mcs/mbas/cfold.cs

   1 //
   2 // cfold.cs: Constant Folding
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //
   7 // (C) 2002 Ximian, Inc.
   8 //
   9
  10 using System;
  11
  12 namespace Mono.MonoBASIC {
  13
  14         public class ConstantFold {
  15
  16                 //
  17                 // Performs the numeric promotions on the left and right expresions
  18                 // and desposits the results on `lc' and `rc'.
  19                 //
  20                 // On success, the types of `lc' and `rc' on output will always match,
  21                 // and the pair will be one of:
  22                 //
  23                 //   (double, double)
  24                 //   (float, float)
  25                 //   (ulong, ulong)
  26                 //   (long, long)
  27                 //   (uint, uint)
  28                 //   (int, int)
  29                 //
  30                 static void DoConstantNumericPromotions (EmitContext ec, Binary.Operator oper,
  31                                                          ref Constant left, ref Constant right,
  32                                                          Location loc)
  33                 {
  34                         if (left is DoubleConstant || right is DoubleConstant || oper == Binary.Operator.Exponentiation){
  35                                 //
  36                                 // If either side is a double, convert the other to a double
  37                                 //
  38                                 if (!(left is DoubleConstant))
  39                                         left = left.ToDouble (loc);
  40
  41                                 if (!(right is DoubleConstant))
  42                                         right = right.ToDouble (loc);
  43                                 return;
  44                         } else if (left is FloatConstant || right is FloatConstant) {
  45                                 //
  46                                 // If either side is a float, convert the other to a float
  47                                 //
  48                                 if (!(left is FloatConstant))
  49                                         left = left.ToFloat (loc);
  50
  51                                 if (!(right is FloatConstant))
  52                                         right = right.ToFloat (loc);
  53 ;                               return;
  54                         } else if (left is ULongConstant || right is ULongConstant){
  55                                 //
  56                                 // If either operand is of type ulong, the other operand is
  57                                 // converted to type ulong.  or an error ocurrs if the other
  58                                 // operand is of type sbyte, short, int or long
  59                                 //
  60                                 Constant match, other;
  61
  62                                 if (left is ULongConstant){
  63                                         other = right;
  64                                         match = left;
  65                                         if (!(right is ULongConstant))
  66                                                 right = right.ToULong (loc);
  67                                 } else {
  68                                         other = left;
  69                                         match = right;
  70                                         left = left.ToULong (loc);
  71                                 }
  72
  73 #if WRONG
  74                                 if (other is SByteConstant || other is ShortConstant ||
  75                                     other is IntConstant || other is LongConstant){
  76                                         Binary.Error_OperatorAmbiguous
  77                                                 (loc, oper, other.Type, match.Type);
  78                                         left = null;
  79                                         right = null;
  80                                 }
  81 #endif
  82                                 return;
  83                         } else if (left is LongConstant || right is LongConstant){
  84                                 //
  85                                 // If either operand is of type long, the other operand is converted
  86                                 // to type long.
  87                                 //
  88                                 if (!(left is LongConstant))
  89                                         left = left.ToLong (loc);
  90                                 else if (!(right is LongConstant))
  91                                         right = right.ToLong (loc);
  92                                 return;
  93                         } else if (left is UIntConstant || right is UIntConstant){
  94                                 //
  95                                 // If either operand is of type uint, and the other
  96                                 // operand is of type sbyte, short or int, the operands are
  97                                 // converted to type long.
  98                                 //
  99                                 Constant match, other;
 100                                 if (left is UIntConstant){
 101                                         other = right;
 102                                         match = left;
 103                                 } else {
 104                                         other = left;
 105                                         match = right;
 106                                 }
 107
 108                                 // Nothing to do.
 109                                 if (other is UIntConstant)
 110                                         return;
 111
 112                                 if (other is SByteConstant || other is ShortConstant ||
 113                                     other is IntConstant){
 114                                         left = left.ToLong (loc);
 115                                         right = right.ToLong (loc);
 116                                 }
 117
 118                                 return;
 119                         } else if (left is EnumConstant || right is EnumConstant){
 120                                 //
 121                                 // If either operand is an enum constant, the other one must
 122                                 // be implicitly convertable to that enum's underlying type.
 123                                 //
 124                                 EnumConstant match;
 125                                 Constant other;
 126                                 if (left is EnumConstant){
 127                                         other = right;
 128                                         match = (EnumConstant) left;
 129                                 } else {
 130                                         other = left;
 131                                         match = (EnumConstant) right;
 132                                 }
 133
 134                                 bool need_check = (other is EnumConstant) ||
 135                                         ((oper != Binary.Operator.Addition) &&
 136                                          (oper != Binary.Operator.Subtraction));
 137
 138                                 if (need_check &&
 139                                     !Expression.ImplicitConversionExists (ec, match, other.Type)) {
 140                                         Expression.Error_CannotConvertImplicit (loc, match.Type, other.Type);
 141                                         left = null;
 142                                         right = null;
 143                                         return;
 144                                 }
 145
 146                                 if (left is EnumConstant)
 147                                         left = ((EnumConstant) left).Child;
 148                                 if (right is EnumConstant)
 149                                         right = ((EnumConstant) right).Child;
 150                                 return;
 151
 152                         } else {
 153                                 //
 154                                 // Force conversions to int32
 155                                 //
 156                                 if (!(left is IntConstant))
 157                                         left = left.ToInt (loc);
 158                                 if (!(right is IntConstant))
 159                                         right = right.ToInt (loc);
 160                         }
 161                         return;
 162                 }
 163
 164                 static void Error_CompileTimeOverflow (Location loc)
 165                 {
 166                         Report.Error (220, loc, "The operation overflows at compile time in checked mode");
 167                 }
 168
 169                 /// <summary>
 170                 ///   Constant expression folder for binary operations.
 171                 ///
 172                 ///   Returns null if the expression can not be folded.
 173                 /// </summary>
 174                 static public Expression BinaryFold (EmitContext ec, Binary.Operator oper,
 175                                                      Constant left, Constant right, Location loc)
 176                 {
 177                         Type lt = left.Type;
 178                         Type rt = right.Type;
 179                         Type result_type = null;
 180                         bool bool_res;
 181
 182                         //
 183                         // Enumerator folding
 184                         //
 185                         if (rt == lt && left is EnumConstant)
 186                                 result_type = lt;
 187
 188                         //
 189                         // During an enum evaluation, we need to unwrap enumerations
 190                         //
 191                         if (ec.InEnumContext){
 192                                 if (left is EnumConstant)
 193                                         left = ((EnumConstant) left).Child;
 194
 195                                 if (right is EnumConstant)
 196                                         right = ((EnumConstant) right).Child;
 197                         }
 198
 199                         Type wrap_as;
 200                         Constant result = null;
 201                         switch (oper){
 202                         case Binary.Operator.BitwiseOr:
 203                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 204                                 if (left == null || right == null)
 205                                         return null;
 206
 207                                 if (left is IntConstant){
 208                                         IntConstant v;
 209                                         int res = ((IntConstant) left).Value | ((IntConstant) right).Value;
 210
 211                                         v = new IntConstant (res);
 212                                         if (result_type == null)
 213                                                 return v;
 214                                         else
 215                                                 return new EnumConstant (v, result_type);
 216                                 } else if (left is UIntConstant){
 217                                         UIntConstant v;
 218                                         uint res = ((UIntConstant)left).Value | ((UIntConstant)right).Value;
 219
 220                                         v = new UIntConstant (res);
 221                                         if (result_type == null)
 222                                                 return v;
 223                                         else
 224                                                 return new EnumConstant (v, result_type);
 225                                 } else if (left is LongConstant){
 226                                         LongConstant v;
 227                                         long res = ((LongConstant)left).Value | ((LongConstant)right).Value;
 228
 229                                         v = new LongConstant (res);
 230                                         if (result_type == null)
 231                                                 return v;
 232                                         else
 233                                                 return new EnumConstant (v, result_type);
 234                                 } else if (left is ULongConstant){
 235                                         ULongConstant v;
 236                                         ulong res = ((ULongConstant)left).Value |
 237                                                 ((ULongConstant)right).Value;
 238
 239                                         v = new ULongConstant (res);
 240                                         if (result_type == null)
 241                                                 return v;
 242                                         else
 243                                                 return new EnumConstant (v, result_type);
 244                                 }
 245                                 break;
 246
 247                         case Binary.Operator.BitwiseAnd:
 248                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 249                                 if (left == null || right == null)
 250                                         return null;
 251
 252                                 if (left is IntConstant){
 253                                         IntConstant v;
 254                                         int res = ((IntConstant) left).Value & ((IntConstant) right).Value;
 255
 256                                         v = new IntConstant (res);
 257                                         if (result_type == null)
 258                                                 return v;
 259                                         else
 260                                                 return new EnumConstant (v, result_type);
 261                                 } else if (left is UIntConstant){
 262                                         UIntConstant v;
 263                                         uint res = ((UIntConstant)left).Value & ((UIntConstant)right).Value;
 264
 265                                         v = new UIntConstant (res);
 266                                         if (result_type == null)
 267                                                 return v;
 268                                         else
 269                                                 return new EnumConstant (v, result_type);
 270                                 } else if (left is LongConstant){
 271                                         LongConstant v;
 272                                         long res = ((LongConstant)left).Value & ((LongConstant)right).Value;
 273
 274                                         v = new LongConstant (res);
 275                                         if (result_type == null)
 276                                                 return v;
 277                                         else
 278                                                 return new EnumConstant (v, result_type);
 279                                 } else if (left is ULongConstant){
 280                                         ULongConstant v;
 281                                         ulong res = ((ULongConstant)left).Value &
 282                                                 ((ULongConstant)right).Value;
 283
 284                                         v = new ULongConstant (res);
 285                                         if (result_type == null)
 286                                                 return v;
 287                                         else
 288                                                 return new EnumConstant (v, result_type);
 289                                 }
 290                                 break;
 291
 292                         case Binary.Operator.ExclusiveOr:
 293                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 294                                 if (left == null || right == null)
 295                                         return null;
 296
 297                                 if (left is IntConstant){
 298                                         IntConstant v;
 299                                         int res = ((IntConstant) left).Value ^ ((IntConstant) right).Value;
 300
 301                                         v = new IntConstant (res);
 302                                         if (result_type == null)
 303                                                 return v;
 304                                         else
 305                                                 return new EnumConstant (v, result_type);
 306                                 } else if (left is UIntConstant){
 307                                         UIntConstant v;
 308                                         uint res = ((UIntConstant)left).Value ^ ((UIntConstant)right).Value;
 309
 310                                         v = new UIntConstant (res);
 311                                         if (result_type == null)
 312                                                 return v;
 313                                         else
 314                                                 return new EnumConstant (v, result_type);
 315                                 } else if (left is LongConstant){
 316                                         LongConstant v;
 317                                         long res = ((LongConstant)left).Value ^ ((LongConstant)right).Value;
 318
 319                                         v = new LongConstant (res);
 320                                         if (result_type == null)
 321                                                 return v;
 322                                         else
 323                                                 return new EnumConstant (v, result_type);
 324                                 } else if (left is ULongConstant){
 325                                         ULongConstant v;
 326                                         ulong res = ((ULongConstant)left).Value ^
 327                                                 ((ULongConstant)right).Value;
 328
 329                                         v = new ULongConstant (res);
 330                                         if (result_type == null)
 331                                                 return v;
 332                                         else
 333                                                 return new EnumConstant (v, result_type);
 334                                 }
 335                                 break;
 336
 337                         case Binary.Operator.Addition:
 338                                 bool left_is_string = left is StringConstant;
 339                                 bool right_is_string = right is StringConstant;
 340
 341                                 //
 342                                 // If both sides are strings, then concatenate, if
 343                                 // one is a string, and the other is not, then defer
 344                                 // to runtime concatenation
 345                                 //
 346                                 wrap_as = null;
 347                                 if (left_is_string || right_is_string){
 348                                         if (left_is_string && right_is_string)
 349                                                 return new StringConstant (
 350                                                         ((StringConstant) left).Value +
 351                                                         ((StringConstant) right).Value);
 352
 353                                         return null;
 354                                 }
 355
 356                                 //
 357                                 // handle "E operator + (E x, U y)"
 358                                 // handle "E operator + (Y y, E x)"
 359                                 //
 360                                 // note that E operator + (E x, E y) is invalid
 361                                 //
 362                                 if (left is EnumConstant){
 363                                         if (right is EnumConstant){
 364                                                 return null;
 365                                         }
 366                                         if (((EnumConstant) left).Child.Type != right.Type)
 367                                                 return null;
 368
 369                                         wrap_as = left.Type;
 370                                 } else if (right is EnumConstant){
 371                                         if (((EnumConstant) right).Child.Type != left.Type)
 372                                                 return null;
 373                                         wrap_as = right.Type;
 374                                 }
 375
 376                                 result = null;
 377                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 378                                 if (left == null || right == null)
 379                                         return null;
 380
 381                                 try {
 382                                         if (left is DoubleConstant){
 383                                                 double res;
 384
 385                                                 if (ec.ConstantCheckState)
 386                                                         res = checked (((DoubleConstant) left).Value +
 387                                                                        ((DoubleConstant) right).Value);
 388                                                 else
 389                                                         res = unchecked (((DoubleConstant) left).Value +
 390                                                                          ((DoubleConstant) right).Value);
 391
 392                                                 result = new DoubleConstant (res);
 393                                         } else if (left is FloatConstant){
 394                                                 float res;
 395
 396                                                 if (ec.ConstantCheckState)
 397                                                         res = checked (((FloatConstant) left).Value +
 398                                                                        ((FloatConstant) right).Value);
 399                                                 else
 400                                                         res = unchecked (((FloatConstant) left).Value +
 401                                                                          ((FloatConstant) right).Value);
 402
 403                                                 result = new FloatConstant (res);
 404                                         } else if (left is ULongConstant){
 405                                                 ulong res;
 406
 407                                                 if (ec.ConstantCheckState)
 408                                                         res = checked (((ULongConstant) left).Value +
 409                                                                        ((ULongConstant) right).Value);
 410                                                 else
 411                                                         res = unchecked (((ULongConstant) left).Value +
 412                                                                          ((ULongConstant) right).Value);
 413
 414                                                 result = new ULongConstant (res);
 415                                         } else if (left is LongConstant){
 416                                                 long res;
 417
 418                                                 if (ec.ConstantCheckState)
 419                                                         res = checked (((LongConstant) left).Value +
 420                                                                        ((LongConstant) right).Value);
 421                                                 else
 422                                                         res = unchecked (((LongConstant) left).Value +
 423                                                                          ((LongConstant) right).Value);
 424
 425                                                 result = new LongConstant (res);
 426                                         } else if (left is UIntConstant){
 427                                                 uint res;
 428
 429                                                 if (ec.ConstantCheckState)
 430                                                         res = checked (((UIntConstant) left).Value +
 431                                                                        ((UIntConstant) right).Value);
 432                                                 else
 433                                                         res = unchecked (((UIntConstant) left).Value +
 434                                                                          ((UIntConstant) right).Value);
 435
 436                                                 result = new UIntConstant (res);
 437                                         } else if (left is IntConstant){
 438                                                 int res;
 439
 440                                                 if (ec.ConstantCheckState)
 441                                                         res = checked (((IntConstant) left).Value +
 442                                                                        ((IntConstant) right).Value);
 443                                                 else
 444                                                         res = unchecked (((IntConstant) left).Value +
 445                                                                          ((IntConstant) right).Value);
 446
 447                                                 result = new IntConstant (res);
 448                                         } else {
 449                                                 throw new Exception ( "Unexepected input: " + left);
 450                                         }
 451                                 } catch (OverflowException){
 452                                         Error_CompileTimeOverflow (loc);
 453                                 }
 454
 455                                 if (wrap_as != null)
 456                                         return new EnumConstant (result, wrap_as);
 457                                 else
 458                                         return result;
 459
 460                         case Binary.Operator.Subtraction:
 461                                 //
 462                                 // handle "E operator - (E x, U y)"
 463                                 // handle "E operator - (Y y, E x)"
 464                                 // handle "U operator - (E x, E y)"
 465                                 //
 466                                 wrap_as = null;
 467                                 if (left is EnumConstant){
 468                                         if (right is EnumConstant){
 469                                                 if (left.Type == right.Type)
 470                                                         wrap_as = TypeManager.EnumToUnderlying (left.Type);
 471                                                 else
 472                                                         return null;
 473                                         }
 474                                         if (((EnumConstant) left).Child.Type != right.Type)
 475                                                 return null;
 476
 477                                         wrap_as = left.Type;
 478                                 } else if (right is EnumConstant){
 479                                         if (((EnumConstant) right).Child.Type != left.Type)
 480                                                 return null;
 481                                         wrap_as = right.Type;
 482                                 }
 483
 484                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 485                                 if (left == null || right == null)
 486                                         return null;
 487
 488                                 try {
 489                                         if (left is DoubleConstant){
 490                                                 double res;
 491
 492                                                 if (ec.ConstantCheckState)
 493                                                         res = checked (((DoubleConstant) left).Value -
 494                                                                        ((DoubleConstant) right).Value);
 495                                                 else
 496                                                         res = unchecked (((DoubleConstant) left).Value -
 497                                                                          ((DoubleConstant) right).Value);
 498
 499                                                 result = new DoubleConstant (res);
 500                                         } else if (left is FloatConstant){
 501                                                 float res;
 502
 503                                                 if (ec.ConstantCheckState)
 504                                                         res = checked (((FloatConstant) left).Value -
 505                                                                        ((FloatConstant) right).Value);
 506                                                 else
 507                                                         res = unchecked (((FloatConstant) left).Value -
 508                                                                          ((FloatConstant) right).Value);
 509
 510                                                 result = new FloatConstant (res);
 511                                         } else if (left is ULongConstant){
 512                                                 ulong res;
 513
 514                                                 if (ec.ConstantCheckState)
 515                                                         res = checked (((ULongConstant) left).Value -
 516                                                                        ((ULongConstant) right).Value);
 517                                                 else
 518                                                         res = unchecked (((ULongConstant) left).Value -
 519                                                                          ((ULongConstant) right).Value);
 520
 521                                                 result = new ULongConstant (res);
 522                                         } else if (left is LongConstant){
 523                                                 long res;
 524
 525                                                 if (ec.ConstantCheckState)
 526                                                         res = checked (((LongConstant) left).Value -
 527                                                                        ((LongConstant) right).Value);
 528                                                 else
 529                                                         res = unchecked (((LongConstant) left).Value -
 530                                                                          ((LongConstant) right).Value);
 531
 532                                                 result = new LongConstant (res);
 533                                         } else if (left is UIntConstant){
 534                                                 uint res;
 535
 536                                                 if (ec.ConstantCheckState)
 537                                                         res = checked (((UIntConstant) left).Value -
 538                                                                        ((UIntConstant) right).Value);
 539                                                 else
 540                                                         res = unchecked (((UIntConstant) left).Value -
 541                                                                          ((UIntConstant) right).Value);
 542
 543                                                 result = new UIntConstant (res);
 544                                         } else if (left is IntConstant){
 545                                                 int res;
 546
 547                                                 if (ec.ConstantCheckState)
 548                                                         res = checked (((IntConstant) left).Value -
 549                                                                        ((IntConstant) right).Value);
 550                                                 else
 551                                                         res = unchecked (((IntConstant) left).Value -
 552                                                                          ((IntConstant) right).Value);
 553
 554                                                 result = new IntConstant (res);
 555                                         } else {
 556                                                 throw new Exception ( "Unexepected input: " + left);
 557                                         }
 558                                 } catch (OverflowException){
 559                                         Error_CompileTimeOverflow (loc);
 560                                 }
 561                                 if (wrap_as != null)
 562                                         return new EnumConstant (result, wrap_as);
 563                                 else
 564                                         return result;
 565
 566                         case Binary.Operator.Multiply:
 567                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 568                                 if (left == null || right == null)
 569                                         return null;
 570
 571                                 try {
 572                                         if (left is DoubleConstant){
 573                                                 double res;
 574
 575                                                 if (ec.ConstantCheckState)
 576                                                         res = checked (((DoubleConstant) left).Value *
 577                                                                        ((DoubleConstant) right).Value);
 578                                                 else
 579                                                         res = unchecked (((DoubleConstant) left).Value *
 580                                                                          ((DoubleConstant) right).Value);
 581
 582                                                 return new DoubleConstant (res);
 583                                         } else if (left is FloatConstant){
 584                                                 float res;
 585
 586                                                 if (ec.ConstantCheckState)
 587                                                         res = checked (((FloatConstant) left).Value *
 588                                                                        ((FloatConstant) right).Value);
 589                                                 else
 590                                                         res = unchecked (((FloatConstant) left).Value *
 591                                                                          ((FloatConstant) right).Value);
 592
 593                                                 return new FloatConstant (res);
 594                                         } else if (left is ULongConstant){
 595                                                 ulong res;
 596
 597                                                 if (ec.ConstantCheckState)
 598                                                         res = checked (((ULongConstant) left).Value *
 599                                                                        ((ULongConstant) right).Value);
 600                                                 else
 601                                                         res = unchecked (((ULongConstant) left).Value *
 602                                                                          ((ULongConstant) right).Value);
 603
 604                                                 return new ULongConstant (res);
 605                                         } else if (left is LongConstant){
 606                                                 long res;
 607
 608                                                 if (ec.ConstantCheckState)
 609                                                         res = checked (((LongConstant) left).Value *
 610                                                                        ((LongConstant) right).Value);
 611                                                 else
 612                                                         res = unchecked (((LongConstant) left).Value *
 613                                                                          ((LongConstant) right).Value);
 614
 615                                                 return new LongConstant (res);
 616                                         } else if (left is UIntConstant){
 617                                                 uint res;
 618
 619                                                 if (ec.ConstantCheckState)
 620                                                         res = checked (((UIntConstant) left).Value *
 621                                                                        ((UIntConstant) right).Value);
 622                                                 else
 623                                                         res = unchecked (((UIntConstant) left).Value *
 624                                                                          ((UIntConstant) right).Value);
 625
 626                                                 return new UIntConstant (res);
 627                                         } else if (left is IntConstant){
 628                                                 int res;
 629
 630                                                 if (ec.ConstantCheckState)
 631                                                         res = checked (((IntConstant) left).Value *
 632                                                                        ((IntConstant) right).Value);
 633                                                 else
 634                                                         res = unchecked (((IntConstant) left).Value *
 635                                                                          ((IntConstant) right).Value);
 636
 637                                                 return new IntConstant (res);
 638                                         } else {
 639                                                 throw new Exception ( "Unexepected input: " + left);
 640                                         }
 641                                 } catch (OverflowException){
 642                                         Error_CompileTimeOverflow (loc);
 643                                 }
 644                                 break;
 645
 646                         case Binary.Operator.Division:
 647                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 648                                 if (left == null || right == null)
 649                                         return null;
 650
 651                                 try {
 652                                         if (left is DoubleConstant){
 653                                                 double res;
 654
 655                                                 if (ec.ConstantCheckState)
 656                                                         res = checked (((DoubleConstant) left).Value /
 657                                                                        ((DoubleConstant) right).Value);
 658                                                 else
 659                                                         res = unchecked (((DoubleConstant) left).Value /
 660                                                                          ((DoubleConstant) right).Value);
 661
 662                                                 return new DoubleConstant (res);
 663                                         } else if (left is FloatConstant){
 664                                                 float res;
 665
 666                                                 if (ec.ConstantCheckState)
 667                                                         res = checked (((FloatConstant) left).Value /
 668                                                                        ((FloatConstant) right).Value);
 669                                                 else
 670                                                         res = unchecked (((FloatConstant) left).Value /
 671                                                                          ((FloatConstant) right).Value);
 672
 673                                                 return new FloatConstant (res);
 674                                         } else if (left is ULongConstant){
 675                                                 ulong res;
 676
 677                                                 if (ec.ConstantCheckState)
 678                                                         res = checked (((ULongConstant) left).Value /
 679                                                                        ((ULongConstant) right).Value);
 680                                                 else
 681                                                         res = unchecked (((ULongConstant) left).Value /
 682                                                                          ((ULongConstant) right).Value);
 683
 684                                                 return new ULongConstant (res);
 685                                         } else if (left is LongConstant){
 686                                                 long res;
 687
 688                                                 if (ec.ConstantCheckState)
 689                                                         res = checked (((LongConstant) left).Value /
 690                                                                        ((LongConstant) right).Value);
 691                                                 else
 692                                                         res = unchecked (((LongConstant) left).Value /
 693                                                                          ((LongConstant) right).Value);
 694
 695                                                 return new LongConstant (res);
 696                                         } else if (left is UIntConstant){
 697                                                 uint res;
 698
 699                                                 if (ec.ConstantCheckState)
 700                                                         res = checked (((UIntConstant) left).Value /
 701                                                                        ((UIntConstant) right).Value);
 702                                                 else
 703                                                         res = unchecked (((UIntConstant) left).Value /
 704                                                                          ((UIntConstant) right).Value);
 705
 706                                                 return new UIntConstant (res);
 707                                         } else if (left is IntConstant){
 708                                                 int res;
 709
 710                                                 if (ec.ConstantCheckState)
 711                                                         res = checked (((IntConstant) left).Value /
 712                                                                        ((IntConstant) right).Value);
 713                                                 else
 714                                                         res = unchecked (((IntConstant) left).Value /
 715                                                                          ((IntConstant) right).Value);
 716
 717                                                 return new IntConstant (res);
 718                                         } else {
 719                                                 throw new Exception ( "Unexepected input: " + left);
 720                                         }
 721                                 } catch (OverflowException){
 722                                         Error_CompileTimeOverflow (loc);
 723
 724                                 } catch (DivideByZeroException) {
 725                                         Report.Error (30542, loc, "Division by constant zero");
 726                                 }
 727
 728                                 break;
 729
 730                         case Binary.Operator.Modulus:
 731                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 732                                 if (left == null || right == null)
 733                                         return null;
 734
 735                                 try {
 736                                         if (left is DoubleConstant){
 737                                                 double res;
 738
 739                                                 if (ec.ConstantCheckState)
 740                                                         res = checked (((DoubleConstant) left).Value %
 741                                                                        ((DoubleConstant) right).Value);
 742                                                 else
 743                                                         res = unchecked (((DoubleConstant) left).Value %
 744                                                                          ((DoubleConstant) right).Value);
 745
 746                                                 return new DoubleConstant (res);
 747                                         } else if (left is FloatConstant){
 748                                                 float res;
 749
 750                                                 if (ec.ConstantCheckState)
 751                                                         res = checked (((FloatConstant) left).Value %
 752                                                                        ((FloatConstant) right).Value);
 753                                                 else
 754                                                         res = unchecked (((FloatConstant) left).Value %
 755                                                                          ((FloatConstant) right).Value);
 756
 757                                                 return new FloatConstant (res);
 758                                         } else if (left is ULongConstant){
 759                                                 ulong res;
 760
 761                                                 if (ec.ConstantCheckState)
 762                                                         res = checked (((ULongConstant) left).Value %
 763                                                                        ((ULongConstant) right).Value);
 764                                                 else
 765                                                         res = unchecked (((ULongConstant) left).Value %
 766                                                                          ((ULongConstant) right).Value);
 767
 768                                                 return new ULongConstant (res);
 769                                         } else if (left is LongConstant){
 770                                                 long res;
 771
 772                                                 if (ec.ConstantCheckState)
 773                                                         res = checked (((LongConstant) left).Value %
 774                                                                        ((LongConstant) right).Value);
 775                                                 else
 776                                                         res = unchecked (((LongConstant) left).Value %
 777                                                                          ((LongConstant) right).Value);
 778
 779                                                 return new LongConstant (res);
 780                                         } else if (left is UIntConstant){
 781                                                 uint res;
 782
 783                                                 if (ec.ConstantCheckState)
 784                                                         res = checked (((UIntConstant) left).Value %
 785                                                                        ((UIntConstant) right).Value);
 786                                                 else
 787                                                         res = unchecked (((UIntConstant) left).Value %
 788                                                                          ((UIntConstant) right).Value);
 789
 790                                                 return new UIntConstant (res);
 791                                         } else if (left is IntConstant){
 792                                                 int res;
 793
 794                                                 if (ec.ConstantCheckState)
 795                                                         res = checked (((IntConstant) left).Value %
 796                                                                        ((IntConstant) right).Value);
 797                                                 else
 798                                                         res = unchecked (((IntConstant) left).Value %
 799                                                                          ((IntConstant) right).Value);
 800
 801                                                 return new IntConstant (res);
 802                                         } else {
 803                                                 throw new Exception ( "Unexepected input: " + left);
 804                                         }
 805                                 } catch (OverflowException){
 806                                         Error_CompileTimeOverflow (loc);
 807                                 }
 808                                 break;
 809
 810                         case Binary.Operator.Exponentiation:
 811                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 812                                 if (left == null || right == null)
 813                                         return null;
 814
 815                                 double powVal = System.Math.Pow(((DoubleConstant) left).Value,
 816                                                                 ((DoubleConstant) right).Value);
 817
 818                                 return new DoubleConstant(powVal);
 819
 820                                 //
 821                                 // There is no overflow checking on left shift
 822                                 //
 823                         case Binary.Operator.LeftShift:
 824                                 IntConstant ic = right.ToInt (loc);
 825                                 if (ic == null){
 826                                         Binary.Error_OperatorCannotBeApplied (loc, "<<", lt, rt);
 827                                         return null;
 828                                 }
 829                                 int lshift_val = ic.Value;
 830
 831                                 IntConstant lic;
 832                                 if ((lic = left.ConvertToInt ()) != null)
 833                                         return new IntConstant (lic.Value << lshift_val);
 834
 835                                 UIntConstant luic;
 836                                 if ((luic = left.ConvertToUInt ()) != null)
 837                                         return new UIntConstant (luic.Value << lshift_val);
 838
 839                                 LongConstant llc;
 840                                 if ((llc = left.ConvertToLong ()) != null)
 841                                         return new LongConstant (llc.Value << lshift_val);
 842
 843                                 ULongConstant lulc;
 844                                 if ((lulc = left.ConvertToULong ()) != null)
 845                                         return new ULongConstant (lulc.Value << lshift_val);
 846
 847                                 Binary.Error_OperatorCannotBeApplied (loc, "<<", lt, rt);
 848                                 break;
 849
 850                                 //
 851                                 // There is no overflow checking on right shift
 852                                 //
 853                         case Binary.Operator.RightShift:
 854                                 IntConstant sic = right.ToInt (loc);
 855                                 if (sic == null){
 856                                         Binary.Error_OperatorCannotBeApplied (loc, ">>", lt, rt);
 857                                         return null;
 858                                 }
 859                                 int rshift_val = sic.Value;
 860
 861                                 IntConstant ric;
 862                                 if ((ric = left.ConvertToInt ()) != null)
 863                                         return new IntConstant (ric.Value >> rshift_val);
 864
 865                                 UIntConstant ruic;
 866                                 if ((ruic = left.ConvertToUInt ()) != null)
 867                                         return new UIntConstant (ruic.Value >> rshift_val);
 868
 869                                 LongConstant rlc;
 870                                 if ((rlc = left.ConvertToLong ()) != null)
 871                                         return new LongConstant (rlc.Value >> rshift_val);
 872
 873                                 ULongConstant rulc;
 874                                 if ((rulc = left.ConvertToULong ()) != null)
 875                                         return new ULongConstant (rulc.Value >> rshift_val);
 876
 877                                 Binary.Error_OperatorCannotBeApplied (loc, ">>", lt, rt);
 878                                 break;
 879
 880                         case Binary.Operator.LogicalAnd:
 881                                 if (left is BoolConstant && right is BoolConstant){
 882                                         return new BoolConstant (
 883                                                 ((BoolConstant) left).Value &&
 884                                                 ((BoolConstant) right).Value);
 885                                 }
 886                                 break;
 887
 888                         case Binary.Operator.LogicalOr:
 889                                 if (left is BoolConstant && right is BoolConstant){
 890                                         return new BoolConstant (
 891                                                 ((BoolConstant) left).Value ||
 892                                                 ((BoolConstant) right).Value);
 893                                 }
 894                                 break;
 895
 896                         case Binary.Operator.Equality:
 897                                 if (left is BoolConstant && right is BoolConstant){
 898                                         return new BoolConstant (
 899                                                 ((BoolConstant) left).Value ==
 900                                                 ((BoolConstant) right).Value);
 901
 902                                 }
 903                                 if (left is StringConstant && right is StringConstant){
 904                                         return new BoolConstant (
 905                                                 ((StringConstant) left).Value ==
 906                                                 ((StringConstant) right).Value);
 907
 908                                 }
 909
 910                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 911                                 if (left == null || right == null)
 912                                         return null;
 913
 914                                 bool_res = false;
 915                                 if (left is DoubleConstant)
 916                                         bool_res = ((DoubleConstant) left).Value ==
 917                                                 ((DoubleConstant) right).Value;
 918                                 else if (left is FloatConstant)
 919                                         bool_res = ((FloatConstant) left).Value ==
 920                                                 ((FloatConstant) right).Value;
 921                                 else if (left is ULongConstant)
 922                                         bool_res = ((ULongConstant) left).Value ==
 923                                                 ((ULongConstant) right).Value;
 924                                 else if (left is LongConstant)
 925                                         bool_res = ((LongConstant) left).Value ==
 926                                                 ((LongConstant) right).Value;
 927                                 else if (left is UIntConstant)
 928                                         bool_res = ((UIntConstant) left).Value ==
 929                                                 ((UIntConstant) right).Value;
 930                                 else if (left is IntConstant)
 931                                         bool_res = ((IntConstant) left).Value ==
 932                                                 ((IntConstant) right).Value;
 933                                 else
 934                                         return null;
 935
 936                                 return new BoolConstant (bool_res);
 937
 938                         case Binary.Operator.Inequality:
 939                                 if (left is BoolConstant && right is BoolConstant){
 940                                         return new BoolConstant (
 941                                                 ((BoolConstant) left).Value !=
 942                                                 ((BoolConstant) right).Value);
 943                                 }
 944                                 if (left is StringConstant && right is StringConstant){
 945                                         return new BoolConstant (
 946                                                 ((StringConstant) left).Value !=
 947                                                 ((StringConstant) right).Value);
 948
 949                                 }
 950                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 951                                 if (left == null || right == null)
 952                                         return null;
 953
 954                                 bool_res = false;
 955                                 if (left is DoubleConstant)
 956                                         bool_res = ((DoubleConstant) left).Value !=
 957                                                 ((DoubleConstant) right).Value;
 958                                 else if (left is FloatConstant)
 959                                         bool_res = ((FloatConstant) left).Value !=
 960                                                 ((FloatConstant) right).Value;
 961                                 else if (left is ULongConstant)
 962                                         bool_res = ((ULongConstant) left).Value !=
 963                                                 ((ULongConstant) right).Value;
 964                                 else if (left is LongConstant)
 965                                         bool_res = ((LongConstant) left).Value !=
 966                                                 ((LongConstant) right).Value;
 967                                 else if (left is UIntConstant)
 968                                         bool_res = ((UIntConstant) left).Value !=
 969                                                 ((UIntConstant) right).Value;
 970                                 else if (left is IntConstant)
 971                                         bool_res = ((IntConstant) left).Value !=
 972                                                 ((IntConstant) right).Value;
 973                                 else
 974                                         return null;
 975
 976                                 return new BoolConstant (bool_res);
 977
 978                         case Binary.Operator.LessThan:
 979                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 980                                 if (left == null || right == null)
 981                                         return null;
 982
 983                                 bool_res = false;
 984                                 if (left is DoubleConstant)
 985                                         bool_res = ((DoubleConstant) left).Value <
 986                                                 ((DoubleConstant) right).Value;
 987                                 else if (left is FloatConstant)
 988                                         bool_res = ((FloatConstant) left).Value <
 989                                                 ((FloatConstant) right).Value;
 990                                 else if (left is ULongConstant)
 991                                         bool_res = ((ULongConstant) left).Value <
 992                                                 ((ULongConstant) right).Value;
 993                                 else if (left is LongConstant)
 994                                         bool_res = ((LongConstant) left).Value <
 995                                                 ((LongConstant) right).Value;
 996                                 else if (left is UIntConstant)
 997                                         bool_res = ((UIntConstant) left).Value <
 998                                                 ((UIntConstant) right).Value;
 999                                 else if (left is IntConstant)
1000                                         bool_res = ((IntConstant) left).Value <
1001                                                 ((IntConstant) right).Value;
1002                                 else
1003                                         return null;
1004
1005                                 return new BoolConstant (bool_res);
1006
1007                         case Binary.Operator.GreaterThan:
1008                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
1009                                 if (left == null || right == null)
1010                                         return null;
1011
1012                                 bool_res = false;
1013                                 if (left is DoubleConstant)
1014                                         bool_res = ((DoubleConstant) left).Value >
1015                                                 ((DoubleConstant) right).Value;
1016                                 else if (left is FloatConstant)
1017                                         bool_res = ((FloatConstant) left).Value >
1018                                                 ((FloatConstant) right).Value;
1019                                 else if (left is ULongConstant)
1020                                         bool_res = ((ULongConstant) left).Value >
1021                                                 ((ULongConstant) right).Value;
1022                                 else if (left is LongConstant)
1023                                         bool_res = ((LongConstant) left).Value >
1024                                                 ((LongConstant) right).Value;
1025                                 else if (left is UIntConstant)
1026                                         bool_res = ((UIntConstant) left).Value >
1027                                                 ((UIntConstant) right).Value;
1028                                 else if (left is IntConstant)
1029                                         bool_res = ((IntConstant) left).Value >
1030                                                 ((IntConstant) right).Value;
1031                                 else
1032                                         return null;
1033
1034                                 return new BoolConstant (bool_res);
1035
1036                         case Binary.Operator.GreaterThanOrEqual:
1037                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
1038                                 if (left == null || right == null)
1039                                         return null;
1040
1041                                 bool_res = false;
1042                                 if (left is DoubleConstant)
1043                                         bool_res = ((DoubleConstant) left).Value >=
1044                                                 ((DoubleConstant) right).Value;
1045                                 else if (left is FloatConstant)
1046                                         bool_res = ((FloatConstant) left).Value >=
1047                                                 ((FloatConstant) right).Value;
1048                                 else if (left is ULongConstant)
1049                                         bool_res = ((ULongConstant) left).Value >=
1050                                                 ((ULongConstant) right).Value;
1051                                 else if (left is LongConstant)
1052                                         bool_res = ((LongConstant) left).Value >=
1053                                                 ((LongConstant) right).Value;
1054                                 else if (left is UIntConstant)
1055                                         bool_res = ((UIntConstant) left).Value >=
1056                                                 ((UIntConstant) right).Value;
1057                                 else if (left is IntConstant)
1058                                         bool_res = ((IntConstant) left).Value >=
1059                                                 ((IntConstant) right).Value;
1060                                 else
1061                                         return null;
1062
1063                                 return new BoolConstant (bool_res);
1064
1065                         case Binary.Operator.LessThanOrEqual:
1066                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
1067                                 if (left == null || right == null)
1068                                         return null;
1069
1070                                 bool_res = false;
1071                                 if (left is DoubleConstant)
1072                                         bool_res = ((DoubleConstant) left).Value <=
1073                                                 ((DoubleConstant) right).Value;
1074                                 else if (left is FloatConstant)
1075                                         bool_res = ((FloatConstant) left).Value <=
1076                                                 ((FloatConstant) right).Value;
1077                                 else if (left is ULongConstant)
1078                                         bool_res = ((ULongConstant) left).Value <=
1079                                                 ((ULongConstant) right).Value;
1080                                 else if (left is LongConstant)
1081                                         bool_res = ((LongConstant) left).Value <=
1082                                                 ((LongConstant) right).Value;
1083                                 else if (left is UIntConstant)
1084                                         bool_res = ((UIntConstant) left).Value <=
1085                                                 ((UIntConstant) right).Value;
1086                                 else if (left is IntConstant)
1087                                         bool_res = ((IntConstant) left).Value <=
1088                                                 ((IntConstant) right).Value;
1089                                 else
1090                                         return null;
1091
1092                                 return new BoolConstant (bool_res);
1093                         }
1094
1095                         return null;
1096                 }
1097         }
1098 }