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