mcs/mcs/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.CSharp {
  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 (Binary.Operator oper,
  31                                                          ref Constant left, ref Constant right,
  32                                                          Location loc)
  33                 {
  34                         if (left is DoubleConstant || right is DoubleConstant){
  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, othe operands are
  97                                 // converted to type long.
  98                                 //
  99                                 if (!(left is UIntConstant))
 100                                         left = left.ToUInt (loc);
 101                                 else if (!(right is UIntConstant))
 102                                         right = right.ToUInt (loc);
 103                                 return;
 104                         } else {
 105                                 //
 106                                 // Force conversions to int32
 107                                 //
 108                                 if (!(left is IntConstant))
 109                                         left = left.ToInt (loc);
 110                                 if (!(right is IntConstant))
 111                                         right = right.ToInt (loc);
 112                         }
 113                         return;
 114                 }
 115
 116                 static void Error_CompileTimeOverflow (Location loc)
 117                 {
 118                         Report.Error (220, loc, "The operation overflows at compile time in checked mode");
 119                 }
 120
 121                 /// <summary>
 122                 ///   Constant expression folder for binary operations.
 123                 ///
 124                 ///   Returns null if the expression can not be folded.
 125                 /// </summary>
 126                 static public Expression BinaryFold (EmitContext ec, Binary.Operator oper,
 127                                                      Constant left, Constant right, Location loc)
 128                 {
 129                         Type lt = left.Type;
 130                         Type rt = right.Type;
 131                         Type result_type = null;
 132                         bool bool_res;
 133
 134                         //
 135                         // Enumerator folding
 136                         //
 137                         if (rt == lt && left is EnumConstant)
 138                                 result_type = lt;
 139
 140                         switch (oper){
 141                         case Binary.Operator.BitwiseOr:
 142                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 143                                 if (left == null || right == null)
 144                                         return null;
 145
 146                                 if (left is IntConstant){
 147                                         IntConstant v;
 148                                         int res = ((IntConstant) left).Value | ((IntConstant) right).Value;
 149
 150                                         v = new IntConstant (res);
 151                                         if (result_type == null)
 152                                                 return v;
 153                                         else
 154                                                 return new EnumConstant (v, result_type);
 155                                 } else if (left is UIntConstant){
 156                                         UIntConstant v;
 157                                         uint res = ((UIntConstant)left).Value | ((UIntConstant)right).Value;
 158
 159                                         v = new UIntConstant (res);
 160                                         if (result_type == null)
 161                                                 return v;
 162                                         else
 163                                                 return new EnumConstant (v, result_type);
 164                                 } else if (left is LongConstant){
 165                                         LongConstant v;
 166                                         long res = ((LongConstant)left).Value | ((LongConstant)right).Value;
 167
 168                                         v = new LongConstant (res);
 169                                         if (result_type == null)
 170                                                 return v;
 171                                         else
 172                                                 return new EnumConstant (v, result_type);
 173                                 } else if (left is ULongConstant){
 174                                         ULongConstant v;
 175                                         ulong res = ((ULongConstant)left).Value |
 176                                                 ((ULongConstant)right).Value;
 177
 178                                         v = new ULongConstant (res);
 179                                         if (result_type == null)
 180                                                 return v;
 181                                         else
 182                                                 return new EnumConstant (v, result_type);
 183                                 }
 184                                 break;
 185
 186                         case Binary.Operator.BitwiseAnd:
 187                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 188                                 if (left == null || right == null)
 189                                         return null;
 190
 191                                 if (left is IntConstant){
 192                                         IntConstant v;
 193                                         int res = ((IntConstant) left).Value & ((IntConstant) right).Value;
 194
 195                                         v = new IntConstant (res);
 196                                         if (result_type == null)
 197                                                 return v;
 198                                         else
 199                                                 return new EnumConstant (v, result_type);
 200                                 } else if (left is UIntConstant){
 201                                         UIntConstant v;
 202                                         uint res = ((UIntConstant)left).Value & ((UIntConstant)right).Value;
 203
 204                                         v = new UIntConstant (res);
 205                                         if (result_type == null)
 206                                                 return v;
 207                                         else
 208                                                 return new EnumConstant (v, result_type);
 209                                 } else if (left is LongConstant){
 210                                         LongConstant v;
 211                                         long res = ((LongConstant)left).Value & ((LongConstant)right).Value;
 212
 213                                         v = new LongConstant (res);
 214                                         if (result_type == null)
 215                                                 return v;
 216                                         else
 217                                                 return new EnumConstant (v, result_type);
 218                                 } else if (left is ULongConstant){
 219                                         ULongConstant v;
 220                                         ulong res = ((ULongConstant)left).Value &
 221                                                 ((ULongConstant)right).Value;
 222
 223                                         v = new ULongConstant (res);
 224                                         if (result_type == null)
 225                                                 return v;
 226                                         else
 227                                                 return new EnumConstant (v, result_type);
 228                                 }
 229                                 break;
 230
 231                         case Binary.Operator.ExclusiveOr:
 232                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 233                                 if (left == null || right == null)
 234                                         return null;
 235
 236                                 if (left is IntConstant){
 237                                         IntConstant v;
 238                                         int res = ((IntConstant) left).Value ^ ((IntConstant) right).Value;
 239
 240                                         v = new IntConstant (res);
 241                                         if (result_type == null)
 242                                                 return v;
 243                                         else
 244                                                 return new EnumConstant (v, result_type);
 245                                 } else if (left is UIntConstant){
 246                                         UIntConstant v;
 247                                         uint res = ((UIntConstant)left).Value ^ ((UIntConstant)right).Value;
 248
 249                                         v = new UIntConstant (res);
 250                                         if (result_type == null)
 251                                                 return v;
 252                                         else
 253                                                 return new EnumConstant (v, result_type);
 254                                 } else if (left is LongConstant){
 255                                         LongConstant v;
 256                                         long res = ((LongConstant)left).Value ^ ((LongConstant)right).Value;
 257
 258                                         v = new LongConstant (res);
 259                                         if (result_type == null)
 260                                                 return v;
 261                                         else
 262                                                 return new EnumConstant (v, result_type);
 263                                 } else if (left is ULongConstant){
 264                                         ULongConstant v;
 265                                         ulong res = ((ULongConstant)left).Value ^
 266                                                 ((ULongConstant)right).Value;
 267
 268                                         v = new ULongConstant (res);
 269                                         if (result_type == null)
 270                                                 return v;
 271                                         else
 272                                                 return new EnumConstant (v, result_type);
 273                                 }
 274                                 break;
 275
 276                         case Binary.Operator.Addition:
 277                                 bool left_is_string = left is StringConstant;
 278                                 bool right_is_string = right is StringConstant;
 279
 280                                 //
 281                                 // If both sides are strings, then concatenate, if
 282                                 // one is a string, and the other is not, then defer
 283                                 // to runtime concatenation
 284                                 //
 285                                 if (left_is_string || right_is_string){
 286                                         if (left_is_string && right_is_string)
 287                                                 return new StringConstant (
 288                                                         ((StringConstant) left).Value +
 289                                                         ((StringConstant) right).Value);
 290
 291                                         return null;
 292                                 }
 293
 294                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 295                                 if (left == null || right == null)
 296                                         return null;
 297
 298                                 try {
 299                                         if (left is DoubleConstant){
 300                                                 double res;
 301
 302                                                 if (ec.ConstantCheckState)
 303                                                         res = checked (((DoubleConstant) left).Value +
 304                                                                        ((DoubleConstant) right).Value);
 305                                                 else
 306                                                         res = unchecked (((DoubleConstant) left).Value +
 307                                                                          ((DoubleConstant) right).Value);
 308
 309                                                 return new DoubleConstant (res);
 310                                         } else if (left is FloatConstant){
 311                                                 float res;
 312
 313                                                 if (ec.ConstantCheckState)
 314                                                         res = checked (((FloatConstant) left).Value +
 315                                                                        ((FloatConstant) right).Value);
 316                                                 else
 317                                                         res = unchecked (((FloatConstant) left).Value +
 318                                                                          ((FloatConstant) right).Value);
 319
 320                                                 return new FloatConstant (res);
 321                                         } else if (left is ULongConstant){
 322                                                 ulong res;
 323
 324                                                 if (ec.ConstantCheckState)
 325                                                         res = checked (((ULongConstant) left).Value +
 326                                                                        ((ULongConstant) right).Value);
 327                                                 else
 328                                                         res = unchecked (((ULongConstant) left).Value +
 329                                                                          ((ULongConstant) right).Value);
 330
 331                                                 return new ULongConstant (res);
 332                                         } else if (left is LongConstant){
 333                                                 long res;
 334
 335                                                 if (ec.ConstantCheckState)
 336                                                         res = checked (((LongConstant) left).Value +
 337                                                                        ((LongConstant) right).Value);
 338                                                 else
 339                                                         res = unchecked (((LongConstant) left).Value +
 340                                                                          ((LongConstant) right).Value);
 341
 342                                                 return new LongConstant (res);
 343                                         } else if (left is UIntConstant){
 344                                                 uint res;
 345
 346                                                 if (ec.ConstantCheckState)
 347                                                         res = checked (((UIntConstant) left).Value +
 348                                                                        ((UIntConstant) right).Value);
 349                                                 else
 350                                                         res = unchecked (((UIntConstant) left).Value +
 351                                                                          ((UIntConstant) right).Value);
 352
 353                                                 return new UIntConstant (res);
 354                                         } else if (left is IntConstant){
 355                                                 int res;
 356
 357                                                 if (ec.ConstantCheckState)
 358                                                         res = checked (((IntConstant) left).Value +
 359                                                                        ((IntConstant) right).Value);
 360                                                 else
 361                                                         res = unchecked (((IntConstant) left).Value +
 362                                                                          ((IntConstant) right).Value);
 363
 364                                                 return new IntConstant (res);
 365                                         } else {
 366                                                 throw new Exception ( "Unexepected input: " + left);
 367                                         }
 368                                 } catch (OverflowException){
 369                                         Error_CompileTimeOverflow (loc);
 370                                 }
 371                                 break;
 372
 373                         case Binary.Operator.Subtraction:
 374                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 375                                 if (left == null || right == null)
 376                                         return null;
 377
 378                                 try {
 379                                         if (left is DoubleConstant){
 380                                                 double res;
 381
 382                                                 if (ec.ConstantCheckState)
 383                                                         res = checked (((DoubleConstant) left).Value -
 384                                                                        ((DoubleConstant) right).Value);
 385                                                 else
 386                                                         res = unchecked (((DoubleConstant) left).Value -
 387                                                                          ((DoubleConstant) right).Value);
 388
 389                                                 return new DoubleConstant (res);
 390                                         } else if (left is FloatConstant){
 391                                                 float res;
 392
 393                                                 if (ec.ConstantCheckState)
 394                                                         res = checked (((FloatConstant) left).Value -
 395                                                                        ((FloatConstant) right).Value);
 396                                                 else
 397                                                         res = unchecked (((FloatConstant) left).Value -
 398                                                                          ((FloatConstant) right).Value);
 399
 400                                                 return new FloatConstant (res);
 401                                         } else if (left is ULongConstant){
 402                                                 ulong res;
 403
 404                                                 if (ec.ConstantCheckState)
 405                                                         res = checked (((ULongConstant) left).Value -
 406                                                                        ((ULongConstant) right).Value);
 407                                                 else
 408                                                         res = unchecked (((ULongConstant) left).Value -
 409                                                                          ((ULongConstant) right).Value);
 410
 411                                                 return new ULongConstant (res);
 412                                         } else if (left is LongConstant){
 413                                                 long res;
 414
 415                                                 if (ec.ConstantCheckState)
 416                                                         res = checked (((LongConstant) left).Value -
 417                                                                        ((LongConstant) right).Value);
 418                                                 else
 419                                                         res = unchecked (((LongConstant) left).Value -
 420                                                                          ((LongConstant) right).Value);
 421
 422                                                 return new LongConstant (res);
 423                                         } else if (left is UIntConstant){
 424                                                 uint res;
 425
 426                                                 if (ec.ConstantCheckState)
 427                                                         res = checked (((UIntConstant) left).Value -
 428                                                                        ((UIntConstant) right).Value);
 429                                                 else
 430                                                         res = unchecked (((UIntConstant) left).Value -
 431                                                                          ((UIntConstant) right).Value);
 432
 433                                                 return new UIntConstant (res);
 434                                         } else if (left is IntConstant){
 435                                                 int res;
 436
 437                                                 if (ec.ConstantCheckState)
 438                                                         res = checked (((IntConstant) left).Value -
 439                                                                        ((IntConstant) right).Value);
 440                                                 else
 441                                                         res = unchecked (((IntConstant) left).Value -
 442                                                                          ((IntConstant) right).Value);
 443
 444                                                 return new IntConstant (res);
 445                                         } else {
 446                                                 throw new Exception ( "Unexepected input: " + left);
 447                                         }
 448                                 } catch (OverflowException){
 449                                         Error_CompileTimeOverflow (loc);
 450                                 }
 451                                 break;
 452
 453                         case Binary.Operator.Multiply:
 454                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 455                                 if (left == null || right == null)
 456                                         return null;
 457
 458                                 try {
 459                                         if (left is DoubleConstant){
 460                                                 double res;
 461
 462                                                 if (ec.ConstantCheckState)
 463                                                         res = checked (((DoubleConstant) left).Value *
 464                                                                        ((DoubleConstant) right).Value);
 465                                                 else
 466                                                         res = unchecked (((DoubleConstant) left).Value *
 467                                                                          ((DoubleConstant) right).Value);
 468
 469                                                 return new DoubleConstant (res);
 470                                         } else if (left is FloatConstant){
 471                                                 float res;
 472
 473                                                 if (ec.ConstantCheckState)
 474                                                         res = checked (((FloatConstant) left).Value *
 475                                                                        ((FloatConstant) right).Value);
 476                                                 else
 477                                                         res = unchecked (((FloatConstant) left).Value *
 478                                                                          ((FloatConstant) right).Value);
 479
 480                                                 return new FloatConstant (res);
 481                                         } else if (left is ULongConstant){
 482                                                 ulong res;
 483
 484                                                 if (ec.ConstantCheckState)
 485                                                         res = checked (((ULongConstant) left).Value *
 486                                                                        ((ULongConstant) right).Value);
 487                                                 else
 488                                                         res = unchecked (((ULongConstant) left).Value *
 489                                                                          ((ULongConstant) right).Value);
 490
 491                                                 return new ULongConstant (res);
 492                                         } else if (left is LongConstant){
 493                                                 long res;
 494
 495                                                 if (ec.ConstantCheckState)
 496                                                         res = checked (((LongConstant) left).Value *
 497                                                                        ((LongConstant) right).Value);
 498                                                 else
 499                                                         res = unchecked (((LongConstant) left).Value *
 500                                                                          ((LongConstant) right).Value);
 501
 502                                                 return new LongConstant (res);
 503                                         } else if (left is UIntConstant){
 504                                                 uint res;
 505
 506                                                 if (ec.ConstantCheckState)
 507                                                         res = checked (((UIntConstant) left).Value *
 508                                                                        ((UIntConstant) right).Value);
 509                                                 else
 510                                                         res = unchecked (((UIntConstant) left).Value *
 511                                                                          ((UIntConstant) right).Value);
 512
 513                                                 return new UIntConstant (res);
 514                                         } else if (left is IntConstant){
 515                                                 int res;
 516
 517                                                 if (ec.ConstantCheckState)
 518                                                         res = checked (((IntConstant) left).Value *
 519                                                                        ((IntConstant) right).Value);
 520                                                 else
 521                                                         res = unchecked (((IntConstant) left).Value *
 522                                                                          ((IntConstant) right).Value);
 523
 524                                                 return new IntConstant (res);
 525                                         } else {
 526                                                 throw new Exception ( "Unexepected input: " + left);
 527                                         }
 528                                 } catch (OverflowException){
 529                                         Error_CompileTimeOverflow (loc);
 530                                 }
 531                                 break;
 532
 533                         case Binary.Operator.Division:
 534                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 535                                 if (left == null || right == null)
 536                                         return null;
 537
 538                                 try {
 539                                         if (left is DoubleConstant){
 540                                                 double res;
 541
 542                                                 if (ec.ConstantCheckState)
 543                                                         res = checked (((DoubleConstant) left).Value /
 544                                                                        ((DoubleConstant) right).Value);
 545                                                 else
 546                                                         res = unchecked (((DoubleConstant) left).Value /
 547                                                                          ((DoubleConstant) right).Value);
 548
 549                                                 return new DoubleConstant (res);
 550                                         } else if (left is FloatConstant){
 551                                                 float res;
 552
 553                                                 if (ec.ConstantCheckState)
 554                                                         res = checked (((FloatConstant) left).Value /
 555                                                                        ((FloatConstant) right).Value);
 556                                                 else
 557                                                         res = unchecked (((FloatConstant) left).Value /
 558                                                                          ((FloatConstant) right).Value);
 559
 560                                                 return new FloatConstant (res);
 561                                         } else if (left is ULongConstant){
 562                                                 ulong res;
 563
 564                                                 if (ec.ConstantCheckState)
 565                                                         res = checked (((ULongConstant) left).Value /
 566                                                                        ((ULongConstant) right).Value);
 567                                                 else
 568                                                         res = unchecked (((ULongConstant) left).Value /
 569                                                                          ((ULongConstant) right).Value);
 570
 571                                                 return new ULongConstant (res);
 572                                         } else if (left is LongConstant){
 573                                                 long res;
 574
 575                                                 if (ec.ConstantCheckState)
 576                                                         res = checked (((LongConstant) left).Value /
 577                                                                        ((LongConstant) right).Value);
 578                                                 else
 579                                                         res = unchecked (((LongConstant) left).Value /
 580                                                                          ((LongConstant) right).Value);
 581
 582                                                 return new LongConstant (res);
 583                                         } else if (left is UIntConstant){
 584                                                 uint res;
 585
 586                                                 if (ec.ConstantCheckState)
 587                                                         res = checked (((UIntConstant) left).Value /
 588                                                                        ((UIntConstant) right).Value);
 589                                                 else
 590                                                         res = unchecked (((UIntConstant) left).Value /
 591                                                                          ((UIntConstant) right).Value);
 592
 593                                                 return new UIntConstant (res);
 594                                         } else if (left is IntConstant){
 595                                                 int res;
 596
 597                                                 if (ec.ConstantCheckState)
 598                                                         res = checked (((IntConstant) left).Value /
 599                                                                        ((IntConstant) right).Value);
 600                                                 else
 601                                                         res = unchecked (((IntConstant) left).Value /
 602                                                                          ((IntConstant) right).Value);
 603
 604                                                 return new IntConstant (res);
 605                                         } else {
 606                                                 throw new Exception ( "Unexepected input: " + left);
 607                                         }
 608                                 } catch (OverflowException){
 609                                         Error_CompileTimeOverflow (loc);
 610                                 }
 611                                 break;
 612
 613                         case Binary.Operator.Modulus:
 614                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 615                                 if (left == null || right == null)
 616                                         return null;
 617
 618                                 try {
 619                                         if (left is DoubleConstant){
 620                                                 double res;
 621
 622                                                 if (ec.ConstantCheckState)
 623                                                         res = checked (((DoubleConstant) left).Value %
 624                                                                        ((DoubleConstant) right).Value);
 625                                                 else
 626                                                         res = unchecked (((DoubleConstant) left).Value %
 627                                                                          ((DoubleConstant) right).Value);
 628
 629                                                 return new DoubleConstant (res);
 630                                         } else if (left is FloatConstant){
 631                                                 float res;
 632
 633                                                 if (ec.ConstantCheckState)
 634                                                         res = checked (((FloatConstant) left).Value %
 635                                                                        ((FloatConstant) right).Value);
 636                                                 else
 637                                                         res = unchecked (((FloatConstant) left).Value %
 638                                                                          ((FloatConstant) right).Value);
 639
 640                                                 return new FloatConstant (res);
 641                                         } else if (left is ULongConstant){
 642                                                 ulong res;
 643
 644                                                 if (ec.ConstantCheckState)
 645                                                         res = checked (((ULongConstant) left).Value %
 646                                                                        ((ULongConstant) right).Value);
 647                                                 else
 648                                                         res = unchecked (((ULongConstant) left).Value %
 649                                                                          ((ULongConstant) right).Value);
 650
 651                                                 return new ULongConstant (res);
 652                                         } else if (left is LongConstant){
 653                                                 long res;
 654
 655                                                 if (ec.ConstantCheckState)
 656                                                         res = checked (((LongConstant) left).Value %
 657                                                                        ((LongConstant) right).Value);
 658                                                 else
 659                                                         res = unchecked (((LongConstant) left).Value %
 660                                                                          ((LongConstant) right).Value);
 661
 662                                                 return new LongConstant (res);
 663                                         } else if (left is UIntConstant){
 664                                                 uint res;
 665
 666                                                 if (ec.ConstantCheckState)
 667                                                         res = checked (((UIntConstant) left).Value %
 668                                                                        ((UIntConstant) right).Value);
 669                                                 else
 670                                                         res = unchecked (((UIntConstant) left).Value %
 671                                                                          ((UIntConstant) right).Value);
 672
 673                                                 return new UIntConstant (res);
 674                                         } else if (left is IntConstant){
 675                                                 int res;
 676
 677                                                 if (ec.ConstantCheckState)
 678                                                         res = checked (((IntConstant) left).Value %
 679                                                                        ((IntConstant) right).Value);
 680                                                 else
 681                                                         res = unchecked (((IntConstant) left).Value %
 682                                                                          ((IntConstant) right).Value);
 683
 684                                                 return new IntConstant (res);
 685                                         } else {
 686                                                 throw new Exception ( "Unexepected input: " + left);
 687                                         }
 688                                 } catch (OverflowException){
 689                                         Error_CompileTimeOverflow (loc);
 690                                 }
 691                                 break;
 692
 693                                 //
 694                                 // There is no overflow checking on left shift
 695                                 //
 696                         case Binary.Operator.LeftShift:
 697                                 IntConstant ic = right.ToInt (loc);
 698                                 if (ic == null){
 699                                         Binary.Error_OperatorCannotBeApplied (loc, "<<", lt, rt);
 700                                         return null;
 701                                 }
 702                                 int lshift_val = ic.Value;
 703
 704                                 IntConstant lic;
 705                                 if ((lic = left.ConvertToInt ()) != null)
 706                                         return new IntConstant (lic.Value << lshift_val);
 707
 708                                 UIntConstant luic;
 709                                 if ((luic = left.ConvertToUInt ()) != null)
 710                                         return new UIntConstant (luic.Value << lshift_val);
 711
 712                                 LongConstant llc;
 713                                 if ((llc = left.ConvertToLong ()) != null)
 714                                         return new LongConstant (llc.Value << lshift_val);
 715
 716                                 ULongConstant lulc;
 717                                 if ((lulc = left.ConvertToULong ()) != null)
 718                                         return new ULongConstant (lulc.Value << lshift_val);
 719
 720                                 Binary.Error_OperatorCannotBeApplied (loc, "<<", lt, rt);
 721                                 break;
 722
 723                                 //
 724                                 // There is no overflow checking on right shift
 725                                 //
 726                         case Binary.Operator.RightShift:
 727                                 IntConstant sic = right.ToInt (loc);
 728                                 if (sic == null){
 729                                         Binary.Error_OperatorCannotBeApplied (loc, ">>", lt, rt);
 730                                         return null;
 731                                 }
 732                                 int rshift_val = sic.Value;
 733
 734                                 IntConstant ric;
 735                                 if ((ric = left.ConvertToInt ()) != null)
 736                                         return new IntConstant (ric.Value >> rshift_val);
 737
 738                                 UIntConstant ruic;
 739                                 if ((ruic = left.ConvertToUInt ()) != null)
 740                                         return new UIntConstant (ruic.Value >> rshift_val);
 741
 742                                 LongConstant rlc;
 743                                 if ((rlc = left.ConvertToLong ()) != null)
 744                                         return new LongConstant (rlc.Value >> rshift_val);
 745
 746                                 ULongConstant rulc;
 747                                 if ((rulc = left.ConvertToULong ()) != null)
 748                                         return new ULongConstant (rulc.Value >> rshift_val);
 749
 750                                 Binary.Error_OperatorCannotBeApplied (loc, ">>", lt, rt);
 751                                 break;
 752
 753                         case Binary.Operator.LogicalAnd:
 754                                 if (left is BoolConstant && right is BoolConstant){
 755                                         return new BoolConstant (
 756                                                 ((BoolConstant) left).Value &&
 757                                                 ((BoolConstant) right).Value);
 758                                 }
 759                                 break;
 760
 761                         case Binary.Operator.LogicalOr:
 762                                 if (left is BoolConstant && right is BoolConstant){
 763                                         return new BoolConstant (
 764                                                 ((BoolConstant) left).Value ||
 765                                                 ((BoolConstant) right).Value);
 766                                 }
 767                                 break;
 768
 769                         case Binary.Operator.Equality:
 770                                 if (left is BoolConstant && right is BoolConstant){
 771                                         return new BoolConstant (
 772                                                 ((BoolConstant) left).Value ==
 773                                                 ((BoolConstant) right).Value);
 774
 775                                 }
 776                                 if (left is StringConstant && right is StringConstant){
 777                                         return new BoolConstant (
 778                                                 ((StringConstant) left).Value ==
 779                                                 ((StringConstant) right).Value);
 780
 781                                 }
 782
 783                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 784                                 if (left == null || right == null)
 785                                         return null;
 786
 787                                 bool_res = false;
 788                                 if (left is DoubleConstant)
 789                                         bool_res = ((DoubleConstant) left).Value ==
 790                                                 ((DoubleConstant) right).Value;
 791                                 else if (left is FloatConstant)
 792                                         bool_res = ((FloatConstant) left).Value ==
 793                                                 ((FloatConstant) right).Value;
 794                                 else if (left is ULongConstant)
 795                                         bool_res = ((ULongConstant) left).Value ==
 796                                                 ((ULongConstant) right).Value;
 797                                 else if (left is LongConstant)
 798                                         bool_res = ((LongConstant) left).Value ==
 799                                                 ((LongConstant) right).Value;
 800                                 else if (left is UIntConstant)
 801                                         bool_res = ((UIntConstant) left).Value ==
 802                                                 ((UIntConstant) right).Value;
 803                                 else if (left is IntConstant)
 804                                         bool_res = ((IntConstant) left).Value ==
 805                                                 ((IntConstant) right).Value;
 806                                 else
 807                                         return null;
 808
 809                                 return new BoolConstant (bool_res);
 810
 811                         case Binary.Operator.Inequality:
 812                                 if (left is BoolConstant && right is BoolConstant){
 813                                         return new BoolConstant (
 814                                                 ((BoolConstant) left).Value !=
 815                                                 ((BoolConstant) right).Value);
 816                                 }
 817                                 if (left is StringConstant && right is StringConstant){
 818                                         return new BoolConstant (
 819                                                 ((StringConstant) left).Value !=
 820                                                 ((StringConstant) right).Value);
 821
 822                                 }
 823                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 824                                 if (left == null || right == null)
 825                                         return null;
 826
 827                                 bool_res = false;
 828                                 if (left is DoubleConstant)
 829                                         bool_res = ((DoubleConstant) left).Value !=
 830                                                 ((DoubleConstant) right).Value;
 831                                 else if (left is FloatConstant)
 832                                         bool_res = ((FloatConstant) left).Value !=
 833                                                 ((FloatConstant) right).Value;
 834                                 else if (left is ULongConstant)
 835                                         bool_res = ((ULongConstant) left).Value !=
 836                                                 ((ULongConstant) right).Value;
 837                                 else if (left is LongConstant)
 838                                         bool_res = ((LongConstant) left).Value !=
 839                                                 ((LongConstant) right).Value;
 840                                 else if (left is UIntConstant)
 841                                         bool_res = ((UIntConstant) left).Value !=
 842                                                 ((UIntConstant) right).Value;
 843                                 else if (left is IntConstant)
 844                                         bool_res = ((IntConstant) left).Value !=
 845                                                 ((IntConstant) right).Value;
 846                                 else
 847                                         return null;
 848
 849                                 return new BoolConstant (bool_res);
 850
 851                         case Binary.Operator.LessThan:
 852                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 853                                 if (left == null || right == null)
 854                                         return null;
 855
 856                                 bool_res = false;
 857                                 if (left is DoubleConstant)
 858                                         bool_res = ((DoubleConstant) left).Value <
 859                                                 ((DoubleConstant) right).Value;
 860                                 else if (left is FloatConstant)
 861                                         bool_res = ((FloatConstant) left).Value <
 862                                                 ((FloatConstant) right).Value;
 863                                 else if (left is ULongConstant)
 864                                         bool_res = ((ULongConstant) left).Value <
 865                                                 ((ULongConstant) right).Value;
 866                                 else if (left is LongConstant)
 867                                         bool_res = ((LongConstant) left).Value <
 868                                                 ((LongConstant) right).Value;
 869                                 else if (left is UIntConstant)
 870                                         bool_res = ((UIntConstant) left).Value <
 871                                                 ((UIntConstant) right).Value;
 872                                 else if (left is IntConstant)
 873                                         bool_res = ((IntConstant) left).Value <
 874                                                 ((IntConstant) right).Value;
 875                                 else
 876                                         return null;
 877
 878                                 return new BoolConstant (bool_res);
 879
 880                         case Binary.Operator.GreaterThan:
 881                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 882                                 if (left == null || right == null)
 883                                         return null;
 884
 885                                 bool_res = false;
 886                                 if (left is DoubleConstant)
 887                                         bool_res = ((DoubleConstant) left).Value >
 888                                                 ((DoubleConstant) right).Value;
 889                                 else if (left is FloatConstant)
 890                                         bool_res = ((FloatConstant) left).Value >
 891                                                 ((FloatConstant) right).Value;
 892                                 else if (left is ULongConstant)
 893                                         bool_res = ((ULongConstant) left).Value >
 894                                                 ((ULongConstant) right).Value;
 895                                 else if (left is LongConstant)
 896                                         bool_res = ((LongConstant) left).Value >
 897                                                 ((LongConstant) right).Value;
 898                                 else if (left is UIntConstant)
 899                                         bool_res = ((UIntConstant) left).Value >
 900                                                 ((UIntConstant) right).Value;
 901                                 else if (left is IntConstant)
 902                                         bool_res = ((IntConstant) left).Value >
 903                                                 ((IntConstant) right).Value;
 904                                 else
 905                                         return null;
 906
 907                                 return new BoolConstant (bool_res);
 908
 909                         case Binary.Operator.GreaterThanOrEqual:
 910                                 DoConstantNumericPromotions (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.LessThanOrEqual:
 939                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 940                                 if (left == null || right == null)
 941                                         return null;
 942
 943                                 bool_res = false;
 944                                 if (left is DoubleConstant)
 945                                         bool_res = ((DoubleConstant) left).Value <=
 946                                                 ((DoubleConstant) right).Value;
 947                                 else if (left is FloatConstant)
 948                                         bool_res = ((FloatConstant) left).Value <=
 949                                                 ((FloatConstant) right).Value;
 950                                 else if (left is ULongConstant)
 951                                         bool_res = ((ULongConstant) left).Value <=
 952                                                 ((ULongConstant) right).Value;
 953                                 else if (left is LongConstant)
 954                                         bool_res = ((LongConstant) left).Value <=
 955                                                 ((LongConstant) right).Value;
 956                                 else if (left is UIntConstant)
 957                                         bool_res = ((UIntConstant) left).Value <=
 958                                                 ((UIntConstant) right).Value;
 959                                 else if (left is IntConstant)
 960                                         bool_res = ((IntConstant) left).Value <=
 961                                                 ((IntConstant) right).Value;
 962                                 else
 963                                         return null;
 964
 965                                 return new BoolConstant (bool_res);
 966                         }
 967
 968                         return null;
 969                 }
 970         }
 971 }