some internal addresses, _last_insn _last_label, are used during code emission,
933
// adjust them in expansion
934
adjust_internal_address(insts_begin(), cb.insts_begin());
936
// Copy the temporary code buffer into the current code buffer.
937
// Basically, do {*this = cb}, except for some control information.
938
this->take_over_code_from(&cb);
939
cb.set_blob(nullptr);
941
// Zap the old code buffer contents, to avoid mistakenly using them.
942
debug_only(Copy::fill_to_bytes(bxp->_total_start, bxp->_total_size,
943
badCodeHeapFreeVal);)
945
// Make certain that the new sections are all snugly inside the new blob.
946
debug_only(verify_section_allocation();)
949
_decode_begin = nullptr; // sanity
950
if (PrintNMethods && (WizardMode || Verbose)) {
951
tty->print("expanded CodeBuffer:");
957
void CodeBuffer::adjust_internal_address(address from, address to) {
958
if (_last_insn != nullptr) {
959
_last_insn += to - from;
961
if (_last_label != nullptr) {
962
_last_label += to - from;
966
void CodeBuffer::take_over_code_from(CodeBuffer* cb) {
967
// Must already have disposed of the old blob somehow.
968
assert(blob() == nullptr, "must be empty");
969
// Take the new blob away from cb.
970
set_blob(cb->blob());
971
// Take over all the section pointers.
972
for (int n = 0; n < (int)SECT_LIMIT; n++) {
973
CodeSection* cb_sect = cb->code_section(n);
974
CodeSection* this_sect = code_section(n);
975
this_sect->take_over_code_from(cb_sect);
977
// Make sure the old cb won't try to use it or free it.
978
DEBUG_ONLY(cb->_blob = (BufferBlob*)badAddress);
981
void CodeBuffer::verify_section_allocation() {
982
address tstart = _total_start;
983
if (tstart == badAddress) return; // smashed by set_blob(nullptr)
984
address tend = tstart + _total_size;
985
if (_blob != nullptr) {
986
guarantee(tstart >= _blob->content_begin(), "sanity");
987
guarantee(tend <= _blob->content_end(), "sanity");
989
// Verify disjointness.
990
for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
991
CodeSection* sect = code_section(n);
992
if (!sect->is_allocated() || sect->is_empty()) {
995
guarantee(_blob == nullptr || is_aligned(sect->start(), sect->alignment()),
997
for (int m = n + 1; m < (int) SECT_LIMIT; m++) {
998
CodeSection* other = code_section(m);
999
if (!other->is_allocated() || other == sect) {
1002
guarantee(other->disjoint(sect), "sanity");
1004
guarantee(sect->end() <= tend, "sanity");
1005
guarantee(sect->end() <= sect->limit(), "sanity");
1009
void CodeBuffer::log_section_sizes(const char* name) {
1010
if (xtty != nullptr) {
1012
// log info about buffer usage
1013
xtty->print_cr("<blob name='%s' total_size='%d'>", name, _total_size);
1014
for (int n = (int) CodeBuffer::SECT_FIRST; n < (int) CodeBuffer::SECT_LIMIT; n++) {
1015
CodeSection* sect = code_section(n);
1016
if (!sect->is_allocated() || sect->is_empty()) continue;
1017
xtty->print_cr("<sect index='%d' capacity='%d' size='%d' remaining='%d'/>",
1018
n, sect->capacity(), sect->size(), sect->remaining());
1020
xtty->print_cr("</blob>");
1024
bool CodeBuffer::finalize_stubs() {
1025
if (_finalize_stubs && !pd_finalize_stubs()) {
1026
// stub allocation failure
1029
_finalize_stubs = false;
1033
void CodeBuffer::shared_stub_to_interp_for(ciMethod* callee, csize_t call_offset) {
1034
if (_shared_stub_to_interp_requests == nullptr) {
1035
_shared_stub_to_interp_requests = new SharedStubToInterpRequests(8);
1037
SharedStubToInterpRequest request(callee, call_offset);
1038
_shared_stub_to_interp_requests->push(request);
1039
_finalize_stubs = true;
1043
void CodeBuffer::block_comment(ptrdiff_t offset, const char* comment) {
1044
if (_collect_comments) {
1045
const char* str = _asm_remarks.insert(offset, comment);
1046
postcond(str != comment);
1050
const char* CodeBuffer::code_string(const char* str) {
1051
const char* tmp = _dbg_strings.insert(str);
1052
postcond(tmp != str);
1056
void CodeBuffer::decode() {
1058
Disassembler::decode(decode_begin(), insts_end(), tty NOT_PRODUCT(COMMA &asm_remarks()));
1059
_decode_begin = insts_end();
1062
void CodeSection::print(const char* name) {
1063
csize_t locs_size = locs_end() - locs_start();
1064
tty->print_cr(" %7s.code = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d)",
1065
name, p2i(start()), p2i(end()), p2i(limit()), size(), capacity());
1066
tty->print_cr(" %7s.locs = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d) point=%d",
1067
name, p2i(locs_start()), p2i(locs_end()), p2i(locs_limit()), locs_size, locs_capacity(), locs_point_off());
1068
if (PrintRelocations && (locs_size != 0)) {
1069
RelocIterator iter(this);
1074
void CodeBuffer::print() {
1075
tty->print_cr("CodeBuffer:");
1076
for (int n = 0; n < (int)SECT_LIMIT; n++) {
1077
// print each section
1078
CodeSection* cs = code_section(n);
1079
cs->print(code_section_name(n));
1083
// ----- CHeapString -----------------------------------------------------------
1085
class CHeapString : public CHeapObj<mtCode> {
1087
CHeapString(const char* str) : _string(os::strdup(str)) {}
1089
os::free((void*)_string);
1092
const char* string() const { return _string; }
1095
const char* _string;
1098
// ----- AsmRemarkCollection ---------------------------------------------------
1100
class AsmRemarkCollection : public CHeapObj<mtCode> {
1102
AsmRemarkCollection() : _ref_cnt(1), _remarks(nullptr), _next(nullptr) {}
1103
~AsmRemarkCollection() {
1104
assert(is_empty(), "Must 'clear()' before deleting!");
1105
assert(_ref_cnt == 0, "No uses must remain when deleting!");
1107
AsmRemarkCollection* reuse() {
1108
precond(_ref_cnt > 0);
1109
return _ref_cnt++, this;
1112
const char* insert(uint offset, const char* remark);
1113
const char* lookup(uint offset) const;
1114
const char* next(uint offset) const;
1116
bool is_empty() const { return _remarks == nullptr; }
1120
struct Cell : CHeapString {
1121
Cell(const char* remark, uint offset) :
1122
CHeapString(remark), offset(offset), prev(nullptr), next(nullptr) {}
1123
void push_back(Cell* cell) {
1137
// Using a 'mutable' iteration pointer to allow 'const' on lookup/next (that
1138
// does not change the state of the list per se), supportig a simplistic
1139
// iteration scheme.
1140
mutable Cell* _next;
1143
// ----- DbgStringCollection ---------------------------------------------------
1145
class DbgStringCollection : public CHeapObj<mtCode> {
1147
DbgStringCollection() : _ref_cnt(1), _strings(nullptr) {}
1148
~DbgStringCollection() {
1149
assert(is_empty(), "Must 'clear()' before deleting!");
1150
assert(_ref_cnt == 0, "No uses must remain when deleting!");
1152
DbgStringCollection* reuse() {
1153
precond(_ref_cnt > 0);
1154
return _ref_cnt++, this;
1157
const char* insert(const char* str);
1158
const char* lookup(const char* str) const;
1160
bool is_empty() const { return _strings == nullptr; }
1164
struct Cell : CHeapString {
1165
Cell(const char* dbgstr) :
1166
CHeapString(dbgstr), prev(nullptr), next(nullptr) {}
1167
void push_back(Cell* cell) {
1182
// ----- AsmRemarks ------------------------------------------------------------
1184
// Acting as interface to reference counted mapping [offset -> remark], where
1185
// offset is a byte offset into an instruction stream (CodeBuffer, CodeBlob or
1186
// other memory buffer) and remark is a string (comment).
1188
AsmRemarks::AsmRemarks() : _remarks(new AsmRemarkCollection()) {
1189
assert(_remarks != nullptr, "Allocation failure!");
1192
AsmRemarks::~AsmRemarks() {
1193
assert(_remarks == nullptr, "Must 'clear()' before deleting!");
1196
const char* AsmRemarks::insert(uint offset, const char* remstr) {
1197
precond(remstr != nullptr);
1198
return _remarks->insert(offset, remstr);
1201
bool AsmRemarks::is_empty() const {
1202
return _remarks->is_empty();
1205
void AsmRemarks::share(const AsmRemarks &src) {
1206
precond(is_empty());
1208
_remarks = src._remarks->reuse();
1211
void AsmRemarks::clear() {
1212
if (_remarks->clear() == 0) {
1218
uint AsmRemarks::print(uint offset, outputStream* strm) const {
1220
const char* prefix = " ;; ";
1221
const char* remstr = _remarks->lookup(offset);
1222
while (remstr != nullptr) {
1224
strm->print("%s", prefix);
1225
// Don't interpret as format strings since it could contain '%'.
1226
strm->print_raw(remstr);
1227
// Advance to next line iff string didn't contain a cr() at the end.
1229
remstr = _remarks->next(offset);
1235
// ----- DbgStrings ------------------------------------------------------------
1237
// Acting as interface to reference counted collection of (debug) strings used
1238
// in the code generated, and thus requiring a fixed address.
1240
DbgStrings::DbgStrings() : _strings(new DbgStringCollection()) {
1241
assert(_strings != nullptr, "Allocation failure!");
1244
DbgStrings::~DbgStrings() {
1245
assert(_strings == nullptr, "Must 'clear()' before deleting!");
1248
const char* DbgStrings::insert(const char* dbgstr) {
1249
const char* str = _strings->lookup(dbgstr);
1250
return str != nullptr ? str : _strings->insert(dbgstr);
1253
bool DbgStrings::is_empty() const {
1254
return _strings->is_empty();
1257
void DbgStrings::share(const DbgStrings &src) {
1258
precond(is_empty());
1260
_strings = src._strings->reuse();
1263
void DbgStrings::clear() {
1264
if (_strings->clear() == 0) {
1270
// ----- AsmRemarkCollection ---------------------------------------------------
1272
const char* AsmRemarkCollection::insert(uint offset, const char* remstr) {
1273
precond(remstr != nullptr);
1274
Cell* cell = new Cell { remstr, offset };
1280
_remarks->push_back(cell);
1282
return cell->string();
1285
const char* AsmRemarkCollection::lookup(uint offset) const {
1287
return next(offset);
1290
const char* AsmRemarkCollection::next(uint offset) const {
1291
if (_next != nullptr) {
1294
if (i->offset == offset) {
1295
_next = i->next == _remarks ? nullptr : i->next;
1299
} while (i != _remarks);
1305
uint AsmRemarkCollection::clear() {
1306
precond(_ref_cnt > 0);
1307
if (--_ref_cnt > 0) {
1314
Cell* next = i->next;
1318
} while (i != _remarks);
1320
log_debug(codestrings)("Clear %u asm-remark%s.", count, count == 1 ? "" : "s");
1323
return 0; // i.e. _ref_cnt == 0
1326
// ----- DbgStringCollection ---------------------------------------------------
1328
const char* DbgStringCollection::insert(const char* dbgstr) {
1329
precond(dbgstr != nullptr);
1330
Cell* cell = new Cell { dbgstr };
1337
_strings->push_back(cell);
1339
return cell->string();
1342
const char* DbgStringCollection::lookup(const char* dbgstr) const {
1343
precond(dbgstr != nullptr);
1344
if (_strings != nullptr) {
1347
if (strcmp(i->string(), dbgstr) == 0) {
1351
} while (i != _strings);
1356
uint DbgStringCollection::clear() {
1357
precond(_ref_cnt > 0);
1358
if (--_ref_cnt > 0) {
1365
Cell* next = i->next;
1369
} while (i != _strings);
1371
log_debug(codestrings)("Clear %u dbg-string%s.", count, count == 1 ? "" : "s");
1374
return 0; // i.e. _ref_cnt == 0
1377
#endif // not PRODUCT