codeBuffer.hpp revision 116:018d5b58dd4f
1/* 2 * Copyright 1997-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 20 * CA 95054 USA or visit www.sun.com if you need additional information or 21 * have any 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 max_Entries }; 43 44 // special value to note codeBlobs where profile (forte) stack walking is 45 // always dangerous and suspect. 46 47 enum { frame_never_safe = -1 }; 48 49private: 50 int _values[max_Entries]; 51 52public: 53 CodeOffsets() { 54 _values[Entry] = 0; 55 _values[Verified_Entry] = 0; 56 _values[Frame_Complete] = frame_never_safe; 57 _values[OSR_Entry] = 0; 58 _values[Exceptions] = -1; 59 _values[Deopt] = -1; 60 } 61 62 int value(Entries e) { return _values[e]; } 63 void set_value(Entries e, int val) { _values[e] = val; } 64}; 65 66// This class represents a stream of code and associated relocations. 67// There are a few in each CodeBuffer. 68// They are filled concurrently, and concatenated at the end. 69class CodeSection VALUE_OBJ_CLASS_SPEC { 70 friend class CodeBuffer; 71 public: 72 typedef int csize_t; // code size type; would be size_t except for history 73 74 private: 75 address _start; // first byte of contents (instructions) 76 address _mark; // user mark, usually an instruction beginning 77 address _end; // current end address 78 address _limit; // last possible (allocated) end address 79 relocInfo* _locs_start; // first byte of relocation information 80 relocInfo* _locs_end; // first byte after relocation information 81 relocInfo* _locs_limit; // first byte after relocation information buf 82 address _locs_point; // last relocated position (grows upward) 83 bool _locs_own; // did I allocate the locs myself? 84 bool _frozen; // no more expansion of this section 85 char _index; // my section number (SECT_INST, etc.) 86 CodeBuffer* _outer; // enclosing CodeBuffer 87 88 // (Note: _locs_point used to be called _last_reloc_offset.) 89 90 CodeSection() { 91 _start = NULL; 92 _mark = NULL; 93 _end = NULL; 94 _limit = NULL; 95 _locs_start = NULL; 96 _locs_end = NULL; 97 _locs_limit = NULL; 98 _locs_point = NULL; 99 _locs_own = false; 100 _frozen = false; 101 debug_only(_index = -1); 102 debug_only(_outer = (CodeBuffer*)badAddress); 103 } 104 105 void initialize_outer(CodeBuffer* outer, int index) { 106 _outer = outer; 107 _index = index; 108 } 109 110 void initialize(address start, csize_t size = 0) { 111 assert(_start == NULL, "only one init step, please"); 112 _start = start; 113 _mark = NULL; 114 _end = start; 115 116 _limit = start + size; 117 _locs_point = start; 118 } 119 120 void initialize_locs(int locs_capacity); 121 void expand_locs(int new_capacity); 122 void initialize_locs_from(const CodeSection* source_cs); 123 124 // helper for CodeBuffer::expand() 125 void take_over_code_from(CodeSection* cs) { 126 _start = cs->_start; 127 _mark = cs->_mark; 128 _end = cs->_end; 129 _limit = cs->_limit; 130 _locs_point = cs->_locs_point; 131 } 132 133 public: 134 address start() const { return _start; } 135 address mark() const { return _mark; } 136 address end() const { return _end; } 137 address limit() const { return _limit; } 138 csize_t size() const { return (csize_t)(_end - _start); } 139 csize_t mark_off() const { assert(_mark != NULL, "not an offset"); 140 return (csize_t)(_mark - _start); } 141 csize_t capacity() const { return (csize_t)(_limit - _start); } 142 csize_t remaining() const { return (csize_t)(_limit - _end); } 143 144 relocInfo* locs_start() const { return _locs_start; } 145 relocInfo* locs_end() const { return _locs_end; } 146 int locs_count() const { return (int)(_locs_end - _locs_start); } 147 relocInfo* locs_limit() const { return _locs_limit; } 148 address locs_point() const { return _locs_point; } 149 csize_t locs_point_off() const{ return (csize_t)(_locs_point - _start); } 150 csize_t locs_capacity() const { return (csize_t)(_locs_limit - _locs_start); } 151 csize_t locs_remaining()const { return (csize_t)(_locs_limit - _locs_end); } 152 153 int index() const { return _index; } 154 bool is_allocated() const { return _start != NULL; } 155 bool is_empty() const { return _start == _end; } 156 bool is_frozen() const { return _frozen; } 157 bool has_locs() const { return _locs_end != NULL; } 158 159 CodeBuffer* outer() const { return _outer; } 160 161 // is a given address in this section? (2nd version is end-inclusive) 162 bool contains(address pc) const { return pc >= _start && pc < _end; } 163 bool contains2(address pc) const { return pc >= _start && pc <= _end; } 164 bool allocates(address pc) const { return pc >= _start && pc < _limit; } 165 bool allocates2(address pc) const { return pc >= _start && pc <= _limit; } 166 167 void set_end(address pc) { assert(allocates2(pc),""); _end = pc; } 168 void set_mark(address pc) { assert(contains2(pc),"not in codeBuffer"); 169 _mark = pc; } 170 void set_mark_off(int offset) { assert(contains2(offset+_start),"not in codeBuffer"); 171 _mark = offset + _start; } 172 void set_mark() { _mark = _end; } 173 void clear_mark() { _mark = NULL; } 174 175 void set_locs_end(relocInfo* p) { 176 assert(p <= locs_limit(), "locs data fits in allocated buffer"); 177 _locs_end = p; 178 } 179 void set_locs_point(address pc) { 180 assert(pc >= locs_point(), "relocation addr may not decrease"); 181 assert(allocates2(pc), "relocation addr must be in this section"); 182 _locs_point = pc; 183 } 184 185 // Share a scratch buffer for relocinfo. (Hacky; saves a resource allocation.) 186 void initialize_shared_locs(relocInfo* buf, int length); 187 188 // Manage labels and their addresses. 189 address target(Label& L, address branch_pc); 190 191 // Emit a relocation. 192 void relocate(address at, RelocationHolder const& rspec, int format = 0); 193 void relocate(address at, relocInfo::relocType rtype, int format = 0) { 194 if (rtype != relocInfo::none) 195 relocate(at, Relocation::spec_simple(rtype), format); 196 } 197 198 // alignment requirement for starting offset 199 // Requirements are that the instruction area and the 200 // stubs area must start on CodeEntryAlignment, and 201 // the ctable on sizeof(jdouble) 202 int alignment() const { return MAX2((int)sizeof(jdouble), (int)CodeEntryAlignment); } 203 204 // Slop between sections, used only when allocating temporary BufferBlob buffers. 205 static csize_t end_slop() { return MAX2((int)sizeof(jdouble), (int)CodeEntryAlignment); } 206 207 csize_t align_at_start(csize_t off) const { return (csize_t) align_size_up(off, alignment()); } 208 209 // Mark a section frozen. Assign its remaining space to 210 // the following section. It will never expand after this point. 211 inline void freeze(); // { _outer->freeze_section(this); } 212 213 // Ensure there's enough space left in the current section. 214 // Return true if there was an expansion. 215 bool maybe_expand_to_ensure_remaining(csize_t amount); 216 217#ifndef PRODUCT 218 void decode(); 219 void dump(); 220 void print(const char* name); 221#endif //PRODUCT 222}; 223 224class CodeComment; 225class CodeComments VALUE_OBJ_CLASS_SPEC { 226private: 227#ifndef PRODUCT 228 CodeComment* _comments; 229#endif 230 231public: 232 CodeComments() { 233#ifndef PRODUCT 234 _comments = NULL; 235#endif 236 } 237 238 void add_comment(intptr_t offset, const char * comment) PRODUCT_RETURN; 239 void print_block_comment(outputStream* stream, intptr_t offset) PRODUCT_RETURN; 240 void assign(CodeComments& other) PRODUCT_RETURN; 241 void free() PRODUCT_RETURN; 242}; 243 244 245// A CodeBuffer describes a memory space into which assembly 246// code is generated. This memory space usually occupies the 247// interior of a single BufferBlob, but in some cases it may be 248// an arbitrary span of memory, even outside the code cache. 249// 250// A code buffer comes in two variants: 251// 252// (1) A CodeBuffer referring to an already allocated piece of memory: 253// This is used to direct 'static' code generation (e.g. for interpreter 254// or stubroutine generation, etc.). This code comes with NO relocation 255// information. 256// 257// (2) A CodeBuffer referring to a piece of memory allocated when the 258// CodeBuffer is allocated. This is used for nmethod generation. 259// 260// The memory can be divided up into several parts called sections. 261// Each section independently accumulates code (or data) an relocations. 262// Sections can grow (at the expense of a reallocation of the BufferBlob 263// and recopying of all active sections). When the buffered code is finally 264// written to an nmethod (or other CodeBlob), the contents (code, data, 265// and relocations) of the sections are padded to an alignment and concatenated. 266// Instructions and data in one section can contain relocatable references to 267// addresses in a sibling section. 268 269class CodeBuffer: public StackObj { 270 friend class CodeSection; 271 272 private: 273 // CodeBuffers must be allocated on the stack except for a single 274 // special case during expansion which is handled internally. This 275 // is done to guarantee proper cleanup of resources. 276 void* operator new(size_t size) { return ResourceObj::operator new(size); } 277 void operator delete(void* p) { ResourceObj::operator delete(p); } 278 279 public: 280 typedef int csize_t; // code size type; would be size_t except for history 281 enum { 282 // Here is the list of all possible sections, in order of ascending address. 283 SECT_INSTS, // Executable instructions. 284 SECT_STUBS, // Outbound trampolines for supporting call sites. 285 SECT_CONSTS, // Non-instruction data: Floats, jump tables, etc. 286 SECT_LIMIT, SECT_NONE = -1 287 }; 288 289 private: 290 enum { 291 sect_bits = 2, // assert (SECT_LIMIT <= (1<<sect_bits)) 292 sect_mask = (1<<sect_bits)-1 293 }; 294 295 const char* _name; 296 297 CodeSection _insts; // instructions (the main section) 298 CodeSection _stubs; // stubs (call site support), deopt, exception handling 299 CodeSection _consts; // constants, jump tables 300 301 CodeBuffer* _before_expand; // dead buffer, from before the last expansion 302 303 BufferBlob* _blob; // optional buffer in CodeCache for generated code 304 address _total_start; // first address of combined memory buffer 305 csize_t _total_size; // size in bytes of combined memory buffer 306 307 OopRecorder* _oop_recorder; 308 CodeComments _comments; 309 OopRecorder _default_oop_recorder; // override with initialize_oop_recorder 310 Arena* _overflow_arena; 311 312 address _decode_begin; // start address for decode 313 address decode_begin(); 314 315 void initialize_misc(const char * name) { 316 // all pointers other than code_start/end and those inside the sections 317 assert(name != NULL, "must have a name"); 318 _name = name; 319 _before_expand = NULL; 320 _blob = NULL; 321 _oop_recorder = NULL; 322 _decode_begin = NULL; 323 _overflow_arena = NULL; 324 } 325 326 void initialize(address code_start, csize_t code_size) { 327 _insts.initialize_outer(this, SECT_INSTS); 328 _stubs.initialize_outer(this, SECT_STUBS); 329 _consts.initialize_outer(this, SECT_CONSTS); 330 _total_start = code_start; 331 _total_size = code_size; 332 // Initialize the main section: 333 _insts.initialize(code_start, code_size); 334 assert(!_stubs.is_allocated(), "no garbage here"); 335 assert(!_consts.is_allocated(), "no garbage here"); 336 _oop_recorder = &_default_oop_recorder; 337 } 338 339 void initialize_section_size(CodeSection* cs, csize_t size); 340 341 void freeze_section(CodeSection* cs); 342 343 // helper for CodeBuffer::expand() 344 void take_over_code_from(CodeBuffer* cs); 345 346#ifdef ASSERT 347 // ensure sections are disjoint, ordered, and contained in the blob 348 bool verify_section_allocation(); 349#endif 350 351 // copies combined relocations to the blob, returns bytes copied 352 // (if target is null, it is a dry run only, just for sizing) 353 csize_t copy_relocations_to(CodeBlob* blob) const; 354 355 // copies combined code to the blob (assumes relocs are already in there) 356 void copy_code_to(CodeBlob* blob); 357 358 // moves code sections to new buffer (assumes relocs are already in there) 359 void relocate_code_to(CodeBuffer* cb) const; 360 361 // set up a model of the final layout of my contents 362 void compute_final_layout(CodeBuffer* dest) const; 363 364 // Expand the given section so at least 'amount' is remaining. 365 // Creates a new, larger BufferBlob, and rewrites the code & relocs. 366 void expand(CodeSection* which_cs, csize_t amount); 367 368 // Helper for expand. 369 csize_t figure_expanded_capacities(CodeSection* which_cs, csize_t amount, csize_t* new_capacity); 370 371 public: 372 // (1) code buffer referring to pre-allocated instruction memory 373 CodeBuffer(address code_start, csize_t code_size); 374 375 // (2) code buffer allocating codeBlob memory for code & relocation 376 // info but with lazy initialization. The name must be something 377 // informative. 378 CodeBuffer(const char* name) { 379 initialize_misc(name); 380 } 381 382 383 // (3) code buffer allocating codeBlob memory for code & relocation 384 // info. The name must be something informative and code_size must 385 // include both code and stubs sizes. 386 CodeBuffer(const char* name, csize_t code_size, csize_t locs_size) { 387 initialize_misc(name); 388 initialize(code_size, locs_size); 389 } 390 391 ~CodeBuffer(); 392 393 // Initialize a CodeBuffer constructed using constructor 2. Using 394 // constructor 3 is equivalent to calling constructor 2 and then 395 // calling this method. It's been factored out for convenience of 396 // construction. 397 void initialize(csize_t code_size, csize_t locs_size); 398 399 CodeSection* insts() { return &_insts; } 400 CodeSection* stubs() { return &_stubs; } 401 CodeSection* consts() { return &_consts; } 402 403 // present sections in order; return NULL at end; insts is #0, etc. 404 CodeSection* code_section(int n) { 405 // This makes the slightly questionable but portable assumption that 406 // the various members (_insts, _stubs, etc.) are adjacent in the 407 // layout of CodeBuffer. 408 CodeSection* cs = &_insts + n; 409 assert(cs->index() == n || !cs->is_allocated(), "sanity"); 410 return cs; 411 } 412 const CodeSection* code_section(int n) const { // yucky const stuff 413 return ((CodeBuffer*)this)->code_section(n); 414 } 415 static const char* code_section_name(int n); 416 int section_index_of(address addr) const; 417 bool contains(address addr) const { 418 // handy for debugging 419 return section_index_of(addr) > SECT_NONE; 420 } 421 422 // A stable mapping between 'locators' (small ints) and addresses. 423 static int locator_pos(int locator) { return locator >> sect_bits; } 424 static int locator_sect(int locator) { return locator & sect_mask; } 425 static int locator(int pos, int sect) { return (pos << sect_bits) | sect; } 426 int locator(address addr) const; 427 address locator_address(int locator) const; 428 429 // Properties 430 const char* name() const { return _name; } 431 CodeBuffer* before_expand() const { return _before_expand; } 432 BufferBlob* blob() const { return _blob; } 433 void set_blob(BufferBlob* blob); 434 void free_blob(); // Free the blob, if we own one. 435 436 // Properties relative to the insts section: 437 address code_begin() const { return _insts.start(); } 438 address code_end() const { return _insts.end(); } 439 void set_code_end(address end) { _insts.set_end(end); } 440 address code_limit() const { return _insts.limit(); } 441 address inst_mark() const { return _insts.mark(); } 442 void set_inst_mark() { _insts.set_mark(); } 443 void clear_inst_mark() { _insts.clear_mark(); } 444 445 // is there anything in the buffer other than the current section? 446 bool is_pure() const { return code_size() == total_code_size(); } 447 448 // size in bytes of output so far in the insts sections 449 csize_t code_size() const { return _insts.size(); } 450 451 // same as code_size(), except that it asserts there is no non-code here 452 csize_t pure_code_size() const { assert(is_pure(), "no non-code"); 453 return code_size(); } 454 // capacity in bytes of the insts sections 455 csize_t code_capacity() const { return _insts.capacity(); } 456 457 // number of bytes remaining in the insts section 458 csize_t code_remaining() const { return _insts.remaining(); } 459 460 // is a given address in the insts section? (2nd version is end-inclusive) 461 bool code_contains(address pc) const { return _insts.contains(pc); } 462 bool code_contains2(address pc) const { return _insts.contains2(pc); } 463 464 // allocated size of code in all sections, when aligned and concatenated 465 // (this is the eventual state of the code in its final CodeBlob) 466 csize_t total_code_size() const; 467 468 // combined offset (relative to start of insts) of given address, 469 // as eventually found in the final CodeBlob 470 csize_t total_offset_of(address addr) const; 471 472 // allocated size of all relocation data, including index, rounded up 473 csize_t total_relocation_size() const; 474 475 // allocated size of any and all recorded oops 476 csize_t total_oop_size() const { 477 OopRecorder* recorder = oop_recorder(); 478 return (recorder == NULL)? 0: recorder->oop_size(); 479 } 480 481 // Configuration functions, called immediately after the CB is constructed. 482 // The section sizes are subtracted from the original insts section. 483 // Note: Call them in reverse section order, because each steals from insts. 484 void initialize_consts_size(csize_t size) { initialize_section_size(&_consts, size); } 485 void initialize_stubs_size(csize_t size) { initialize_section_size(&_stubs, size); } 486 // Override default oop recorder. 487 void initialize_oop_recorder(OopRecorder* r); 488 489 OopRecorder* oop_recorder() const { return _oop_recorder; } 490 CodeComments& comments() { return _comments; } 491 492 // Code generation 493 void relocate(address at, RelocationHolder const& rspec, int format = 0) { 494 _insts.relocate(at, rspec, format); 495 } 496 void relocate(address at, relocInfo::relocType rtype, int format = 0) { 497 _insts.relocate(at, rtype, format); 498 } 499 500 // Management of overflow storage for binding of Labels. 501 GrowableArray<int>* create_patch_overflow(); 502 503 // NMethod generation 504 void copy_code_and_locs_to(CodeBlob* blob) { 505 assert(blob != NULL, "sane"); 506 copy_relocations_to(blob); 507 copy_code_to(blob); 508 } 509 void copy_oops_to(CodeBlob* blob) { 510 if (!oop_recorder()->is_unused()) { 511 oop_recorder()->copy_to(blob); 512 } 513 } 514 515 // Transform an address from the code in this code buffer to a specified code buffer 516 address transform_address(const CodeBuffer &cb, address addr) const; 517 518 void block_comment(intptr_t offset, const char * comment) PRODUCT_RETURN; 519 520#ifndef PRODUCT 521 public: 522 // Printing / Decoding 523 // decodes from decode_begin() to code_end() and sets decode_begin to end 524 void decode(); 525 void decode_all(); // decodes all the code 526 void skip_decode(); // sets decode_begin to code_end(); 527 void print(); 528#endif 529 530 531 // The following header contains architecture-specific implementations 532 #include "incls/_codeBuffer_pd.hpp.incl" 533}; 534 535 536inline void CodeSection::freeze() { 537 _outer->freeze_section(this); 538} 539 540inline bool CodeSection::maybe_expand_to_ensure_remaining(csize_t amount) { 541 if (remaining() < amount) { _outer->expand(this, amount); return true; } 542 return false; 543} 544