mcs/mbas/cfold.cs

   1 //
   2 // cfold.cs: Constant Folding
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //
   7 // (C) 2002 Ximian, Inc.
   8 //
   9
  10 using System;
  11
  12 namespace Mono.MonoBASIC {
  13
  14         public class ConstantFold {
  15
  16                 //
  17                 // Performs the numeric promotions on the left and right expresions
  18                 // and desposits the results on `lc' and `rc'.
  19                 //
  20                 // On success, the types of `lc' and `rc' on output will always match,
  21                 // and the pair will be one of:
  22                 //
  23                 //   (double, double)
  24                 //   (float, float)
  25                 //   (ulong, ulong)
  26                 //   (long, long)
  27                 //   (uint, uint)
  28                 //   (int, int)
  29                 //
  30                 static void DoConstantNumericPromotions (EmitContext ec, Binary.Operator oper,
  31                                                          ref Constant left, ref Constant right,
  32                                                          Location loc)
  33                 {
  34                         if (left is DoubleConstant || right is DoubleConstant ||
  35                             oper == Binary.Operator.Exponentiation || oper == Binary.Operator.Division) {
  36                                 //
  37                                 // If either side is a double, convert the other to a double
  38                                 //
  39                                 if (!(left is DoubleConstant))
  40                                         left = left.ToDouble (loc);
  41
  42                                 if (!(right is DoubleConstant))
  43                                         right = right.ToDouble (loc);
  44                                 return;
  45                         } else if (left is FloatConstant || right is FloatConstant) {
  46                                 //
  47                                 // If either side is a float, convert the other to a float
  48                                 //
  49                                 if (!(left is FloatConstant))
  50                                         left = left.ToFloat (loc);
  51
  52                                 if (!(right is FloatConstant))
  53                                         right = right.ToFloat (loc);
  54 ;                               return;
  55                         } else if (left is ULongConstant || right is ULongConstant){
  56                                 //
  57                                 // If either operand is of type ulong, the other operand is
  58                                 // converted to type ulong.  or an error ocurrs if the other
  59                                 // operand is of type sbyte, short, int or long
  60                                 //
  61 #if WRONG
  62                                 Constant match, other;
  63 #endif
  64
  65                                 if (left is ULongConstant){
  66 #if WRONG
  67                                         other = right;
  68                                         match = left;
  69 #endif
  70                                         if (!(right is ULongConstant))
  71                                                 right = right.ToULong (loc);
  72                                 } else {
  73 #if WRONG
  74                                         other = left;
  75                                         match = right;
  76 #endif
  77                                         left = left.ToULong (loc);
  78                                 }
  79
  80 #if WRONG
  81                                 if (other is SByteConstant || other is ShortConstant ||
  82                                     other is IntConstant || other is LongConstant){
  83                                         Binary.Error_OperatorAmbiguous
  84                                                 (loc, oper, other.Type, match.Type);
  85                                         left = null;
  86                                         right = null;
  87                                 }
  88 #endif
  89                                 return;
  90                         } else if (left is LongConstant || right is LongConstant){
  91                                 //
  92                                 // If either operand is of type long, the other operand is converted
  93                                 // to type long.
  94                                 //
  95                                 if (!(left is LongConstant))
  96                                         left = left.ToLong (loc);
  97                                 else if (!(right is LongConstant))
  98                                         right = right.ToLong (loc);
  99                                 return;
 100                         } else if (left is UIntConstant || right is UIntConstant){
 101                                 //
 102                                 // If either operand is of type uint, and the other
 103                                 // operand is of type sbyte, short or int, the operands are
 104                                 // converted to type long.
 105                                 //
 106                                 Constant other;
 107                                 if (left is UIntConstant){
 108                                         other = right;
 109                                 } else {
 110                                         other = left;
 111                                 }
 112
 113                                 // Nothing to do.
 114                                 if (other is UIntConstant)
 115                                         return;
 116
 117                                 if (other is SByteConstant || other is ShortConstant ||
 118                                     other is IntConstant){
 119                                         left = left.ToLong (loc);
 120                                         right = right.ToLong (loc);
 121                                 }
 122
 123                                 return;
 124                         } else if (left is EnumConstant || right is EnumConstant){
 125                                 //
 126                                 // If either operand is an enum constant, the other one must
 127                                 // be implicitly convertable to that enum's underlying type.
 128                                 //
 129                                 EnumConstant match;
 130                                 Constant other;
 131                                 if (left is EnumConstant){
 132                                         other = right;
 133                                         match = (EnumConstant) left;
 134                                 } else {
 135                                         other = left;
 136                                         match = (EnumConstant) right;
 137                                 }
 138
 139                                 bool need_check = (other is EnumConstant) ||
 140                                         ((oper != Binary.Operator.Addition) &&
 141                                          (oper != Binary.Operator.Subtraction));
 142
 143                                 if (need_check &&
 144                                     !Expression.ImplicitConversionExists (ec, match, other.Type)) {
 145                                         Expression.Error_CannotConvertImplicit (loc, match.Type, other.Type);
 146                                         left = null;
 147                                         right = null;
 148                                         return;
 149                                 }
 150
 151                                 if (left is EnumConstant)
 152                                         left = ((EnumConstant) left).Child;
 153                                 if (right is EnumConstant)
 154                                         right = ((EnumConstant) right).Child;
 155                                 return;
 156
 157                         } else {
 158                                 //
 159                                 // Force conversions to int32
 160                                 //
 161                                 if (!(left is IntConstant))
 162                                         left = left.ToInt (loc);
 163                                 if (!(right is IntConstant))
 164                                         right = right.ToInt (loc);
 165                         }
 166                         return;
 167                 }
 168
 169                 static void Error_CompileTimeOverflow (Location loc)
 170                 {
 171                         Report.Error (220, loc, "The operation overflows at compile time in checked mode");
 172                 }
 173
 174                 /// <summary>
 175                 ///   Constant expression folder for binary operations.
 176                 ///
 177                 ///   Returns null if the expression can not be folded.
 178                 /// </summary>
 179                 static public Expression BinaryFold (EmitContext ec, Binary.Operator oper,
 180                                                      Constant left, Constant right, Location loc)
 181                 {
 182                         Type lt = left.Type;
 183                         Type rt = right.Type;
 184                         Type result_type = null;
 185                         bool bool_res;
 186
 187                         //
 188                         // Enumerator folding
 189                         //
 190                         if (rt == lt && left is EnumConstant)
 191                                 result_type = lt;
 192
 193                         //
 194                         // During an enum evaluation, we need to unwrap enumerations
 195                         //
 196                         if (ec.InEnumContext){
 197                                 if (left is EnumConstant)
 198                                         left = ((EnumConstant) left).Child;
 199
 200                                 if (right is EnumConstant)
 201                                         right = ((EnumConstant) right).Child;
 202                         }
 203
 204                         Type wrap_as;
 205                         Constant result = null;
 206                         switch (oper){
 207                         case Binary.Operator.BitwiseOr:
 208                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 209                                 if (left == null || right == null)
 210                                         return null;
 211
 212                                 if (left is IntConstant){
 213                                         IntConstant v;
 214                                         int res = ((IntConstant) left).Value | ((IntConstant) right).Value;
 215
 216                                         v = new IntConstant (res);
 217                                         if (result_type == null)
 218                                                 return v;
 219                                         else
 220                                                 return new EnumConstant (v, result_type);
 221                                 } else if (left is UIntConstant){
 222                                         UIntConstant v;
 223                                         uint res = ((UIntConstant)left).Value | ((UIntConstant)right).Value;
 224
 225                                         v = new UIntConstant (res);
 226                                         if (result_type == null)
 227                                                 return v;
 228                                         else
 229                                                 return new EnumConstant (v, result_type);
 230                                 } else if (left is LongConstant){
 231                                         LongConstant v;
 232                                         long res = ((LongConstant)left).Value | ((LongConstant)right).Value;
 233
 234                                         v = new LongConstant (res);
 235                                         if (result_type == null)
 236                                                 return v;
 237                                         else
 238                                                 return new EnumConstant (v, result_type);
 239                                 } else if (left is ULongConstant){
 240                                         ULongConstant v;
 241                                         ulong res = ((ULongConstant)left).Value |
 242                                                 ((ULongConstant)right).Value;
 243
 244                                         v = new ULongConstant (res);
 245                                         if (result_type == null)
 246                                                 return v;
 247                                         else
 248                                                 return new EnumConstant (v, result_type);
 249                                 }
 250                                 break;
 251
 252                         case Binary.Operator.BitwiseAnd:
 253                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 254                                 if (left == null || right == null)
 255                                         return null;
 256
 257                                 if (left is IntConstant){
 258                                         IntConstant v;
 259                                         int res = ((IntConstant) left).Value & ((IntConstant) right).Value;
 260
 261                                         v = new IntConstant (res);
 262                                         if (result_type == null)
 263                                                 return v;
 264                                         else
 265                                                 return new EnumConstant (v, result_type);
 266                                 } else if (left is UIntConstant){
 267                                         UIntConstant v;
 268                                         uint res = ((UIntConstant)left).Value & ((UIntConstant)right).Value;
 269
 270                                         v = new UIntConstant (res);
 271                                         if (result_type == null)
 272                                                 return v;
 273                                         else
 274                                                 return new EnumConstant (v, result_type);
 275                                 } else if (left is LongConstant){
 276                                         LongConstant v;
 277                                         long res = ((LongConstant)left).Value & ((LongConstant)right).Value;
 278
 279                                         v = new LongConstant (res);
 280                                         if (result_type == null)
 281                                                 return v;
 282                                         else
 283                                                 return new EnumConstant (v, result_type);
 284                                 } else if (left is ULongConstant){
 285                                         ULongConstant v;
 286                                         ulong res = ((ULongConstant)left).Value &
 287                                                 ((ULongConstant)right).Value;
 288
 289                                         v = new ULongConstant (res);
 290                                         if (result_type == null)
 291                                                 return v;
 292                                         else
 293                                                 return new EnumConstant (v, result_type);
 294                                 }
 295                                 break;
 296
 297                         case Binary.Operator.ExclusiveOr:
 298                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 299                                 if (left == null || right == null)
 300                                         return null;
 301
 302                                 if (left is IntConstant){
 303                                         IntConstant v;
 304                                         int res = ((IntConstant) left).Value ^ ((IntConstant) right).Value;
 305
 306                                         v = new IntConstant (res);
 307                                         if (result_type == null)
 308                                                 return v;
 309                                         else
 310                                                 return new EnumConstant (v, result_type);
 311                                 } else if (left is UIntConstant){
 312                                         UIntConstant v;
 313                                         uint res = ((UIntConstant)left).Value ^ ((UIntConstant)right).Value;
 314
 315                                         v = new UIntConstant (res);
 316                                         if (result_type == null)
 317                                                 return v;
 318                                         else
 319                                                 return new EnumConstant (v, result_type);
 320                                 } else if (left is LongConstant){
 321                                         LongConstant v;
 322                                         long res = ((LongConstant)left).Value ^ ((LongConstant)right).Value;
 323
 324                                         v = new LongConstant (res);
 325                                         if (result_type == null)
 326                                                 return v;
 327                                         else
 328                                                 return new EnumConstant (v, result_type);
 329                                 } else if (left is ULongConstant){
 330                                         ULongConstant v;
 331                                         ulong res = ((ULongConstant)left).Value ^
 332                                                 ((ULongConstant)right).Value;
 333
 334                                         v = new ULongConstant (res);
 335                                         if (result_type == null)
 336                                                 return v;
 337                                         else
 338                                                 return new EnumConstant (v, result_type);
 339                                 }
 340                                 break;
 341
 342                         case Binary.Operator.Addition:
 343                                 bool left_is_string = left is StringConstant;
 344                                 bool right_is_string = right is StringConstant;
 345
 346                                 //
 347                                 // If both sides are strings, then concatenate, if
 348                                 // one is a string, and the other is not, then defer
 349                                 // to runtime concatenation
 350                                 //
 351                                 wrap_as = null;
 352                                 if (left_is_string || right_is_string){
 353                                         if (left_is_string && right_is_string)
 354                                                 return new StringConstant (
 355                                                         ((StringConstant) left).Value +
 356                                                         ((StringConstant) right).Value);
 357
 358                                         return null;
 359                                 }
 360
 361                                 //
 362                                 // handle "E operator + (E x, U y)"
 363                                 // handle "E operator + (Y y, E x)"
 364                                 //
 365                                 // note that E operator + (E x, E y) is invalid
 366                                 //
 367                                 if (left is EnumConstant){
 368                                         if (right is EnumConstant){
 369                                                 return null;
 370                                         }
 371                                         if (((EnumConstant) left).Child.Type != right.Type)
 372                                                 return null;
 373
 374                                         wrap_as = left.Type;
 375                                 } else if (right is EnumConstant){
 376                                         if (((EnumConstant) right).Child.Type != left.Type)
 377                                                 return null;
 378                                         wrap_as = right.Type;
 379                                 }
 380
 381                                 result = null;
 382                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 383                                 if (left == null || right == null)
 384                                         return null;
 385
 386                                 try {
 387                                         if (left is DoubleConstant){
 388                                                 double res;
 389
 390                                                 if (ec.ConstantCheckState)
 391                                                         res = checked (((DoubleConstant) left).Value +
 392                                                                        ((DoubleConstant) right).Value);
 393                                                 else
 394                                                         res = unchecked (((DoubleConstant) left).Value +
 395                                                                          ((DoubleConstant) right).Value);
 396
 397                                                 result = new DoubleConstant (res);
 398                                         } else if (left is FloatConstant){
 399                                                 float res;
 400
 401                                                 if (ec.ConstantCheckState)
 402                                                         res = checked (((FloatConstant) left).Value +
 403                                                                        ((FloatConstant) right).Value);
 404                                                 else
 405                                                         res = unchecked (((FloatConstant) left).Value +
 406                                                                          ((FloatConstant) right).Value);
 407
 408                                                 result = new FloatConstant (res);
 409                                         } else if (left is ULongConstant){
 410                                                 ulong res;
 411
 412                                                 if (ec.ConstantCheckState)
 413                                                         res = checked (((ULongConstant) left).Value +
 414                                                                        ((ULongConstant) right).Value);
 415                                                 else
 416                                                         res = unchecked (((ULongConstant) left).Value +
 417                                                                          ((ULongConstant) right).Value);
 418
 419                                                 result = new ULongConstant (res);
 420                                         } else if (left is LongConstant){
 421                                                 long res;
 422
 423                                                 if (ec.ConstantCheckState)
 424                                                         res = checked (((LongConstant) left).Value +
 425                                                                        ((LongConstant) right).Value);
 426                                                 else
 427                                                         res = unchecked (((LongConstant) left).Value +
 428                                                                          ((LongConstant) right).Value);
 429
 430                                                 result = new LongConstant (res);
 431                                         } else if (left is UIntConstant){
 432                                                 uint res;
 433
 434                                                 if (ec.ConstantCheckState)
 435                                                         res = checked (((UIntConstant) left).Value +
 436                                                                        ((UIntConstant) right).Value);
 437                                                 else
 438                                                         res = unchecked (((UIntConstant) left).Value +
 439                                                                          ((UIntConstant) right).Value);
 440
 441                                                 result = new UIntConstant (res);
 442                                         } else if (left is IntConstant){
 443                                                 int res;
 444
 445                                                 if (ec.ConstantCheckState)
 446                                                         res = checked (((IntConstant) left).Value +
 447                                                                        ((IntConstant) right).Value);
 448                                                 else
 449                                                         res = unchecked (((IntConstant) left).Value +
 450                                                                          ((IntConstant) right).Value);
 451
 452                                                 result = new IntConstant (res);
 453                                         } else {
 454                                                 throw new Exception ( "Unexepected input: " + left);
 455                                         }
 456                                 } catch (OverflowException){
 457                                         Error_CompileTimeOverflow (loc);
 458                                 }
 459
 460                                 if (wrap_as != null)
 461                                         return new EnumConstant (result, wrap_as);
 462                                 else
 463                                         return result;
 464
 465                         case Binary.Operator.Subtraction:
 466                                 //
 467                                 // handle "E operator - (E x, U y)"
 468                                 // handle "E operator - (Y y, E x)"
 469                                 // handle "U operator - (E x, E y)"
 470                                 //
 471                                 wrap_as = null;
 472                                 if (left is EnumConstant){
 473                                         if (right is EnumConstant){
 474                                                 if (left.Type == right.Type)
 475                                                         wrap_as = TypeManager.EnumToUnderlying (left.Type);
 476                                                 else
 477                                                         return null;
 478                                         }
 479                                         if (((EnumConstant) left).Child.Type != right.Type)
 480                                                 return null;
 481
 482                                         wrap_as = left.Type;
 483                                 } else if (right is EnumConstant){
 484                                         if (((EnumConstant) right).Child.Type != left.Type)
 485                                                 return null;
 486                                         wrap_as = right.Type;
 487                                 }
 488
 489                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 490                                 if (left == null || right == null)
 491                                         return null;
 492
 493                                 try {
 494                                         if (left is DoubleConstant){
 495                                                 double res;
 496
 497                                                 if (ec.ConstantCheckState)
 498                                                         res = checked (((DoubleConstant) left).Value -
 499                                                                        ((DoubleConstant) right).Value);
 500                                                 else
 501                                                         res = unchecked (((DoubleConstant) left).Value -
 502                                                                          ((DoubleConstant) right).Value);
 503
 504                                                 result = new DoubleConstant (res);
 505                                         } else if (left is FloatConstant){
 506                                                 float res;
 507
 508                                                 if (ec.ConstantCheckState)
 509                                                         res = checked (((FloatConstant) left).Value -
 510                                                                        ((FloatConstant) right).Value);
 511                                                 else
 512                                                         res = unchecked (((FloatConstant) left).Value -
 513                                                                          ((FloatConstant) right).Value);
 514
 515                                                 result = new FloatConstant (res);
 516                                         } else if (left is ULongConstant){
 517                                                 ulong res;
 518
 519                                                 if (ec.ConstantCheckState)
 520                                                         res = checked (((ULongConstant) left).Value -
 521                                                                        ((ULongConstant) right).Value);
 522                                                 else
 523                                                         res = unchecked (((ULongConstant) left).Value -
 524                                                                          ((ULongConstant) right).Value);
 525
 526                                                 result = new ULongConstant (res);
 527                                         } else if (left is LongConstant){
 528                                                 long res;
 529
 530                                                 if (ec.ConstantCheckState)
 531                                                         res = checked (((LongConstant) left).Value -
 532                                                                        ((LongConstant) right).Value);
 533                                                 else
 534                                                         res = unchecked (((LongConstant) left).Value -
 535                                                                          ((LongConstant) right).Value);
 536
 537                                                 result = new LongConstant (res);
 538                                         } else if (left is UIntConstant){
 539                                                 uint res;
 540
 541                                                 if (ec.ConstantCheckState)
 542                                                         res = checked (((UIntConstant) left).Value -
 543                                                                        ((UIntConstant) right).Value);
 544                                                 else
 545                                                         res = unchecked (((UIntConstant) left).Value -
 546                                                                          ((UIntConstant) right).Value);
 547
 548                                                 result = new UIntConstant (res);
 549                                         } else if (left is IntConstant){
 550                                                 int res;
 551
 552                                                 if (ec.ConstantCheckState)
 553                                                         res = checked (((IntConstant) left).Value -
 554                                                                        ((IntConstant) right).Value);
 555                                                 else
 556                                                         res = unchecked (((IntConstant) left).Value -
 557                                                                          ((IntConstant) right).Value);
 558
 559                                                 result = new IntConstant (res);
 560                                         } else {
 561                                                 throw new Exception ( "Unexepected input: " + left);
 562                                         }
 563                                 } catch (OverflowException){
 564                                         Error_CompileTimeOverflow (loc);
 565                                 }
 566                                 if (wrap_as != null)
 567                                         return new EnumConstant (result, wrap_as);
 568                                 else
 569                                         return result;
 570
 571                         case Binary.Operator.Multiply:
 572                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 573                                 if (left == null || right == null)
 574                                         return null;
 575
 576                                 try {
 577                                         if (left is DoubleConstant){
 578                                                 double res;
 579
 580                                                 if (ec.ConstantCheckState)
 581                                                         res = checked (((DoubleConstant) left).Value *
 582                                                                        ((DoubleConstant) right).Value);
 583                                                 else
 584                                                         res = unchecked (((DoubleConstant) left).Value *
 585                                                                          ((DoubleConstant) right).Value);
 586
 587                                                 return new DoubleConstant (res);
 588                                         } else if (left is FloatConstant){
 589                                                 float res;
 590
 591                                                 if (ec.ConstantCheckState)
 592                                                         res = checked (((FloatConstant) left).Value *
 593                                                                        ((FloatConstant) right).Value);
 594                                                 else
 595                                                         res = unchecked (((FloatConstant) left).Value *
 596                                                                          ((FloatConstant) right).Value);
 597
 598                                                 return new FloatConstant (res);
 599                                         } else if (left is ULongConstant){
 600                                                 ulong res;
 601
 602                                                 if (ec.ConstantCheckState)
 603                                                         res = checked (((ULongConstant) left).Value *
 604                                                                        ((ULongConstant) right).Value);
 605                                                 else
 606                                                         res = unchecked (((ULongConstant) left).Value *
 607                                                                          ((ULongConstant) right).Value);
 608
 609                                                 return new ULongConstant (res);
 610                                         } else if (left is LongConstant){
 611                                                 long res;
 612
 613                                                 if (ec.ConstantCheckState)
 614                                                         res = checked (((LongConstant) left).Value *
 615                                                                        ((LongConstant) right).Value);
 616                                                 else
 617                                                         res = unchecked (((LongConstant) left).Value *
 618                                                                          ((LongConstant) right).Value);
 619
 620                                                 return new LongConstant (res);
 621                                         } else if (left is UIntConstant){
 622                                                 uint res;
 623
 624                                                 if (ec.ConstantCheckState)
 625                                                         res = checked (((UIntConstant) left).Value *
 626                                                                        ((UIntConstant) right).Value);
 627                                                 else
 628                                                         res = unchecked (((UIntConstant) left).Value *
 629                                                                          ((UIntConstant) right).Value);
 630
 631                                                 return new UIntConstant (res);
 632                                         } else if (left is IntConstant){
 633                                                 int res;
 634
 635                                                 if (ec.ConstantCheckState)
 636                                                         res = checked (((IntConstant) left).Value *
 637                                                                        ((IntConstant) right).Value);
 638                                                 else
 639                                                         res = unchecked (((IntConstant) left).Value *
 640                                                                          ((IntConstant) right).Value);
 641
 642                                                 return new IntConstant (res);
 643                                         } else {
 644                                                 throw new Exception ( "Unexepected input: " + left);
 645                                         }
 646                                 } catch (OverflowException){
 647                                         Error_CompileTimeOverflow (loc);
 648                                 }
 649                                 break;
 650
 651                         case Binary.Operator.IntDivision:
 652                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 653                                 if (left == null || right == null)
 654                                         return null;
 655
 656                                 try {
 657                                         if (left is DoubleConstant) {
 658                                                 long left_val, right_val, res;
 659                                                 left_val = (long) ((DoubleConstant) left).Value;
 660                                                 right_val = (long) ((DoubleConstant) right).Value;
 661
 662                                                 if (ec.ConstantCheckState)
 663                                                         res = checked (left_val / right_val);
 664                                                 else
 665                                                         res = unchecked (left_val / right_val);
 666
 667                                                 return new LongConstant (res);
 668                                         } else if (left is FloatConstant) {
 669                                                 long left_val, right_val, res;
 670                                                 left_val = (long) ((FloatConstant) left).Value;
 671                                                 right_val = (long) ((FloatConstant) right).Value;
 672
 673                                                 if (ec.ConstantCheckState)
 674                                                         res = checked (left_val / right_val);
 675                                                 else
 676                                                         res = unchecked (left_val / right_val);
 677
 678                                                 return new LongConstant (res);
 679                                         } else if (left is DecimalConstant) {
 680                                                 long left_val, right_val, res;
 681                                                 left_val = (long) ((DecimalConstant) left).Value;
 682                                                 right_val = (long) ((DecimalConstant) right).Value;
 683
 684                                                 if (ec.ConstantCheckState)
 685                                                         res = checked (left_val / right_val);
 686                                                 else
 687                                                         res = unchecked (left_val / right_val);
 688
 689                                                 return new LongConstant (res);
 690                                         } else if (left is LongConstant) {
 691                                                 long res;
 692
 693                                                 if (ec.ConstantCheckState)
 694                                                         res = checked (((LongConstant) left).Value /
 695                                                                        ((LongConstant) right).Value);
 696                                                 else
 697                                                         res = unchecked (((LongConstant) left).Value /
 698                                                                          ((LongConstant) right).Value);
 699
 700                                                 return new LongConstant (res);
 701                                         } else {
 702                                                 int res;
 703
 704                                                 if (ec.ConstantCheckState)
 705                                                         res = checked (((IntConstant) left).Value /
 706                                                                        ((IntConstant) right).Value);
 707                                                 else
 708                                                         res = unchecked (((IntConstant) left).Value /
 709                                                                          ((IntConstant) right).Value);
 710
 711                                                 return new IntConstant (res);
 712                                         }
 713                                 } catch (OverflowException){
 714                                         Error_CompileTimeOverflow (loc);
 715
 716                                 } catch (DivideByZeroException) {
 717                                         Report.Error (30542, loc, "Division by constant zero");
 718                                 }
 719
 720                                 break;
 721                         case Binary.Operator.Division:
 722                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 723                                 if (left == null || right == null)
 724                                         return null;
 725
 726                                 try {
 727                                         double res;
 728
 729                                         if (ec.ConstantCheckState)
 730                                                 res = checked (((DoubleConstant) left).Value /
 731                                                                ((DoubleConstant) right).Value);
 732                                         else
 733                                                 res = unchecked (((DoubleConstant) left).Value /
 734                                                                  ((DoubleConstant) right).Value);
 735
 736                                         return new DoubleConstant (res);
 737                                 } catch (OverflowException){
 738                                         Error_CompileTimeOverflow (loc);
 739
 740                                 } catch (DivideByZeroException) {
 741                                         Report.Error (30542, loc, "Division by constant zero");
 742                                 }
 743
 744                                 break;
 745
 746                         case Binary.Operator.Modulus:
 747                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 748                                 if (left == null || right == null)
 749                                         return null;
 750
 751                                 try {
 752                                         if (left is DoubleConstant){
 753                                                 double res;
 754
 755                                                 if (ec.ConstantCheckState)
 756                                                         res = checked (((DoubleConstant) left).Value %
 757                                                                        ((DoubleConstant) right).Value);
 758                                                 else
 759                                                         res = unchecked (((DoubleConstant) left).Value %
 760                                                                          ((DoubleConstant) right).Value);
 761
 762                                                 return new DoubleConstant (res);
 763                                         } else if (left is FloatConstant){
 764                                                 float res;
 765
 766                                                 if (ec.ConstantCheckState)
 767                                                         res = checked (((FloatConstant) left).Value %
 768                                                                        ((FloatConstant) right).Value);
 769                                                 else
 770                                                         res = unchecked (((FloatConstant) left).Value %
 771                                                                          ((FloatConstant) right).Value);
 772
 773                                                 return new FloatConstant (res);
 774                                         } else if (left is ULongConstant){
 775                                                 ulong res;
 776
 777                                                 if (ec.ConstantCheckState)
 778                                                         res = checked (((ULongConstant) left).Value %
 779                                                                        ((ULongConstant) right).Value);
 780                                                 else
 781                                                         res = unchecked (((ULongConstant) left).Value %
 782                                                                          ((ULongConstant) right).Value);
 783
 784                                                 return new ULongConstant (res);
 785                                         } else if (left is LongConstant){
 786                                                 long res;
 787
 788                                                 if (ec.ConstantCheckState)
 789                                                         res = checked (((LongConstant) left).Value %
 790                                                                        ((LongConstant) right).Value);
 791                                                 else
 792                                                         res = unchecked (((LongConstant) left).Value %
 793                                                                          ((LongConstant) right).Value);
 794
 795                                                 return new LongConstant (res);
 796                                         } else if (left is UIntConstant){
 797                                                 uint res;
 798
 799                                                 if (ec.ConstantCheckState)
 800                                                         res = checked (((UIntConstant) left).Value %
 801                                                                        ((UIntConstant) right).Value);
 802                                                 else
 803                                                         res = unchecked (((UIntConstant) left).Value %
 804                                                                          ((UIntConstant) right).Value);
 805
 806                                                 return new UIntConstant (res);
 807                                         } else if (left is IntConstant){
 808                                                 int res;
 809
 810                                                 if (ec.ConstantCheckState)
 811                                                         res = checked (((IntConstant) left).Value %
 812                                                                        ((IntConstant) right).Value);
 813                                                 else
 814                                                         res = unchecked (((IntConstant) left).Value %
 815                                                                          ((IntConstant) right).Value);
 816
 817                                                 return new IntConstant (res);
 818                                         } else {
 819                                                 throw new Exception ( "Unexepected input: " + left);
 820                                         }
 821                                 } catch (OverflowException){
 822                                         Error_CompileTimeOverflow (loc);
 823                                 }
 824                                 break;
 825
 826                         case Binary.Operator.Exponentiation:
 827                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 828                                 if (left == null || right == null)
 829                                         return null;
 830
 831                                 double powVal = System.Math.Pow(((DoubleConstant) left).Value,
 832                                                                 ((DoubleConstant) right).Value);
 833
 834                                 return new DoubleConstant(powVal);
 835
 836                                 //
 837                                 // There is no overflow checking on left shift
 838                                 //
 839                         case Binary.Operator.LeftShift:
 840                                 IntConstant ic = right.ToInt (loc);
 841                                 if (ic == null){
 842                                         Binary.Error_OperatorCannotBeApplied (loc, "<<", lt, rt);
 843                                         return null;
 844                                 }
 845                                 int lshift_val = ic.Value;
 846
 847                                 IntConstant lic;
 848                                 if ((lic = left.ConvertToInt ()) != null)
 849                                         return new IntConstant (lic.Value << lshift_val);
 850
 851                                 UIntConstant luic;
 852                                 if ((luic = left.ConvertToUInt ()) != null)
 853                                         return new UIntConstant (luic.Value << lshift_val);
 854
 855                                 LongConstant llc;
 856                                 if ((llc = left.ConvertToLong ()) != null)
 857                                         return new LongConstant (llc.Value << lshift_val);
 858
 859                                 ULongConstant lulc;
 860                                 if ((lulc = left.ConvertToULong ()) != null)
 861                                         return new ULongConstant (lulc.Value << lshift_val);
 862
 863                                 Binary.Error_OperatorCannotBeApplied (loc, "<<", lt, rt);
 864                                 break;
 865
 866                                 //
 867                                 // There is no overflow checking on right shift
 868                                 //
 869                         case Binary.Operator.RightShift:
 870                                 IntConstant sic = right.ToInt (loc);
 871                                 if (sic == null){
 872                                         Binary.Error_OperatorCannotBeApplied (loc, ">>", lt, rt);
 873                                         return null;
 874                                 }
 875                                 int rshift_val = sic.Value;
 876
 877                                 IntConstant ric;
 878                                 if ((ric = left.ConvertToInt ()) != null)
 879                                         return new IntConstant (ric.Value >> rshift_val);
 880
 881                                 UIntConstant ruic;
 882                                 if ((ruic = left.ConvertToUInt ()) != null)
 883                                         return new UIntConstant (ruic.Value >> rshift_val);
 884
 885                                 LongConstant rlc;
 886                                 if ((rlc = left.ConvertToLong ()) != null)
 887                                         return new LongConstant (rlc.Value >> rshift_val);
 888
 889                                 ULongConstant rulc;
 890                                 if ((rulc = left.ConvertToULong ()) != null)
 891                                         return new ULongConstant (rulc.Value >> rshift_val);
 892
 893                                 Binary.Error_OperatorCannotBeApplied (loc, ">>", lt, rt);
 894                                 break;
 895
 896                         case Binary.Operator.LogicalAnd:
 897                                 if (left is BoolConstant && right is BoolConstant){
 898                                         return new BoolConstant (
 899                                                 ((BoolConstant) left).Value &&
 900                                                 ((BoolConstant) right).Value);
 901                                 }
 902                                 break;
 903
 904                         case Binary.Operator.LogicalOr:
 905                                 if (left is BoolConstant && right is BoolConstant){
 906                                         return new BoolConstant (
 907                                                 ((BoolConstant) left).Value ||
 908                                                 ((BoolConstant) right).Value);
 909                                 }
 910                                 break;
 911
 912                         case Binary.Operator.Equality:
 913                                 if (left is BoolConstant && right is BoolConstant){
 914                                         return new BoolConstant (
 915                                                 ((BoolConstant) left).Value ==
 916                                                 ((BoolConstant) right).Value);
 917
 918                                 }
 919                                 if (left is StringConstant && right is StringConstant){
 920                                         return new BoolConstant (
 921                                                 ((StringConstant) left).Value ==
 922                                                 ((StringConstant) right).Value);
 923
 924                                 }
 925
 926                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 927                                 if (left == null || right == null)
 928                                         return null;
 929
 930                                 bool_res = false;
 931                                 if (left is DoubleConstant)
 932                                         bool_res = ((DoubleConstant) left).Value ==
 933                                                 ((DoubleConstant) right).Value;
 934                                 else if (left is FloatConstant)
 935                                         bool_res = ((FloatConstant) left).Value ==
 936                                                 ((FloatConstant) right).Value;
 937                                 else if (left is ULongConstant)
 938                                         bool_res = ((ULongConstant) left).Value ==
 939                                                 ((ULongConstant) right).Value;
 940                                 else if (left is LongConstant)
 941                                         bool_res = ((LongConstant) left).Value ==
 942                                                 ((LongConstant) right).Value;
 943                                 else if (left is UIntConstant)
 944                                         bool_res = ((UIntConstant) left).Value ==
 945                                                 ((UIntConstant) right).Value;
 946                                 else if (left is IntConstant)
 947                                         bool_res = ((IntConstant) left).Value ==
 948                                                 ((IntConstant) right).Value;
 949                                 else
 950                                         return null;
 951
 952                                 return new BoolConstant (bool_res);
 953
 954                         case Binary.Operator.Inequality:
 955                                 if (left is BoolConstant && right is BoolConstant){
 956                                         return new BoolConstant (
 957                                                 ((BoolConstant) left).Value !=
 958                                                 ((BoolConstant) right).Value);
 959                                 }
 960                                 if (left is StringConstant && right is StringConstant){
 961                                         return new BoolConstant (
 962                                                 ((StringConstant) left).Value !=
 963                                                 ((StringConstant) right).Value);
 964
 965                                 }
 966                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 967                                 if (left == null || right == null)
 968                                         return null;
 969
 970                                 bool_res = false;
 971                                 if (left is DoubleConstant)
 972                                         bool_res = ((DoubleConstant) left).Value !=
 973                                                 ((DoubleConstant) right).Value;
 974                                 else if (left is FloatConstant)
 975                                         bool_res = ((FloatConstant) left).Value !=
 976                                                 ((FloatConstant) right).Value;
 977                                 else if (left is ULongConstant)
 978                                         bool_res = ((ULongConstant) left).Value !=
 979                                                 ((ULongConstant) right).Value;
 980                                 else if (left is LongConstant)
 981                                         bool_res = ((LongConstant) left).Value !=
 982                                                 ((LongConstant) right).Value;
 983                                 else if (left is UIntConstant)
 984                                         bool_res = ((UIntConstant) left).Value !=
 985                                                 ((UIntConstant) right).Value;
 986                                 else if (left is IntConstant)
 987                                         bool_res = ((IntConstant) left).Value !=
 988                                                 ((IntConstant) right).Value;
 989                                 else
 990                                         return null;
 991
 992                                 return new BoolConstant (bool_res);
 993
 994                         case Binary.Operator.LessThan:
 995                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
 996                                 if (left == null || right == null)
 997                                         return null;
 998
 999                                 bool_res = false;
1000                                 if (left is DoubleConstant)
1001                                         bool_res = ((DoubleConstant) left).Value <
1002                                                 ((DoubleConstant) right).Value;
1003                                 else if (left is FloatConstant)
1004                                         bool_res = ((FloatConstant) left).Value <
1005                                                 ((FloatConstant) right).Value;
1006                                 else if (left is ULongConstant)
1007                                         bool_res = ((ULongConstant) left).Value <
1008                                                 ((ULongConstant) right).Value;
1009                                 else if (left is LongConstant)
1010                                         bool_res = ((LongConstant) left).Value <
1011                                                 ((LongConstant) right).Value;
1012                                 else if (left is UIntConstant)
1013                                         bool_res = ((UIntConstant) left).Value <
1014                                                 ((UIntConstant) right).Value;
1015                                 else if (left is IntConstant)
1016                                         bool_res = ((IntConstant) left).Value <
1017                                                 ((IntConstant) right).Value;
1018                                 else
1019                                         return null;
1020
1021                                 return new BoolConstant (bool_res);
1022
1023                         case Binary.Operator.GreaterThan:
1024                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
1025                                 if (left == null || right == null)
1026                                         return null;
1027
1028                                 bool_res = false;
1029                                 if (left is DoubleConstant)
1030                                         bool_res = ((DoubleConstant) left).Value >
1031                                                 ((DoubleConstant) right).Value;
1032                                 else if (left is FloatConstant)
1033                                         bool_res = ((FloatConstant) left).Value >
1034                                                 ((FloatConstant) right).Value;
1035                                 else if (left is ULongConstant)
1036                                         bool_res = ((ULongConstant) left).Value >
1037                                                 ((ULongConstant) right).Value;
1038                                 else if (left is LongConstant)
1039                                         bool_res = ((LongConstant) left).Value >
1040                                                 ((LongConstant) right).Value;
1041                                 else if (left is UIntConstant)
1042                                         bool_res = ((UIntConstant) left).Value >
1043                                                 ((UIntConstant) right).Value;
1044                                 else if (left is IntConstant)
1045                                         bool_res = ((IntConstant) left).Value >
1046                                                 ((IntConstant) right).Value;
1047                                 else
1048                                         return null;
1049
1050                                 return new BoolConstant (bool_res);
1051
1052                         case Binary.Operator.GreaterThanOrEqual:
1053                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
1054                                 if (left == null || right == null)
1055                                         return null;
1056
1057                                 bool_res = false;
1058                                 if (left is DoubleConstant)
1059                                         bool_res = ((DoubleConstant) left).Value >=
1060                                                 ((DoubleConstant) right).Value;
1061                                 else if (left is FloatConstant)
1062                                         bool_res = ((FloatConstant) left).Value >=
1063                                                 ((FloatConstant) right).Value;
1064                                 else if (left is ULongConstant)
1065                                         bool_res = ((ULongConstant) left).Value >=
1066                                                 ((ULongConstant) right).Value;
1067                                 else if (left is LongConstant)
1068                                         bool_res = ((LongConstant) left).Value >=
1069                                                 ((LongConstant) right).Value;
1070                                 else if (left is UIntConstant)
1071                                         bool_res = ((UIntConstant) left).Value >=
1072                                                 ((UIntConstant) right).Value;
1073                                 else if (left is IntConstant)
1074                                         bool_res = ((IntConstant) left).Value >=
1075                                                 ((IntConstant) right).Value;
1076                                 else
1077                                         return null;
1078
1079                                 return new BoolConstant (bool_res);
1080
1081                         case Binary.Operator.LessThanOrEqual:
1082                                 DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
1083                                 if (left == null || right == null)
1084                                         return null;
1085
1086                                 bool_res = false;
1087                                 if (left is DoubleConstant)
1088                                         bool_res = ((DoubleConstant) left).Value <=
1089                                                 ((DoubleConstant) right).Value;
1090                                 else if (left is FloatConstant)
1091                                         bool_res = ((FloatConstant) left).Value <=
1092                                                 ((FloatConstant) right).Value;
1093                                 else if (left is ULongConstant)
1094                                         bool_res = ((ULongConstant) left).Value <=
1095                                                 ((ULongConstant) right).Value;
1096                                 else if (left is LongConstant)
1097                                         bool_res = ((LongConstant) left).Value <=
1098                                                 ((LongConstant) right).Value;
1099                                 else if (left is UIntConstant)
1100                                         bool_res = ((UIntConstant) left).Value <=
1101                                                 ((UIntConstant) right).Value;
1102                                 else if (left is IntConstant)
1103                                         bool_res = ((IntConstant) left).Value <=
1104                                                 ((IntConstant) right).Value;
1105                                 else
1106                                         return null;
1107
1108                                 return new BoolConstant (bool_res);
1109                         }
1110
1111                         return null;
1112                 }
1113         }
1114 }