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 #ifndef SHARE_VM_ASM_CODEBUFFER_HPP
26 #define SHARE_VM_ASM_CODEBUFFER_HPP
27
28 #include "asm/assembler.hpp"
29 #include "code/oopRecorder.hpp"
30 #include "code/relocInfo.hpp"
31
32 class CodeComments;
33 class AbstractAssembler;
34 class MacroAssembler;
35 class PhaseCFG;
36 class Compile;
37 class BufferBlob;
38 class CodeBuffer;
39
40 class CodeOffsets: public StackObj {
41 public:
42 enum Entries { Entry,
43 Verified_Entry,
44 Frame_Complete, // Offset in the code where the frame setup is (for forte stackwalks) is complete
45 OSR_Entry,
46 Dtrace_trap = OSR_Entry, // dtrace probes can never have an OSR entry so reuse it
47 Exceptions, // Offset where exception handler lives
48 Deopt, // Offset where deopt handler lives
49 DeoptMH, // Offset where MethodHandle deopt handler lives
50 UnwindHandler, // Offset to default unwind handler
51 max_Entries };
52
53 // special value to note codeBlobs where profile (forte) stack walking is
54 // always dangerous and suspect.
55
56 enum { frame_never_safe = -1 };
57
58 private:
59 int _values[max_Entries];
60
61 public:
62 CodeOffsets() {
63 _values[Entry ] = 0;
64 _values[Verified_Entry] = 0;
65 _values[Frame_Complete] = frame_never_safe;
66 _values[OSR_Entry ] = 0;
67 _values[Exceptions ] = -1;
68 _values[Deopt ] = -1;
69 _values[DeoptMH ] = -1;
70 _values[UnwindHandler ] = -1;
71 }
72
73 int value(Entries e) { return _values[e]; }
74 void set_value(Entries e, int val) { _values[e] = val; }
75 };
76
77 // This class represents a stream of code and associated relocations.
78 // There are a few in each CodeBuffer.
79 // They are filled concurrently, and concatenated at the end.
80 class CodeSection VALUE_OBJ_CLASS_SPEC {
81 friend class CodeBuffer;
82 public:
83 typedef int csize_t; // code size type; would be size_t except for history
84
85 private:
86 address _start; // first byte of contents (instructions)
87 address _mark; // user mark, usually an instruction beginning
88 address _end; // current end address
89 address _limit; // last possible (allocated) end address
90 relocInfo* _locs_start; // first byte of relocation information
91 relocInfo* _locs_end; // first byte after relocation information
92 relocInfo* _locs_limit; // first byte after relocation information buf
93 address _locs_point; // last relocated position (grows upward)
94 bool _locs_own; // did I allocate the locs myself?
95 bool _frozen; // no more expansion of this section
96 char _index; // my section number (SECT_INST, etc.)
97 CodeBuffer* _outer; // enclosing CodeBuffer
98
99 // (Note: _locs_point used to be called _last_reloc_offset.)
100
101 CodeSection() {
102 _start = NULL;
103 _mark = NULL;
104 _end = NULL;
105 _limit = NULL;
106 _locs_start = NULL;
107 _locs_end = NULL;
108 _locs_limit = NULL;
109 _locs_point = NULL;
110 _locs_own = false;
111 _frozen = false;
112 debug_only(_index = (char)-1);
113 debug_only(_outer = (CodeBuffer*)badAddress);
114 }
115
116 void initialize_outer(CodeBuffer* outer, int index) {
117 _outer = outer;
118 _index = index;
119 }
120
121 void initialize(address start, csize_t size = 0) {
122 assert(_start == NULL, "only one init step, please");
123 _start = start;
124 _mark = NULL;
125 _end = start;
126
127 _limit = start + size;
128 _locs_point = start;
129 }
130
131 void initialize_locs(int locs_capacity);
132 void expand_locs(int new_capacity);
133 void initialize_locs_from(const CodeSection* source_cs);
134
135 // helper for CodeBuffer::expand()
136 void take_over_code_from(CodeSection* cs) {
137 _start = cs->_start;
138 _mark = cs->_mark;
139 _end = cs->_end;
140 _limit = cs->_limit;
141 _locs_point = cs->_locs_point;
142 }
143
144 public:
145 address start() const { return _start; }
146 address mark() const { return _mark; }
147 address end() const { return _end; }
148 address limit() const { return _limit; }
149 csize_t size() const { return (csize_t)(_end - _start); }
150 csize_t mark_off() const { assert(_mark != NULL, "not an offset");
151 return (csize_t)(_mark - _start); }
152 csize_t capacity() const { return (csize_t)(_limit - _start); }
153 csize_t remaining() const { return (csize_t)(_limit - _end); }
154
155 relocInfo* locs_start() const { return _locs_start; }
156 relocInfo* locs_end() const { return _locs_end; }
157 int locs_count() const { return (int)(_locs_end - _locs_start); }
158 relocInfo* locs_limit() const { return _locs_limit; }
159 address locs_point() const { return _locs_point; }
160 csize_t locs_point_off() const{ return (csize_t)(_locs_point - _start); }
161 csize_t locs_capacity() const { return (csize_t)(_locs_limit - _locs_start); }
162 csize_t locs_remaining()const { return (csize_t)(_locs_limit - _locs_end); }
163
164 int index() const { return _index; }
165 bool is_allocated() const { return _start != NULL; }
166 bool is_empty() const { return _start == _end; }
167 bool is_frozen() const { return _frozen; }
168 bool has_locs() const { return _locs_end != NULL; }
169
170 CodeBuffer* outer() const { return _outer; }
171
172 // is a given address in this section? (2nd version is end-inclusive)
173 bool contains(address pc) const { return pc >= _start && pc < _end; }
174 bool contains2(address pc) const { return pc >= _start && pc <= _end; }
175 bool allocates(address pc) const { return pc >= _start && pc < _limit; }
176 bool allocates2(address pc) const { return pc >= _start && pc <= _limit; }
177
178 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; }
179 void set_mark(address pc) { assert(contains2(pc), "not in codeBuffer");
180 _mark = pc; }
181 void set_mark_off(int offset) { assert(contains2(offset+_start),"not in codeBuffer");
182 _mark = offset + _start; }
183 void set_mark() { _mark = _end; }
184 void clear_mark() { _mark = NULL; }
185
186 void set_locs_end(relocInfo* p) {
187 assert(p <= locs_limit(), "locs data fits in allocated buffer");
188 _locs_end = p;
189 }
190 void set_locs_point(address pc) {
191 assert(pc >= locs_point(), "relocation addr may not decrease");
192 assert(allocates2(pc), "relocation addr must be in this section");
193 _locs_point = pc;
194 }
195
196 // Code emission
197 void emit_int8 (int8_t x) { *((int8_t*) end()) = x; set_end(end() + 1); }
198 void emit_int16(int16_t x) { *((int16_t*) end()) = x; set_end(end() + 2); }
199 void emit_int32(int32_t x) { *((int32_t*) end()) = x; set_end(end() + 4); }
200 void emit_int64(int64_t x) { *((int64_t*) end()) = x; set_end(end() + 8); }
201
202 // Share a scratch buffer for relocinfo. (Hacky; saves a resource allocation.)
203 void initialize_shared_locs(relocInfo* buf, int length);
204
205 // Manage labels and their addresses.
206 address target(Label& L, address branch_pc);
207
208 // Emit a relocation.
209 void relocate(address at, RelocationHolder const& rspec, int format = 0);
210 void relocate(address at, relocInfo::relocType rtype, int format = 0) {
211 if (rtype != relocInfo::none)
212 relocate(at, Relocation::spec_simple(rtype), format);
213 }
214
215 // alignment requirement for starting offset
216 // Requirements are that the instruction area and the
217 // stubs area must start on CodeEntryAlignment, and
218 // the ctable on sizeof(jdouble)
219 int alignment() const { return MAX2((int)sizeof(jdouble), (int)CodeEntryAlignment); }
220
221 // Slop between sections, used only when allocating temporary BufferBlob buffers.
222 static csize_t end_slop() { return MAX2((int)sizeof(jdouble), (int)CodeEntryAlignment); }
223
224 csize_t align_at_start(csize_t off) const { return (csize_t) align_size_up(off, alignment()); }
225
226 // Mark a section frozen. Assign its remaining space to
227 // the following section. It will never expand after this point.
228 inline void freeze(); // { _outer->freeze_section(this); }
229
230 // Ensure there's enough space left in the current section.
231 // Return true if there was an expansion.
232 bool maybe_expand_to_ensure_remaining(csize_t amount);
233
234 #ifndef PRODUCT
235 void decode();
236 void dump();
237 void print(const char* name);
238 #endif //PRODUCT
239 };
240
241 class CodeComment;
242 class CodeComments VALUE_OBJ_CLASS_SPEC {
243 private:
244 #ifndef PRODUCT
245 CodeComment* _comments;
246 #endif
247
248 public:
249 CodeComments() {
250 #ifndef PRODUCT
251 _comments = NULL;
252 #endif
253 }
254
255 void add_comment(intptr_t offset, const char * comment) PRODUCT_RETURN;
256 void print_block_comment(outputStream* stream, intptr_t offset) PRODUCT_RETURN;
257 void assign(CodeComments& other) PRODUCT_RETURN;
258 void free() PRODUCT_RETURN;
259 };
260
261
262 // A CodeBuffer describes a memory space into which assembly
263 // code is generated. This memory space usually occupies the
264 // interior of a single BufferBlob, but in some cases it may be
265 // an arbitrary span of memory, even outside the code cache.
266 //
267 // A code buffer comes in two variants:
268 //
269 // (1) A CodeBuffer referring to an already allocated piece of memory:
270 // This is used to direct 'static' code generation (e.g. for interpreter
271 // or stubroutine generation, etc.). This code comes with NO relocation
272 // information.
273 //
274 // (2) A CodeBuffer referring to a piece of memory allocated when the
275 // CodeBuffer is allocated. This is used for nmethod generation.
276 //
277 // The memory can be divided up into several parts called sections.
278 // Each section independently accumulates code (or data) an relocations.
279 // Sections can grow (at the expense of a reallocation of the BufferBlob
280 // and recopying of all active sections). When the buffered code is finally
281 // written to an nmethod (or other CodeBlob), the contents (code, data,
282 // and relocations) of the sections are padded to an alignment and concatenated.
283 // Instructions and data in one section can contain relocatable references to
284 // addresses in a sibling section.
285
286 class CodeBuffer: public StackObj {
287 friend class CodeSection;
288
289 private:
290 // CodeBuffers must be allocated on the stack except for a single
291 // special case during expansion which is handled internally. This
292 // is done to guarantee proper cleanup of resources.
293 void* operator new(size_t size) { return ResourceObj::operator new(size); }
294 void operator delete(void* p) { ShouldNotCallThis(); }
295
296 public:
297 typedef int csize_t; // code size type; would be size_t except for history
298 enum {
299 // Here is the list of all possible sections. The order reflects
300 // the final layout.
301 SECT_FIRST = 0,
302 SECT_CONSTS = SECT_FIRST, // Non-instruction data: Floats, jump tables, etc.
303 SECT_INSTS, // Executable instructions.
304 SECT_STUBS, // Outbound trampolines for supporting call sites.
305 SECT_LIMIT, SECT_NONE = -1
306 };
307
308 private:
309 enum {
310 sect_bits = 2, // assert (SECT_LIMIT <= (1<<sect_bits))
311 sect_mask = (1<<sect_bits)-1
312 };
313
314 const char* _name;
315
316 CodeSection _consts; // constants, jump tables
317 CodeSection _insts; // instructions (the main section)
318 CodeSection _stubs; // stubs (call site support), deopt, exception handling
319
320 CodeBuffer* _before_expand; // dead buffer, from before the last expansion
321
322 BufferBlob* _blob; // optional buffer in CodeCache for generated code
323 address _total_start; // first address of combined memory buffer
324 csize_t _total_size; // size in bytes of combined memory buffer
325
326 OopRecorder* _oop_recorder;
327 CodeComments _comments;
328 OopRecorder _default_oop_recorder; // override with initialize_oop_recorder
329 Arena* _overflow_arena;
330
331 address _decode_begin; // start address for decode
332 address decode_begin();
333
334 void initialize_misc(const char * name) {
335 // all pointers other than code_start/end and those inside the sections
336 assert(name != NULL, "must have a name");
337 _name = name;
338 _before_expand = NULL;
339 _blob = NULL;
340 _oop_recorder = NULL;
341 _decode_begin = NULL;
342 _overflow_arena = NULL;
343 }
344
345 void initialize(address code_start, csize_t code_size) {
346 _consts.initialize_outer(this, SECT_CONSTS);
347 _insts.initialize_outer(this, SECT_INSTS);
348 _stubs.initialize_outer(this, SECT_STUBS);
349 _total_start = code_start;
350 _total_size = code_size;
351 // Initialize the main section:
352 _insts.initialize(code_start, code_size);
353 assert(!_stubs.is_allocated(), "no garbage here");
354 assert(!_consts.is_allocated(), "no garbage here");
355 _oop_recorder = &_default_oop_recorder;
356 }
357
358 void initialize_section_size(CodeSection* cs, csize_t size);
359
360 void freeze_section(CodeSection* cs);
361
362 // helper for CodeBuffer::expand()
363 void take_over_code_from(CodeBuffer* cs);
364
365 #ifdef ASSERT
366 // ensure sections are disjoint, ordered, and contained in the blob
367 bool verify_section_allocation();
368 #endif
369
370 // copies combined relocations to the blob, returns bytes copied
371 // (if target is null, it is a dry run only, just for sizing)
372 csize_t copy_relocations_to(CodeBlob* blob) const;
373
374 // copies combined code to the blob (assumes relocs are already in there)
375 void copy_code_to(CodeBlob* blob);
376
377 // moves code sections to new buffer (assumes relocs are already in there)
378 void relocate_code_to(CodeBuffer* cb) const;
379
380 // set up a model of the final layout of my contents
381 void compute_final_layout(CodeBuffer* dest) const;
382
383 // Expand the given section so at least 'amount' is remaining.
384 // Creates a new, larger BufferBlob, and rewrites the code & relocs.
385 void expand(CodeSection* which_cs, csize_t amount);
386
387 // Helper for expand.
388 csize_t figure_expanded_capacities(CodeSection* which_cs, csize_t amount, csize_t* new_capacity);
389
390 public:
391 // (1) code buffer referring to pre-allocated instruction memory
392 CodeBuffer(address code_start, csize_t code_size) {
393 assert(code_start != NULL, "sanity");
394 initialize_misc("static buffer");
395 initialize(code_start, code_size);
396 assert(verify_section_allocation(), "initial use of buffer OK");
397 }
398
399 // (2) CodeBuffer referring to pre-allocated CodeBlob.
400 CodeBuffer(CodeBlob* blob);
401
402 // (3) code buffer allocating codeBlob memory for code & relocation
403 // info but with lazy initialization. The name must be something
404 // informative.
405 CodeBuffer(const char* name) {
406 initialize_misc(name);
407 }
408
409
410 // (4) code buffer allocating codeBlob memory for code & relocation
411 // info. The name must be something informative and code_size must
412 // include both code and stubs sizes.
413 CodeBuffer(const char* name, csize_t code_size, csize_t locs_size) {
414 initialize_misc(name);
415 initialize(code_size, locs_size);
416 }
417
418 ~CodeBuffer();
419
420 // Initialize a CodeBuffer constructed using constructor 3. Using
421 // constructor 4 is equivalent to calling constructor 3 and then
422 // calling this method. It's been factored out for convenience of
423 // construction.
424 void initialize(csize_t code_size, csize_t locs_size);
425
426 CodeSection* consts() { return &_consts; }
427 CodeSection* insts() { return &_insts; }
428 CodeSection* stubs() { return &_stubs; }
429
430 // present sections in order; return NULL at end; consts is #0, etc.
431 CodeSection* code_section(int n) {
432 // This makes the slightly questionable but portable assumption
433 // that the various members (_consts, _insts, _stubs, etc.) are
434 // adjacent in the layout of CodeBuffer.
435 CodeSection* cs = &_consts + n;
436 assert(cs->index() == n || !cs->is_allocated(), "sanity");
437 return cs;
438 }
439 const CodeSection* code_section(int n) const { // yucky const stuff
440 return ((CodeBuffer*)this)->code_section(n);
441 }
442 static const char* code_section_name(int n);
443 int section_index_of(address addr) const;
444 bool contains(address addr) const {
445 // handy for debugging
446 return section_index_of(addr) > SECT_NONE;
447 }
448
449 // A stable mapping between 'locators' (small ints) and addresses.
450 static int locator_pos(int locator) { return locator >> sect_bits; }
451 static int locator_sect(int locator) { return locator & sect_mask; }
452 static int locator(int pos, int sect) { return (pos << sect_bits) | sect; }
453 int locator(address addr) const;
454 address locator_address(int locator) const;
455
456 // Properties
457 const char* name() const { return _name; }
458 CodeBuffer* before_expand() const { return _before_expand; }
459 BufferBlob* blob() const { return _blob; }
460 void set_blob(BufferBlob* blob);
461 void free_blob(); // Free the blob, if we own one.
462
463 // Properties relative to the insts section:
464 address insts_begin() const { return _insts.start(); }
465 address insts_end() const { return _insts.end(); }
466 void set_insts_end(address end) { _insts.set_end(end); }
467 address insts_limit() const { return _insts.limit(); }
468 address insts_mark() const { return _insts.mark(); }
469 void set_insts_mark() { _insts.set_mark(); }
470 void clear_insts_mark() { _insts.clear_mark(); }
471
472 // is there anything in the buffer other than the current section?
473 bool is_pure() const { return insts_size() == total_content_size(); }
474
475 // size in bytes of output so far in the insts sections
476 csize_t insts_size() const { return _insts.size(); }
477
478 // same as insts_size(), except that it asserts there is no non-code here
479 csize_t pure_insts_size() const { assert(is_pure(), "no non-code");
480 return insts_size(); }
481 // capacity in bytes of the insts sections
482 csize_t insts_capacity() const { return _insts.capacity(); }
483
484 // number of bytes remaining in the insts section
485 csize_t insts_remaining() const { return _insts.remaining(); }
486
487 // is a given address in the insts section? (2nd version is end-inclusive)
488 bool insts_contains(address pc) const { return _insts.contains(pc); }
489 bool insts_contains2(address pc) const { return _insts.contains2(pc); }
490
491 // Allocated size in all sections, when aligned and concatenated
492 // (this is the eventual state of the content in its final
493 // CodeBlob).
494 csize_t total_content_size() const;
495
496 // Combined offset (relative to start of first section) of given
497 // section, as eventually found in the final CodeBlob.
498 csize_t total_offset_of(CodeSection* cs) const;
499
500 // allocated size of all relocation data, including index, rounded up
501 csize_t total_relocation_size() const;
502
503 // allocated size of any and all recorded oops
504 csize_t total_oop_size() const {
505 OopRecorder* recorder = oop_recorder();
506 return (recorder == NULL)? 0: recorder->oop_size();
507 }
508
509 // Configuration functions, called immediately after the CB is constructed.
510 // The section sizes are subtracted from the original insts section.
511 // Note: Call them in reverse section order, because each steals from insts.
512 void initialize_consts_size(csize_t size) { initialize_section_size(&_consts, size); }
513 void initialize_stubs_size(csize_t size) { initialize_section_size(&_stubs, size); }
514 // Override default oop recorder.
515 void initialize_oop_recorder(OopRecorder* r);
516
517 OopRecorder* oop_recorder() const { return _oop_recorder; }
518 CodeComments& comments() { return _comments; }
519
520 // Code generation
521 void relocate(address at, RelocationHolder const& rspec, int format = 0) {
522 _insts.relocate(at, rspec, format);
523 }
524 void relocate(address at, relocInfo::relocType rtype, int format = 0) {
525 _insts.relocate(at, rtype, format);
526 }
527
528 // Management of overflow storage for binding of Labels.
529 GrowableArray<int>* create_patch_overflow();
530
531 // NMethod generation
532 void copy_code_and_locs_to(CodeBlob* blob) {
533 assert(blob != NULL, "sane");
534 copy_relocations_to(blob);
535 copy_code_to(blob);
536 }
537 void copy_oops_to(nmethod* nm) {
538 if (!oop_recorder()->is_unused()) {
539 oop_recorder()->copy_to(nm);
540 }
541 }
542
543 // Transform an address from the code in this code buffer to a specified code buffer
544 address transform_address(const CodeBuffer &cb, address addr) const;
545
546 void block_comment(intptr_t offset, const char * comment) PRODUCT_RETURN;
547
548 #ifndef PRODUCT
549 public:
550 // Printing / Decoding
551 // decodes from decode_begin() to code_end() and sets decode_begin to end
552 void decode();
553 void decode_all(); // decodes all the code
554 void skip_decode(); // sets decode_begin to code_end();
555 void print();
556 #endif
557
558
559 // The following header contains architecture-specific implementations
560 #ifdef TARGET_ARCH_x86
561 # include "codeBuffer_x86.hpp"
562 #endif
563 #ifdef TARGET_ARCH_sparc
564 # include "codeBuffer_sparc.hpp"
565 #endif
566 #ifdef TARGET_ARCH_zero
567 # include "codeBuffer_zero.hpp"
568 #endif
569
570 };
571
572
573 inline void CodeSection::freeze() {
574 _outer->freeze_section(this);
575 }
576
577 inline bool CodeSection::maybe_expand_to_ensure_remaining(csize_t amount) {
578 if (remaining() < amount) { _outer->expand(this, amount); return true; }
579 return false;
580 }
581
582 #endif // SHARE_VM_ASM_CODEBUFFER_HPP