Tue, 18 Dec 2012 10:47:23 -0800
8004536: replace AbstractAssembler emit_word with emit_int16
Reviewed-by: jrose, kvn, twisti
Contributed-by: Morris Meyer <morris.meyer@oracle.com>
1 /*
2 * Copyright (c) 1997, 2012, 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 */
25 #include "precompiled.hpp"
26 #include "asm/codeBuffer.hpp"
27 #include "compiler/disassembler.hpp"
28 #include "memory/gcLocker.hpp"
29 #include "oops/methodData.hpp"
30 #include "oops/oop.inline.hpp"
31 #include "utilities/copy.hpp"
32 #include "utilities/xmlstream.hpp"
34 // The structure of a CodeSection:
35 //
36 // _start -> +----------------+
37 // | machine code...|
38 // _end -> |----------------|
39 // | |
40 // | (empty) |
41 // | |
42 // | |
43 // +----------------+
44 // _limit -> | |
45 //
46 // _locs_start -> +----------------+
47 // |reloc records...|
48 // |----------------|
49 // _locs_end -> | |
50 // | |
51 // | (empty) |
52 // | |
53 // | |
54 // +----------------+
55 // _locs_limit -> | |
56 // The _end (resp. _limit) pointer refers to the first
57 // unused (resp. unallocated) byte.
59 // The structure of the CodeBuffer while code is being accumulated:
60 //
61 // _total_start -> \
62 // _insts._start -> +----------------+
63 // | |
64 // | Code |
65 // | |
66 // _stubs._start -> |----------------|
67 // | |
68 // | Stubs | (also handlers for deopt/exception)
69 // | |
70 // _consts._start -> |----------------|
71 // | |
72 // | Constants |
73 // | |
74 // +----------------+
75 // + _total_size -> | |
76 //
77 // When the code and relocations are copied to the code cache,
78 // the empty parts of each section are removed, and everything
79 // is copied into contiguous locations.
81 typedef CodeBuffer::csize_t csize_t; // file-local definition
83 // External buffer, in a predefined CodeBlob.
84 // Important: The code_start must be taken exactly, and not realigned.
85 CodeBuffer::CodeBuffer(CodeBlob* blob) {
86 initialize_misc("static buffer");
87 initialize(blob->content_begin(), blob->content_size());
88 verify_section_allocation();
89 }
91 void CodeBuffer::initialize(csize_t code_size, csize_t locs_size) {
92 // Compute maximal alignment.
93 int align = _insts.alignment();
94 // Always allow for empty slop around each section.
95 int slop = (int) CodeSection::end_slop();
97 assert(blob() == NULL, "only once");
98 set_blob(BufferBlob::create(_name, code_size + (align+slop) * (SECT_LIMIT+1)));
99 if (blob() == NULL) {
100 // The assembler constructor will throw a fatal on an empty CodeBuffer.
101 return; // caller must test this
102 }
104 // Set up various pointers into the blob.
105 initialize(_total_start, _total_size);
107 assert((uintptr_t)insts_begin() % CodeEntryAlignment == 0, "instruction start not code entry aligned");
109 pd_initialize();
111 if (locs_size != 0) {
112 _insts.initialize_locs(locs_size / sizeof(relocInfo));
113 }
115 verify_section_allocation();
116 }
119 CodeBuffer::~CodeBuffer() {
120 verify_section_allocation();
122 // If we allocate our code buffer from the CodeCache
123 // via a BufferBlob, and it's not permanent, then
124 // free the BufferBlob.
125 // The rest of the memory will be freed when the ResourceObj
126 // is released.
127 for (CodeBuffer* cb = this; cb != NULL; cb = cb->before_expand()) {
128 // Previous incarnations of this buffer are held live, so that internal
129 // addresses constructed before expansions will not be confused.
130 cb->free_blob();
131 }
133 // free any overflow storage
134 delete _overflow_arena;
136 #ifdef ASSERT
137 // Save allocation type to execute assert in ~ResourceObj()
138 // which is called after this destructor.
139 assert(_default_oop_recorder.allocated_on_stack(), "should be embedded object");
140 ResourceObj::allocation_type at = _default_oop_recorder.get_allocation_type();
141 Copy::fill_to_bytes(this, sizeof(*this), badResourceValue);
142 ResourceObj::set_allocation_type((address)(&_default_oop_recorder), at);
143 #endif
144 }
146 void CodeBuffer::initialize_oop_recorder(OopRecorder* r) {
147 assert(_oop_recorder == &_default_oop_recorder && _default_oop_recorder.is_unused(), "do this once");
148 DEBUG_ONLY(_default_oop_recorder.freeze()); // force unused OR to be frozen
149 _oop_recorder = r;
150 }
152 void CodeBuffer::initialize_section_size(CodeSection* cs, csize_t size) {
153 assert(cs != &_insts, "insts is the memory provider, not the consumer");
154 csize_t slop = CodeSection::end_slop(); // margin between sections
155 int align = cs->alignment();
156 assert(is_power_of_2(align), "sanity");
157 address start = _insts._start;
158 address limit = _insts._limit;
159 address middle = limit - size;
160 middle -= (intptr_t)middle & (align-1); // align the division point downward
161 guarantee(middle - slop > start, "need enough space to divide up");
162 _insts._limit = middle - slop; // subtract desired space, plus slop
163 cs->initialize(middle, limit - middle);
164 assert(cs->start() == middle, "sanity");
165 assert(cs->limit() == limit, "sanity");
166 // give it some relocations to start with, if the main section has them
167 if (_insts.has_locs()) cs->initialize_locs(1);
168 }
170 void CodeBuffer::freeze_section(CodeSection* cs) {
171 CodeSection* next_cs = (cs == consts())? NULL: code_section(cs->index()+1);
172 csize_t frozen_size = cs->size();
173 if (next_cs != NULL) {
174 frozen_size = next_cs->align_at_start(frozen_size);
175 }
176 address old_limit = cs->limit();
177 address new_limit = cs->start() + frozen_size;
178 relocInfo* old_locs_limit = cs->locs_limit();
179 relocInfo* new_locs_limit = cs->locs_end();
180 // Patch the limits.
181 cs->_limit = new_limit;
182 cs->_locs_limit = new_locs_limit;
183 cs->_frozen = true;
184 if (!next_cs->is_allocated() && !next_cs->is_frozen()) {
185 // Give remaining buffer space to the following section.
186 next_cs->initialize(new_limit, old_limit - new_limit);
187 next_cs->initialize_shared_locs(new_locs_limit,
188 old_locs_limit - new_locs_limit);
189 }
190 }
192 void CodeBuffer::set_blob(BufferBlob* blob) {
193 _blob = blob;
194 if (blob != NULL) {
195 address start = blob->content_begin();
196 address end = blob->content_end();
197 // Round up the starting address.
198 int align = _insts.alignment();
199 start += (-(intptr_t)start) & (align-1);
200 _total_start = start;
201 _total_size = end - start;
202 } else {
203 #ifdef ASSERT
204 // Clean out dangling pointers.
205 _total_start = badAddress;
206 _consts._start = _consts._end = badAddress;
207 _insts._start = _insts._end = badAddress;
208 _stubs._start = _stubs._end = badAddress;
209 #endif //ASSERT
210 }
211 }
213 void CodeBuffer::free_blob() {
214 if (_blob != NULL) {
215 BufferBlob::free(_blob);
216 set_blob(NULL);
217 }
218 }
220 const char* CodeBuffer::code_section_name(int n) {
221 #ifdef PRODUCT
222 return NULL;
223 #else //PRODUCT
224 switch (n) {
225 case SECT_CONSTS: return "consts";
226 case SECT_INSTS: return "insts";
227 case SECT_STUBS: return "stubs";
228 default: return NULL;
229 }
230 #endif //PRODUCT
231 }
233 int CodeBuffer::section_index_of(address addr) const {
234 for (int n = 0; n < (int)SECT_LIMIT; n++) {
235 const CodeSection* cs = code_section(n);
236 if (cs->allocates(addr)) return n;
237 }
238 return SECT_NONE;
239 }
241 int CodeBuffer::locator(address addr) const {
242 for (int n = 0; n < (int)SECT_LIMIT; n++) {
243 const CodeSection* cs = code_section(n);
244 if (cs->allocates(addr)) {
245 return locator(addr - cs->start(), n);
246 }
247 }
248 return -1;
249 }
251 address CodeBuffer::locator_address(int locator) const {
252 if (locator < 0) return NULL;
253 address start = code_section(locator_sect(locator))->start();
254 return start + locator_pos(locator);
255 }
257 bool CodeBuffer::is_backward_branch(Label& L) {
258 return L.is_bound() && insts_end() <= locator_address(L.loc());
259 }
261 address CodeBuffer::decode_begin() {
262 address begin = _insts.start();
263 if (_decode_begin != NULL && _decode_begin > begin)
264 begin = _decode_begin;
265 return begin;
266 }
269 GrowableArray<int>* CodeBuffer::create_patch_overflow() {
270 if (_overflow_arena == NULL) {
271 _overflow_arena = new (mtCode) Arena();
272 }
273 return new (_overflow_arena) GrowableArray<int>(_overflow_arena, 8, 0, 0);
274 }
277 // Helper function for managing labels and their target addresses.
278 // Returns a sensible address, and if it is not the label's final
279 // address, notes the dependency (at 'branch_pc') on the label.
280 address CodeSection::target(Label& L, address branch_pc) {
281 if (L.is_bound()) {
282 int loc = L.loc();
283 if (index() == CodeBuffer::locator_sect(loc)) {
284 return start() + CodeBuffer::locator_pos(loc);
285 } else {
286 return outer()->locator_address(loc);
287 }
288 } else {
289 assert(allocates2(branch_pc), "sanity");
290 address base = start();
291 int patch_loc = CodeBuffer::locator(branch_pc - base, index());
292 L.add_patch_at(outer(), patch_loc);
294 // Need to return a pc, doesn't matter what it is since it will be
295 // replaced during resolution later.
296 // Don't return NULL or badAddress, since branches shouldn't overflow.
297 // Don't return base either because that could overflow displacements
298 // for shorter branches. It will get checked when bound.
299 return branch_pc;
300 }
301 }
303 void CodeSection::relocate(address at, RelocationHolder const& spec, int format) {
304 Relocation* reloc = spec.reloc();
305 relocInfo::relocType rtype = (relocInfo::relocType) reloc->type();
306 if (rtype == relocInfo::none) return;
308 // The assertion below has been adjusted, to also work for
309 // relocation for fixup. Sometimes we want to put relocation
310 // information for the next instruction, since it will be patched
311 // with a call.
312 assert(start() <= at && at <= end()+1,
313 "cannot relocate data outside code boundaries");
315 if (!has_locs()) {
316 // no space for relocation information provided => code cannot be
317 // relocated. Make sure that relocate is only called with rtypes
318 // that can be ignored for this kind of code.
319 assert(rtype == relocInfo::none ||
320 rtype == relocInfo::runtime_call_type ||
321 rtype == relocInfo::internal_word_type||
322 rtype == relocInfo::section_word_type ||
323 rtype == relocInfo::external_word_type,
324 "code needs relocation information");
325 // leave behind an indication that we attempted a relocation
326 DEBUG_ONLY(_locs_start = _locs_limit = (relocInfo*)badAddress);
327 return;
328 }
330 // Advance the point, noting the offset we'll have to record.
331 csize_t offset = at - locs_point();
332 set_locs_point(at);
334 // Test for a couple of overflow conditions; maybe expand the buffer.
335 relocInfo* end = locs_end();
336 relocInfo* req = end + relocInfo::length_limit;
337 // Check for (potential) overflow
338 if (req >= locs_limit() || offset >= relocInfo::offset_limit()) {
339 req += (uint)offset / (uint)relocInfo::offset_limit();
340 if (req >= locs_limit()) {
341 // Allocate or reallocate.
342 expand_locs(locs_count() + (req - end));
343 // reload pointer
344 end = locs_end();
345 }
346 }
348 // If the offset is giant, emit filler relocs, of type 'none', but
349 // each carrying the largest possible offset, to advance the locs_point.
350 while (offset >= relocInfo::offset_limit()) {
351 assert(end < locs_limit(), "adjust previous paragraph of code");
352 *end++ = filler_relocInfo();
353 offset -= filler_relocInfo().addr_offset();
354 }
356 // If it's a simple reloc with no data, we'll just write (rtype | offset).
357 (*end) = relocInfo(rtype, offset, format);
359 // If it has data, insert the prefix, as (data_prefix_tag | data1), data2.
360 end->initialize(this, reloc);
361 }
363 void CodeSection::initialize_locs(int locs_capacity) {
364 assert(_locs_start == NULL, "only one locs init step, please");
365 // Apply a priori lower limits to relocation size:
366 csize_t min_locs = MAX2(size() / 16, (csize_t)4);
367 if (locs_capacity < min_locs) locs_capacity = min_locs;
368 relocInfo* locs_start = NEW_RESOURCE_ARRAY(relocInfo, locs_capacity);
369 _locs_start = locs_start;
370 _locs_end = locs_start;
371 _locs_limit = locs_start + locs_capacity;
372 _locs_own = true;
373 }
375 void CodeSection::initialize_shared_locs(relocInfo* buf, int length) {
376 assert(_locs_start == NULL, "do this before locs are allocated");
377 // Internal invariant: locs buf must be fully aligned.
378 // See copy_relocations_to() below.
379 while ((uintptr_t)buf % HeapWordSize != 0 && length > 0) {
380 ++buf; --length;
381 }
382 if (length > 0) {
383 _locs_start = buf;
384 _locs_end = buf;
385 _locs_limit = buf + length;
386 _locs_own = false;
387 }
388 }
390 void CodeSection::initialize_locs_from(const CodeSection* source_cs) {
391 int lcount = source_cs->locs_count();
392 if (lcount != 0) {
393 initialize_shared_locs(source_cs->locs_start(), lcount);
394 _locs_end = _locs_limit = _locs_start + lcount;
395 assert(is_allocated(), "must have copied code already");
396 set_locs_point(start() + source_cs->locs_point_off());
397 }
398 assert(this->locs_count() == source_cs->locs_count(), "sanity");
399 }
401 void CodeSection::expand_locs(int new_capacity) {
402 if (_locs_start == NULL) {
403 initialize_locs(new_capacity);
404 return;
405 } else {
406 int old_count = locs_count();
407 int old_capacity = locs_capacity();
408 if (new_capacity < old_capacity * 2)
409 new_capacity = old_capacity * 2;
410 relocInfo* locs_start;
411 if (_locs_own) {
412 locs_start = REALLOC_RESOURCE_ARRAY(relocInfo, _locs_start, old_capacity, new_capacity);
413 } else {
414 locs_start = NEW_RESOURCE_ARRAY(relocInfo, new_capacity);
415 Copy::conjoint_jbytes(_locs_start, locs_start, old_capacity * sizeof(relocInfo));
416 _locs_own = true;
417 }
418 _locs_start = locs_start;
419 _locs_end = locs_start + old_count;
420 _locs_limit = locs_start + new_capacity;
421 }
422 }
425 /// Support for emitting the code to its final location.
426 /// The pattern is the same for all functions.
427 /// We iterate over all the sections, padding each to alignment.
429 csize_t CodeBuffer::total_content_size() const {
430 csize_t size_so_far = 0;
431 for (int n = 0; n < (int)SECT_LIMIT; n++) {
432 const CodeSection* cs = code_section(n);
433 if (cs->is_empty()) continue; // skip trivial section
434 size_so_far = cs->align_at_start(size_so_far);
435 size_so_far += cs->size();
436 }
437 return size_so_far;
438 }
440 void CodeBuffer::compute_final_layout(CodeBuffer* dest) const {
441 address buf = dest->_total_start;
442 csize_t buf_offset = 0;
443 assert(dest->_total_size >= total_content_size(), "must be big enough");
445 {
446 // not sure why this is here, but why not...
447 int alignSize = MAX2((intx) sizeof(jdouble), CodeEntryAlignment);
448 assert( (dest->_total_start - _insts.start()) % alignSize == 0, "copy must preserve alignment");
449 }
451 const CodeSection* prev_cs = NULL;
452 CodeSection* prev_dest_cs = NULL;
454 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
455 // figure compact layout of each section
456 const CodeSection* cs = code_section(n);
457 csize_t csize = cs->size();
459 CodeSection* dest_cs = dest->code_section(n);
460 if (!cs->is_empty()) {
461 // Compute initial padding; assign it to the previous non-empty guy.
462 // Cf. figure_expanded_capacities.
463 csize_t padding = cs->align_at_start(buf_offset) - buf_offset;
464 if (padding != 0) {
465 buf_offset += padding;
466 assert(prev_dest_cs != NULL, "sanity");
467 prev_dest_cs->_limit += padding;
468 }
469 #ifdef ASSERT
470 if (prev_cs != NULL && prev_cs->is_frozen() && n < (SECT_LIMIT - 1)) {
471 // Make sure the ends still match up.
472 // This is important because a branch in a frozen section
473 // might target code in a following section, via a Label,
474 // and without a relocation record. See Label::patch_instructions.
475 address dest_start = buf+buf_offset;
476 csize_t start2start = cs->start() - prev_cs->start();
477 csize_t dest_start2start = dest_start - prev_dest_cs->start();
478 assert(start2start == dest_start2start, "cannot stretch frozen sect");
479 }
480 #endif //ASSERT
481 prev_dest_cs = dest_cs;
482 prev_cs = cs;
483 }
485 debug_only(dest_cs->_start = NULL); // defeat double-initialization assert
486 dest_cs->initialize(buf+buf_offset, csize);
487 dest_cs->set_end(buf+buf_offset+csize);
488 assert(dest_cs->is_allocated(), "must always be allocated");
489 assert(cs->is_empty() == dest_cs->is_empty(), "sanity");
491 buf_offset += csize;
492 }
494 // Done calculating sections; did it come out to the right end?
495 assert(buf_offset == total_content_size(), "sanity");
496 dest->verify_section_allocation();
497 }
499 // Anonymous classes need mirror to keep the metadata alive but
500 // for regular classes, the class_loader is sufficient.
501 static void append_oop_references(GrowableArray<oop>* oops, Klass* k) {
502 if (k->oop_is_instance()) {
503 InstanceKlass* ik = InstanceKlass::cast(k);
504 if (ik->is_anonymous()) {
505 oop o = ik->java_mirror();
506 assert (o != NULL, "should have a mirror");
507 if (!oops->contains(o)) {
508 oops->append(o);
509 }
510 return; // only need the mirror
511 }
512 }
513 oop cl = k->class_loader();
514 if (cl != NULL && !oops->contains(cl)) {
515 oops->append(cl);
516 }
517 }
519 void CodeBuffer::finalize_oop_references(methodHandle mh) {
520 No_Safepoint_Verifier nsv;
522 GrowableArray<oop> oops;
524 // Make sure that immediate metadata records something in the OopRecorder
525 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
526 // pull code out of each section
527 CodeSection* cs = code_section(n);
528 if (cs->is_empty()) continue; // skip trivial section
529 RelocIterator iter(cs);
530 while (iter.next()) {
531 if (iter.type() == relocInfo::metadata_type) {
532 metadata_Relocation* md = iter.metadata_reloc();
533 if (md->metadata_is_immediate()) {
534 Metadata* m = md->metadata_value();
535 if (oop_recorder()->is_real(m)) {
536 if (m->is_methodData()) {
537 m = ((MethodData*)m)->method();
538 }
539 if (m->is_method()) {
540 m = ((Method*)m)->method_holder();
541 }
542 if (m->is_klass()) {
543 append_oop_references(&oops, (Klass*)m);
544 } else {
545 // XXX This will currently occur for MDO which don't
546 // have a backpointer. This has to be fixed later.
547 m->print();
548 ShouldNotReachHere();
549 }
550 }
551 }
552 }
553 }
554 }
556 if (!oop_recorder()->is_unused()) {
557 for (int i = 0; i < oop_recorder()->metadata_count(); i++) {
558 Metadata* m = oop_recorder()->metadata_at(i);
559 if (oop_recorder()->is_real(m)) {
560 if (m->is_methodData()) {
561 m = ((MethodData*)m)->method();
562 }
563 if (m->is_method()) {
564 m = ((Method*)m)->method_holder();
565 }
566 if (m->is_klass()) {
567 append_oop_references(&oops, (Klass*)m);
568 } else {
569 m->print();
570 ShouldNotReachHere();
571 }
572 }
573 }
575 }
577 // Add the class loader of Method* for the nmethod itself
578 append_oop_references(&oops, mh->method_holder());
580 // Add any oops that we've found
581 Thread* thread = Thread::current();
582 for (int i = 0; i < oops.length(); i++) {
583 oop_recorder()->find_index((jobject)thread->handle_area()->allocate_handle(oops.at(i)));
584 }
585 }
589 csize_t CodeBuffer::total_offset_of(CodeSection* cs) const {
590 csize_t size_so_far = 0;
591 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
592 const CodeSection* cur_cs = code_section(n);
593 if (!cur_cs->is_empty()) {
594 size_so_far = cur_cs->align_at_start(size_so_far);
595 }
596 if (cur_cs->index() == cs->index()) {
597 return size_so_far;
598 }
599 size_so_far += cur_cs->size();
600 }
601 ShouldNotReachHere();
602 return -1;
603 }
605 csize_t CodeBuffer::total_relocation_size() const {
606 csize_t lsize = copy_relocations_to(NULL); // dry run only
607 csize_t csize = total_content_size();
608 csize_t total = RelocIterator::locs_and_index_size(csize, lsize);
609 return (csize_t) align_size_up(total, HeapWordSize);
610 }
612 csize_t CodeBuffer::copy_relocations_to(CodeBlob* dest) const {
613 address buf = NULL;
614 csize_t buf_offset = 0;
615 csize_t buf_limit = 0;
616 if (dest != NULL) {
617 buf = (address)dest->relocation_begin();
618 buf_limit = (address)dest->relocation_end() - buf;
619 assert((uintptr_t)buf % HeapWordSize == 0, "buf must be fully aligned");
620 assert(buf_limit % HeapWordSize == 0, "buf must be evenly sized");
621 }
622 // if dest == NULL, this is just the sizing pass
624 csize_t code_end_so_far = 0;
625 csize_t code_point_so_far = 0;
626 for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) {
627 // pull relocs out of each section
628 const CodeSection* cs = code_section(n);
629 assert(!(cs->is_empty() && cs->locs_count() > 0), "sanity");
630 if (cs->is_empty()) continue; // skip trivial section
631 relocInfo* lstart = cs->locs_start();
632 relocInfo* lend = cs->locs_end();
633 csize_t lsize = (csize_t)( (address)lend - (address)lstart );
634 csize_t csize = cs->size();
635 code_end_so_far = cs->align_at_start(code_end_so_far);
637 if (lsize > 0) {
638 // Figure out how to advance the combined relocation point
639 // first to the beginning of this section.
640 // We'll insert one or more filler relocs to span that gap.
641 // (Don't bother to improve this by editing the first reloc's offset.)
642 csize_t new_code_point = code_end_so_far;
643 for (csize_t jump;
644 code_point_so_far < new_code_point;
645 code_point_so_far += jump) {
646 jump = new_code_point - code_point_so_far;
647 relocInfo filler = filler_relocInfo();
648 if (jump >= filler.addr_offset()) {
649 jump = filler.addr_offset();
650 } else { // else shrink the filler to fit
651 filler = relocInfo(relocInfo::none, jump);
652 }
653 if (buf != NULL) {
654 assert(buf_offset + (csize_t)sizeof(filler) <= buf_limit, "filler in bounds");
655 *(relocInfo*)(buf+buf_offset) = filler;
656 }
657 buf_offset += sizeof(filler);
658 }
660 // Update code point and end to skip past this section:
661 csize_t last_code_point = code_end_so_far + cs->locs_point_off();
662 assert(code_point_so_far <= last_code_point, "sanity");
663 code_point_so_far = last_code_point; // advance past this guy's relocs
664 }
665 code_end_so_far += csize; // advance past this guy's instructions too
667 // Done with filler; emit the real relocations:
668 if (buf != NULL && lsize != 0) {
669 assert(buf_offset + lsize <= buf_limit, "target in bounds");
670 assert((uintptr_t)lstart % HeapWordSize == 0, "sane start");
671 if (buf_offset % HeapWordSize == 0) {
672 // Use wordwise copies if possible:
673 Copy::disjoint_words((HeapWord*)lstart,
674 (HeapWord*)(buf+buf_offset),
675 (lsize + HeapWordSize-1) / HeapWordSize);
676 } else {
677 Copy::conjoint_jbytes(lstart, buf+buf_offset, lsize);
678 }
679 }
680 buf_offset += lsize;
681 }
683 // Align end of relocation info in target.
684 while (buf_offset % HeapWordSize != 0) {
685 if (buf != NULL) {
686 relocInfo padding = relocInfo(relocInfo::none, 0);
687 assert(buf_offset + (csize_t)sizeof(padding) <= buf_limit, "padding in bounds");
688 *(relocInfo*)(buf+buf_offset) = padding;
689 }
690 buf_offset += sizeof(relocInfo);
691 }
693 assert(code_end_so_far == total_content_size(), "sanity");
695 // Account for index:
696 if (buf != NULL) {
697 RelocIterator::create_index(dest->relocation_begin(),
698 buf_offset / sizeof(relocInfo),
699 dest->relocation_end());
700 }
702 return buf_offset;
703 }
705 void CodeBuffer::copy_code_to(CodeBlob* dest_blob) {
706 #ifndef PRODUCT
707 if (PrintNMethods && (WizardMode || Verbose)) {
708 tty->print("done with CodeBuffer:");
709 ((CodeBuffer*)this)->print();
710 }
711 #endif //PRODUCT
713 CodeBuffer dest(dest_blob);
714 assert(dest_blob->content_size() >= total_content_size(), "good sizing");
715 this->compute_final_layout(&dest);
716 relocate_code_to(&dest);
718 // transfer comments from buffer to blob
719 dest_blob->set_comments(_comments);
721 // Done moving code bytes; were they the right size?
722 assert(round_to(dest.total_content_size(), oopSize) == dest_blob->content_size(), "sanity");
724 // Flush generated code
725 ICache::invalidate_range(dest_blob->code_begin(), dest_blob->code_size());
726 }
728 // Move all my code into another code buffer. Consult applicable
729 // relocs to repair embedded addresses. The layout in the destination
730 // CodeBuffer is different to the source CodeBuffer: the destination
731 // CodeBuffer gets the final layout (consts, insts, stubs in order of
732 // ascending address).
733 void CodeBuffer::relocate_code_to(CodeBuffer* dest) const {
734 address dest_end = dest->_total_start + dest->_total_size;
735 address dest_filled = NULL;
736 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
737 // pull code out of each section
738 const CodeSection* cs = code_section(n);
739 if (cs->is_empty()) continue; // skip trivial section
740 CodeSection* dest_cs = dest->code_section(n);
741 assert(cs->size() == dest_cs->size(), "sanity");
742 csize_t usize = dest_cs->size();
743 csize_t wsize = align_size_up(usize, HeapWordSize);
744 assert(dest_cs->start() + wsize <= dest_end, "no overflow");
745 // Copy the code as aligned machine words.
746 // This may also include an uninitialized partial word at the end.
747 Copy::disjoint_words((HeapWord*)cs->start(),
748 (HeapWord*)dest_cs->start(),
749 wsize / HeapWordSize);
751 if (dest->blob() == NULL) {
752 // Destination is a final resting place, not just another buffer.
753 // Normalize uninitialized bytes in the final padding.
754 Copy::fill_to_bytes(dest_cs->end(), dest_cs->remaining(),
755 Assembler::code_fill_byte());
756 }
757 // Keep track of the highest filled address
758 dest_filled = MAX2(dest_filled, dest_cs->end() + dest_cs->remaining());
760 assert(cs->locs_start() != (relocInfo*)badAddress,
761 "this section carries no reloc storage, but reloc was attempted");
763 // Make the new code copy use the old copy's relocations:
764 dest_cs->initialize_locs_from(cs);
765 }
767 // Do relocation after all sections are copied.
768 // This is necessary if the code uses constants in stubs, which are
769 // relocated when the corresponding instruction in the code (e.g., a
770 // call) is relocated. Stubs are placed behind the main code
771 // section, so that section has to be copied before relocating.
772 for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) {
773 // pull code out of each section
774 const CodeSection* cs = code_section(n);
775 if (cs->is_empty()) continue; // skip trivial section
776 CodeSection* dest_cs = dest->code_section(n);
777 { // Repair the pc relative information in the code after the move
778 RelocIterator iter(dest_cs);
779 while (iter.next()) {
780 iter.reloc()->fix_relocation_after_move(this, dest);
781 }
782 }
783 }
785 if (dest->blob() == NULL && dest_filled != NULL) {
786 // Destination is a final resting place, not just another buffer.
787 // Normalize uninitialized bytes in the final padding.
788 Copy::fill_to_bytes(dest_filled, dest_end - dest_filled,
789 Assembler::code_fill_byte());
791 }
792 }
794 csize_t CodeBuffer::figure_expanded_capacities(CodeSection* which_cs,
795 csize_t amount,
796 csize_t* new_capacity) {
797 csize_t new_total_cap = 0;
799 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
800 const CodeSection* sect = code_section(n);
802 if (!sect->is_empty()) {
803 // Compute initial padding; assign it to the previous section,
804 // even if it's empty (e.g. consts section can be empty).
805 // Cf. compute_final_layout
806 csize_t padding = sect->align_at_start(new_total_cap) - new_total_cap;
807 if (padding != 0) {
808 new_total_cap += padding;
809 assert(n - 1 >= SECT_FIRST, "sanity");
810 new_capacity[n - 1] += padding;
811 }
812 }
814 csize_t exp = sect->size(); // 100% increase
815 if ((uint)exp < 4*K) exp = 4*K; // minimum initial increase
816 if (sect == which_cs) {
817 if (exp < amount) exp = amount;
818 if (StressCodeBuffers) exp = amount; // expand only slightly
819 } else if (n == SECT_INSTS) {
820 // scale down inst increases to a more modest 25%
821 exp = 4*K + ((exp - 4*K) >> 2);
822 if (StressCodeBuffers) exp = amount / 2; // expand only slightly
823 } else if (sect->is_empty()) {
824 // do not grow an empty secondary section
825 exp = 0;
826 }
827 // Allow for inter-section slop:
828 exp += CodeSection::end_slop();
829 csize_t new_cap = sect->size() + exp;
830 if (new_cap < sect->capacity()) {
831 // No need to expand after all.
832 new_cap = sect->capacity();
833 }
834 new_capacity[n] = new_cap;
835 new_total_cap += new_cap;
836 }
838 return new_total_cap;
839 }
841 void CodeBuffer::expand(CodeSection* which_cs, csize_t amount) {
842 #ifndef PRODUCT
843 if (PrintNMethods && (WizardMode || Verbose)) {
844 tty->print("expanding CodeBuffer:");
845 this->print();
846 }
848 if (StressCodeBuffers && blob() != NULL) {
849 static int expand_count = 0;
850 if (expand_count >= 0) expand_count += 1;
851 if (expand_count > 100 && is_power_of_2(expand_count)) {
852 tty->print_cr("StressCodeBuffers: have expanded %d times", expand_count);
853 // simulate an occasional allocation failure:
854 free_blob();
855 }
856 }
857 #endif //PRODUCT
859 // Resizing must be allowed
860 {
861 if (blob() == NULL) return; // caller must check for blob == NULL
862 for (int n = 0; n < (int)SECT_LIMIT; n++) {
863 guarantee(!code_section(n)->is_frozen(), "resizing not allowed when frozen");
864 }
865 }
867 // Figure new capacity for each section.
868 csize_t new_capacity[SECT_LIMIT];
869 csize_t new_total_cap
870 = figure_expanded_capacities(which_cs, amount, new_capacity);
872 // Create a new (temporary) code buffer to hold all the new data
873 CodeBuffer cb(name(), new_total_cap, 0);
874 if (cb.blob() == NULL) {
875 // Failed to allocate in code cache.
876 free_blob();
877 return;
878 }
880 // Create an old code buffer to remember which addresses used to go where.
881 // This will be useful when we do final assembly into the code cache,
882 // because we will need to know how to warp any internal address that
883 // has been created at any time in this CodeBuffer's past.
884 CodeBuffer* bxp = new CodeBuffer(_total_start, _total_size);
885 bxp->take_over_code_from(this); // remember the old undersized blob
886 DEBUG_ONLY(this->_blob = NULL); // silence a later assert
887 bxp->_before_expand = this->_before_expand;
888 this->_before_expand = bxp;
890 // Give each section its required (expanded) capacity.
891 for (int n = (int)SECT_LIMIT-1; n >= SECT_FIRST; n--) {
892 CodeSection* cb_sect = cb.code_section(n);
893 CodeSection* this_sect = code_section(n);
894 if (new_capacity[n] == 0) continue; // already nulled out
895 if (n != SECT_INSTS) {
896 cb.initialize_section_size(cb_sect, new_capacity[n]);
897 }
898 assert(cb_sect->capacity() >= new_capacity[n], "big enough");
899 address cb_start = cb_sect->start();
900 cb_sect->set_end(cb_start + this_sect->size());
901 if (this_sect->mark() == NULL) {
902 cb_sect->clear_mark();
903 } else {
904 cb_sect->set_mark(cb_start + this_sect->mark_off());
905 }
906 }
908 // Move all the code and relocations to the new blob:
909 relocate_code_to(&cb);
911 // Copy the temporary code buffer into the current code buffer.
912 // Basically, do {*this = cb}, except for some control information.
913 this->take_over_code_from(&cb);
914 cb.set_blob(NULL);
916 // Zap the old code buffer contents, to avoid mistakenly using them.
917 debug_only(Copy::fill_to_bytes(bxp->_total_start, bxp->_total_size,
918 badCodeHeapFreeVal));
920 _decode_begin = NULL; // sanity
922 // Make certain that the new sections are all snugly inside the new blob.
923 verify_section_allocation();
925 #ifndef PRODUCT
926 if (PrintNMethods && (WizardMode || Verbose)) {
927 tty->print("expanded CodeBuffer:");
928 this->print();
929 }
930 #endif //PRODUCT
931 }
933 void CodeBuffer::take_over_code_from(CodeBuffer* cb) {
934 // Must already have disposed of the old blob somehow.
935 assert(blob() == NULL, "must be empty");
936 #ifdef ASSERT
938 #endif
939 // Take the new blob away from cb.
940 set_blob(cb->blob());
941 // Take over all the section pointers.
942 for (int n = 0; n < (int)SECT_LIMIT; n++) {
943 CodeSection* cb_sect = cb->code_section(n);
944 CodeSection* this_sect = code_section(n);
945 this_sect->take_over_code_from(cb_sect);
946 }
947 _overflow_arena = cb->_overflow_arena;
948 // Make sure the old cb won't try to use it or free it.
949 DEBUG_ONLY(cb->_blob = (BufferBlob*)badAddress);
950 }
952 void CodeBuffer::verify_section_allocation() {
953 address tstart = _total_start;
954 if (tstart == badAddress) return; // smashed by set_blob(NULL)
955 address tend = tstart + _total_size;
956 if (_blob != NULL) {
958 guarantee(tstart >= _blob->content_begin(), "sanity");
959 guarantee(tend <= _blob->content_end(), "sanity");
960 }
961 // Verify disjointness.
962 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
963 CodeSection* sect = code_section(n);
964 if (!sect->is_allocated() || sect->is_empty()) continue;
965 guarantee((intptr_t)sect->start() % sect->alignment() == 0
966 || sect->is_empty() || _blob == NULL,
967 "start is aligned");
968 for (int m = (int) SECT_FIRST; m < (int) SECT_LIMIT; m++) {
969 CodeSection* other = code_section(m);
970 if (!other->is_allocated() || other == sect) continue;
971 guarantee(!other->contains(sect->start() ), "sanity");
972 // limit is an exclusive address and can be the start of another
973 // section.
974 guarantee(!other->contains(sect->limit() - 1), "sanity");
975 }
976 guarantee(sect->end() <= tend, "sanity");
977 guarantee(sect->end() <= sect->limit(), "sanity");
978 }
979 }
981 void CodeBuffer::log_section_sizes(const char* name) {
982 if (xtty != NULL) {
983 // log info about buffer usage
984 xtty->print_cr("<blob name='%s' size='%d'>", name, _total_size);
985 for (int n = (int) CodeBuffer::SECT_FIRST; n < (int) CodeBuffer::SECT_LIMIT; n++) {
986 CodeSection* sect = code_section(n);
987 if (!sect->is_allocated() || sect->is_empty()) continue;
988 xtty->print_cr("<sect index='%d' size='" SIZE_FORMAT "' free='" SIZE_FORMAT "'/>",
989 n, sect->limit() - sect->start(), sect->limit() - sect->end());
990 }
991 xtty->print_cr("</blob>");
992 }
993 }
995 #ifndef PRODUCT
997 void CodeSection::dump() {
998 address ptr = start();
999 for (csize_t step; ptr < end(); ptr += step) {
1000 step = end() - ptr;
1001 if (step > jintSize * 4) step = jintSize * 4;
1002 tty->print(PTR_FORMAT ": ", ptr);
1003 while (step > 0) {
1004 tty->print(" " PTR32_FORMAT, *(jint*)ptr);
1005 ptr += jintSize;
1006 }
1007 tty->cr();
1008 }
1009 }
1012 void CodeSection::decode() {
1013 Disassembler::decode(start(), end());
1014 }
1017 void CodeBuffer::block_comment(intptr_t offset, const char * comment) {
1018 _comments.add_comment(offset, comment);
1019 }
1021 class CodeComment: public CHeapObj<mtCode> {
1022 private:
1023 friend class CodeComments;
1024 intptr_t _offset;
1025 const char * _comment;
1026 CodeComment* _next;
1028 ~CodeComment() {
1029 assert(_next == NULL, "wrong interface for freeing list");
1030 os::free((void*)_comment, mtCode);
1031 }
1033 public:
1034 CodeComment(intptr_t offset, const char * comment) {
1035 _offset = offset;
1036 _comment = os::strdup(comment, mtCode);
1037 _next = NULL;
1038 }
1040 intptr_t offset() const { return _offset; }
1041 const char * comment() const { return _comment; }
1042 CodeComment* next() { return _next; }
1044 void set_next(CodeComment* next) { _next = next; }
1046 CodeComment* find(intptr_t offset) {
1047 CodeComment* a = this;
1048 while (a != NULL && a->_offset != offset) {
1049 a = a->_next;
1050 }
1051 return a;
1052 }
1054 // Convenience for add_comment.
1055 CodeComment* find_last(intptr_t offset) {
1056 CodeComment* a = find(offset);
1057 if (a != NULL) {
1058 while ((a->_next != NULL) && (a->_next->_offset == offset)) {
1059 a = a->_next;
1060 }
1061 }
1062 return a;
1063 }
1064 };
1067 void CodeComments::add_comment(intptr_t offset, const char * comment) {
1068 CodeComment* c = new CodeComment(offset, comment);
1069 CodeComment* inspos = (_comments == NULL) ? NULL : _comments->find_last(offset);
1071 if (inspos) {
1072 // insert after already existing comments with same offset
1073 c->set_next(inspos->next());
1074 inspos->set_next(c);
1075 } else {
1076 // no comments with such offset, yet. Insert before anything else.
1077 c->set_next(_comments);
1078 _comments = c;
1079 }
1080 }
1083 void CodeComments::assign(CodeComments& other) {
1084 _comments = other._comments;
1085 }
1088 void CodeComments::print_block_comment(outputStream* stream, intptr_t offset) const {
1089 if (_comments != NULL) {
1090 CodeComment* c = _comments->find(offset);
1091 while (c && c->offset() == offset) {
1092 stream->bol();
1093 stream->print(" ;; ");
1094 stream->print_cr(c->comment());
1095 c = c->next();
1096 }
1097 }
1098 }
1101 void CodeComments::free() {
1102 CodeComment* n = _comments;
1103 while (n) {
1104 // unlink the node from the list saving a pointer to the next
1105 CodeComment* p = n->_next;
1106 n->_next = NULL;
1107 delete n;
1108 n = p;
1109 }
1110 _comments = NULL;
1111 }
1115 void CodeBuffer::decode() {
1116 ttyLocker ttyl;
1117 Disassembler::decode(decode_begin(), insts_end());
1118 _decode_begin = insts_end();
1119 }
1122 void CodeBuffer::skip_decode() {
1123 _decode_begin = insts_end();
1124 }
1127 void CodeBuffer::decode_all() {
1128 ttyLocker ttyl;
1129 for (int n = 0; n < (int)SECT_LIMIT; n++) {
1130 // dump contents of each section
1131 CodeSection* cs = code_section(n);
1132 tty->print_cr("! %s:", code_section_name(n));
1133 if (cs != consts())
1134 cs->decode();
1135 else
1136 cs->dump();
1137 }
1138 }
1141 void CodeSection::print(const char* name) {
1142 csize_t locs_size = locs_end() - locs_start();
1143 tty->print_cr(" %7s.code = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d)%s",
1144 name, start(), end(), limit(), size(), capacity(),
1145 is_frozen()? " [frozen]": "");
1146 tty->print_cr(" %7s.locs = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d) point=%d",
1147 name, locs_start(), locs_end(), locs_limit(), locs_size, locs_capacity(), locs_point_off());
1148 if (PrintRelocations) {
1149 RelocIterator iter(this);
1150 iter.print();
1151 }
1152 }
1154 void CodeBuffer::print() {
1155 if (this == NULL) {
1156 tty->print_cr("NULL CodeBuffer pointer");
1157 return;
1158 }
1160 tty->print_cr("CodeBuffer:");
1161 for (int n = 0; n < (int)SECT_LIMIT; n++) {
1162 // print each section
1163 CodeSection* cs = code_section(n);
1164 cs->print(code_section_name(n));
1165 }
1166 }
1168 #endif // PRODUCT