1 #!/usr/bin/env python 2 3 """ 4 Optimise object layouts and generate access instruction plans. 5 6 Copyright (C) 2014, 2015, 2016, 2017 Paul Boddie <paul@boddie.org.uk> 7 8 This program is free software; you can redistribute it and/or modify it under 9 the terms of the GNU General Public License as published by the Free Software 10 Foundation; either version 3 of the License, or (at your option) any later 11 version. 12 13 This program is distributed in the hope that it will be useful, but WITHOUT 14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 15 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more 16 details. 17 18 You should have received a copy of the GNU General Public License along with 19 this program. If not, see <http://www.gnu.org/licenses/>. 20 """ 21 22 from common import add_counter_item, get_attrname_from_location, init_item, \ 23 sorted_output 24 from encoders import encode_access_location, encode_instruction, get_kinds 25 from os.path import exists, join 26 from os import makedirs 27 from referencing import Reference 28 29 class Optimiser: 30 31 "Optimise objects in a program." 32 33 def __init__(self, importer, deducer, output): 34 35 """ 36 Initialise an instance using the given 'importer' and 'deducer' that 37 will perform the arrangement of attributes for program objects, writing 38 the results to the given 'output' directory. 39 """ 40 41 self.importer = importer 42 self.deducer = deducer 43 self.output = output 44 45 # Locations/offsets of attributes in objects. 46 47 self.locations = None 48 self.attr_locations = None 49 self.all_attrnames = None 50 51 # Locations of parameters in parameter tables. 52 53 self.arg_locations = None 54 self.param_locations = None 55 self.all_paramnames = None 56 57 # Specific attribute access information. 58 59 self.access_instructions = {} 60 self.accessor_kinds = {} 61 62 # Object structure information. 63 64 self.structures = {} 65 self.attr_table = {} 66 67 # Parameter list information. 68 69 self.parameters = {} 70 self.param_table = {} 71 72 # Constant literal information. 73 74 self.constants = [] 75 self.constant_numbers = {} 76 77 # Optimiser activities. 78 79 self.populate_objects() 80 self.position_attributes() 81 self.populate_parameters() 82 self.position_parameters() 83 self.populate_tables() 84 self.populate_constants() 85 self.initialise_access_instructions() 86 87 def to_output(self): 88 89 "Write the output files using optimisation information." 90 91 if not exists(self.output): 92 makedirs(self.output) 93 94 self.write_objects() 95 96 def write_objects(self): 97 98 """ 99 Write object-related output. 100 101 The locations are a list of positions indicating the attributes residing 102 at each position in the different structures in a program. 103 104 ---- 105 106 The parameter locations are a list of positions indicating the parameters 107 residing at each position in the different parameter lists in a program. 108 109 ---- 110 111 Each attribute plan provides attribute details in the following format: 112 113 location " " name " " test " " test type " " base 114 " " traversed attributes " " traversed attribute ambiguity 115 " " traversal access modes 116 " " attributes to traverse " " attribute ambiguity 117 " " context " " access method " " static attribute 118 119 Locations have the following format: 120 121 qualified name of scope "." local name ":" name version 122 123 Traversal access modes are either "class" (obtain accessor class to 124 access attribute) or "object" (obtain attribute directly from accessor). 125 126 ---- 127 128 The structures are presented as a table in the following format: 129 130 qualified name " " attribute names 131 132 The attribute names are separated by ", " characters and indicate the 133 attribute provided at each position in the structure associated with the 134 given type. Where no attribute is provided at a particular location 135 within a structure, "-" is given. 136 137 ---- 138 139 The parameters are presented as a table in the following format: 140 141 qualified name " " parameter details 142 143 The parameter details are separated by ", " characters and indicate 144 the parameter name and list position for each parameter described at 145 each location in the parameter table associated with the given 146 function. Where no parameter details are provided at a particular 147 location within a parameter table, "-" is given. The name and list 148 position are separated by a colon (":"). 149 150 ---- 151 152 The attribute table is presented as a table in the following format: 153 154 qualified name " " attribute identifiers 155 156 Instead of attribute names, identifiers defined according to the order 157 given in the "attrnames" file are employed to denote the attributes 158 featured in each type's structure. Where no attribute is provided at a 159 particular location within a structure, "-" is given. 160 161 ---- 162 163 The parameter table is presented as a table in the following format: 164 165 qualified name " " parameter details 166 167 Instead of parameter names, identifiers defined according to the order 168 given in the "paramnames" file are employed to denote the parameters 169 featured in each function's parameter table. Where no parameter is 170 provided at a particular location within a table, "-" is given. 171 172 ---- 173 174 The ordered list of attribute names is given in the "attrnames" file. 175 176 ---- 177 178 The ordered list of parameter names is given in the "paramnames" file. 179 180 ---- 181 182 The ordered list of constant literals is given in the "constants" file. 183 """ 184 185 f = open(join(self.output, "locations"), "w") 186 try: 187 for attrnames in self.locations: 188 print >>f, sorted_output(attrnames) 189 190 finally: 191 f.close() 192 193 f = open(join(self.output, "parameter_locations"), "w") 194 try: 195 for argnames in self.arg_locations: 196 print >>f, sorted_output(argnames) 197 198 finally: 199 f.close() 200 201 f = open(join(self.output, "instruction_plans"), "w") 202 try: 203 access_instructions = self.access_instructions.items() 204 access_instructions.sort() 205 206 for location, instructions in access_instructions: 207 print >>f, encode_access_location(location), "..." 208 for instruction in instructions: 209 print >>f, encode_instruction(instruction) 210 print >>f 211 212 finally: 213 f.close() 214 215 f = open(join(self.output, "structures"), "w") 216 try: 217 structures = self.structures.items() 218 structures.sort() 219 220 for name, attrnames in structures: 221 print >>f, name, ", ".join([s or "-" for s in attrnames]) 222 223 finally: 224 f.close() 225 226 f = open(join(self.output, "parameters"), "w") 227 try: 228 parameters = self.parameters.items() 229 parameters.sort() 230 231 for name, argnames in parameters: 232 print >>f, name, ", ".join([s and ("%s:%d" % s) or "-" for s in argnames]) 233 234 finally: 235 f.close() 236 237 f = open(join(self.output, "attrtable"), "w") 238 try: 239 attr_table = self.attr_table.items() 240 attr_table.sort() 241 242 for name, attrcodes in attr_table: 243 print >>f, name, ", ".join([i is not None and str(i) or "-" for i in attrcodes]) 244 245 finally: 246 f.close() 247 248 f = open(join(self.output, "paramtable"), "w") 249 try: 250 param_table = self.param_table.items() 251 param_table.sort() 252 253 for name, paramcodes in param_table: 254 print >>f, name, ", ".join([s and ("%d:%d" % s) or "-" for s in paramcodes]) 255 256 finally: 257 f.close() 258 259 f = open(join(self.output, "attrnames"), "w") 260 try: 261 for name in self.all_attrnames: 262 print >>f, name 263 264 finally: 265 f.close() 266 267 f = open(join(self.output, "paramnames"), "w") 268 try: 269 for name in self.all_paramnames: 270 print >>f, name 271 272 finally: 273 f.close() 274 275 f = open(join(self.output, "constants"), "w") 276 try: 277 constants = [] 278 for (value, value_type, encoding), n in self.constants.items(): 279 constants.append((n, value_type, encoding, value)) 280 constants.sort() 281 for n, value_type, encoding, value in constants: 282 print >>f, value_type, encoding or "{}", repr(value) 283 284 finally: 285 f.close() 286 287 def populate_objects(self): 288 289 "Populate objects using attribute and usage information." 290 291 self.all_attrs = {} 292 293 # Partition attributes into separate sections so that class and instance 294 # attributes are treated separately. 295 296 for source, objkind in [ 297 (self.importer.all_class_attrs, "<class>"), 298 (self.importer.all_instance_attrs, "<instance>"), 299 (self.importer.all_module_attrs, "<module>") 300 ]: 301 302 for name, attrnames in source.items(): 303 304 # Remove temporary names from structures. 305 306 attrnames = filter(lambda x: not x.startswith("$t"), attrnames) 307 self.all_attrs[(objkind, name)] = attrnames 308 309 self.locations = get_allocated_locations(self.all_attrs, get_attributes_and_sizes) 310 311 def populate_parameters(self): 312 313 "Populate parameter tables using parameter information." 314 315 self.arg_locations = [set()] + get_allocated_locations(self.importer.function_parameters, get_parameters_and_sizes) 316 317 def position_attributes(self): 318 319 "Position specific attribute references." 320 321 # Reverse the location mappings. 322 323 attr_locations = self.attr_locations = {} 324 325 for i, attrnames in enumerate(self.locations): 326 for attrname in attrnames: 327 attr_locations[attrname] = i 328 329 # Record the structures. 330 331 for (objkind, name), attrnames in self.all_attrs.items(): 332 key = Reference(objkind, name) 333 l = self.structures[key] = [None] * len(attrnames) 334 for attrname in attrnames: 335 position = attr_locations[attrname] 336 if position >= len(l): 337 l.extend([None] * (position - len(l) + 1)) 338 l[position] = attrname 339 340 def initialise_access_instructions(self): 341 342 "Expand access plans into instruction sequences." 343 344 for access_location, access_plan in self.deducer.access_plans.items(): 345 346 # Obtain the access details. 347 348 name, test, test_type, base, \ 349 traversed, traversal_modes, attrnames, \ 350 context, context_test, \ 351 first_method, final_method, \ 352 origin, accessor_kinds = access_plan 353 354 instructions = [] 355 emit = instructions.append 356 357 if base: 358 original_accessor = base 359 else: 360 original_accessor = "<expr>" # use a generic placeholder 361 362 # Prepare for any first attribute access. 363 364 if traversed: 365 attrname = traversed[0] 366 del traversed[0] 367 elif attrnames: 368 attrname = attrnames[0] 369 del attrnames[0] 370 371 # Perform the first access explicitly if at least one operation 372 # requires it. 373 374 access_first_attribute = final_method in ("access", "access-invoke", "assign") or traversed or attrnames 375 376 # Determine whether the first access involves assignment. 377 378 assigning = not traversed and not attrnames and final_method == "assign" 379 set_accessor = assigning and "<set_target_accessor>" or "<set_accessor>" 380 stored_accessor = assigning and "<target_accessor>" or "<accessor>" 381 382 # Set the context if already available. 383 384 if context == "base": 385 accessor = context_var = (base,) 386 elif context == "original-accessor": 387 388 # Prevent re-evaluation of any dynamic expression by storing it. 389 390 if original_accessor == "<expr>": 391 if final_method in ("access-invoke", "static-invoke"): 392 emit(("<set_context>", original_accessor)) 393 accessor = context_var = ("<context>",) 394 else: 395 emit((set_accessor, original_accessor)) 396 accessor = context_var = (stored_accessor,) 397 else: 398 accessor = context_var = (original_accessor,) 399 400 # Assigning does not set the context. 401 402 elif context in ("final-accessor", "unset") and access_first_attribute: 403 404 # Prevent re-evaluation of any dynamic expression by storing it. 405 406 if original_accessor == "<expr>": 407 emit((set_accessor, original_accessor)) 408 accessor = (stored_accessor,) 409 else: 410 accessor = (original_accessor,) 411 412 # Apply any test. 413 414 if test[0] == "test": 415 accessor = ("__%s_%s_%s" % test, accessor, test_type) 416 417 # Perform the first or final access. 418 # The access only needs performing if the resulting accessor is used. 419 420 remaining = len(traversed + attrnames) 421 422 if access_first_attribute: 423 424 if first_method == "relative-class": 425 if assigning: 426 emit(("__store_via_class", accessor, attrname, "<assexpr>")) 427 else: 428 accessor = ("__load_via_class", accessor, attrname) 429 430 elif first_method == "relative-object": 431 if assigning: 432 emit(("__store_via_object", accessor, attrname, "<assexpr>")) 433 else: 434 accessor = ("__load_via_object", accessor, attrname) 435 436 elif first_method == "relative-object-class": 437 if assigning: 438 emit(("__get_class_and_store", accessor, attrname, "<assexpr>")) 439 else: 440 accessor = ("__get_class_and_load", accessor, attrname) 441 442 elif first_method == "check-class": 443 if assigning: 444 emit(("__check_and_store_via_class", accessor, attrname, "<assexpr>")) 445 else: 446 accessor = ("__check_and_load_via_class", accessor, attrname) 447 448 elif first_method == "check-object": 449 if assigning: 450 emit(("__check_and_store_via_object", accessor, attrname, "<assexpr>")) 451 else: 452 accessor = ("__check_and_load_via_object", accessor, attrname) 453 454 elif first_method == "check-object-class": 455 if assigning: 456 emit(("__check_and_store_via_any", accessor, attrname, "<assexpr>")) 457 else: 458 accessor = ("__check_and_load_via_any", accessor, attrname) 459 460 # Traverse attributes using the accessor. 461 462 if traversed: 463 for attrname, traversal_mode in zip(traversed, traversal_modes): 464 assigning = remaining == 1 and final_method == "assign" 465 466 # Set the context, if appropriate. 467 468 if remaining == 1 and final_method != "assign" and context == "final-accessor": 469 emit(("<set_context>", accessor)) 470 accessor = context_var = "<context>" 471 472 # Perform the access only if not achieved directly. 473 474 if remaining > 1 or final_method in ("access", "access-invoke", "assign"): 475 476 if traversal_mode == "class": 477 if assigning: 478 emit(("__store_via_class", accessor, attrname, "<assexpr>")) 479 else: 480 accessor = ("__load_via_class", accessor, attrname) 481 else: 482 if assigning: 483 emit(("__store_via_object", accessor, attrname, "<assexpr>")) 484 else: 485 accessor = ("__load_via_object", accessor, attrname) 486 487 remaining -= 1 488 489 if attrnames: 490 for attrname in attrnames: 491 assigning = remaining == 1 and final_method == "assign" 492 493 # Set the context, if appropriate. 494 495 if remaining == 1 and final_method != "assign" and context == "final-accessor": 496 emit(("<set_context>", accessor)) 497 accessor = context_var = "<context>" 498 499 # Perform the access only if not achieved directly. 500 501 if remaining > 1 or final_method in ("access", "access-invoke", "assign"): 502 503 if assigning: 504 emit(("__check_and_store_via_any", accessor, attrname, "<assexpr>")) 505 else: 506 accessor = ("__check_and_load_via_any", accessor, attrname) 507 508 remaining -= 1 509 510 # Define or emit the means of accessing the actual target. 511 512 # Assignments to known attributes. 513 514 if final_method == "static-assign": 515 parent, attrname = origin.rsplit(".", 1) 516 emit(("__store_via_object", parent, attrname, "<assexpr>")) 517 518 # Invoked attributes employ a separate context. 519 520 elif final_method in ("static", "static-invoke"): 521 accessor = ("__load_static_ignore", origin) 522 523 # Wrap accesses in context operations. 524 525 if context_test == "test": 526 if final_method in ("static", "static-invoke"): 527 emit(("__load_static_test", context_var, origin)) 528 else: 529 emit(("__test_context", context_var, accessor)) 530 531 elif context_test == "replace": 532 533 # Produce an object with updated context. 534 535 if final_method == "static": 536 emit(("__load_static_replace", context_var, origin)) 537 538 # Omit the context update operation where the target is static 539 # and the context is recorded separately. 540 541 elif final_method == "static-invoke": 542 pass 543 544 # Only update any context if no separate context is used. 545 546 elif final_method != "access-invoke": 547 emit(("__update_context", context_var, accessor)) 548 549 else: 550 emit(accessor) 551 552 # Omit the accessor for assignments and for invocations of static 553 # targets. 554 555 elif final_method not in ("assign", "static-assign", "static-invoke"): 556 emit(accessor) 557 558 self.access_instructions[access_location] = instructions 559 self.accessor_kinds[access_location] = accessor_kinds 560 561 def get_ambiguity_for_attributes(self, attrnames): 562 563 """ 564 Return a list of attribute position alternatives corresponding to each 565 of the given 'attrnames'. 566 """ 567 568 ambiguity = [] 569 570 for attrname in attrnames: 571 position = self.attr_locations[attrname] 572 ambiguity.append(len(self.locations[position])) 573 574 return ambiguity 575 576 def position_parameters(self): 577 578 "Position the parameters for each function's parameter table." 579 580 # Reverse the location mappings. 581 582 param_locations = self.param_locations = {} 583 584 for i, argnames in enumerate(self.arg_locations): 585 586 # Position the arguments. 587 588 for argname in argnames: 589 param_locations[argname] = i 590 591 for name, argnames in self.importer.function_parameters.items(): 592 593 # Allocate an extra context parameter in the table. 594 595 l = self.parameters[name] = [None] + [None] * len(argnames) 596 597 # Store an entry for the name along with the name's position in the 598 # parameter list. 599 600 for pos, argname in enumerate(argnames): 601 602 # Position the argument in the table. 603 604 position = param_locations[argname] 605 if position >= len(l): 606 l.extend([None] * (position - len(l) + 1)) 607 608 # Indicate an argument list position starting from 1 (after the 609 # initial context argument). 610 611 l[position] = (argname, pos + 1) 612 613 def populate_tables(self): 614 615 """ 616 Assign identifiers to attributes and encode structure information using 617 these identifiers. 618 """ 619 620 self.all_attrnames, d = self._get_name_mapping(self.attr_locations) 621 622 # Record the numbers indicating the locations of the names. 623 624 for key, attrnames in self.structures.items(): 625 l = self.attr_table[key] = [] 626 for attrname in attrnames: 627 if attrname is None: 628 l.append(None) 629 else: 630 l.append(d[attrname]) 631 632 self.all_paramnames, d = self._get_name_mapping(self.param_locations) 633 634 # Record the numbers indicating the locations of the names. 635 636 for key, values in self.parameters.items(): 637 l = self.param_table[key] = [] 638 for value in values: 639 if value is None: 640 l.append(None) 641 else: 642 name, pos = value 643 l.append((d[name], pos)) 644 645 def _get_name_mapping(self, locations): 646 647 """ 648 Get a sorted list of names from 'locations', then map them to 649 identifying numbers. Return the list and the mapping. 650 """ 651 652 all_names = locations.keys() 653 all_names.sort() 654 d = {} 655 for i, name in enumerate(all_names): 656 d[name] = i 657 return all_names, d 658 659 def populate_constants(self): 660 661 """ 662 Obtain a collection of distinct constant literals, building a mapping 663 from constant references to those in this collection. 664 """ 665 666 # Obtain mappings from constant values to identifiers. 667 668 self.constants = {} 669 670 for path, constants in self.importer.all_constants.items(): 671 672 # Record constants and obtain a number for them. 673 # Each constant is actually (value, value_type, encoding). 674 675 for constant, n in constants.items(): 676 add_counter_item(self.constants, constant) 677 678 self.constant_numbers = {} 679 680 for name, constant in self.importer.all_constant_values.items(): 681 self.constant_numbers[name] = self.constants[constant] 682 683 def combine_rows(a, b): 684 c = [] 685 for i, j in zip(a, b): 686 if i is None or j is None: 687 c.append(i or j) 688 else: 689 return None 690 return c 691 692 def get_attributes_and_sizes(d): 693 694 """ 695 Return a matrix of attributes, a list of type names corresponding to columns 696 in the matrix, and a list of ranked sizes each indicating... 697 698 * a weighted size depending on the kind of object 699 * the minimum size of an object employing an attribute 700 * the number of free columns in the matrix for the attribute 701 * the attribute name itself 702 """ 703 704 attrs = {} 705 sizes = {} 706 objkinds = {} 707 708 for name, attrnames in d.items(): 709 objkind, _name = name 710 711 for attrname in attrnames: 712 713 # Record each type supporting the attribute. 714 715 init_item(attrs, attrname, set) 716 attrs[attrname].add(name) 717 718 # Maintain a record of the smallest object size supporting the given 719 # attribute. 720 721 if not sizes.has_key(attrname): 722 sizes[attrname] = len(attrnames) 723 else: 724 sizes[attrname] = min(sizes[attrname], len(attrnames)) 725 726 # Record the object types/kinds supporting the attribute. 727 728 init_item(objkinds, attrname, set) 729 objkinds[attrname].add(objkind) 730 731 # Obtain attribute details in order of size and occupancy. 732 733 names = d.keys() 734 735 rsizes = [] 736 for attrname, size in sizes.items(): 737 priority = "<instance>" in objkinds[attrname] and 0.5 or 1 738 occupied = len(attrs[attrname]) 739 key = (priority * size, size, len(names) - occupied, attrname) 740 rsizes.append(key) 741 742 rsizes.sort() 743 744 # Make a matrix of attributes. 745 746 matrix = {} 747 for attrname, types in attrs.items(): 748 row = [] 749 for name in names: 750 if name in types: 751 row.append(attrname) 752 else: 753 row.append(None) 754 matrix[attrname] = row 755 756 return matrix, names, rsizes 757 758 def get_parameters_and_sizes(d): 759 760 """ 761 Return a matrix of parameters, a list of functions corresponding to columns 762 in the matrix, and a list of ranked sizes each indicating... 763 764 * a weighted size depending on the kind of object 765 * the minimum size of a parameter list employing a parameter 766 * the number of free columns in the matrix for the parameter 767 * the parameter name itself 768 769 This is a slightly simpler version of the above 'get_attributes_and_sizes' 770 function. 771 """ 772 773 params = {} 774 sizes = {} 775 776 for name, argnames in d.items(): 777 for argname in argnames: 778 779 # Record each function supporting the parameter. 780 781 init_item(params, argname, set) 782 params[argname].add(name) 783 784 # Maintain a record of the smallest parameter list supporting the 785 # given parameter. 786 787 if not sizes.has_key(argname): 788 sizes[argname] = len(argnames) 789 else: 790 sizes[argname] = min(sizes[argname], len(argnames)) 791 792 # Obtain attribute details in order of size and occupancy. 793 794 names = d.keys() 795 796 rsizes = [] 797 for argname, size in sizes.items(): 798 occupied = len(params[argname]) 799 key = (size, size, len(names) - occupied, argname) 800 rsizes.append(key) 801 802 rsizes.sort() 803 804 # Make a matrix of parameters. 805 806 matrix = {} 807 for argname, types in params.items(): 808 row = [] 809 for name in names: 810 if name in types: 811 row.append(argname) 812 else: 813 row.append(None) 814 matrix[argname] = row 815 816 return matrix, names, rsizes 817 818 def get_allocated_locations(d, fn): 819 820 """ 821 Return a list where each element corresponds to a structure location and 822 contains a set of attribute names that may be stored at that location, given 823 a mapping 'd' whose keys are (object kind, object name) tuples and whose 824 values are collections of attributes. 825 """ 826 827 matrix, names, rsizes = fn(d) 828 allocated = [] 829 830 x = 0 831 while x < len(rsizes): 832 weight, size, free, attrname = rsizes[x] 833 base = matrix[attrname] 834 y = x + 1 835 while y < len(rsizes): 836 _weight, _size, _free, _attrname = rsizes[y] 837 occupied = len(names) - _free 838 if occupied > free: 839 break 840 new = combine_rows(base, matrix[_attrname]) 841 if new: 842 del matrix[_attrname] 843 del rsizes[y] 844 base = new 845 free -= occupied 846 else: 847 y += 1 848 allocated.append(base) 849 x += 1 850 851 # Return the list of attribute names from each row of the allocated 852 # attributes table. 853 854 locations = [] 855 for attrnames in allocated: 856 l = set() 857 for attrname in attrnames: 858 if attrname: 859 l.add(attrname) 860 locations.append(l) 861 return locations 862 863 # vim: tabstop=4 expandtab shiftwidth=4