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

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