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