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 (true, loc);
  40
  41                                 if (!(right is DoubleConstant))
  42                                         right = right.ToDouble (true, 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 (true, loc);
  50
  51                                 if (!(right is FloatConstant))
  52                                         right = right.ToFloat (true, 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 (true, loc);
  67                                 } else {
  68                                         other = left;
  69                                         match = right;
  70                                         left = left.ToULong (true, loc);
  71                                 }
  72
  73                                 if (other is SByteConstant || other is ShortConstant ||
  74                                     other is IntConstant || other is LongConstant){
  75                                         Binary.Error_OperatorAmbiguous
  76                                                 (loc, oper, other.Type, match.Type);
  77                                         left = null;
  78                                         right = null;
  79                                 }
  80                                 return;
  81                         } else if (left is LongConstant || right is LongConstant){
  82                                 //
  83                                 // If either operand is of type long, the other operand is converted
  84                                 // to type long.
  85                                 //
  86                                 if (!(left is LongConstant))
  87                                         left = left.ToLong (true, loc);
  88                                 else if (!(right is LongConstant))
  89                                         right = right.ToLong (true, loc);
  90                                 return;
  91                         } else if (left is UIntConstant || right is UIntConstant){
  92                                 //
  93                                 // If either operand is of type uint, and the other
  94                                 // operand is of type sbyte, short or int, othe operands are
  95                                 // converted to type long.
  96                                 //
  97                                 if (!(left is UIntConstant))
  98                                         left = left.ToUInt (true, loc);
  99                                 else if (!(right is UIntConstant))
 100                                         right = right.ToUInt (true, loc);
 101                                 return;
 102                         } else {
 103                                 //
 104                                 // Force conversions to int32
 105                                 //
 106                                 if (!(left is IntConstant))
 107                                         left = left.ToInt (true, loc);
 108                                 if (!(right is IntConstant))
 109                                         right = right.ToInt (true, loc);
 110                         }
 111                         return;
 112                 }
 113
 114                 static void Error_CompileTimeOverflow (Location loc)
 115                 {
 116                         Report.Error (220, loc, "The operation overflows at compile time in checked mode");
 117                 }
 118
 119                 /// <summary>
 120                 ///   Constant expression folder for binary operations.
 121                 ///
 122                 ///   Returns null if the expression can not be folded.
 123                 /// </summary>
 124                 static public Expression BinaryFold (EmitContext ec, Binary.Operator oper,
 125                                                      Constant left, Constant right, Location loc)
 126                 {
 127                         Type lt = left.Type;
 128                         Type rt = right.Type;
 129                         Type result_type = null;
 130                         bool bool_res;
 131
 132                         //
 133                         // Enumerator folding
 134                         //
 135                         if (rt == lt && left is EnumConstant)
 136                                 result_type = lt;
 137
 138                         switch (oper){
 139                         case Binary.Operator.BitwiseOr:
 140                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 141                                 if (left == null || right == null)
 142                                         return null;
 143
 144                                 if (left is IntConstant){
 145                                         IntConstant v;
 146                                         int res = ((IntConstant) left).Value | ((IntConstant) right).Value;
 147
 148                                         v = new IntConstant (res);
 149                                         if (result_type == null)
 150                                                 return v;
 151                                         else
 152                                                 return new EnumConstant (v, result_type);
 153                                 } else if (left is UIntConstant){
 154                                         UIntConstant v;
 155                                         uint res = ((UIntConstant)left).Value | ((UIntConstant)right).Value;
 156
 157                                         v = new UIntConstant (res);
 158                                         if (result_type == null)
 159                                                 return v;
 160                                         else
 161                                                 return new EnumConstant (v, result_type);
 162                                 } else if (left is LongConstant){
 163                                         LongConstant v;
 164                                         long res = ((LongConstant)left).Value | ((LongConstant)right).Value;
 165
 166                                         v = new LongConstant (res);
 167                                         if (result_type == null)
 168                                                 return v;
 169                                         else
 170                                                 return new EnumConstant (v, result_type);
 171                                 } else if (left is ULongConstant){
 172                                         ULongConstant v;
 173                                         ulong res = ((ULongConstant)left).Value |
 174                                                 ((ULongConstant)right).Value;
 175
 176                                         v = new ULongConstant (res);
 177                                         if (result_type == null)
 178                                                 return v;
 179                                         else
 180                                                 return new EnumConstant (v, result_type);
 181                                 }
 182                                 break;
 183
 184                         case Binary.Operator.BitwiseAnd:
 185                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 186                                 if (left == null || right == null)
 187                                         return null;
 188
 189                                 if (left is IntConstant){
 190                                         IntConstant v;
 191                                         int res = ((IntConstant) left).Value & ((IntConstant) right).Value;
 192
 193                                         v = new IntConstant (res);
 194                                         if (result_type == null)
 195                                                 return v;
 196                                         else
 197                                                 return new EnumConstant (v, result_type);
 198                                 } else if (left is UIntConstant){
 199                                         UIntConstant v;
 200                                         uint res = ((UIntConstant)left).Value & ((UIntConstant)right).Value;
 201
 202                                         v = new UIntConstant (res);
 203                                         if (result_type == null)
 204                                                 return v;
 205                                         else
 206                                                 return new EnumConstant (v, result_type);
 207                                 } else if (left is LongConstant){
 208                                         LongConstant v;
 209                                         long res = ((LongConstant)left).Value & ((LongConstant)right).Value;
 210
 211                                         v = new LongConstant (res);
 212                                         if (result_type == null)
 213                                                 return v;
 214                                         else
 215                                                 return new EnumConstant (v, result_type);
 216                                 } else if (left is ULongConstant){
 217                                         ULongConstant v;
 218                                         ulong res = ((ULongConstant)left).Value &
 219                                                 ((ULongConstant)right).Value;
 220
 221                                         v = new ULongConstant (res);
 222                                         if (result_type == null)
 223                                                 return v;
 224                                         else
 225                                                 return new EnumConstant (v, result_type);
 226                                 }
 227                                 break;
 228
 229                         case Binary.Operator.ExclusiveOr:
 230                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 231                                 if (left == null || right == null)
 232                                         return null;
 233
 234                                 if (left is IntConstant){
 235                                         IntConstant v;
 236                                         int res = ((IntConstant) left).Value ^ ((IntConstant) right).Value;
 237
 238                                         v = new IntConstant (res);
 239                                         if (result_type == null)
 240                                                 return v;
 241                                         else
 242                                                 return new EnumConstant (v, result_type);
 243                                 } else if (left is UIntConstant){
 244                                         UIntConstant v;
 245                                         uint res = ((UIntConstant)left).Value ^ ((UIntConstant)right).Value;
 246
 247                                         v = new UIntConstant (res);
 248                                         if (result_type == null)
 249                                                 return v;
 250                                         else
 251                                                 return new EnumConstant (v, result_type);
 252                                 } else if (left is LongConstant){
 253                                         LongConstant v;
 254                                         long res = ((LongConstant)left).Value ^ ((LongConstant)right).Value;
 255
 256                                         v = new LongConstant (res);
 257                                         if (result_type == null)
 258                                                 return v;
 259                                         else
 260                                                 return new EnumConstant (v, result_type);
 261                                 } else if (left is ULongConstant){
 262                                         ULongConstant v;
 263                                         ulong res = ((ULongConstant)left).Value ^
 264                                                 ((ULongConstant)right).Value;
 265
 266                                         v = new ULongConstant (res);
 267                                         if (result_type == null)
 268                                                 return v;
 269                                         else
 270                                                 return new EnumConstant (v, result_type);
 271                                 }
 272                                 break;
 273
 274                         case Binary.Operator.Addition:
 275                                 if (left is StringConstant && right is StringConstant)
 276                                         return new StringConstant (
 277                                                 ((StringConstant) left).Value +
 278                                                 ((StringConstant) right).Value);
 279
 280                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 281                                 if (left == null || right == null)
 282                                         return null;
 283
 284                                 try {
 285                                         if (left is DoubleConstant){
 286                                                 double res;
 287
 288                                                 if (ec.ConstantCheckState)
 289                                                         res = checked (((DoubleConstant) left).Value +
 290                                                                        ((DoubleConstant) right).Value);
 291                                                 else
 292                                                         res = unchecked (((DoubleConstant) left).Value +
 293                                                                          ((DoubleConstant) right).Value);
 294
 295                                                 return new DoubleConstant (res);
 296                                         } else if (left is FloatConstant){
 297                                                 float res;
 298
 299                                                 if (ec.ConstantCheckState)
 300                                                         res = checked (((FloatConstant) left).Value +
 301                                                                        ((FloatConstant) right).Value);
 302                                                 else
 303                                                         res = unchecked (((FloatConstant) left).Value +
 304                                                                          ((FloatConstant) right).Value);
 305
 306                                                 return new FloatConstant (res);
 307                                         } else if (left is ULongConstant){
 308                                                 ulong res;
 309
 310                                                 if (ec.ConstantCheckState)
 311                                                         res = checked (((ULongConstant) left).Value +
 312                                                                        ((ULongConstant) right).Value);
 313                                                 else
 314                                                         res = unchecked (((ULongConstant) left).Value +
 315                                                                          ((ULongConstant) right).Value);
 316
 317                                                 return new ULongConstant (res);
 318                                         } else if (left is LongConstant){
 319                                                 long res;
 320
 321                                                 if (ec.ConstantCheckState)
 322                                                         res = checked (((LongConstant) left).Value +
 323                                                                        ((LongConstant) right).Value);
 324                                                 else
 325                                                         res = unchecked (((LongConstant) left).Value +
 326                                                                          ((LongConstant) right).Value);
 327
 328                                                 return new LongConstant (res);
 329                                         } else if (left is UIntConstant){
 330                                                 uint res;
 331
 332                                                 if (ec.ConstantCheckState)
 333                                                         res = checked (((UIntConstant) left).Value +
 334                                                                        ((UIntConstant) right).Value);
 335                                                 else
 336                                                         res = unchecked (((UIntConstant) left).Value +
 337                                                                          ((UIntConstant) right).Value);
 338
 339                                                 return new UIntConstant (res);
 340                                         } else if (left is IntConstant){
 341                                                 int res;
 342
 343                                                 if (ec.ConstantCheckState)
 344                                                         res = checked (((IntConstant) left).Value +
 345                                                                        ((IntConstant) right).Value);
 346                                                 else
 347                                                         res = unchecked (((IntConstant) left).Value +
 348                                                                          ((IntConstant) right).Value);
 349
 350                                                 return new IntConstant (res);
 351                                         } else {
 352                                                 throw new Exception ( "Unexepected input: " + left);
 353                                         }
 354                                 } catch (OverflowException){
 355                                         Error_CompileTimeOverflow (loc);
 356                                 }
 357                                 break;
 358
 359                         case Binary.Operator.Subtraction:
 360                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 361                                 if (left == null || right == null)
 362                                         return null;
 363
 364                                 try {
 365                                         if (left is DoubleConstant){
 366                                                 double res;
 367
 368                                                 if (ec.ConstantCheckState)
 369                                                         res = checked (((DoubleConstant) left).Value -
 370                                                                        ((DoubleConstant) right).Value);
 371                                                 else
 372                                                         res = unchecked (((DoubleConstant) left).Value -
 373                                                                          ((DoubleConstant) right).Value);
 374
 375                                                 return new DoubleConstant (res);
 376                                         } else if (left is FloatConstant){
 377                                                 float res;
 378
 379                                                 if (ec.ConstantCheckState)
 380                                                         res = checked (((FloatConstant) left).Value -
 381                                                                        ((FloatConstant) right).Value);
 382                                                 else
 383                                                         res = unchecked (((FloatConstant) left).Value -
 384                                                                          ((FloatConstant) right).Value);
 385
 386                                                 return new FloatConstant (res);
 387                                         } else if (left is ULongConstant){
 388                                                 ulong res;
 389
 390                                                 if (ec.ConstantCheckState)
 391                                                         res = checked (((ULongConstant) left).Value -
 392                                                                        ((ULongConstant) right).Value);
 393                                                 else
 394                                                         res = unchecked (((ULongConstant) left).Value -
 395                                                                          ((ULongConstant) right).Value);
 396
 397                                                 return new ULongConstant (res);
 398                                         } else if (left is LongConstant){
 399                                                 long res;
 400
 401                                                 if (ec.ConstantCheckState)
 402                                                         res = checked (((LongConstant) left).Value -
 403                                                                        ((LongConstant) right).Value);
 404                                                 else
 405                                                         res = unchecked (((LongConstant) left).Value -
 406                                                                          ((LongConstant) right).Value);
 407
 408                                                 return new LongConstant (res);
 409                                         } else if (left is UIntConstant){
 410                                                 uint res;
 411
 412                                                 if (ec.ConstantCheckState)
 413                                                         res = checked (((UIntConstant) left).Value -
 414                                                                        ((UIntConstant) right).Value);
 415                                                 else
 416                                                         res = unchecked (((UIntConstant) left).Value -
 417                                                                          ((UIntConstant) right).Value);
 418
 419                                                 return new UIntConstant (res);
 420                                         } else if (left is IntConstant){
 421                                                 int res;
 422
 423                                                 if (ec.ConstantCheckState)
 424                                                         res = checked (((IntConstant) left).Value -
 425                                                                        ((IntConstant) right).Value);
 426                                                 else
 427                                                         res = unchecked (((IntConstant) left).Value -
 428                                                                          ((IntConstant) right).Value);
 429
 430                                                 return new IntConstant (res);
 431                                         } else {
 432                                                 throw new Exception ( "Unexepected input: " + left);
 433                                         }
 434                                 } catch (OverflowException){
 435                                         Error_CompileTimeOverflow (loc);
 436                                 }
 437                                 break;
 438
 439                         case Binary.Operator.Multiply:
 440                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 441                                 if (left == null || right == null)
 442                                         return null;
 443
 444                                 try {
 445                                         if (left is DoubleConstant){
 446                                                 double res;
 447
 448                                                 if (ec.ConstantCheckState)
 449                                                         res = checked (((DoubleConstant) left).Value *
 450                                                                        ((DoubleConstant) right).Value);
 451                                                 else
 452                                                         res = unchecked (((DoubleConstant) left).Value *
 453                                                                          ((DoubleConstant) right).Value);
 454
 455                                                 return new DoubleConstant (res);
 456                                         } else if (left is FloatConstant){
 457                                                 float res;
 458
 459                                                 if (ec.ConstantCheckState)
 460                                                         res = checked (((FloatConstant) left).Value *
 461                                                                        ((FloatConstant) right).Value);
 462                                                 else
 463                                                         res = unchecked (((FloatConstant) left).Value *
 464                                                                          ((FloatConstant) right).Value);
 465
 466                                                 return new FloatConstant (res);
 467                                         } else if (left is ULongConstant){
 468                                                 ulong res;
 469
 470                                                 if (ec.ConstantCheckState)
 471                                                         res = checked (((ULongConstant) left).Value *
 472                                                                        ((ULongConstant) right).Value);
 473                                                 else
 474                                                         res = unchecked (((ULongConstant) left).Value *
 475                                                                          ((ULongConstant) right).Value);
 476
 477                                                 return new ULongConstant (res);
 478                                         } else if (left is LongConstant){
 479                                                 long res;
 480
 481                                                 if (ec.ConstantCheckState)
 482                                                         res = checked (((LongConstant) left).Value *
 483                                                                        ((LongConstant) right).Value);
 484                                                 else
 485                                                         res = unchecked (((LongConstant) left).Value *
 486                                                                          ((LongConstant) right).Value);
 487
 488                                                 return new LongConstant (res);
 489                                         } else if (left is UIntConstant){
 490                                                 uint res;
 491
 492                                                 if (ec.ConstantCheckState)
 493                                                         res = checked (((UIntConstant) left).Value *
 494                                                                        ((UIntConstant) right).Value);
 495                                                 else
 496                                                         res = unchecked (((UIntConstant) left).Value *
 497                                                                          ((UIntConstant) right).Value);
 498
 499                                                 return new UIntConstant (res);
 500                                         } else if (left is IntConstant){
 501                                                 int res;
 502
 503                                                 if (ec.ConstantCheckState)
 504                                                         res = checked (((IntConstant) left).Value *
 505                                                                        ((IntConstant) right).Value);
 506                                                 else
 507                                                         res = unchecked (((IntConstant) left).Value *
 508                                                                          ((IntConstant) right).Value);
 509
 510                                                 return new IntConstant (res);
 511                                         } else {
 512                                                 throw new Exception ( "Unexepected input: " + left);
 513                                         }
 514                                 } catch (OverflowException){
 515                                         Error_CompileTimeOverflow (loc);
 516                                 }
 517                                 break;
 518
 519                         case Binary.Operator.Division:
 520                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 521                                 if (left == null || right == null)
 522                                         return null;
 523
 524                                 try {
 525                                         if (left is DoubleConstant){
 526                                                 double res;
 527
 528                                                 if (ec.ConstantCheckState)
 529                                                         res = checked (((DoubleConstant) left).Value /
 530                                                                        ((DoubleConstant) right).Value);
 531                                                 else
 532                                                         res = unchecked (((DoubleConstant) left).Value /
 533                                                                          ((DoubleConstant) right).Value);
 534
 535                                                 return new DoubleConstant (res);
 536                                         } else if (left is FloatConstant){
 537                                                 float res;
 538
 539                                                 if (ec.ConstantCheckState)
 540                                                         res = checked (((FloatConstant) left).Value /
 541                                                                        ((FloatConstant) right).Value);
 542                                                 else
 543                                                         res = unchecked (((FloatConstant) left).Value /
 544                                                                          ((FloatConstant) right).Value);
 545
 546                                                 return new FloatConstant (res);
 547                                         } else if (left is ULongConstant){
 548                                                 ulong res;
 549
 550                                                 if (ec.ConstantCheckState)
 551                                                         res = checked (((ULongConstant) left).Value /
 552                                                                        ((ULongConstant) right).Value);
 553                                                 else
 554                                                         res = unchecked (((ULongConstant) left).Value /
 555                                                                          ((ULongConstant) right).Value);
 556
 557                                                 return new ULongConstant (res);
 558                                         } else if (left is LongConstant){
 559                                                 long res;
 560
 561                                                 if (ec.ConstantCheckState)
 562                                                         res = checked (((LongConstant) left).Value /
 563                                                                        ((LongConstant) right).Value);
 564                                                 else
 565                                                         res = unchecked (((LongConstant) left).Value /
 566                                                                          ((LongConstant) right).Value);
 567
 568                                                 return new LongConstant (res);
 569                                         } else if (left is UIntConstant){
 570                                                 uint res;
 571
 572                                                 if (ec.ConstantCheckState)
 573                                                         res = checked (((UIntConstant) left).Value /
 574                                                                        ((UIntConstant) right).Value);
 575                                                 else
 576                                                         res = unchecked (((UIntConstant) left).Value /
 577                                                                          ((UIntConstant) right).Value);
 578
 579                                                 return new UIntConstant (res);
 580                                         } else if (left is IntConstant){
 581                                                 int res;
 582
 583                                                 if (ec.ConstantCheckState)
 584                                                         res = checked (((IntConstant) left).Value /
 585                                                                        ((IntConstant) right).Value);
 586                                                 else
 587                                                         res = unchecked (((IntConstant) left).Value /
 588                                                                          ((IntConstant) right).Value);
 589
 590                                                 return new IntConstant (res);
 591                                         } else {
 592                                                 throw new Exception ( "Unexepected input: " + left);
 593                                         }
 594                                 } catch (OverflowException){
 595                                         Error_CompileTimeOverflow (loc);
 596                                 }
 597                                 break;
 598
 599                         case Binary.Operator.Modulus:
 600                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 601                                 if (left == null || right == null)
 602                                         return null;
 603
 604                                 try {
 605                                         if (left is DoubleConstant){
 606                                                 double res;
 607
 608                                                 if (ec.ConstantCheckState)
 609                                                         res = checked (((DoubleConstant) left).Value %
 610                                                                        ((DoubleConstant) right).Value);
 611                                                 else
 612                                                         res = unchecked (((DoubleConstant) left).Value %
 613                                                                          ((DoubleConstant) right).Value);
 614
 615                                                 return new DoubleConstant (res);
 616                                         } else if (left is FloatConstant){
 617                                                 float res;
 618
 619                                                 if (ec.ConstantCheckState)
 620                                                         res = checked (((FloatConstant) left).Value %
 621                                                                        ((FloatConstant) right).Value);
 622                                                 else
 623                                                         res = unchecked (((FloatConstant) left).Value %
 624                                                                          ((FloatConstant) right).Value);
 625
 626                                                 return new FloatConstant (res);
 627                                         } else if (left is ULongConstant){
 628                                                 ulong res;
 629
 630                                                 if (ec.ConstantCheckState)
 631                                                         res = checked (((ULongConstant) left).Value %
 632                                                                        ((ULongConstant) right).Value);
 633                                                 else
 634                                                         res = unchecked (((ULongConstant) left).Value %
 635                                                                          ((ULongConstant) right).Value);
 636
 637                                                 return new ULongConstant (res);
 638                                         } else if (left is LongConstant){
 639                                                 long res;
 640
 641                                                 if (ec.ConstantCheckState)
 642                                                         res = checked (((LongConstant) left).Value %
 643                                                                        ((LongConstant) right).Value);
 644                                                 else
 645                                                         res = unchecked (((LongConstant) left).Value %
 646                                                                          ((LongConstant) right).Value);
 647
 648                                                 return new LongConstant (res);
 649                                         } else if (left is UIntConstant){
 650                                                 uint res;
 651
 652                                                 if (ec.ConstantCheckState)
 653                                                         res = checked (((UIntConstant) left).Value %
 654                                                                        ((UIntConstant) right).Value);
 655                                                 else
 656                                                         res = unchecked (((UIntConstant) left).Value %
 657                                                                          ((UIntConstant) right).Value);
 658
 659                                                 return new UIntConstant (res);
 660                                         } else if (left is IntConstant){
 661                                                 int res;
 662
 663                                                 if (ec.ConstantCheckState)
 664                                                         res = checked (((IntConstant) left).Value %
 665                                                                        ((IntConstant) right).Value);
 666                                                 else
 667                                                         res = unchecked (((IntConstant) left).Value %
 668                                                                          ((IntConstant) right).Value);
 669
 670                                                 return new IntConstant (res);
 671                                         } else {
 672                                                 throw new Exception ( "Unexepected input: " + left);
 673                                         }
 674                                 } catch (OverflowException){
 675                                         Error_CompileTimeOverflow (loc);
 676                                 }
 677                                 break;
 678
 679                                 //
 680                                 // There is no overflow checking on left shift
 681                                 //
 682                         case Binary.Operator.LeftShift:
 683                                 IntConstant ic = right.ToInt (true, loc);
 684                                 if (ic == null){
 685                                         Binary.Error_OperatorCannotBeApplied (loc, "<<", lt, rt);
 686                                         return null;
 687                                 }
 688                                 int lshift_val = ic.Value;
 689
 690                                 IntConstant lic;
 691                                 if ((lic = left.ConvertToInt (true)) != null)
 692                                         return new IntConstant (lic.Value << lshift_val);
 693
 694                                 UIntConstant luic;
 695                                 if ((luic = left.ConvertToUInt (true)) != null)
 696                                         return new UIntConstant (luic.Value << lshift_val);
 697
 698                                 LongConstant llc;
 699                                 if ((llc = left.ConvertToLong (true)) != null)
 700                                         return new LongConstant (llc.Value << lshift_val);
 701
 702                                 ULongConstant lulc;
 703                                 if ((lulc = left.ConvertToULong (true)) != null)
 704                                         return new ULongConstant (lulc.Value << lshift_val);
 705
 706                                 Binary.Error_OperatorCannotBeApplied (loc, "<<", lt, rt);
 707                                 break;
 708
 709                                 //
 710                                 // There is no overflow checking on right shift
 711                                 //
 712                         case Binary.Operator.RightShift:
 713                                 IntConstant sic = right.ToInt (true, loc);
 714                                 if (sic == null){
 715                                         Binary.Error_OperatorCannotBeApplied (loc, ">>", lt, rt);
 716                                         return null;
 717                                 }
 718                                 int rshift_val = sic.Value;
 719
 720                                 IntConstant ric;
 721                                 if ((ric = left.ConvertToInt (true)) != null)
 722                                         return new IntConstant (ric.Value >> rshift_val);
 723
 724                                 UIntConstant ruic;
 725                                 if ((ruic = left.ConvertToUInt (true)) != null)
 726                                         return new UIntConstant (ruic.Value >> rshift_val);
 727
 728                                 LongConstant rlc;
 729                                 if ((rlc = left.ConvertToLong (true)) != null)
 730                                         return new LongConstant (rlc.Value >> rshift_val);
 731
 732                                 ULongConstant rulc;
 733                                 if ((rulc = left.ConvertToULong (true)) != null)
 734                                         return new ULongConstant (rulc.Value >> rshift_val);
 735
 736                                 Binary.Error_OperatorCannotBeApplied (loc, ">>", lt, rt);
 737                                 break;
 738
 739                         case Binary.Operator.LogicalAnd:
 740                                 if (left is BoolConstant && right is BoolConstant){
 741                                         return new BoolConstant (
 742                                                 ((BoolConstant) left).Value &&
 743                                                 ((BoolConstant) right).Value);
 744                                 }
 745                                 break;
 746
 747                         case Binary.Operator.LogicalOr:
 748                                 if (left is BoolConstant && right is BoolConstant){
 749                                         return new BoolConstant (
 750                                                 ((BoolConstant) left).Value ||
 751                                                 ((BoolConstant) right).Value);
 752                                 }
 753                                 break;
 754
 755                         case Binary.Operator.Equality:
 756                                 if (left is BoolConstant && right is BoolConstant){
 757                                         return new BoolConstant (
 758                                                 ((BoolConstant) left).Value ==
 759                                                 ((BoolConstant) right).Value);
 760
 761                                 }
 762                                 if (left is StringConstant && right is StringConstant){
 763                                         return new BoolConstant (
 764                                                 ((StringConstant) left).Value ==
 765                                                 ((StringConstant) right).Value);
 766
 767                                 }
 768
 769                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 770                                 if (left == null || right == null)
 771                                         return null;
 772
 773                                 bool_res = false;
 774                                 if (left is DoubleConstant)
 775                                         bool_res = ((DoubleConstant) left).Value ==
 776                                                 ((DoubleConstant) right).Value;
 777                                 else if (left is FloatConstant)
 778                                         bool_res = ((FloatConstant) left).Value ==
 779                                                 ((FloatConstant) right).Value;
 780                                 else if (left is ULongConstant)
 781                                         bool_res = ((ULongConstant) left).Value ==
 782                                                 ((ULongConstant) right).Value;
 783                                 else if (left is LongConstant)
 784                                         bool_res = ((LongConstant) left).Value ==
 785                                                 ((LongConstant) right).Value;
 786                                 else if (left is UIntConstant)
 787                                         bool_res = ((UIntConstant) left).Value ==
 788                                                 ((UIntConstant) right).Value;
 789                                 else if (left is IntConstant)
 790                                         bool_res = ((IntConstant) left).Value ==
 791                                                 ((IntConstant) right).Value;
 792                                 else
 793                                         return null;
 794
 795                                 return new BoolConstant (bool_res);
 796
 797                         case Binary.Operator.Inequality:
 798                                 if (left is BoolConstant && right is BoolConstant){
 799                                         return new BoolConstant (
 800                                                 ((BoolConstant) left).Value !=
 801                                                 ((BoolConstant) right).Value);
 802                                 }
 803                                 if (left is StringConstant && right is StringConstant){
 804                                         return new BoolConstant (
 805                                                 ((StringConstant) left).Value !=
 806                                                 ((StringConstant) right).Value);
 807
 808                                 }
 809                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 810                                 if (left == null || right == null)
 811                                         return null;
 812
 813                                 bool_res = false;
 814                                 if (left is DoubleConstant)
 815                                         bool_res = ((DoubleConstant) left).Value !=
 816                                                 ((DoubleConstant) right).Value;
 817                                 else if (left is FloatConstant)
 818                                         bool_res = ((FloatConstant) left).Value !=
 819                                                 ((FloatConstant) right).Value;
 820                                 else if (left is ULongConstant)
 821                                         bool_res = ((ULongConstant) left).Value !=
 822                                                 ((ULongConstant) right).Value;
 823                                 else if (left is LongConstant)
 824                                         bool_res = ((LongConstant) left).Value !=
 825                                                 ((LongConstant) right).Value;
 826                                 else if (left is UIntConstant)
 827                                         bool_res = ((UIntConstant) left).Value !=
 828                                                 ((UIntConstant) right).Value;
 829                                 else if (left is IntConstant)
 830                                         bool_res = ((IntConstant) left).Value !=
 831                                                 ((IntConstant) right).Value;
 832                                 else
 833                                         return null;
 834
 835                                 return new BoolConstant (bool_res);
 836
 837                         case Binary.Operator.LessThan:
 838                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 839                                 if (left == null || right == null)
 840                                         return null;
 841
 842                                 bool_res = false;
 843                                 if (left is DoubleConstant)
 844                                         bool_res = ((DoubleConstant) left).Value <
 845                                                 ((DoubleConstant) right).Value;
 846                                 else if (left is FloatConstant)
 847                                         bool_res = ((FloatConstant) left).Value <
 848                                                 ((FloatConstant) right).Value;
 849                                 else if (left is ULongConstant)
 850                                         bool_res = ((ULongConstant) left).Value <
 851                                                 ((ULongConstant) right).Value;
 852                                 else if (left is LongConstant)
 853                                         bool_res = ((LongConstant) left).Value <
 854                                                 ((LongConstant) right).Value;
 855                                 else if (left is UIntConstant)
 856                                         bool_res = ((UIntConstant) left).Value <
 857                                                 ((UIntConstant) right).Value;
 858                                 else if (left is IntConstant)
 859                                         bool_res = ((IntConstant) left).Value <
 860                                                 ((IntConstant) right).Value;
 861                                 else
 862                                         return null;
 863
 864                                 return new BoolConstant (bool_res);
 865
 866                         case Binary.Operator.GreaterThan:
 867                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 868                                 if (left == null || right == null)
 869                                         return null;
 870
 871                                 bool_res = false;
 872                                 if (left is DoubleConstant)
 873                                         bool_res = ((DoubleConstant) left).Value >
 874                                                 ((DoubleConstant) right).Value;
 875                                 else if (left is FloatConstant)
 876                                         bool_res = ((FloatConstant) left).Value >
 877                                                 ((FloatConstant) right).Value;
 878                                 else if (left is ULongConstant)
 879                                         bool_res = ((ULongConstant) left).Value >
 880                                                 ((ULongConstant) right).Value;
 881                                 else if (left is LongConstant)
 882                                         bool_res = ((LongConstant) left).Value >
 883                                                 ((LongConstant) right).Value;
 884                                 else if (left is UIntConstant)
 885                                         bool_res = ((UIntConstant) left).Value >
 886                                                 ((UIntConstant) right).Value;
 887                                 else if (left is IntConstant)
 888                                         bool_res = ((IntConstant) left).Value >
 889                                                 ((IntConstant) right).Value;
 890                                 else
 891                                         return null;
 892
 893                                 return new BoolConstant (bool_res);
 894
 895                         case Binary.Operator.GreaterThanOrEqual:
 896                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 897                                 if (left == null || right == null)
 898                                         return null;
 899
 900                                 bool_res = false;
 901                                 if (left is DoubleConstant)
 902                                         bool_res = ((DoubleConstant) left).Value >=
 903                                                 ((DoubleConstant) right).Value;
 904                                 else if (left is FloatConstant)
 905                                         bool_res = ((FloatConstant) left).Value >=
 906                                                 ((FloatConstant) right).Value;
 907                                 else if (left is ULongConstant)
 908                                         bool_res = ((ULongConstant) left).Value >=
 909                                                 ((ULongConstant) right).Value;
 910                                 else if (left is LongConstant)
 911                                         bool_res = ((LongConstant) left).Value >=
 912                                                 ((LongConstant) right).Value;
 913                                 else if (left is UIntConstant)
 914                                         bool_res = ((UIntConstant) left).Value >=
 915                                                 ((UIntConstant) right).Value;
 916                                 else if (left is IntConstant)
 917                                         bool_res = ((IntConstant) left).Value >=
 918                                                 ((IntConstant) right).Value;
 919                                 else
 920                                         return null;
 921
 922                                 return new BoolConstant (bool_res);
 923
 924                         case Binary.Operator.LessThanOrEqual:
 925                                 DoConstantNumericPromotions (oper, ref left, ref right, loc);
 926                                 if (left == null || right == null)
 927                                         return null;
 928
 929                                 bool_res = false;
 930                                 if (left is DoubleConstant)
 931                                         bool_res = ((DoubleConstant) left).Value <=
 932                                                 ((DoubleConstant) right).Value;
 933                                 else if (left is FloatConstant)
 934                                         bool_res = ((FloatConstant) left).Value <=
 935                                                 ((FloatConstant) right).Value;
 936                                 else if (left is ULongConstant)
 937                                         bool_res = ((ULongConstant) left).Value <=
 938                                                 ((ULongConstant) right).Value;
 939                                 else if (left is LongConstant)
 940                                         bool_res = ((LongConstant) left).Value <=
 941                                                 ((LongConstant) right).Value;
 942                                 else if (left is UIntConstant)
 943                                         bool_res = ((UIntConstant) left).Value <=
 944                                                 ((UIntConstant) right).Value;
 945                                 else if (left is IntConstant)
 946                                         bool_res = ((IntConstant) left).Value <=
 947                                                 ((IntConstant) right).Value;
 948                                 else
 949                                         return null;
 950
 951                                 return new BoolConstant (bool_res);
 952                         }
 953
 954                         return null;
 955                 }
 956         }
 957 }