1 /*
2 * Copyright (c) 1997, 2010, 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 class CodeComments;
26 class AbstractAssembler;
27 class MacroAssembler;
28 class PhaseCFG;
29 class Compile;
30 class BufferBlob;
31 class CodeBuffer;
32
33 class CodeOffsets: public StackObj {
34 public:
35 enum Entries { Entry,
36 Verified_Entry,
37 Frame_Complete, // Offset in the code where the frame setup is (for forte stackwalks) is complete
38 OSR_Entry,
39 Dtrace_trap = OSR_Entry, // dtrace probes can never have an OSR entry so reuse it
40 Exceptions, // Offset where exception handler lives
41 Deopt, // Offset where deopt handler lives
42 DeoptMH, // Offset where MethodHandle deopt handler lives
43 UnwindHandler, // Offset to default unwind handler
44 max_Entries };
45
46 // special value to note codeBlobs where profile (forte) stack walking is
47 // always dangerous and suspect.
48
49 enum { frame_never_safe = -1 };
50
51 private:
52 int _values[max_Entries];
53
54 public:
55 CodeOffsets() {
56 _values[Entry ] = 0;
57 _values[Verified_Entry] = 0;
58 _values[Frame_Complete] = frame_never_safe;
59 _values[OSR_Entry ] = 0;
60 _values[Exceptions ] = -1;
61 _values[Deopt ] = -1;
62 _values[DeoptMH ] = -1;
63 _values[UnwindHandler ] = -1;
64 }
65
66 int value(Entries e) { return _values[e]; }
67 void set_value(Entries e, int val) { _values[e] = val; }
68 };
69
70 // This class represents a stream of code and associated relocations.
71 // There are a few in each CodeBuffer.
72 // They are filled concurrently, and concatenated at the end.
73 class CodeSection VALUE_OBJ_CLASS_SPEC {
74 friend class CodeBuffer;
75 public:
76 typedef int csize_t; // code size type; would be size_t except for history
77
78 private:
79 address _start; // first byte of contents (instructions)
80 address _mark; // user mark, usually an instruction beginning
81 address _end; // current end address
82 address _limit; // last possible (allocated) end address
83 relocInfo* _locs_start; // first byte of relocation information
84 relocInfo* _locs_end; // first byte after relocation information
85 relocInfo* _locs_limit; // first byte after relocation information buf
86 address _locs_point; // last relocated position (grows upward)
87 bool _locs_own; // did I allocate the locs myself?
88 bool _frozen; // no more expansion of this section
89 char _index; // my section number (SECT_INST, etc.)
90 CodeBuffer* _outer; // enclosing CodeBuffer
91
92 // (Note: _locs_point used to be called _last_reloc_offset.)
93
94 CodeSection() {
95 _start = NULL;
96 _mark = NULL;
97 _end = NULL;
98 _limit = NULL;
99 _locs_start = NULL;
100 _locs_end = NULL;
101 _locs_limit = NULL;
102 _locs_point = NULL;
103 _locs_own = false;
104 _frozen = false;
105 debug_only(_index = (char)-1);
106 debug_only(_outer = (CodeBuffer*)badAddress);
107 }
108
109 void initialize_outer(CodeBuffer* outer, int index) {
110 _outer = outer;
111 _index = index;
112 }
113
114 void initialize(address start, csize_t size = 0) {
115 assert(_start == NULL, "only one init step, please");
116 _start = start;
117 _mark = NULL;
118 _end = start;
119
120 _limit = start + size;
121 _locs_point = start;
122 }
123
124 void initialize_locs(int locs_capacity);
125 void expand_locs(int new_capacity);
126 void initialize_locs_from(const CodeSection* source_cs);
127
128 // helper for CodeBuffer::expand()
129 void take_over_code_from(CodeSection* cs) {
130 _start = cs->_start;
131 _mark = cs->_mark;
132 _end = cs->_end;
133 _limit = cs->_limit;
134 _locs_point = cs->_locs_point;
135 }
136
137 public:
138 address start() const { return _start; }
139 address mark() const { return _mark; }
140 address end() const { return _end; }
141 address limit() const { return _limit; }
142 csize_t size() const { return (csize_t)(_end - _start); }
143 csize_t mark_off() const { assert(_mark != NULL, "not an offset");
144 return (csize_t)(_mark - _start); }
145 csize_t capacity() const { return (csize_t)(_limit - _start); }
146 csize_t remaining() const { return (csize_t)(_limit - _end); }
147
148 relocInfo* locs_start() const { return _locs_start; }
149 relocInfo* locs_end() const { return _locs_end; }
150 int locs_count() const { return (int)(_locs_end - _locs_start); }
151 relocInfo* locs_limit() const { return _locs_limit; }
152 address locs_point() const { return _locs_point; }
153 csize_t locs_point_off() const{ return (csize_t)(_locs_point - _start); }
154 csize_t locs_capacity() const { return (csize_t)(_locs_limit - _locs_start); }
155 csize_t locs_remaining()const { return (csize_t)(_locs_limit - _locs_end); }
156
157 int index() const { return _index; }
158 bool is_allocated() const { return _start != NULL; }
159 bool is_empty() const { return _start == _end; }
160 bool is_frozen() const { return _frozen; }
161 bool has_locs() const { return _locs_end != NULL; }
162
163 CodeBuffer* outer() const { return _outer; }
164
165 // is a given address in this section? (2nd version is end-inclusive)
166 bool contains(address pc) const { return pc >= _start && pc < _end; }
167 bool contains2(address pc) const { return pc >= _start && pc <= _end; }
168 bool allocates(address pc) const { return pc >= _start && pc < _limit; }
169 bool allocates2(address pc) const { return pc >= _start && pc <= _limit; }
170
171 void set_end(address pc) { assert(allocates2(pc), err_msg("not in CodeBuffer memory: " PTR_FORMAT " <= " PTR_FORMAT " <= " PTR_FORMAT, _start, pc, _limit)); _end = pc; }
172 void set_mark(address pc) { assert(contains2(pc), "not in codeBuffer");
173 _mark = pc; }
174 void set_mark_off(int offset) { assert(contains2(offset+_start),"not in codeBuffer");
175 _mark = offset + _start; }
176 void set_mark() { _mark = _end; }
177 void clear_mark() { _mark = NULL; }
178
179 void set_locs_end(relocInfo* p) {
180 assert(p <= locs_limit(), "locs data fits in allocated buffer");
181 _locs_end = p;
182 }
183 void set_locs_point(address pc) {
184 assert(pc >= locs_point(), "relocation addr may not decrease");
185 assert(allocates2(pc), "relocation addr must be in this section");
186 _locs_point = pc;
187 }
188
189 // Code emission
190 void emit_int8 (int8_t x) { *((int8_t*) end()) = x; set_end(end() + 1); }
191 void emit_int16(int16_t x) { *((int16_t*) end()) = x; set_end(end() + 2); }
192 void emit_int32(int32_t x) { *((int32_t*) end()) = x; set_end(end() + 4); }
193 void emit_int64(int64_t x) { *((int64_t*) end()) = x; set_end(end() + 8); }
194
195 // Share a scratch buffer for relocinfo. (Hacky; saves a resource allocation.)
196 void initialize_shared_locs(relocInfo* buf, int length);
197
198 // Manage labels and their addresses.
199 address target(Label& L, address branch_pc);
200
201 // Emit a relocation.
202 void relocate(address at, RelocationHolder const& rspec, int format = 0);
203 void relocate(address at, relocInfo::relocType rtype, int format = 0) {
204 if (rtype != relocInfo::none)
205 relocate(at, Relocation::spec_simple(rtype), format);
206 }
207
208 // alignment requirement for starting offset
209 // Requirements are that the instruction area and the
210 // stubs area must start on CodeEntryAlignment, and
211 // the ctable on sizeof(jdouble)
212 int alignment() const { return MAX2((int)sizeof(jdouble), (int)CodeEntryAlignment); }
213
214 // Slop between sections, used only when allocating temporary BufferBlob buffers.
215 static csize_t end_slop() { return MAX2((int)sizeof(jdouble), (int)CodeEntryAlignment); }
216
217 csize_t align_at_start(csize_t off) const { return (csize_t) align_size_up(off, alignment()); }
218
219 // Mark a section frozen. Assign its remaining space to
220 // the following section. It will never expand after this point.
221 inline void freeze(); // { _outer->freeze_section(this); }
222
223 // Ensure there's enough space left in the current section.
224 // Return true if there was an expansion.
225 bool maybe_expand_to_ensure_remaining(csize_t amount);
226
227 #ifndef PRODUCT
228 void decode();
229 void dump();
230 void print(const char* name);
231 #endif //PRODUCT
232 };
233
234 class CodeComment;
235 class CodeComments VALUE_OBJ_CLASS_SPEC {
236 private:
237 #ifndef PRODUCT
238 CodeComment* _comments;
239 #endif
240
241 public:
242 CodeComments() {
243 #ifndef PRODUCT
244 _comments = NULL;
245 #endif
246 }
247
248 void add_comment(intptr_t offset, const char * comment) PRODUCT_RETURN;
249 void print_block_comment(outputStream* stream, intptr_t offset) PRODUCT_RETURN;
250 void assign(CodeComments& other) PRODUCT_RETURN;
251 void free() PRODUCT_RETURN;
252 };
253
254
255 // A CodeBuffer describes a memory space into which assembly
256 // code is generated. This memory space usually occupies the
257 // interior of a single BufferBlob, but in some cases it may be
258 // an arbitrary span of memory, even outside the code cache.
259 //
260 // A code buffer comes in two variants:
261 //
262 // (1) A CodeBuffer referring to an already allocated piece of memory:
263 // This is used to direct 'static' code generation (e.g. for interpreter
264 // or stubroutine generation, etc.). This code comes with NO relocation
265 // information.
266 //
267 // (2) A CodeBuffer referring to a piece of memory allocated when the
268 // CodeBuffer is allocated. This is used for nmethod generation.
269 //
270 // The memory can be divided up into several parts called sections.
271 // Each section independently accumulates code (or data) an relocations.
272 // Sections can grow (at the expense of a reallocation of the BufferBlob
273 // and recopying of all active sections). When the buffered code is finally
274 // written to an nmethod (or other CodeBlob), the contents (code, data,
275 // and relocations) of the sections are padded to an alignment and concatenated.
276 // Instructions and data in one section can contain relocatable references to
277 // addresses in a sibling section.
278
279 class CodeBuffer: public StackObj {
280 friend class CodeSection;
281
282 private:
283 // CodeBuffers must be allocated on the stack except for a single
284 // special case during expansion which is handled internally. This
285 // is done to guarantee proper cleanup of resources.
286 void* operator new(size_t size) { return ResourceObj::operator new(size); }
287 void operator delete(void* p) { ShouldNotCallThis(); }
288
289 public:
290 typedef int csize_t; // code size type; would be size_t except for history
291 enum {
292 // Here is the list of all possible sections. The order reflects
293 // the final layout.
294 SECT_FIRST = 0,
295 SECT_CONSTS = SECT_FIRST, // Non-instruction data: Floats, jump tables, etc.
296 SECT_INSTS, // Executable instructions.
297 SECT_STUBS, // Outbound trampolines for supporting call sites.
298 SECT_LIMIT, SECT_NONE = -1
299 };
300
301 private:
302 enum {
303 sect_bits = 2, // assert (SECT_LIMIT <= (1<<sect_bits))
304 sect_mask = (1<<sect_bits)-1
305 };
306
307 const char* _name;
308
309 CodeSection _consts; // constants, jump tables
310 CodeSection _insts; // instructions (the main section)
311 CodeSection _stubs; // stubs (call site support), deopt, exception handling
312
313 CodeBuffer* _before_expand; // dead buffer, from before the last expansion
314
315 BufferBlob* _blob; // optional buffer in CodeCache for generated code
316 address _total_start; // first address of combined memory buffer
317 csize_t _total_size; // size in bytes of combined memory buffer
318
319 OopRecorder* _oop_recorder;
320 CodeComments _comments;
321 OopRecorder _default_oop_recorder; // override with initialize_oop_recorder
322 Arena* _overflow_arena;
323
324 address _decode_begin; // start address for decode
325 address decode_begin();
326
327 void initialize_misc(const char * name) {
328 // all pointers other than code_start/end and those inside the sections
329 assert(name != NULL, "must have a name");
330 _name = name;
331 _before_expand = NULL;
332 _blob = NULL;
333 _oop_recorder = NULL;
334 _decode_begin = NULL;
335 _overflow_arena = NULL;
336 }
337
338 void initialize(address code_start, csize_t code_size) {
339 _consts.initialize_outer(this, SECT_CONSTS);
340 _insts.initialize_outer(this, SECT_INSTS);
341 _stubs.initialize_outer(this, SECT_STUBS);
342 _total_start = code_start;
343 _total_size = code_size;
344 // Initialize the main section:
345 _insts.initialize(code_start, code_size);
346 assert(!_stubs.is_allocated(), "no garbage here");
347 assert(!_consts.is_allocated(), "no garbage here");
348 _oop_recorder = &_default_oop_recorder;
349 }
350
351 void initialize_section_size(CodeSection* cs, csize_t size);
352
353 void freeze_section(CodeSection* cs);
354
355 // helper for CodeBuffer::expand()
356 void take_over_code_from(CodeBuffer* cs);
357
358 #ifdef ASSERT
359 // ensure sections are disjoint, ordered, and contained in the blob
360 bool verify_section_allocation();
361 #endif
362
363 // copies combined relocations to the blob, returns bytes copied
364 // (if target is null, it is a dry run only, just for sizing)
365 csize_t copy_relocations_to(CodeBlob* blob) const;
366
367 // copies combined code to the blob (assumes relocs are already in there)
368 void copy_code_to(CodeBlob* blob);
369
370 // moves code sections to new buffer (assumes relocs are already in there)
371 void relocate_code_to(CodeBuffer* cb) const;
372
373 // set up a model of the final layout of my contents
374 void compute_final_layout(CodeBuffer* dest) const;
375
376 // Expand the given section so at least 'amount' is remaining.
377 // Creates a new, larger BufferBlob, and rewrites the code & relocs.
378 void expand(CodeSection* which_cs, csize_t amount);
379
380 // Helper for expand.
381 csize_t figure_expanded_capacities(CodeSection* which_cs, csize_t amount, csize_t* new_capacity);
382
383 public:
384 // (1) code buffer referring to pre-allocated instruction memory
385 CodeBuffer(address code_start, csize_t code_size) {
386 assert(code_start != NULL, "sanity");
387 initialize_misc("static buffer");
388 initialize(code_start, code_size);
389 assert(verify_section_allocation(), "initial use of buffer OK");
390 }
391
392 // (2) CodeBuffer referring to pre-allocated CodeBlob.
393 CodeBuffer(CodeBlob* blob);
394
395 // (3) code buffer allocating codeBlob memory for code & relocation
396 // info but with lazy initialization. The name must be something
397 // informative.
398 CodeBuffer(const char* name) {
399 initialize_misc(name);
400 }
401
402
403 // (4) code buffer allocating codeBlob memory for code & relocation
404 // info. The name must be something informative and code_size must
405 // include both code and stubs sizes.
406 CodeBuffer(const char* name, csize_t code_size, csize_t locs_size) {
407 initialize_misc(name);
408 initialize(code_size, locs_size);
409 }
410
411 ~CodeBuffer();
412
413 // Initialize a CodeBuffer constructed using constructor 3. Using
414 // constructor 4 is equivalent to calling constructor 3 and then
415 // calling this method. It's been factored out for convenience of
416 // construction.
417 void initialize(csize_t code_size, csize_t locs_size);
418
419 CodeSection* consts() { return &_consts; }
420 CodeSection* insts() { return &_insts; }
421 CodeSection* stubs() { return &_stubs; }
422
423 // present sections in order; return NULL at end; consts is #0, etc.
424 CodeSection* code_section(int n) {
425 // This makes the slightly questionable but portable assumption
426 // that the various members (_consts, _insts, _stubs, etc.) are
427 // adjacent in the layout of CodeBuffer.
428 CodeSection* cs = &_consts + n;
429 assert(cs->index() == n || !cs->is_allocated(), "sanity");
430 return cs;
431 }
432 const CodeSection* code_section(int n) const { // yucky const stuff
433 return ((CodeBuffer*)this)->code_section(n);
434 }
435 static const char* code_section_name(int n);
436 int section_index_of(address addr) const;
437 bool contains(address addr) const {
438 // handy for debugging
439 return section_index_of(addr) > SECT_NONE;
440 }
441
442 // A stable mapping between 'locators' (small ints) and addresses.
443 static int locator_pos(int locator) { return locator >> sect_bits; }
444 static int locator_sect(int locator) { return locator & sect_mask; }
445 static int locator(int pos, int sect) { return (pos << sect_bits) | sect; }
446 int locator(address addr) const;
447 address locator_address(int locator) const;
448
449 // Properties
450 const char* name() const { return _name; }
451 CodeBuffer* before_expand() const { return _before_expand; }
452 BufferBlob* blob() const { return _blob; }
453 void set_blob(BufferBlob* blob);
454 void free_blob(); // Free the blob, if we own one.
455
456 // Properties relative to the insts section:
457 address insts_begin() const { return _insts.start(); }
458 address insts_end() const { return _insts.end(); }
459 void set_insts_end(address end) { _insts.set_end(end); }
460 address insts_limit() const { return _insts.limit(); }
461 address insts_mark() const { return _insts.mark(); }
462 void set_insts_mark() { _insts.set_mark(); }
463 void clear_insts_mark() { _insts.clear_mark(); }
464
465 // is there anything in the buffer other than the current section?
466 bool is_pure() const { return insts_size() == total_content_size(); }
467
468 // size in bytes of output so far in the insts sections
469 csize_t insts_size() const { return _insts.size(); }
470
471 // same as insts_size(), except that it asserts there is no non-code here
472 csize_t pure_insts_size() const { assert(is_pure(), "no non-code");
473 return insts_size(); }
474 // capacity in bytes of the insts sections
475 csize_t insts_capacity() const { return _insts.capacity(); }
476
477 // number of bytes remaining in the insts section
478 csize_t insts_remaining() const { return _insts.remaining(); }
479
480 // is a given address in the insts section? (2nd version is end-inclusive)
481 bool insts_contains(address pc) const { return _insts.contains(pc); }
482 bool insts_contains2(address pc) const { return _insts.contains2(pc); }
483
484 // Allocated size in all sections, when aligned and concatenated
485 // (this is the eventual state of the content in its final
486 // CodeBlob).
487 csize_t total_content_size() const;
488
489 // Combined offset (relative to start of first section) of given
490 // section, as eventually found in the final CodeBlob.
491 csize_t total_offset_of(CodeSection* cs) const;
492
493 // allocated size of all relocation data, including index, rounded up
494 csize_t total_relocation_size() const;
495
496 // allocated size of any and all recorded oops
497 csize_t total_oop_size() const {
498 OopRecorder* recorder = oop_recorder();
499 return (recorder == NULL)? 0: recorder->oop_size();
500 }
501
502 // Configuration functions, called immediately after the CB is constructed.
503 // The section sizes are subtracted from the original insts section.
504 // Note: Call them in reverse section order, because each steals from insts.
505 void initialize_consts_size(csize_t size) { initialize_section_size(&_consts, size); }
506 void initialize_stubs_size(csize_t size) { initialize_section_size(&_stubs, size); }
507 // Override default oop recorder.
508 void initialize_oop_recorder(OopRecorder* r);
509
510 OopRecorder* oop_recorder() const { return _oop_recorder; }
511 CodeComments& comments() { return _comments; }
512
513 // Code generation
514 void relocate(address at, RelocationHolder const& rspec, int format = 0) {
515 _insts.relocate(at, rspec, format);
516 }
517 void relocate(address at, relocInfo::relocType rtype, int format = 0) {
518 _insts.relocate(at, rtype, format);
519 }
520
521 // Management of overflow storage for binding of Labels.
522 GrowableArray<int>* create_patch_overflow();
523
524 // NMethod generation
525 void copy_code_and_locs_to(CodeBlob* blob) {
526 assert(blob != NULL, "sane");
527 copy_relocations_to(blob);
528 copy_code_to(blob);
529 }
530 void copy_oops_to(nmethod* nm) {
531 if (!oop_recorder()->is_unused()) {
532 oop_recorder()->copy_to(nm);
533 }
534 }
535
536 // Transform an address from the code in this code buffer to a specified code buffer
537 address transform_address(const CodeBuffer &cb, address addr) const;
538
539 void block_comment(intptr_t offset, const char * comment) PRODUCT_RETURN;
540
541 #ifndef PRODUCT
542 public:
543 // Printing / Decoding
544 // decodes from decode_begin() to code_end() and sets decode_begin to end
545 void decode();
546 void decode_all(); // decodes all the code
547 void skip_decode(); // sets decode_begin to code_end();
548 void print();
549 #endif
550
551
552 // The following header contains architecture-specific implementations
553 #include "incls/_codeBuffer_pd.hpp.incl"
554 };
555
556
557 inline void CodeSection::freeze() {
558 _outer->freeze_section(this);
559 }
560
561 inline bool CodeSection::maybe_expand_to_ensure_remaining(csize_t amount) {
562 if (remaining() < amount) { _outer->expand(this, amount); return true; }
563 return false;
564 }