codeBuffer.hpp revision 3883:cd3d6a6b95d9
1/* 2 * Copyright (c) 1997, 2012, 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 "code/oopRecorder.hpp" 29#include "code/relocInfo.hpp" 30 31class CodeComments; 32class PhaseCFG; 33class Compile; 34class BufferBlob; 35class CodeBuffer; 36class Label; 37 38class CodeOffsets: public StackObj { 39public: 40 enum Entries { Entry, 41 Verified_Entry, 42 Frame_Complete, // Offset in the code where the frame setup is (for forte stackwalks) is complete 43 OSR_Entry, 44 Dtrace_trap = OSR_Entry, // dtrace probes can never have an OSR entry so reuse it 45 Exceptions, // Offset where exception handler lives 46 Deopt, // Offset where deopt handler lives 47 DeoptMH, // Offset where MethodHandle deopt handler lives 48 UnwindHandler, // Offset to default unwind handler 49 max_Entries }; 50 51 // special value to note codeBlobs where profile (forte) stack walking is 52 // always dangerous and suspect. 53 54 enum { frame_never_safe = -1 }; 55 56private: 57 int _values[max_Entries]; 58 59public: 60 CodeOffsets() { 61 _values[Entry ] = 0; 62 _values[Verified_Entry] = 0; 63 _values[Frame_Complete] = frame_never_safe; 64 _values[OSR_Entry ] = 0; 65 _values[Exceptions ] = -1; 66 _values[Deopt ] = -1; 67 _values[DeoptMH ] = -1; 68 _values[UnwindHandler ] = -1; 69 } 70 71 int value(Entries e) { return _values[e]; } 72 void set_value(Entries e, int val) { _values[e] = val; } 73}; 74 75// This class represents a stream of code and associated relocations. 76// There are a few in each CodeBuffer. 77// They are filled concurrently, and concatenated at the end. 78class CodeSection VALUE_OBJ_CLASS_SPEC { 79 friend class CodeBuffer; 80 public: 81 typedef int csize_t; // code size type; would be size_t except for history 82 83 private: 84 address _start; // first byte of contents (instructions) 85 address _mark; // user mark, usually an instruction beginning 86 address _end; // current end address 87 address _limit; // last possible (allocated) end address 88 relocInfo* _locs_start; // first byte of relocation information 89 relocInfo* _locs_end; // first byte after relocation information 90 relocInfo* _locs_limit; // first byte after relocation information buf 91 address _locs_point; // last relocated position (grows upward) 92 bool _locs_own; // did I allocate the locs myself? 93 bool _frozen; // no more expansion of this section 94 char _index; // my section number (SECT_INST, etc.) 95 CodeBuffer* _outer; // enclosing CodeBuffer 96 97 // (Note: _locs_point used to be called _last_reloc_offset.) 98 99 CodeSection() { 100 _start = NULL; 101 _mark = NULL; 102 _end = NULL; 103 _limit = NULL; 104 _locs_start = NULL; 105 _locs_end = NULL; 106 _locs_limit = NULL; 107 _locs_point = NULL; 108 _locs_own = false; 109 _frozen = false; 110 debug_only(_index = (char)-1); 111 debug_only(_outer = (CodeBuffer*)badAddress); 112 } 113 114 void initialize_outer(CodeBuffer* outer, int index) { 115 _outer = outer; 116 _index = index; 117 } 118 119 void initialize(address start, csize_t size = 0) { 120 assert(_start == NULL, "only one init step, please"); 121 _start = start; 122 _mark = NULL; 123 _end = start; 124 125 _limit = start + size; 126 _locs_point = start; 127 } 128 129 void initialize_locs(int locs_capacity); 130 void expand_locs(int new_capacity); 131 void initialize_locs_from(const CodeSection* source_cs); 132 133 // helper for CodeBuffer::expand() 134 void take_over_code_from(CodeSection* cs) { 135 _start = cs->_start; 136 _mark = cs->_mark; 137 _end = cs->_end; 138 _limit = cs->_limit; 139 _locs_point = cs->_locs_point; 140 } 141 142 public: 143 address start() const { return _start; } 144 address mark() const { return _mark; } 145 address end() const { return _end; } 146 address limit() const { return _limit; } 147 csize_t size() const { return (csize_t)(_end - _start); } 148 csize_t mark_off() const { assert(_mark != NULL, "not an offset"); 149 return (csize_t)(_mark - _start); } 150 csize_t capacity() const { return (csize_t)(_limit - _start); } 151 csize_t remaining() const { return (csize_t)(_limit - _end); } 152 153 relocInfo* locs_start() const { return _locs_start; } 154 relocInfo* locs_end() const { return _locs_end; } 155 int locs_count() const { return (int)(_locs_end - _locs_start); } 156 relocInfo* locs_limit() const { return _locs_limit; } 157 address locs_point() const { return _locs_point; } 158 csize_t locs_point_off() const{ return (csize_t)(_locs_point - _start); } 159 csize_t locs_capacity() const { return (csize_t)(_locs_limit - _locs_start); } 160 csize_t locs_remaining()const { return (csize_t)(_locs_limit - _locs_end); } 161 162 int index() const { return _index; } 163 bool is_allocated() const { return _start != NULL; } 164 bool is_empty() const { return _start == _end; } 165 bool is_frozen() const { return _frozen; } 166 bool has_locs() const { return _locs_end != NULL; } 167 168 CodeBuffer* outer() const { return _outer; } 169 170 // is a given address in this section? (2nd version is end-inclusive) 171 bool contains(address pc) const { return pc >= _start && pc < _end; } 172 bool contains2(address pc) const { return pc >= _start && pc <= _end; } 173 bool allocates(address pc) const { return pc >= _start && pc < _limit; } 174 bool allocates2(address pc) const { return pc >= _start && pc <= _limit; } 175 176 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; } 177 void set_mark(address pc) { assert(contains2(pc), "not in codeBuffer"); 178 _mark = pc; } 179 void set_mark_off(int offset) { assert(contains2(offset+_start),"not in codeBuffer"); 180 _mark = offset + _start; } 181 void set_mark() { _mark = _end; } 182 void clear_mark() { _mark = NULL; } 183 184 void set_locs_end(relocInfo* p) { 185 assert(p <= locs_limit(), "locs data fits in allocated buffer"); 186 _locs_end = p; 187 } 188 void set_locs_point(address pc) { 189 assert(pc >= locs_point(), "relocation addr may not decrease"); 190 assert(allocates2(pc), "relocation addr must be in this section"); 191 _locs_point = pc; 192 } 193 194 // Code emission 195 void emit_int8 ( int8_t x) { *((int8_t*) end()) = x; set_end(end() + sizeof(int8_t)); } 196 void emit_int16( int16_t x) { *((int16_t*) end()) = x; set_end(end() + sizeof(int16_t)); } 197 void emit_int32( int32_t x) { *((int32_t*) end()) = x; set_end(end() + sizeof(int32_t)); } 198 void emit_int64( int64_t x) { *((int64_t*) end()) = x; set_end(end() + sizeof(int64_t)); } 199 200 void emit_float( jfloat x) { *((jfloat*) end()) = x; set_end(end() + sizeof(jfloat)); } 201 void emit_double(jdouble x) { *((jdouble*) end()) = x; set_end(end() + sizeof(jdouble)); } 202 void emit_address(address x) { *((address*) end()) = x; set_end(end() + sizeof(address)); } 203 204 // Share a scratch buffer for relocinfo. (Hacky; saves a resource allocation.) 205 void initialize_shared_locs(relocInfo* buf, int length); 206 207 // Manage labels and their addresses. 208 address target(Label& L, address branch_pc); 209 210 // Emit a relocation. 211 void relocate(address at, RelocationHolder const& rspec, int format = 0); 212 void relocate(address at, relocInfo::relocType rtype, int format = 0) { 213 if (rtype != relocInfo::none) 214 relocate(at, Relocation::spec_simple(rtype), format); 215 } 216 217 // alignment requirement for starting offset 218 // Requirements are that the instruction area and the 219 // stubs area must start on CodeEntryAlignment, and 220 // the ctable on sizeof(jdouble) 221 int alignment() const { return MAX2((int)sizeof(jdouble), (int)CodeEntryAlignment); } 222 223 // Slop between sections, used only when allocating temporary BufferBlob buffers. 224 static csize_t end_slop() { return MAX2((int)sizeof(jdouble), (int)CodeEntryAlignment); } 225 226 csize_t align_at_start(csize_t off) const { return (csize_t) align_size_up(off, alignment()); } 227 228 // Mark a section frozen. Assign its remaining space to 229 // the following section. It will never expand after this point. 230 inline void freeze(); // { _outer->freeze_section(this); } 231 232 // Ensure there's enough space left in the current section. 233 // Return true if there was an expansion. 234 bool maybe_expand_to_ensure_remaining(csize_t amount); 235 236#ifndef PRODUCT 237 void decode(); 238 void dump(); 239 void print(const char* name); 240#endif //PRODUCT 241}; 242 243class CodeComment; 244class CodeComments VALUE_OBJ_CLASS_SPEC { 245private: 246#ifndef PRODUCT 247 CodeComment* _comments; 248#endif 249 250public: 251 CodeComments() { 252#ifndef PRODUCT 253 _comments = NULL; 254#endif 255 } 256 257 void add_comment(intptr_t offset, const char * comment) PRODUCT_RETURN; 258 void print_block_comment(outputStream* stream, intptr_t offset) const PRODUCT_RETURN; 259 void assign(CodeComments& other) PRODUCT_RETURN; 260 void free() PRODUCT_RETURN; 261}; 262 263 264// A CodeBuffer describes a memory space into which assembly 265// code is generated. This memory space usually occupies the 266// interior of a single BufferBlob, but in some cases it may be 267// an arbitrary span of memory, even outside the code cache. 268// 269// A code buffer comes in two variants: 270// 271// (1) A CodeBuffer referring to an already allocated piece of memory: 272// This is used to direct 'static' code generation (e.g. for interpreter 273// or stubroutine generation, etc.). This code comes with NO relocation 274// information. 275// 276// (2) A CodeBuffer referring to a piece of memory allocated when the 277// CodeBuffer is allocated. This is used for nmethod generation. 278// 279// The memory can be divided up into several parts called sections. 280// Each section independently accumulates code (or data) an relocations. 281// Sections can grow (at the expense of a reallocation of the BufferBlob 282// and recopying of all active sections). When the buffered code is finally 283// written to an nmethod (or other CodeBlob), the contents (code, data, 284// and relocations) of the sections are padded to an alignment and concatenated. 285// Instructions and data in one section can contain relocatable references to 286// addresses in a sibling section. 287 288class CodeBuffer: public StackObj { 289 friend class CodeSection; 290 291 private: 292 // CodeBuffers must be allocated on the stack except for a single 293 // special case during expansion which is handled internally. This 294 // is done to guarantee proper cleanup of resources. 295 void* operator new(size_t size) { return ResourceObj::operator new(size); } 296 void operator delete(void* p) { ShouldNotCallThis(); } 297 298 public: 299 typedef int csize_t; // code size type; would be size_t except for history 300 enum { 301 // Here is the list of all possible sections. The order reflects 302 // the final layout. 303 SECT_FIRST = 0, 304 SECT_CONSTS = SECT_FIRST, // Non-instruction data: Floats, jump tables, etc. 305 SECT_INSTS, // Executable instructions. 306 SECT_STUBS, // Outbound trampolines for supporting call sites. 307 SECT_LIMIT, SECT_NONE = -1 308 }; 309 310 private: 311 enum { 312 sect_bits = 2, // assert (SECT_LIMIT <= (1<<sect_bits)) 313 sect_mask = (1<<sect_bits)-1 314 }; 315 316 const char* _name; 317 318 CodeSection _consts; // constants, jump tables 319 CodeSection _insts; // instructions (the main section) 320 CodeSection _stubs; // stubs (call site support), deopt, exception handling 321 322 CodeBuffer* _before_expand; // dead buffer, from before the last expansion 323 324 BufferBlob* _blob; // optional buffer in CodeCache for generated code 325 address _total_start; // first address of combined memory buffer 326 csize_t _total_size; // size in bytes of combined memory buffer 327 328 OopRecorder* _oop_recorder; 329 CodeComments _comments; 330 OopRecorder _default_oop_recorder; // override with initialize_oop_recorder 331 Arena* _overflow_arena; 332 333 address _decode_begin; // start address for decode 334 address decode_begin(); 335 336 void initialize_misc(const char * name) { 337 // all pointers other than code_start/end and those inside the sections 338 assert(name != NULL, "must have a name"); 339 _name = name; 340 _before_expand = NULL; 341 _blob = NULL; 342 _oop_recorder = NULL; 343 _decode_begin = NULL; 344 _overflow_arena = NULL; 345 } 346 347 void initialize(address code_start, csize_t code_size) { 348 _consts.initialize_outer(this, SECT_CONSTS); 349 _insts.initialize_outer(this, SECT_INSTS); 350 _stubs.initialize_outer(this, SECT_STUBS); 351 _total_start = code_start; 352 _total_size = code_size; 353 // Initialize the main section: 354 _insts.initialize(code_start, code_size); 355 assert(!_stubs.is_allocated(), "no garbage here"); 356 assert(!_consts.is_allocated(), "no garbage here"); 357 _oop_recorder = &_default_oop_recorder; 358 } 359 360 void initialize_section_size(CodeSection* cs, csize_t size); 361 362 void freeze_section(CodeSection* cs); 363 364 // helper for CodeBuffer::expand() 365 void take_over_code_from(CodeBuffer* cs); 366 367 // ensure sections are disjoint, ordered, and contained in the blob 368 void verify_section_allocation(); 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 verify_section_allocation(); 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 // Heuristic for pre-packing the taken/not-taken bit of a predicted branch. 457 bool is_backward_branch(Label& L); 458 459 // Properties 460 const char* name() const { return _name; } 461 CodeBuffer* before_expand() const { return _before_expand; } 462 BufferBlob* blob() const { return _blob; } 463 void set_blob(BufferBlob* blob); 464 void free_blob(); // Free the blob, if we own one. 465 466 // Properties relative to the insts section: 467 address insts_begin() const { return _insts.start(); } 468 address insts_end() const { return _insts.end(); } 469 void set_insts_end(address end) { _insts.set_end(end); } 470 address insts_limit() const { return _insts.limit(); } 471 address insts_mark() const { return _insts.mark(); } 472 void set_insts_mark() { _insts.set_mark(); } 473 void clear_insts_mark() { _insts.clear_mark(); } 474 475 // is there anything in the buffer other than the current section? 476 bool is_pure() const { return insts_size() == total_content_size(); } 477 478 // size in bytes of output so far in the insts sections 479 csize_t insts_size() const { return _insts.size(); } 480 481 // same as insts_size(), except that it asserts there is no non-code here 482 csize_t pure_insts_size() const { assert(is_pure(), "no non-code"); 483 return insts_size(); } 484 // capacity in bytes of the insts sections 485 csize_t insts_capacity() const { return _insts.capacity(); } 486 487 // number of bytes remaining in the insts section 488 csize_t insts_remaining() const { return _insts.remaining(); } 489 490 // is a given address in the insts section? (2nd version is end-inclusive) 491 bool insts_contains(address pc) const { return _insts.contains(pc); } 492 bool insts_contains2(address pc) const { return _insts.contains2(pc); } 493 494 // Record any extra oops required to keep embedded metadata alive 495 void finalize_oop_references(methodHandle method); 496 497 // Allocated size in all sections, when aligned and concatenated 498 // (this is the eventual state of the content in its final 499 // CodeBlob). 500 csize_t total_content_size() const; 501 502 // Combined offset (relative to start of first section) of given 503 // section, as eventually found in the final CodeBlob. 504 csize_t total_offset_of(CodeSection* cs) const; 505 506 // allocated size of all relocation data, including index, rounded up 507 csize_t total_relocation_size() const; 508 509 // allocated size of any and all recorded oops 510 csize_t total_oop_size() const { 511 OopRecorder* recorder = oop_recorder(); 512 return (recorder == NULL)? 0: recorder->oop_size(); 513 } 514 515 // allocated size of any and all recorded metadata 516 csize_t total_metadata_size() const { 517 OopRecorder* recorder = oop_recorder(); 518 return (recorder == NULL)? 0: recorder->metadata_size(); 519 } 520 521 // Configuration functions, called immediately after the CB is constructed. 522 // The section sizes are subtracted from the original insts section. 523 // Note: Call them in reverse section order, because each steals from insts. 524 void initialize_consts_size(csize_t size) { initialize_section_size(&_consts, size); } 525 void initialize_stubs_size(csize_t size) { initialize_section_size(&_stubs, size); } 526 // Override default oop recorder. 527 void initialize_oop_recorder(OopRecorder* r); 528 529 OopRecorder* oop_recorder() const { return _oop_recorder; } 530 CodeComments& comments() { return _comments; } 531 532 // Code generation 533 void relocate(address at, RelocationHolder const& rspec, int format = 0) { 534 _insts.relocate(at, rspec, format); 535 } 536 void relocate(address at, relocInfo::relocType rtype, int format = 0) { 537 _insts.relocate(at, rtype, format); 538 } 539 540 // Management of overflow storage for binding of Labels. 541 GrowableArray<int>* create_patch_overflow(); 542 543 // NMethod generation 544 void copy_code_and_locs_to(CodeBlob* blob) { 545 assert(blob != NULL, "sane"); 546 copy_relocations_to(blob); 547 copy_code_to(blob); 548 } 549 void copy_values_to(nmethod* nm) { 550 if (!oop_recorder()->is_unused()) { 551 oop_recorder()->copy_values_to(nm); 552 } 553 } 554 555 // Transform an address from the code in this code buffer to a specified code buffer 556 address transform_address(const CodeBuffer &cb, address addr) const; 557 558 void block_comment(intptr_t offset, const char * comment) PRODUCT_RETURN; 559 560 // Log a little info about section usage in the CodeBuffer 561 void log_section_sizes(const char* name); 562 563#ifndef PRODUCT 564 public: 565 // Printing / Decoding 566 // decodes from decode_begin() to code_end() and sets decode_begin to end 567 void decode(); 568 void decode_all(); // decodes all the code 569 void skip_decode(); // sets decode_begin to code_end(); 570 void print(); 571#endif 572 573 574 // The following header contains architecture-specific implementations 575#ifdef TARGET_ARCH_x86 576# include "codeBuffer_x86.hpp" 577#endif 578#ifdef TARGET_ARCH_sparc 579# include "codeBuffer_sparc.hpp" 580#endif 581#ifdef TARGET_ARCH_zero 582# include "codeBuffer_zero.hpp" 583#endif 584#ifdef TARGET_ARCH_arm 585# include "codeBuffer_arm.hpp" 586#endif 587#ifdef TARGET_ARCH_ppc 588# include "codeBuffer_ppc.hpp" 589#endif 590 591}; 592 593 594inline void CodeSection::freeze() { 595 _outer->freeze_section(this); 596} 597 598inline bool CodeSection::maybe_expand_to_ensure_remaining(csize_t amount) { 599 if (remaining() < amount) { _outer->expand(this, amount); return true; } 600 return false; 601} 602 603#endif // SHARE_VM_ASM_CODEBUFFER_HPP 604