nsz Git - libfirm/blob - ir/be/scripts/generate_regalloc_if.pl

   1 #!/usr/bin/perl -w
   2
   3 # This script generates C code which creates ands sets up functions and
   4 # data structures for the register allocator.
   5 # Creation: 2005/11/14
   6 # $Id$
   7
   8 use strict;
   9 use Data::Dumper;
  10
  11 my $specfile   = $ARGV[0];
  12 my $target_dir = $ARGV[1];
  13
  14 our $arch;
  15 our %reg_classes;
  16 our %nodes;
  17
  18 # include spec file
  19
  20 my $return;
  21
  22 no strict "subs";
  23 unless ($return = do $specfile) {
  24         warn "couldn't parse $specfile: $@" if $@;
  25         warn "couldn't do $specfile: $!"    unless defined $return;
  26         warn "couldn't run $specfile"       unless $return;
  27 }
  28 use strict "subs";
  29
  30 my $target_c   = $target_dir."/gen_".$arch."_regalloc_if.c";
  31 my $target_h   = $target_dir."/gen_".$arch."_regalloc_if.h";
  32 my $target_h_t = $target_dir."/gen_".$arch."_regalloc_if_t.h";
  33
  34 # helper function
  35 sub translate_reg_type {
  36         my $t = shift;
  37
  38         if ($t == 0) {
  39                 return "arch_register_type_none";
  40         }
  41         else {
  42                 my @types;
  43
  44                 if ($t & 1) {
  45                         push(@types, "arch_register_type_caller_save");
  46                 }
  47
  48                 if ($t & 2) {
  49                         push(@types, "arch_register_type_callee_save");
  50                 }
  51
  52                 if ($t & 4) {
  53                         push(@types, "arch_register_type_ignore");
  54                 }
  55
  56                 if ($t & 8) {
  57                         push(@types, "arch_register_type_joker");
  58                 }
  59
  60                 if ($t & 16) {
  61                         push(@types, "arch_register_type_virtual");
  62                 }
  63
  64                 return join(" | ", @types);
  65         }
  66 }
  67
  68 # stacks for output
  69 my @obst_regtypes_def; # stack for the register type variables definitions
  70 my @obst_regtypes_decl;# stack for the register type variables declarations
  71 my @obst_regclasses;   # stack for the register class variables
  72 my @obst_classdef;     # stack to define a name for a class index
  73 my @obst_regdef;       # stack to define a name for a register index
  74 my @obst_reginit;      # stack for the register type inits
  75 my @obst_req;          # stack for the register requirements
  76 my @obst_limit_func;   # stack for functions to return a subset of a register class
  77 my @obst_defreq_head;  # stack for prototypes of default requirement function
  78 my @obst_header_all;   # stack for some extern struct defs needed for bearch_$arch include
  79 my @obst_requirement_def;  # stack for requirement name defines
  80
  81 my $numregs;
  82 my $class_ptr;
  83 my $class_idx = 0;
  84
  85 my $tmp;
  86
  87 my %reg2class;
  88
  89 # there is a default NONE requirement
  90 $tmp = "/* Default NONE register requirements */\n";
  91 $tmp .= "const $arch\_register_req_t $arch\_default_req_none = {\n";
  92 $tmp .= "  {\n";
  93 $tmp .= "    arch_register_req_type_none,  /* register type  */\n";
  94 $tmp .= "    NULL,                         /* register class */\n";
  95 $tmp .= "    NULL,                         /* limit function */\n";
  96 $tmp .= "    NULL,                         /* limit environment */\n";
  97 $tmp .= "    NULL,                         /* node for same */\n";
  98 $tmp .= "    NULL                          /* node for different */\n";
  99 $tmp .= "  },\n";
 100 $tmp .= "  0,                              /* same pos */\n";
 101 $tmp .= "  0                               /* different pos */\n";
 102 $tmp .= "};\n\n";
 103 push(@obst_req, $tmp);
 104 push(@obst_header_all, "extern const $arch\_register_req_t $arch\_default_req_none;\n");
 105
 106 push(@obst_classdef, "enum reg_classes {\n");
 107
 108 my $class_mode;
 109
 110 # generate register type and class variable, init function and default requirements
 111 foreach my $class_name (keys(%reg_classes)) {
 112         my @class         = @{ $reg_classes{"$class_name"} };
 113         my $old_classname = $class_name;
 114
 115         $class_name = $arch."_".$class_name;
 116         $numregs    = "N_".$class_name."_REGS";
 117         $class_ptr  = "&".$arch."_reg_classes[CLASS_".$class_name."]";
 118         $class_mode = pop(@class)->{"mode"};
 119
 120         push(@obst_regtypes_decl, "extern arch_register_t ".$class_name."_regs[$numregs];\n");
 121         push(@obst_regtypes_def, "arch_register_t ".$class_name."_regs[$numregs];\n");
 122
 123         push(@obst_classdef, "  CLASS_$class_name = $class_idx,\n");
 124         push(@obst_regclasses, "{ \"$class_name\", $numregs, NULL, ".$class_name."_regs }");
 125
 126         # there is a default NORMAL requirement for each class
 127         $tmp  = "/* Default NORMAL register requirements for class $class_name */\n";
 128         $tmp .= "const $arch\_register_req_t $arch\_default_req_$class_name = {\n";
 129         $tmp .= "  {\n";
 130         $tmp .= "    arch_register_req_type_normal,\n";
 131         $tmp .= "    $class_ptr,\n";
 132         $tmp .= "    NULL,                    /* limit function */ \n";
 133         $tmp .= "    NULL,                    /* limit environment */\n";
 134         $tmp .= "    NULL,                    /* node for same */\n";
 135         $tmp .= "    NULL                     /* node for different */\n";
 136         $tmp .= "  },\n";
 137         $tmp .= "  0,                         /* same pos */\n";
 138         $tmp .= "  0                          /* different pos */\n";
 139         $tmp .= "};\n\n";
 140         push(@obst_req, $tmp);
 141         push(@obst_header_all, "extern const $arch\_register_req_t $arch\_default_req_$class_name;\n");
 142
 143         my $idx = 0;
 144         push(@obst_reginit, "  /* Init of all registers in class '$class_name' */\n\n");
 145         push(@obst_reginit, "  /* set largest possible mode for '$class_name' */\n");
 146         push(@obst_reginit, "  $arch\_reg_classes[CLASS_".$class_name."].mode = $class_mode;\n\n");
 147         push(@obst_regdef, "enum reg_".$class_name."_values {\n");
 148         foreach (@class) {
 149                 # For each class we build for each of it's member registers a limit function
 150                 # which limits the class to this particular register. We also build the
 151                 # corresponding requirement structs.
 152                 # We need those functions to set register requirements on demand in transformation
 153                 # esp. for Call and RegParams where we can mix int and float parameters.
 154
 155                 my $limit_func_name = $arch."_limit_".$class_name."_".$_->{"name"};
 156
 157                 # push the function prototype
 158                 $tmp = "void $limit_func_name(void *_unused, bitset_t *bs)";
 159                 push(@obst_defreq_head, $tmp.";\n");
 160
 161                 # push the function definition
 162                 $tmp .= " {\n";
 163                 $tmp .= "    bs = bitset_clear_all(bs);\n";
 164                 $tmp .= "    bitset_set(bs, REG_".uc($_->{"name"}).");\n";  # REGISTER to index assignment is done some lines down
 165                 $tmp .= "}\n\n";
 166                 push(@obst_limit_func, $tmp);
 167
 168                 # push the default requirement struct
 169                 $tmp  = "const $arch\_register_req_t $arch\_default_req_$class_name\_".$_->{"name"}." = {\n";
 170                 $tmp .= "  {\n";
 171                 $tmp .= "    arch_register_req_type_limited,\n";
 172                 $tmp .= "    $class_ptr,\n";
 173                 $tmp .= "    $limit_func_name,\n";
 174                 $tmp .= "    NULL,                     /* limit environment */\n";
 175                 $tmp .= "    NULL,                     /* node for same */\n";
 176                 $tmp .= "    NULL                      /* node for different */\n";
 177                 $tmp .= "  },\n";
 178                 $tmp .= "  0,                          /* same pos */\n";
 179                 $tmp .= "  0                           /* different pos */\n";
 180                 $tmp .= "};\n\n";
 181                 push(@obst_req, $tmp);
 182                 push(@obst_header_all,"extern const $arch\_register_req_t $arch\_default_req_$class_name\_".$_->{"name"}.";\n");
 183
 184                 $reg2class{$_->{"name"}} = { "class" => $old_classname, "index" => $idx }; # remember reg to class for later use
 185                 push(@obst_regdef, "  REG_".uc($_->{"name"})." = $idx,\n");
 186                 push(@obst_reginit, "  ".$class_name."_regs[$idx].name      = \"".$_->{"name"}."\";\n");
 187                 push(@obst_reginit, "  ".$class_name."_regs[$idx].reg_class = $class_ptr;\n");
 188                 push(@obst_reginit, "  ".$class_name."_regs[$idx].index     = $idx;\n");
 189                 push(@obst_reginit, "  ".$class_name."_regs[$idx].type      = ".translate_reg_type($_->{"type"}).";\n");
 190                 push(@obst_reginit, "\n");
 191                 $idx++;
 192         }
 193         push(@obst_regdef, "  $numregs = $idx\n");
 194         push(@obst_regdef, "};\n\n");
 195
 196         $class_idx++;
 197 }
 198
 199 push(@obst_classdef, "  N_CLASSES = ".scalar(keys(%reg_classes))."\n");
 200 push(@obst_classdef, "};\n\n");
 201
 202 # generate node-register constraints
 203 foreach my $op (keys(%nodes)) {
 204         my %n = %{ $nodes{"$op"} };
 205
 206         next if (!exists($n{"reg_req"}));
 207
 208         $op = $arch."_".$op;
 209
 210         push(@obst_req, "/* IN requirements for '$op' */\n");
 211         # check for argument requirements
 212         if (exists($n{"reg_req"}{"in"})) {
 213                 generate_requirements(\%n, $op, "in");
 214         }
 215
 216         push(@obst_req, "/* OUT requirements for '$op' */\n");
 217         # check for result requirements
 218         if (exists($n{"reg_req"}{"out"})) {
 219                 generate_requirements(\%n, $op, "out");
 220         }
 221 }
 222
 223
 224
 225 # generate header _t (internal usage) file
 226 open(OUT, ">$target_h_t") || die("Could not open $target_h_t, reason: $!\n");
 227
 228 my $creation_time = localtime(time());
 229
 230 $tmp = uc($arch);
 231
 232 print OUT<<EOF;
 233 #ifndef _GEN_$tmp\_REGALLOC_IF_T_H_
 234 #define _GEN_$tmp\_REGALLOC_IF_T_H_
 235
 236 /**
 237  * Generated register classes from spec.
 238  *
 239  * DO NOT EDIT THIS FILE, your changes will be lost.
 240  * Edit $specfile instead.
 241  * created by: $0 $specfile $target_dir
 242  * date:       $creation_time
 243  */
 244
 245 EOF
 246
 247 print OUT @obst_requirement_def;
 248
 249 print OUT "\n#endif /* _GEN_$tmp\_REGALLOC_IF_T_H_ */\n";
 250
 251
 252
 253 # generate header (external usage) file
 254 open(OUT, ">$target_h") || die("Could not open $target_h, reason: $!\n");
 255
 256 $creation_time = localtime(time());
 257
 258 print OUT<<EOF;
 259 #ifndef _GEN_$tmp\_REGALLOC_IF_H_
 260 #define _GEN_$tmp\_REGALLOC_IF_H_
 261
 262 /**
 263  * Contains additional external requirements defs for external includes.
 264  *
 265  * DO NOT EDIT THIS FILE, your changes will be lost.
 266  * Edit $specfile instead.
 267  * created by: $0 $specfile $target_dir
 268  * date:       $creation_time
 269  */
 270
 271 #include "../bearch.h"
 272 #include "$arch\_nodes_attr.h"
 273
 274 EOF
 275
 276 print OUT @obst_regdef, "\n";
 277
 278 print OUT @obst_classdef, "\n";
 279
 280 print OUT @obst_regtypes_decl, "\n";
 281
 282 print OUT "extern arch_register_class_t $arch\_reg_classes[N_CLASSES];\n\n";
 283
 284 print OUT "void ".$arch."_register_init(void *isa_ptr);\n\n";
 285
 286 print OUT @obst_header_all, "\n";
 287
 288 print OUT @obst_defreq_head, "\n";
 289
 290 print OUT "\n#endif /* _GEN_$tmp\_REGALLOC_IF_H_ */\n";
 291
 292 close(OUT);
 293
 294
 295
 296 # generate c file
 297 open(OUT, ">$target_c") || die("Could not open $target_c, reason: $!\n");
 298
 299 $creation_time = localtime(time());
 300
 301 print OUT<<EOF;
 302 /**
 303  * The generated interface for the register allocator.
 304  * Contains register classes and types and register constraints
 305  * for all nodes where constraints were given in spec.
 306  *
 307  * DO NOT EDIT THIS FILE, your changes will be lost.
 308  * Edit $specfile instead.
 309  * created by: $0 $specfile $target_dir
 310  * date:       $creation_time
 311  */
 312
 313 #include "gen_$arch\_regalloc_if.h"
 314 #include "bearch_$arch\_t.h"   /* we need this to put the caller saved registers into the isa set */
 315 #include "$arch\_map_regs.h"
 316 #include "irmode.h"
 317
 318 EOF
 319
 320 print OUT "arch_register_class_t $arch\_reg_classes[] = {\n  ".join(",\n  ", @obst_regclasses)."\n};\n\n";
 321
 322 print OUT @obst_regtypes_def, "\n";
 323
 324 print OUT "void ".$arch."_register_init(void *isa_ptr) {\n";
 325 print OUT @obst_reginit;
 326 print OUT "}\n\n";
 327
 328 print OUT @obst_limit_func;
 329
 330 print OUT @obst_req;
 331
 332 close(OUT);
 333
 334 ###
 335 # Remember the register class for each index in the given requirements.
 336 # We need this information for requirements like "in_sX" or "out_dX"
 337 # @return array of classes corresponding to the requirement for each index
 338 ###
 339 sub build_inout_idx_class {
 340         my $n     = shift;
 341         my $op    = shift;
 342         my $inout = shift;
 343         my @idx_class;
 344
 345         if (exists($n->{"reg_req"}{"$inout"})) {
 346                 my @reqs = @{ $n->{"reg_req"}{"$inout"} };
 347
 348                 for (my $idx = 0; $idx <= $#reqs; $idx++) {
 349                         my $class = undef;
 350
 351                         if ($reqs[$idx] eq "none") {
 352                                 $class = "none";
 353                         }
 354                         elsif (is_reg_class($reqs[$idx])) {
 355                                 $class = $reqs[$idx];
 356                         }
 357                         else {
 358                                 my @regs = split(/ /, $reqs[$idx]);
 359 GET_CLASS:              foreach my $reg (@regs) {
 360                                         if ($reg =~ /!?(in|out)\_r\d+/ || $reg =~ /!in/) {
 361                                                 $class = "UNKNOWN_CLASS";
 362                                         }
 363                                         else {
 364                                                 $class = get_reg_class($reg);
 365                                                 if (!defined $class) {
 366                                                         die("Could not get ".uc($inout)." register class for '$op' pos $idx (reg $reg) ... exiting.\n");
 367                                                 }
 368                                                 else {
 369                                                         last GET_CLASS;
 370                                                 } # !defined class
 371                                         } # if (reg =~ ...
 372                                 } # foreach
 373                         } # if
 374
 375                         push(@idx_class, $class);
 376                 } # for
 377         } # if
 378
 379         return @idx_class;
 380 }
 381
 382 ###
 383 # Generates the requirements for the given description
 384 ###
 385 sub generate_requirements {
 386         my $n     = shift;
 387         my $op    = shift;
 388         my $inout = shift;
 389
 390         # get classes for the complementary direction
 391         my $outin     = ($inout eq "in") ? "out" : "in";
 392
 393         my @reqs = @{ $n->{"reg_req"}{"$inout"} };
 394
 395         for (my $idx = 0; $idx <= $#reqs; $idx++) {
 396                 my $class = undef;
 397
 398                 my $tmp2 = "const $arch\_register_req_t _".$op."_reg_req_$inout\_$idx = ";
 399                 my $tmp  = "#define ".$op."_reg_req_$inout\_$idx ";
 400
 401                 if ($reqs[$idx] eq "none") {
 402                         $tmp .= "&$arch\_default_req_none\n";
 403                 }
 404                 elsif ($reqs[$idx] =~ /^new_reg_(.*)$/) {
 405                         if (is_reg_class($1)) {
 406                                 $tmp  .=  "&_".$op."_reg_req_$inout\_$idx\n";
 407                                 $tmp2 .= "{\n";
 408                                 $tmp2 .= "  {\n";
 409                                 $tmp2 .= "    arch_register_req_type_should_be_different_from_all,\n";
 410                                 $tmp2 .= "    &$arch\_reg_classes[CLASS_$arch\_".$1."],\n";
 411                                 $tmp2 .= "    NULL,        /* limit function */\n";
 412                                 $tmp2 .= "    NULL,        /* limit environment */\n";
 413                                 $tmp2 .= "    NULL,        /* same node */\n";
 414                                 $tmp2 .= "    NULL         /* different node */\n";
 415                                 $tmp2 .= "  },\n";
 416                                 $tmp2 .= "  0,\n";
 417                                 $tmp2 .= "  0\n";
 418                                 $tmp2 .= "};\n";
 419
 420                                 push(@obst_req, $tmp2."\n");
 421                                 push(@obst_header_all, "extern const $arch\_register_req_t _".$op."_reg_req_$inout\_$idx;\n");
 422                         }
 423                         else {
 424                                 print STDERR "Invalid register class '$1' given in OUT requirement $idx for '$op'.\n";
 425                         }
 426                 }
 427                 elsif (is_reg_class($reqs[$idx])) {
 428                         $tmp .= "&$arch\_default_req_".$arch."_".$reqs[$idx]."\n";
 429                 }
 430                 else {
 431                         my @req_type_mask;
 432                         my ($class, $has_limit, $same_pos, $different_pos) = build_subset_class_func($n, $op, $idx, (($inout eq "in") ? 1 : 0), $reqs[$idx]);
 433
 434                         if (!defined($class)) {
 435                                 die("Could not build subset for ".uc($inout)." requirements '$op' pos $idx ... exiting.\n");
 436                         }
 437
 438                         if ($has_limit) {
 439                                 push(@req_type_mask, "arch_register_req_type_limited");
 440                         }
 441                         if (defined($same_pos)) {
 442                                 push(@req_type_mask, "arch_register_req_type_should_be_same");
 443                         }
 444                         if (defined($different_pos)) {
 445                                 if ($different_pos == 666) {
 446                                         push(@req_type_mask, "arch_register_req_type_should_be_different_from_all");
 447                                         undef $different_pos;
 448                                 }
 449                                 else {
 450                                         push(@req_type_mask, "arch_register_req_type_should_be_different");
 451                                 }
 452                         }
 453
 454                         $tmp  .= "&_".$op."_reg_req_$inout\_$idx\n";
 455                         $tmp2 .= "{\n";
 456                         $tmp2 .= "  {\n";
 457                         $tmp2 .= "    ".join(" | ", @req_type_mask).",\n";
 458                         $tmp2 .= "    &$arch\_reg_classes[CLASS_$arch\_".$class."],\n";
 459                         $tmp2 .= "    ".($has_limit ? "limit_reg_".$op."_$inout\_".$idx : "NULL").",\n";
 460                         $tmp2 .= "    NULL,        /* limit environment */\n";
 461                         $tmp2 .= "    NULL,        /* same node */\n";
 462                         $tmp2 .= "    NULL         /* different node */\n";
 463                         $tmp2 .= "  },\n";
 464                         $tmp2 .= "  ".(defined($same_pos) ? $same_pos : "0").",\n";
 465                         $tmp2 .= "  ".(defined($different_pos) ? $different_pos : "0")."\n";
 466                         $tmp2 .= "};\n";
 467
 468                         push(@obst_req, $tmp2."\n");
 469                         push(@obst_header_all, "extern const $arch\_register_req_t _".$op."_reg_req_$inout\_$idx;\n");
 470                 }
 471
 472                 push(@obst_requirement_def, $tmp);
 473         }
 474
 475 }
 476
 477 ###
 478 # Determines whether $name is a specified register class or not.
 479 # @return 1 if name is register class, 0 otherwise
 480 ###
 481 sub is_reg_class {
 482         my $name = shift;
 483         return 1 if exists($reg_classes{"$name"});
 484         return 0;
 485 }
 486
 487 ###
 488 # Returns the register class for a given register.
 489 # @return class or undef
 490 ###
 491 sub get_reg_class {
 492         my $reg = shift;
 493         $reg = substr($reg, 1) if ($reg =~ /!.*/);
 494         return $reg2class{"$reg"}{"class"} if (exists($reg2class{"$reg"}));
 495         return undef;
 496 }
 497
 498 ###
 499 # Returns the index of a given register within it's register class.
 500 # @return index or undef
 501 ###
 502 sub get_reg_index {
 503         my $reg = shift;
 504         return $reg2class{"$reg"}{"index"} if (exists($reg2class{"$reg"}));
 505         return undef;
 506 }
 507
 508 ###
 509 # Generates the function for a given $op and a given IN-index
 510 # which returns a subset of possible register from a register class
 511 # @return classname from which the subset is derived or undef and
 512 #         pos which corresponds to in/out reference position or undef
 513 ###
 514 sub build_subset_class_func {
 515         my $neg           = undef;
 516         my $class         = undef;
 517         my $has_limit     = 0;
 518         my $same_pos      = undef;
 519         my $different_pos = undef;
 520         my $temp;
 521         my @obst_init;
 522         my @obst_limits;
 523         my @obst_ignore;
 524
 525
 526         # build function header
 527         my $n   = shift;
 528         my $op  = shift;
 529         my $idx = shift;
 530         my $in  = shift;
 531
 532         my $outin = $in ? "out" : "in";
 533         my @regs  = split(/ /, shift);
 534
 535         my @idx_class = build_inout_idx_class($n, $op, $outin);
 536
 537         # set/unset registers
 538 CHECK_REQS: foreach (@regs) {
 539                 if (/(!)?$outin\_r(\d+)/) {
 540                         if (($1 && defined($different_pos)) || (!$1 && defined($same_pos))) {
 541                                 print STDERR "Multiple in/out references of same type in one requirement not allowed.\n";
 542                                 return (undef, undef, undef, undef);
 543                         }
 544
 545                         if ($1) {
 546                                 $different_pos = $in ? -$2 : $2 - 1;
 547                         }
 548                         else {
 549                                 $same_pos = $in ? -$2 : $2 - 1;
 550                         }
 551
 552                         $class = $idx_class[$2 - 1];
 553                         next CHECK_REQS;
 554                 }
 555                 elsif (/!in/) {
 556                         $class = $idx_class[0];
 557                         return ($class, 0, undef, 666);
 558                 }
 559
 560                 # check for negate
 561                 if (substr($_, 0, 1) eq "!") {
 562                         if (defined($neg) && $neg == 0) {
 563                                 # we have seen a positiv constraint as first one but this one is negative
 564                                 # this doesn't make sense
 565                                 print STDERR "Mixed positive and negative constraints for the same slot are not allowed.\n";
 566                                 return (undef, undef, undef, undef);
 567                         }
 568
 569                         if (!defined($neg)) {
 570                                 $has_limit = 1;
 571                                 push(@obst_init, "  bs = bitset_set_all(bs);     /* allow all register (negative constraints given) */\n");
 572                         }
 573
 574                         $_   = substr($_, 1); # skip '!'
 575                         $neg = 1;
 576                 }
 577                 else {
 578                         if (defined($neg) && $neg == 1) {
 579                                 # we have seen a negative constraint as first one but this one is positive
 580                                 # this doesn't make sense
 581                                 print STDERR "Mixed positive and negative constraints for the same slot are not allowed.\n";
 582                                 return (undef, undef, undef, undef);
 583                         }
 584
 585                         if (!defined($neg)) {
 586                                 $has_limit = 1;
 587                                 push(@obst_init, "  bs = bitset_clear_all(bs);   /* disallow all register (positive constraints given) */\n");
 588                         }
 589                         $neg = 0;
 590                 }
 591
 592                 # check if register belongs to one of the given classes
 593                 $temp = get_reg_class($_);
 594                 if (!defined($temp)) {
 595                         print STDERR "Unknown register '$_'!\n";
 596                         return (undef, undef, undef, undef);
 597                 }
 598
 599                 # set class
 600                 if (!defined($class)) {
 601                         $class = $temp;
 602                 }
 603                 elsif ($class ne $temp) {
 604                         # all registers must belong to the same class
 605                         print STDERR "Registerclass mismatch. '$_' is not member of class '$class'.\n";
 606                         return (undef, undef, undef, undef);
 607                 }
 608
 609                 if ($neg == 1) {
 610                         $has_limit = 1;
 611                         push(@obst_limits, "  bitset_clear(bs, ".get_reg_index($_).");         /* disallow $_ */\n");
 612                 }
 613                 else {
 614                         $has_limit = 1;
 615                         push(@obst_limits, "  bitset_set(bs, ".get_reg_index($_).");           /* allow $_ */\n");
 616                 }
 617         }
 618
 619         my @cur_class = @{ $reg_classes{"$class"} };
 620         for (my $idx = 0; $idx <= $#cur_class; $idx++) {
 621                 if (defined($cur_class[$idx]{"type"}) && ($cur_class[$idx]{"type"} & 4)) {
 622                         push(@obst_ignore, "  bitset_clear(bs, ".get_reg_index($cur_class[$idx]{"name"}).");");
 623                         push(@obst_ignore, "         /* disallow ignore reg ".$cur_class[$idx]{"name"}." */\n");
 624                 }
 625         }
 626
 627         if ($has_limit == 1) {
 628                 push(@obst_header_all, "void limit_reg_".$op."_".($in ? "in" : "out")."_".$idx."(void *_unused, bitset_t *bs);\n");
 629
 630                 push(@obst_limit_func, "/* limit the possible registers for ".($in ? "IN" : "OUT")." $idx at op $op */\n");
 631                 push(@obst_limit_func, "void limit_reg_".$op."_".($in ? "in" : "out")."_".$idx."(void *_unused, bitset_t *bs) {\n");
 632                 push(@obst_limit_func, @obst_init);
 633                 push(@obst_limit_func, @obst_ignore);
 634                 push(@obst_limit_func, @obst_limits);
 635                 push(@obst_limit_func, "}\n\n");
 636         }
 637
 638         return ($class, $has_limit, $same_pos, $different_pos);
 639 }