1 /*
2 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_ASM_CODEBUFFER_HPP
26 #define SHARE_ASM_CODEBUFFER_HPP
27
28 #include "code/oopRecorder.hpp"
29 #include "code/relocInfo.hpp"
30 #include "compiler/compiler_globals.hpp"
31 #include "runtime/os.hpp"
32 #include "utilities/align.hpp"
33 #include "utilities/debug.hpp"
34 #include "utilities/growableArray.hpp"
35 #include "utilities/linkedlist.hpp"
36 #include "utilities/resizeableResourceHash.hpp"
37 #include "utilities/macros.hpp"
38
39 template <typename T>
40 static inline void put_native(address p, T x) {
41 memcpy((void*)p, &x, sizeof x);
42 }
43
44 class PhaseCFG;
45 class Compile;
46 class BufferBlob;
47 class CodeBuffer;
48 class Label;
49 class ciMethod;
50 class SharedStubToInterpRequest;
51
52 class CodeOffsets: public StackObj {
53 public:
54 enum Entries { Entry,
55 Verified_Entry,
56 Inline_Entry,
57 Verified_Inline_Entry,
58 Verified_Inline_Entry_RO,
59 Frame_Complete, // Offset in the code where the frame setup is (for forte stackwalks) is complete
60 OSR_Entry,
61 Exceptions, // Offset where exception handler lives
62 Deopt, // Offset where deopt handler lives
63 DeoptMH, // Offset where MethodHandle deopt handler lives
64 UnwindHandler, // Offset to default unwind handler
65 max_Entries };
66
67 // special value to note codeBlobs where profile (forte) stack walking is
68 // always dangerous and suspect.
69
70 enum { frame_never_safe = -1 };
71
72 private:
73 int _values[max_Entries];
74 void check(int e) const { assert(0 <= e && e < max_Entries, "must be"); }
75
76 public:
77 CodeOffsets() {
78 _values[Entry ] = 0;
79 _values[Verified_Entry] = 0;
80 _values[Inline_Entry ] = 0;
81 _values[Verified_Inline_Entry] = -1;
82 _values[Verified_Inline_Entry_RO] = -1;
83 _values[Frame_Complete] = frame_never_safe;
84 _values[OSR_Entry ] = 0;
85 _values[Exceptions ] = -1;
86 _values[Deopt ] = -1;
87 _values[DeoptMH ] = -1;
88 _values[UnwindHandler ] = -1;
89 }
90
91 int value(Entries e) const { check(e); return _values[e]; }
92 void set_value(Entries e, int val) { check(e); _values[e] = val; }
93 };
94
95 // This class represents a stream of code and associated relocations.
96 // There are a few in each CodeBuffer.
97 // They are filled concurrently, and concatenated at the end.
98 class CodeSection {
99 friend class CodeBuffer;
100 friend class AOTCodeReader;
101 public:
102 typedef int csize_t; // code size type; would be size_t except for history
103
104 private:
105 address _start; // first byte of contents (instructions)
106 address _mark; // user mark, usually an instruction beginning
107 address _end; // current end address
108 address _limit; // last possible (allocated) end address
109 relocInfo* _locs_start; // first byte of relocation information
110 relocInfo* _locs_end; // first byte after relocation information
111 relocInfo* _locs_limit; // first byte after relocation information buf
112 address _locs_point; // last relocated position (grows upward)
113 bool _locs_own; // did I allocate the locs myself?
114 bool _scratch_emit; // Buffer is used for scratch emit, don't relocate.
115 int _skipped_instructions_size;
116 int8_t _index; // my section number (SECT_INST, etc.)
117 CodeBuffer* _outer; // enclosing CodeBuffer
118
119 // (Note: _locs_point used to be called _last_reloc_offset.)
120
121 CodeSection() {
122 _start = nullptr;
123 _mark = nullptr;
124 _end = nullptr;
125 _limit = nullptr;
126 _locs_start = nullptr;
127 _locs_end = nullptr;
128 _locs_limit = nullptr;
129 _locs_point = nullptr;
130 _locs_own = false;
131 _scratch_emit = false;
132 _skipped_instructions_size = 0;
133 DEBUG_ONLY(_index = -1);
134 DEBUG_ONLY(_outer = (CodeBuffer*)badAddress);
135 }
136
137 void initialize_outer(CodeBuffer* outer, int8_t index) {
138 _outer = outer;
139 _index = index;
140 }
141
142 void initialize(address start, csize_t size = 0) {
143 assert(_start == nullptr, "only one init step, please");
144 _start = start;
145 _mark = nullptr;
146 _end = start;
147
148 _limit = start + size;
149 _locs_point = start;
150 }
151
152 void initialize_locs(int locs_capacity);
153 void expand_locs(int new_capacity);
154 void initialize_locs_from(const CodeSection* source_cs);
155
156 // helper for CodeBuffer::expand()
157 void take_over_code_from(CodeSection* cs) {
158 _start = cs->_start;
159 _mark = cs->_mark;
160 _end = cs->_end;
161 _limit = cs->_limit;
162 _locs_point = cs->_locs_point;
163 _skipped_instructions_size = cs->_skipped_instructions_size;
164 }
165
166 public:
167 address start() const { return _start; }
168 address mark() const { return _mark; }
169 address end() const { return _end; }
170 address limit() const { return _limit; }
171 csize_t size() const { return (csize_t)(_end - _start); }
172 csize_t mark_off() const { assert(_mark != nullptr, "not an offset");
173 return (csize_t)(_mark - _start); }
174 csize_t capacity() const { return (csize_t)(_limit - _start); }
175 csize_t remaining() const { return (csize_t)(_limit - _end); }
176
177 relocInfo* locs_start() const { return _locs_start; }
178 relocInfo* locs_end() const { return _locs_end; }
179 int locs_count() const { return (int)(_locs_end - _locs_start); }
180 relocInfo* locs_limit() const { return _locs_limit; }
181 address locs_point() const { return _locs_point; }
182 csize_t locs_point_off() const{ return (csize_t)(_locs_point - _start); }
183 csize_t locs_capacity() const { return (csize_t)(_locs_limit - _locs_start); }
184
185 int8_t index() const { return _index; }
186 bool is_allocated() const { return _start != nullptr; }
187 bool is_empty() const { return _start == _end; }
188 bool has_locs() const { return _locs_end != nullptr; }
189
190 // Mark scratch buffer.
191 void set_scratch_emit() { _scratch_emit = true; }
192 void clear_scratch_emit() { _scratch_emit = false; }
193 bool scratch_emit() { return _scratch_emit; }
194
195 CodeBuffer* outer() const { return _outer; }
196
197 // is a given address in this section? (2nd version is end-inclusive)
198 bool contains(address pc) const { return pc >= _start && pc < _end; }
199 bool contains2(address pc) const { return pc >= _start && pc <= _end; }
200 bool allocates(address pc) const { return pc >= _start && pc < _limit; }
201 bool allocates2(address pc) const { return pc >= _start && pc <= _limit; }
202
203 // checks if two CodeSections are disjoint
204 //
205 // limit is an exclusive address and can be the start of another
206 // section.
207 bool disjoint(CodeSection* cs) const { return cs->_limit <= _start || cs->_start >= _limit; }
208
209 void set_end(address pc) { assert(allocates2(pc), "not in CodeBuffer memory: " INTPTR_FORMAT " <= " INTPTR_FORMAT " <= " INTPTR_FORMAT, p2i(_start), p2i(pc), p2i(_limit)); _end = pc; }
210 void set_mark(address pc) { assert(contains2(pc), "not in codeBuffer");
211 _mark = pc; }
212 void set_mark() { _mark = _end; }
213 void clear_mark() { _mark = nullptr; }
214
215 void set_locs_end(relocInfo* p) {
216 assert(p <= locs_limit(), "locs data fits in allocated buffer");
217 _locs_end = p;
218 }
219 void set_locs_point(address pc) {
220 assert(pc >= locs_point(), "relocation addr may not decrease");
221 assert(allocates2(pc), "relocation addr " INTPTR_FORMAT " must be in this section from " INTPTR_FORMAT " to " INTPTR_FORMAT, p2i(pc), p2i(_start), p2i(_limit));
222 _locs_point = pc;
223 }
224
225 void register_skipped(int size) {
226 _skipped_instructions_size += size;
227 }
228
229 // Code emission
230 void emit_int8(uint8_t x1) {
231 address curr = end();
232 *((uint8_t*) curr++) = x1;
233 set_end(curr);
234 }
235
236 template <typename T>
237 void emit_native(T x) { put_native(end(), x); set_end(end() + sizeof x); }
238
239 void emit_int16(uint16_t x) { emit_native(x); }
240 void emit_int16(uint8_t x1, uint8_t x2) {
241 address curr = end();
242 *((uint8_t*) curr++) = x1;
243 *((uint8_t*) curr++) = x2;
244 set_end(curr);
245 }
246
247 void emit_int24(uint8_t x1, uint8_t x2, uint8_t x3) {
248 address curr = end();
249 *((uint8_t*) curr++) = x1;
250 *((uint8_t*) curr++) = x2;
251 *((uint8_t*) curr++) = x3;
252 set_end(curr);
253 }
254
255 void emit_int32(uint32_t x) { emit_native(x); }
256 void emit_int32(uint8_t x1, uint8_t x2, uint8_t x3, uint8_t x4) {
257 address curr = end();
258 *((uint8_t*) curr++) = x1;
259 *((uint8_t*) curr++) = x2;
260 *((uint8_t*) curr++) = x3;
261 *((uint8_t*) curr++) = x4;
262 set_end(curr);
263 }
264
265 void emit_int64(uint64_t x) { emit_native(x); }
266 void emit_float(jfloat x) { emit_native(x); }
267 void emit_double(jdouble x) { emit_native(x); }
268 void emit_address(address x) { emit_native(x); }
269
270 // Share a scratch buffer for relocinfo. (Hacky; saves a resource allocation.)
271 void initialize_shared_locs(relocInfo* buf, int length);
272
273 // Manage labels and their addresses.
274 address target(Label& L, address branch_pc);
275
276 // Emit a relocation.
277 void relocate(address at, RelocationHolder const& rspec, int format = 0);
278 void relocate(address at, relocInfo::relocType rtype, int format = 0, jint method_index = 0);
279
280 int alignment() const;
281
282 // Slop between sections, used only when allocating temporary BufferBlob buffers.
283 static csize_t end_slop() { return MAX2((int)sizeof(jdouble), (int)CodeEntryAlignment); }
284
285 csize_t align_at_start(csize_t off) const {
286 return (csize_t) align_up(off, alignment());
287 }
288
289 // Ensure there's enough space left in the current section.
290 // Return true if there was an expansion.
291 bool maybe_expand_to_ensure_remaining(csize_t amount);
292
293 #ifndef PRODUCT
294 void decode();
295 void print_on(outputStream* st, const char* name);
296 #endif //PRODUCT
297 };
298
299
300 #ifndef PRODUCT
301
302 // ----- CHeapString -----------------------------------------------------------
303
304 class CHeapString : public CHeapObj<mtCode> {
305 public:
306 CHeapString(const char* str) : _string(os::strdup(str)) {}
307 ~CHeapString();
308 const char* string() const { return _string; }
309
310 private:
311 const char* _string;
312 };
313
314 // ----- AsmRemarkCollection ---------------------------------------------------
315
316 class AsmRemarkCollection : public CHeapObj<mtCode> {
317 public:
318 AsmRemarkCollection() : _ref_cnt(1), _remarks(nullptr), _next(nullptr) {}
319 ~AsmRemarkCollection() {
320 assert(is_empty(), "Must 'clear()' before deleting!");
321 assert(_ref_cnt == 0, "No uses must remain when deleting!");
322 }
323 AsmRemarkCollection* reuse() {
324 precond(_ref_cnt > 0);
325 return _ref_cnt++, this;
326 }
327
328 const char* insert(uint offset, const char* remark);
329 const char* lookup(uint offset) const;
330 const char* next(uint offset) const;
331
332 bool is_empty() const { return _remarks == nullptr; }
333 uint clear();
334
335 template<typename Function>
336 bool iterate(Function function) const { // lambda enabled API
337 if (_remarks != nullptr) {
338 Cell* tmp = _remarks;
339 do {
340 if(!function(tmp->offset, tmp->string())) {
341 return false;
342 }
343 tmp = tmp->next;
344 } while (tmp != _remarks);
345 }
346 return true;
347 }
348
349 private:
350 struct Cell : CHeapString {
351 Cell(const char* remark, uint offset) :
352 CHeapString(remark), offset(offset), prev(nullptr), next(nullptr) {}
353 void push_back(Cell* cell) {
354 Cell* head = this;
355 Cell* tail = prev;
356 tail->next = cell;
357 cell->next = head;
358 cell->prev = tail;
359 prev = cell;
360 }
361 uint offset;
362 Cell* prev;
363 Cell* next;
364 };
365 uint _ref_cnt;
366 Cell* _remarks;
367 // Using a 'mutable' iteration pointer to allow 'const' on lookup/next (that
368 // does not change the state of the list per se), supportig a simplistic
369 // iteration scheme.
370 mutable Cell* _next;
371 };
372
373 // ----- DbgStringCollection ---------------------------------------------------
374
375 class DbgStringCollection : public CHeapObj<mtCode> {
376 public:
377 DbgStringCollection() : _ref_cnt(1), _strings(nullptr) {}
378 ~DbgStringCollection() {
379 assert(is_empty(), "Must 'clear()' before deleting!");
380 assert(_ref_cnt == 0, "No uses must remain when deleting!");
381 }
382 DbgStringCollection* reuse() {
383 precond(_ref_cnt > 0);
384 return _ref_cnt++, this;
385 }
386
387 const char* insert(const char* str);
388 const char* lookup(const char* str) const;
389
390 bool is_empty() const { return _strings == nullptr; }
391 uint clear();
392
393 template<typename Function>
394 bool iterate(Function function) const { // lambda enabled API
395 if (_strings != nullptr) {
396 Cell* tmp = _strings;
397 do {
398 if (!function(tmp->string())) {
399 return false;
400 }
401 tmp = tmp->next;
402 } while (tmp != _strings);
403 }
404 return true;
405 }
406
407 private:
408 struct Cell : CHeapString {
409 Cell(const char* dbgstr) :
410 CHeapString(dbgstr), prev(nullptr), next(nullptr) {}
411 void push_back(Cell* cell) {
412 Cell* head = this;
413 Cell* tail = prev;
414 tail->next = cell;
415 cell->next = head;
416 cell->prev = tail;
417 prev = cell;
418 }
419 Cell* prev;
420 Cell* next;
421 };
422 uint _ref_cnt;
423 Cell* _strings;
424 };
425
426 // The assumption made here is that most code remarks (or comments) added to
427 // the generated assembly code are unique, i.e. there is very little gain in
428 // trying to share the strings between the different offsets tracked in a
429 // buffer (or blob).
430
431 class AsmRemarks {
432 public:
433 AsmRemarks();
434 ~AsmRemarks();
435
436 void init();
437
438 const char* insert(uint offset, const char* remstr);
439
440 bool is_empty() const;
441
442 void share(const AsmRemarks &src);
443 void clear();
444 uint print(uint offset, outputStream* strm = tty) const;
445
446 // For testing purposes only.
447 const AsmRemarkCollection* ref() const { return _remarks; }
448
449 template<typename Function>
450 inline bool iterate(Function function) const { return _remarks->iterate(function); }
451
452 private:
453 AsmRemarkCollection* _remarks;
454 };
455
456 // The assumption made here is that the number of debug strings (with a fixed
457 // address requirement) is a rather small set per compilation unit.
458
459 class DbgStrings {
460 public:
461 DbgStrings();
462 ~DbgStrings();
463
464 void init();
465
466 const char* insert(const char* dbgstr);
467
468 bool is_empty() const;
469
470 void share(const DbgStrings &src);
471 void clear();
472
473 // For testing purposes only.
474 const DbgStringCollection* ref() const { return _strings; }
475
476 template<typename Function>
477 bool iterate(Function function) const { return _strings->iterate(function); }
478
479 private:
480 DbgStringCollection* _strings;
481 };
482 #endif // not PRODUCT
483
484
485 #ifdef ASSERT
486 #include "utilities/copy.hpp"
487
488 class Scrubber {
489 public:
490 Scrubber(void* addr, size_t size) : _addr(addr), _size(size) {}
491 ~Scrubber() {
492 Copy::fill_to_bytes(_addr, _size, badResourceValue);
493 }
494 private:
495 void* _addr;
496 size_t _size;
497 };
498 #endif // ASSERT
499
500 typedef GrowableArray<SharedStubToInterpRequest> SharedStubToInterpRequests;
501
502 // A CodeBuffer describes a memory space into which assembly
503 // code is generated. This memory space usually occupies the
504 // interior of a single BufferBlob, but in some cases it may be
505 // an arbitrary span of memory, even outside the code cache.
506 //
507 // A code buffer comes in two variants:
508 //
509 // (1) A CodeBuffer referring to an already allocated piece of memory:
510 // This is used to direct 'static' code generation (e.g. for interpreter
511 // or stubroutine generation, etc.). This code comes with NO relocation
512 // information.
513 //
514 // (2) A CodeBuffer referring to a piece of memory allocated when the
515 // CodeBuffer is allocated. This is used for nmethod generation.
516 //
517 // The memory can be divided up into several parts called sections.
518 // Each section independently accumulates code (or data) an relocations.
519 // Sections can grow (at the expense of a reallocation of the BufferBlob
520 // and recopying of all active sections). When the buffered code is finally
521 // written to an nmethod (or other CodeBlob), the contents (code, data,
522 // and relocations) of the sections are padded to an alignment and concatenated.
523 // Instructions and data in one section can contain relocatable references to
524 // addresses in a sibling section.
525
526 class CodeBuffer: public StackObj DEBUG_ONLY(COMMA private Scrubber) {
527 friend class CodeSection;
528 friend class StubCodeGenerator;
529 friend class AOTCodeReader;
530
531 private:
532 // CodeBuffers must be allocated on the stack except for a single
533 // special case during expansion which is handled internally. This
534 // is done to guarantee proper cleanup of resources.
535 void* operator new(size_t size) throw() { return resource_allocate_bytes(size); }
536 void operator delete(void* p) { ShouldNotCallThis(); }
537
538 public:
539 typedef int csize_t; // code size type; would be size_t except for history
540 enum : int8_t {
541 // Here is the list of all possible sections. The order reflects
542 // the final layout.
543 SECT_FIRST = 0,
544 SECT_CONSTS = SECT_FIRST, // Non-instruction data: Floats, jump tables, etc.
545 SECT_INSTS, // Executable instructions.
546 SECT_STUBS, // Outbound trampolines for supporting call sites.
547 SECT_LIMIT, SECT_NONE = -1
548 };
549
550 typedef LinkedListImpl<int> Offsets;
551 typedef ResizeableResourceHashtable<address, Offsets, AnyObj::C_HEAP, mtCompiler> SharedTrampolineRequests;
552
553 private:
554 enum {
555 sect_bits = 2, // assert (SECT_LIMIT <= (1<<sect_bits))
556 sect_mask = (1<<sect_bits)-1
557 };
558
559 const char* _name;
560
561 CodeSection _consts; // constants, jump tables
562 CodeSection _insts; // instructions (the main section)
563 CodeSection _stubs; // stubs (call site support), deopt, exception handling
564
565 CodeBuffer* _before_expand; // dead buffer, from before the last expansion
566
567 BufferBlob* _blob; // optional buffer in CodeCache for generated code
568 address _total_start; // first address of combined memory buffer
569 csize_t _total_size; // size in bytes of combined memory buffer
570
571 OopRecorder* _oop_recorder;
572
573 OopRecorder _default_oop_recorder; // override with initialize_oop_recorder
574 Arena* _overflow_arena;
575
576 address _last_insn; // used to merge consecutive memory barriers, loads or stores.
577 address _last_label; // record last bind label address, it's also the start of current bb.
578
579 SharedStubToInterpRequests* _shared_stub_to_interp_requests; // used to collect requests for shared iterpreter stubs
580 SharedTrampolineRequests* _shared_trampoline_requests; // used to collect requests for shared trampolines
581 bool _finalize_stubs; // Indicate if we need to finalize stubs to make CodeBuffer final.
582
583 int _const_section_alignment;
584
585 #ifndef PRODUCT
586 AsmRemarks _asm_remarks;
587 DbgStrings _dbg_strings;
588 bool _collect_comments; // Indicate if we need to collect block comments at all.
589 address _decode_begin; // start address for decode
590 address decode_begin();
591 #endif
592
593 void initialize_misc(const char * name) {
594 // all pointers other than code_start/end and those inside the sections
595 assert(name != nullptr, "must have a name");
596 _name = name;
597 _before_expand = nullptr;
598 _blob = nullptr;
599 _total_start = nullptr;
600 _total_size = 0;
601 _oop_recorder = nullptr;
602 _overflow_arena = nullptr;
603 _last_insn = nullptr;
604 _last_label = nullptr;
605 _finalize_stubs = false;
606 _shared_stub_to_interp_requests = nullptr;
607 _shared_trampoline_requests = nullptr;
608
609 _consts.initialize_outer(this, SECT_CONSTS);
610 _insts.initialize_outer(this, SECT_INSTS);
611 _stubs.initialize_outer(this, SECT_STUBS);
612
613 // Default is to align on 8 bytes. A compiler can change this
614 // if larger alignment (e.g., 32-byte vector masks) is required.
615 _const_section_alignment = (int) sizeof(jdouble);
616
617 #ifndef PRODUCT
618 _decode_begin = nullptr;
619 // Collect block comments, but restrict collection to cases where a disassembly is output.
620 _collect_comments = ( PrintAssembly
621 || PrintStubCode
622 || PrintMethodHandleStubs
623 || PrintInterpreter
624 || PrintSignatureHandlers
625 || UnlockDiagnosticVMOptions
626 );
627 #endif
628 }
629
630 void initialize(address code_start, csize_t code_size) {
631 _total_start = code_start;
632 _total_size = code_size;
633 // Initialize the main section:
634 _insts.initialize(code_start, code_size);
635 assert(!_stubs.is_allocated(), "no garbage here");
636 assert(!_consts.is_allocated(), "no garbage here");
637 _oop_recorder = &_default_oop_recorder;
638 }
639
640 void initialize_section_size(CodeSection* cs, csize_t size);
641
642 // helper for CodeBuffer::expand()
643 void take_over_code_from(CodeBuffer* cs);
644
645 // ensure sections are disjoint, ordered, and contained in the blob
646 void verify_section_allocation();
647
648 // copies combined relocations to the blob, returns bytes copied
649 // (if target is null, it is a dry run only, just for sizing)
650 csize_t copy_relocations_to(CodeBlob* blob) const;
651
652 // copies combined code to the blob (assumes relocs are already in there)
653 void copy_code_to(CodeBlob* blob);
654
655 // moves code sections to new buffer (assumes relocs are already in there)
656 void relocate_code_to(CodeBuffer* cb) const;
657
658 // adjust some internal address during expand
659 void adjust_internal_address(address from, address to);
660
661 // set up a model of the final layout of my contents
662 void compute_final_layout(CodeBuffer* dest) const;
663
664 // Expand the given section so at least 'amount' is remaining.
665 // Creates a new, larger BufferBlob, and rewrites the code & relocs.
666 void expand(CodeSection* which_cs, csize_t amount);
667
668 // Helper for expand.
669 csize_t figure_expanded_capacities(CodeSection* which_cs, csize_t amount, csize_t* new_capacity);
670
671 public:
672 // (1) code buffer referring to pre-allocated instruction memory
673 CodeBuffer(address code_start, csize_t code_size)
674 DEBUG_ONLY(: Scrubber(this, sizeof(*this)))
675 {
676 assert(code_start != nullptr, "sanity");
677 initialize_misc("static buffer");
678 initialize(code_start, code_size);
679 DEBUG_ONLY(verify_section_allocation();)
680 }
681
682 // (2) CodeBuffer referring to pre-allocated CodeBlob.
683 CodeBuffer(CodeBlob* blob);
684
685 // (3) code buffer allocating codeBlob memory for code & relocation
686 // info but with lazy initialization. The name must be something
687 // informative.
688 CodeBuffer(const char* name)
689 DEBUG_ONLY(: Scrubber(this, sizeof(*this)))
690 {
691 initialize_misc(name);
692 }
693
694 // (4) code buffer allocating codeBlob memory for code & relocation
695 // info. The name must be something informative and code_size must
696 // include both code and stubs sizes.
697 CodeBuffer(const char* name, csize_t code_size, csize_t locs_size)
698 DEBUG_ONLY(: Scrubber(this, sizeof(*this)))
699 {
700 initialize_misc(name);
701 initialize(code_size, locs_size);
702 }
703
704 ~CodeBuffer();
705
706 // Initialize a CodeBuffer constructed using constructor 3. Using
707 // constructor 4 is equivalent to calling constructor 3 and then
708 // calling this method. It's been factored out for convenience of
709 // construction.
710 void initialize(csize_t code_size, csize_t locs_size);
711
712 CodeSection* consts() { return &_consts; }
713 CodeSection* insts() { return &_insts; }
714 CodeSection* stubs() { return &_stubs; }
715
716 const CodeSection* insts() const { return &_insts; }
717
718 // present sections in order; return null at end; consts is #0, etc.
719 CodeSection* code_section(int n) {
720 // This makes the slightly questionable but portable assumption
721 // that the various members (_consts, _insts, _stubs, etc.) are
722 // adjacent in the layout of CodeBuffer.
723 CodeSection* cs = &_consts + n;
724 assert(cs->index() == n || !cs->is_allocated(), "sanity");
725 return cs;
726 }
727 const CodeSection* code_section(int n) const { // yucky const stuff
728 return ((CodeBuffer*)this)->code_section(n);
729 }
730 static const char* code_section_name(int n);
731 int section_index_of(address addr) const;
732 bool contains(address addr) const {
733 // handy for debugging
734 return section_index_of(addr) > SECT_NONE;
735 }
736
737 // A stable mapping between 'locators' (small ints) and addresses.
738 static int locator_pos(int locator) { return locator >> sect_bits; }
739 static int locator_sect(int locator) { return locator & sect_mask; }
740 static int locator(int pos, int sect) { return (pos << sect_bits) | sect; }
741 int locator(address addr) const;
742 address locator_address(int locator) const {
743 if (locator < 0) return nullptr;
744 address start = code_section(locator_sect(locator))->start();
745 return start + locator_pos(locator);
746 }
747
748 // Heuristic for pre-packing the taken/not-taken bit of a predicted branch.
749 bool is_backward_branch(Label& L);
750
751 // Properties
752 const char* name() const { return _name; }
753 CodeBuffer* before_expand() const { return _before_expand; }
754 BufferBlob* blob() const { return _blob; }
755 void set_blob(BufferBlob* blob);
756 void free_blob(); // Free the blob, if we own one.
757
758 // Properties relative to the insts section:
759 address insts_begin() const { return _insts.start(); }
760 address insts_end() const { return _insts.end(); }
761 void set_insts_end(address end) { _insts.set_end(end); }
762 address insts_mark() const { return _insts.mark(); }
763 void set_insts_mark() { _insts.set_mark(); }
764
765 // is there anything in the buffer other than the current section?
766 bool is_pure() const { return insts_size() == total_content_size(); }
767
768 // size in bytes of output so far in the insts sections
769 csize_t insts_size() const { return _insts.size(); }
770
771 // same as insts_size(), except that it asserts there is no non-code here
772 csize_t pure_insts_size() const { assert(is_pure(), "no non-code");
773 return insts_size(); }
774 // capacity in bytes of the insts sections
775 csize_t insts_capacity() const { return _insts.capacity(); }
776
777 // number of bytes remaining in the insts section
778 csize_t insts_remaining() const { return _insts.remaining(); }
779
780 // is a given address in the insts section? (2nd version is end-inclusive)
781 bool insts_contains(address pc) const { return _insts.contains(pc); }
782 bool insts_contains2(address pc) const { return _insts.contains2(pc); }
783
784 // Record any extra oops required to keep embedded metadata alive
785 void finalize_oop_references(const methodHandle& method);
786
787 // Allocated size in all sections, when aligned and concatenated
788 // (this is the eventual state of the content in its final
789 // CodeBlob).
790 csize_t total_content_size() const;
791
792 // Combined offset (relative to start of first section) of given
793 // section, as eventually found in the final CodeBlob.
794 csize_t total_offset_of(const CodeSection* cs) const;
795
796 // allocated size of all relocation data, including index, rounded up
797 csize_t total_relocation_size() const;
798
799 int total_skipped_instructions_size() const;
800
801 csize_t copy_relocations_to(address buf, csize_t buf_limit, bool only_inst) const;
802
803 // allocated size of any and all recorded oops
804 csize_t total_oop_size() const {
805 OopRecorder* recorder = oop_recorder();
806 return (recorder == nullptr)? 0: recorder->oop_size();
807 }
808
809 // allocated size of any and all recorded metadata
810 csize_t total_metadata_size() const {
811 OopRecorder* recorder = oop_recorder();
812 return (recorder == nullptr)? 0: recorder->metadata_size();
813 }
814
815 // Configuration functions, called immediately after the CB is constructed.
816 // The section sizes are subtracted from the original insts section.
817 // Note: Call them in reverse section order, because each steals from insts.
818 void initialize_consts_size(csize_t size) { initialize_section_size(&_consts, size); }
819 void initialize_stubs_size(csize_t size) { initialize_section_size(&_stubs, size); }
820 // Override default oop recorder.
821 void initialize_oop_recorder(OopRecorder* r);
822
823 OopRecorder* oop_recorder() const { return _oop_recorder; }
824
825 address last_insn() const { return _last_insn; }
826 void set_last_insn(address a) { _last_insn = a; }
827 void clear_last_insn() { set_last_insn(nullptr); }
828
829 address last_label() const { return _last_label; }
830 void set_last_label(address a) { _last_label = a; }
831
832 #ifndef PRODUCT
833 AsmRemarks &asm_remarks() { return _asm_remarks; }
834 DbgStrings &dbg_strings() { return _dbg_strings; }
835
836 void clear_strings() {
837 _asm_remarks.clear();
838 _dbg_strings.clear();
839 }
840 #endif
841
842 // Code generation
843 void relocate(address at, RelocationHolder const& rspec, int format = 0) {
844 _insts.relocate(at, rspec, format);
845 }
846 void relocate(address at, relocInfo::relocType rtype, int format = 0) {
847 _insts.relocate(at, rtype, format);
848 }
849
850 // Management of overflow storage for binding of Labels.
851 GrowableArray<int>* create_patch_overflow();
852
853 // NMethod generation
854 void copy_code_and_locs_to(CodeBlob* blob) {
855 assert(blob != nullptr, "sane");
856 copy_relocations_to(blob);
857 copy_code_to(blob);
858 }
859 void copy_values_to(nmethod* nm) {
860 if (!oop_recorder()->is_unused()) {
861 oop_recorder()->copy_values_to(nm);
862 }
863 }
864
865 void block_comment(ptrdiff_t offset, const char* comment) PRODUCT_RETURN;
866 const char* code_string(const char* str) PRODUCT_RETURN_(return nullptr;);
867
868 // Log a little info about section usage in the CodeBuffer
869 void log_section_sizes(const char* name);
870
871 // Make a set of stubs final. It can create/optimize stubs.
872 bool finalize_stubs();
873
874 // Request for a shared stub to the interpreter
875 void shared_stub_to_interp_for(ciMethod* callee, csize_t call_offset);
876
877 void set_const_section_alignment(int align) {
878 _const_section_alignment = align_up(align, HeapWordSize);
879 }
880
881 #ifndef PRODUCT
882 public:
883 // Printing / Decoding
884 // decodes from decode_begin() to code_end() and sets decode_begin to end
885 void decode();
886 void print_on(outputStream* st);
887 #endif
888 // Directly disassemble code buffer.
889 void decode(address start, address end);
890
891 // The following header contains architecture-specific implementations
892 #include CPU_HEADER(codeBuffer)
893
894 };
895
896 // A Java method can have calls of Java methods which can be statically bound.
897 // Calls of Java methods need stubs to the interpreter. Calls sharing the same Java method
898 // can share a stub to the interpreter.
899 // A SharedStubToInterpRequest is a request for a shared stub to the interpreter.
900 class SharedStubToInterpRequest : public ResourceObj {
901 private:
902 ciMethod* _shared_method;
903 CodeBuffer::csize_t _call_offset; // The offset of the call in CodeBuffer
904
905 public:
906 SharedStubToInterpRequest(ciMethod* method = nullptr, CodeBuffer::csize_t call_offset = -1) : _shared_method(method),
907 _call_offset(call_offset) {}
908
909 ciMethod* shared_method() const { return _shared_method; }
910 CodeBuffer::csize_t call_offset() const { return _call_offset; }
911 };
912
913 inline bool CodeSection::maybe_expand_to_ensure_remaining(csize_t amount) {
914 if (remaining() < amount) { _outer->expand(this, amount); return true; }
915 return false;
916 }
917
918 #endif // SHARE_ASM_CODEBUFFER_HPP