codeBuffer.hpp revision 1472:c18cbe5936b8
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 25class CodeComments; 26class AbstractAssembler; 27class MacroAssembler; 28class PhaseCFG; 29class Compile; 30class BufferBlob; 31class CodeBuffer; 32 33class CodeOffsets: public StackObj { 34public: 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 51private: 52 int _values[max_Entries]; 53 54public: 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. 73class 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 = -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),""); _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 // Share a scratch buffer for relocinfo. (Hacky; saves a resource allocation.) 190 void initialize_shared_locs(relocInfo* buf, int length); 191 192 // Manage labels and their addresses. 193 address target(Label& L, address branch_pc); 194 195 // Emit a relocation. 196 void relocate(address at, RelocationHolder const& rspec, int format = 0); 197 void relocate(address at, relocInfo::relocType rtype, int format = 0) { 198 if (rtype != relocInfo::none) 199 relocate(at, Relocation::spec_simple(rtype), format); 200 } 201 202 // alignment requirement for starting offset 203 // Requirements are that the instruction area and the 204 // stubs area must start on CodeEntryAlignment, and 205 // the ctable on sizeof(jdouble) 206 int alignment() const { return MAX2((int)sizeof(jdouble), (int)CodeEntryAlignment); } 207 208 // Slop between sections, used only when allocating temporary BufferBlob buffers. 209 static csize_t end_slop() { return MAX2((int)sizeof(jdouble), (int)CodeEntryAlignment); } 210 211 csize_t align_at_start(csize_t off) const { return (csize_t) align_size_up(off, alignment()); } 212 213 // Mark a section frozen. Assign its remaining space to 214 // the following section. It will never expand after this point. 215 inline void freeze(); // { _outer->freeze_section(this); } 216 217 // Ensure there's enough space left in the current section. 218 // Return true if there was an expansion. 219 bool maybe_expand_to_ensure_remaining(csize_t amount); 220 221#ifndef PRODUCT 222 void decode(); 223 void dump(); 224 void print(const char* name); 225#endif //PRODUCT 226}; 227 228class CodeComment; 229class CodeComments VALUE_OBJ_CLASS_SPEC { 230private: 231#ifndef PRODUCT 232 CodeComment* _comments; 233#endif 234 235public: 236 CodeComments() { 237#ifndef PRODUCT 238 _comments = NULL; 239#endif 240 } 241 242 void add_comment(intptr_t offset, const char * comment) PRODUCT_RETURN; 243 void print_block_comment(outputStream* stream, intptr_t offset) PRODUCT_RETURN; 244 void assign(CodeComments& other) PRODUCT_RETURN; 245 void free() PRODUCT_RETURN; 246}; 247 248 249// A CodeBuffer describes a memory space into which assembly 250// code is generated. This memory space usually occupies the 251// interior of a single BufferBlob, but in some cases it may be 252// an arbitrary span of memory, even outside the code cache. 253// 254// A code buffer comes in two variants: 255// 256// (1) A CodeBuffer referring to an already allocated piece of memory: 257// This is used to direct 'static' code generation (e.g. for interpreter 258// or stubroutine generation, etc.). This code comes with NO relocation 259// information. 260// 261// (2) A CodeBuffer referring to a piece of memory allocated when the 262// CodeBuffer is allocated. This is used for nmethod generation. 263// 264// The memory can be divided up into several parts called sections. 265// Each section independently accumulates code (or data) an relocations. 266// Sections can grow (at the expense of a reallocation of the BufferBlob 267// and recopying of all active sections). When the buffered code is finally 268// written to an nmethod (or other CodeBlob), the contents (code, data, 269// and relocations) of the sections are padded to an alignment and concatenated. 270// Instructions and data in one section can contain relocatable references to 271// addresses in a sibling section. 272 273class CodeBuffer: public StackObj { 274 friend class CodeSection; 275 276 private: 277 // CodeBuffers must be allocated on the stack except for a single 278 // special case during expansion which is handled internally. This 279 // is done to guarantee proper cleanup of resources. 280 void* operator new(size_t size) { return ResourceObj::operator new(size); } 281 void operator delete(void* p) { ResourceObj::operator delete(p); } 282 283 public: 284 typedef int csize_t; // code size type; would be size_t except for history 285 enum { 286 // Here is the list of all possible sections, in order of ascending address. 287 SECT_INSTS, // Executable instructions. 288 SECT_STUBS, // Outbound trampolines for supporting call sites. 289 SECT_CONSTS, // Non-instruction data: Floats, jump tables, etc. 290 SECT_LIMIT, SECT_NONE = -1 291 }; 292 293 private: 294 enum { 295 sect_bits = 2, // assert (SECT_LIMIT <= (1<<sect_bits)) 296 sect_mask = (1<<sect_bits)-1 297 }; 298 299 const char* _name; 300 301 CodeSection _insts; // instructions (the main section) 302 CodeSection _stubs; // stubs (call site support), deopt, exception handling 303 CodeSection _consts; // constants, jump tables 304 305 CodeBuffer* _before_expand; // dead buffer, from before the last expansion 306 307 BufferBlob* _blob; // optional buffer in CodeCache for generated code 308 address _total_start; // first address of combined memory buffer 309 csize_t _total_size; // size in bytes of combined memory buffer 310 311 OopRecorder* _oop_recorder; 312 CodeComments _comments; 313 OopRecorder _default_oop_recorder; // override with initialize_oop_recorder 314 Arena* _overflow_arena; 315 316 address _decode_begin; // start address for decode 317 address decode_begin(); 318 319 void initialize_misc(const char * name) { 320 // all pointers other than code_start/end and those inside the sections 321 assert(name != NULL, "must have a name"); 322 _name = name; 323 _before_expand = NULL; 324 _blob = NULL; 325 _oop_recorder = NULL; 326 _decode_begin = NULL; 327 _overflow_arena = NULL; 328 } 329 330 void initialize(address code_start, csize_t code_size) { 331 _insts.initialize_outer(this, SECT_INSTS); 332 _stubs.initialize_outer(this, SECT_STUBS); 333 _consts.initialize_outer(this, SECT_CONSTS); 334 _total_start = code_start; 335 _total_size = code_size; 336 // Initialize the main section: 337 _insts.initialize(code_start, code_size); 338 assert(!_stubs.is_allocated(), "no garbage here"); 339 assert(!_consts.is_allocated(), "no garbage here"); 340 _oop_recorder = &_default_oop_recorder; 341 } 342 343 void initialize_section_size(CodeSection* cs, csize_t size); 344 345 void freeze_section(CodeSection* cs); 346 347 // helper for CodeBuffer::expand() 348 void take_over_code_from(CodeBuffer* cs); 349 350#ifdef ASSERT 351 // ensure sections are disjoint, ordered, and contained in the blob 352 bool verify_section_allocation(); 353#endif 354 355 // copies combined relocations to the blob, returns bytes copied 356 // (if target is null, it is a dry run only, just for sizing) 357 csize_t copy_relocations_to(CodeBlob* blob) const; 358 359 // copies combined code to the blob (assumes relocs are already in there) 360 void copy_code_to(CodeBlob* blob); 361 362 // moves code sections to new buffer (assumes relocs are already in there) 363 void relocate_code_to(CodeBuffer* cb) const; 364 365 // set up a model of the final layout of my contents 366 void compute_final_layout(CodeBuffer* dest) const; 367 368 // Expand the given section so at least 'amount' is remaining. 369 // Creates a new, larger BufferBlob, and rewrites the code & relocs. 370 void expand(CodeSection* which_cs, csize_t amount); 371 372 // Helper for expand. 373 csize_t figure_expanded_capacities(CodeSection* which_cs, csize_t amount, csize_t* new_capacity); 374 375 public: 376 // (1) code buffer referring to pre-allocated instruction memory 377 CodeBuffer(address code_start, csize_t code_size); 378 379 // (2) code buffer allocating codeBlob memory for code & relocation 380 // info but with lazy initialization. The name must be something 381 // informative. 382 CodeBuffer(const char* name) { 383 initialize_misc(name); 384 } 385 386 387 // (3) code buffer allocating codeBlob memory for code & relocation 388 // info. The name must be something informative and code_size must 389 // include both code and stubs sizes. 390 CodeBuffer(const char* name, csize_t code_size, csize_t locs_size) { 391 initialize_misc(name); 392 initialize(code_size, locs_size); 393 } 394 395 ~CodeBuffer(); 396 397 // Initialize a CodeBuffer constructed using constructor 2. Using 398 // constructor 3 is equivalent to calling constructor 2 and then 399 // calling this method. It's been factored out for convenience of 400 // construction. 401 void initialize(csize_t code_size, csize_t locs_size); 402 403 CodeSection* insts() { return &_insts; } 404 CodeSection* stubs() { return &_stubs; } 405 CodeSection* consts() { return &_consts; } 406 407 // present sections in order; return NULL at end; insts is #0, etc. 408 CodeSection* code_section(int n) { 409 // This makes the slightly questionable but portable assumption that 410 // the various members (_insts, _stubs, etc.) are adjacent in the 411 // layout of CodeBuffer. 412 CodeSection* cs = &_insts + n; 413 assert(cs->index() == n || !cs->is_allocated(), "sanity"); 414 return cs; 415 } 416 const CodeSection* code_section(int n) const { // yucky const stuff 417 return ((CodeBuffer*)this)->code_section(n); 418 } 419 static const char* code_section_name(int n); 420 int section_index_of(address addr) const; 421 bool contains(address addr) const { 422 // handy for debugging 423 return section_index_of(addr) > SECT_NONE; 424 } 425 426 // A stable mapping between 'locators' (small ints) and addresses. 427 static int locator_pos(int locator) { return locator >> sect_bits; } 428 static int locator_sect(int locator) { return locator & sect_mask; } 429 static int locator(int pos, int sect) { return (pos << sect_bits) | sect; } 430 int locator(address addr) const; 431 address locator_address(int locator) const; 432 433 // Properties 434 const char* name() const { return _name; } 435 CodeBuffer* before_expand() const { return _before_expand; } 436 BufferBlob* blob() const { return _blob; } 437 void set_blob(BufferBlob* blob); 438 void free_blob(); // Free the blob, if we own one. 439 440 // Properties relative to the insts section: 441 address code_begin() const { return _insts.start(); } 442 address code_end() const { return _insts.end(); } 443 void set_code_end(address end) { _insts.set_end(end); } 444 address code_limit() const { return _insts.limit(); } 445 address inst_mark() const { return _insts.mark(); } 446 void set_inst_mark() { _insts.set_mark(); } 447 void clear_inst_mark() { _insts.clear_mark(); } 448 449 // is there anything in the buffer other than the current section? 450 bool is_pure() const { return code_size() == total_code_size(); } 451 452 // size in bytes of output so far in the insts sections 453 csize_t code_size() const { return _insts.size(); } 454 455 // same as code_size(), except that it asserts there is no non-code here 456 csize_t pure_code_size() const { assert(is_pure(), "no non-code"); 457 return code_size(); } 458 // capacity in bytes of the insts sections 459 csize_t code_capacity() const { return _insts.capacity(); } 460 461 // number of bytes remaining in the insts section 462 csize_t code_remaining() const { return _insts.remaining(); } 463 464 // is a given address in the insts section? (2nd version is end-inclusive) 465 bool code_contains(address pc) const { return _insts.contains(pc); } 466 bool code_contains2(address pc) const { return _insts.contains2(pc); } 467 468 // allocated size of code in all sections, when aligned and concatenated 469 // (this is the eventual state of the code in its final CodeBlob) 470 csize_t total_code_size() const; 471 472 // combined offset (relative to start of insts) of given address, 473 // as eventually found in the final CodeBlob 474 csize_t total_offset_of(address addr) const; 475 476 // allocated size of all relocation data, including index, rounded up 477 csize_t total_relocation_size() const; 478 479 // allocated size of any and all recorded oops 480 csize_t total_oop_size() const { 481 OopRecorder* recorder = oop_recorder(); 482 return (recorder == NULL)? 0: recorder->oop_size(); 483 } 484 485 // Configuration functions, called immediately after the CB is constructed. 486 // The section sizes are subtracted from the original insts section. 487 // Note: Call them in reverse section order, because each steals from insts. 488 void initialize_consts_size(csize_t size) { initialize_section_size(&_consts, size); } 489 void initialize_stubs_size(csize_t size) { initialize_section_size(&_stubs, size); } 490 // Override default oop recorder. 491 void initialize_oop_recorder(OopRecorder* r); 492 493 OopRecorder* oop_recorder() const { return _oop_recorder; } 494 CodeComments& comments() { return _comments; } 495 496 // Code generation 497 void relocate(address at, RelocationHolder const& rspec, int format = 0) { 498 _insts.relocate(at, rspec, format); 499 } 500 void relocate(address at, relocInfo::relocType rtype, int format = 0) { 501 _insts.relocate(at, rtype, format); 502 } 503 504 // Management of overflow storage for binding of Labels. 505 GrowableArray<int>* create_patch_overflow(); 506 507 // NMethod generation 508 void copy_code_and_locs_to(CodeBlob* blob) { 509 assert(blob != NULL, "sane"); 510 copy_relocations_to(blob); 511 copy_code_to(blob); 512 } 513 void copy_oops_to(CodeBlob* blob) { 514 if (!oop_recorder()->is_unused()) { 515 oop_recorder()->copy_to(blob); 516 } 517 } 518 519 // Transform an address from the code in this code buffer to a specified code buffer 520 address transform_address(const CodeBuffer &cb, address addr) const; 521 522 void block_comment(intptr_t offset, const char * comment) PRODUCT_RETURN; 523 524#ifndef PRODUCT 525 public: 526 // Printing / Decoding 527 // decodes from decode_begin() to code_end() and sets decode_begin to end 528 void decode(); 529 void decode_all(); // decodes all the code 530 void skip_decode(); // sets decode_begin to code_end(); 531 void print(); 532#endif 533 534 535 // The following header contains architecture-specific implementations 536 #include "incls/_codeBuffer_pd.hpp.incl" 537}; 538 539 540inline void CodeSection::freeze() { 541 _outer->freeze_section(this); 542} 543 544inline bool CodeSection::maybe_expand_to_ensure_remaining(csize_t amount) { 545 if (remaining() < amount) { _outer->expand(this, amount); return true; } 546 return false; 547} 548