gcc/ada/exp_vfpt.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             E X P _ V F P T                              --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --                                                                          --
  10 --          Copyright (C) 1997-2001 Free Software Foundation, Inc.          --
  11 --                                                                          --
  12 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  13 -- terms of the  GNU General Public License as published  by the Free Soft- --
  14 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  15 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  16 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  17 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  18 -- for  more details.  You should have  received  a copy of the GNU General --
  19 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  20 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  21 -- MA 02111-1307, USA.                                                      --
  22 --                                                                          --
  23 -- GNAT was originally developed  by the GNAT team at  New York University. --
  24 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  25 --                                                                          --
  26 ------------------------------------------------------------------------------
  27
  28 with Atree;    use Atree;
  29 with Einfo;    use Einfo;
  30 with Nlists;   use Nlists;
  31 with Nmake;    use Nmake;
  32 with Rtsfind;  use Rtsfind;
  33 with Sem_Res;  use Sem_Res;
  34 with Sinfo;    use Sinfo;
  35 with Snames;   use Snames;
  36 with Stand;    use Stand;
  37 with Tbuild;   use Tbuild;
  38 with Ttypef;   use Ttypef;
  39 with Uintp;    use Uintp;
  40 with Urealp;   use Urealp;
  41
  42 package body Exp_VFpt is
  43
  44    ----------------------
  45    -- Expand_Vax_Arith --
  46    ----------------------
  47
  48    procedure Expand_Vax_Arith (N : Node_Id) is
  49       Loc   : constant Source_Ptr := Sloc (N);
  50       Typ   : constant Entity_Id  := Base_Type (Etype (N));
  51       Typc  : Character;
  52       Atyp  : Entity_Id;
  53       Func  : RE_Id;
  54       Args  : List_Id;
  55
  56    begin
  57       --  Get arithmetic type, note that we do D stuff in G
  58
  59       if Digits_Value (Typ) = VAXFF_Digits then
  60          Typc := 'F';
  61          Atyp := RTE (RE_F);
  62       else
  63          Typc := 'G';
  64          Atyp := RTE (RE_G);
  65       end if;
  66
  67       case Nkind (N) is
  68
  69          when N_Op_Abs =>
  70             if Typc = 'F' then
  71                Func := RE_Abs_F;
  72             else
  73                Func := RE_Abs_G;
  74             end if;
  75
  76          when N_Op_Add =>
  77             if Typc = 'F' then
  78                Func := RE_Add_F;
  79             else
  80                Func := RE_Add_G;
  81             end if;
  82
  83          when N_Op_Divide =>
  84             if Typc = 'F' then
  85                Func := RE_Div_F;
  86             else
  87                Func := RE_Div_G;
  88             end if;
  89
  90          when N_Op_Multiply =>
  91             if Typc = 'F' then
  92                Func := RE_Mul_F;
  93             else
  94                Func := RE_Mul_G;
  95             end if;
  96
  97          when N_Op_Minus =>
  98             if Typc = 'F' then
  99                Func := RE_Neg_F;
 100             else
 101                Func := RE_Neg_G;
 102             end if;
 103
 104          when N_Op_Subtract =>
 105             if Typc = 'F' then
 106                Func := RE_Sub_F;
 107             else
 108                Func := RE_Sub_G;
 109             end if;
 110
 111          when others =>
 112             Func := RE_Null;
 113             raise Program_Error;
 114
 115       end case;
 116
 117       Args := New_List;
 118
 119       if Nkind (N) in N_Binary_Op then
 120          Append_To (Args,
 121            Convert_To (Atyp, Left_Opnd (N)));
 122       end if;
 123
 124       Append_To (Args,
 125         Convert_To (Atyp, Right_Opnd (N)));
 126
 127       Rewrite (N,
 128         Convert_To (Typ,
 129           Make_Function_Call (Loc,
 130             Name => New_Occurrence_Of (RTE (Func), Loc),
 131             Parameter_Associations => Args)));
 132
 133       Analyze_And_Resolve (N, Typ, Suppress => All_Checks);
 134    end Expand_Vax_Arith;
 135
 136    ---------------------------
 137    -- Expand_Vax_Comparison --
 138    ---------------------------
 139
 140    procedure Expand_Vax_Comparison (N : Node_Id) is
 141       Loc   : constant Source_Ptr := Sloc (N);
 142       Typ   : constant Entity_Id  := Base_Type (Etype (Left_Opnd (N)));
 143       Typc  : Character;
 144       Func  : RE_Id;
 145       Atyp  : Entity_Id;
 146       Revrs : Boolean := False;
 147       Args  : List_Id;
 148
 149    begin
 150       --  Get arithmetic type, note that we do D stuff in G
 151
 152       if Digits_Value (Typ) = VAXFF_Digits then
 153          Typc := 'F';
 154          Atyp := RTE (RE_F);
 155       else
 156          Typc := 'G';
 157          Atyp := RTE (RE_G);
 158       end if;
 159
 160       case Nkind (N) is
 161
 162          when N_Op_Eq =>
 163             if Typc = 'F' then
 164                Func := RE_Eq_F;
 165             else
 166                Func := RE_Eq_G;
 167             end if;
 168
 169          when N_Op_Ge =>
 170             if Typc = 'F' then
 171                Func := RE_Le_F;
 172             else
 173                Func := RE_Le_G;
 174             end if;
 175
 176             Revrs := True;
 177
 178          when N_Op_Gt =>
 179             if Typc = 'F' then
 180                Func := RE_Lt_F;
 181             else
 182                Func := RE_Lt_G;
 183             end if;
 184
 185             Revrs := True;
 186
 187          when N_Op_Le =>
 188             if Typc = 'F' then
 189                Func := RE_Le_F;
 190             else
 191                Func := RE_Le_G;
 192             end if;
 193
 194          when N_Op_Lt =>
 195             if Typc = 'F' then
 196                Func := RE_Lt_F;
 197             else
 198                Func := RE_Lt_G;
 199             end if;
 200
 201          when others =>
 202             Func := RE_Null;
 203             raise Program_Error;
 204
 205       end case;
 206
 207       if not Revrs then
 208          Args := New_List (
 209            Convert_To (Atyp, Left_Opnd  (N)),
 210            Convert_To (Atyp, Right_Opnd (N)));
 211
 212       else
 213          Args := New_List (
 214            Convert_To (Atyp, Right_Opnd (N)),
 215            Convert_To (Atyp, Left_Opnd  (N)));
 216       end if;
 217
 218       Rewrite (N,
 219         Make_Function_Call (Loc,
 220           Name => New_Occurrence_Of (RTE (Func), Loc),
 221           Parameter_Associations => Args));
 222
 223       Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
 224    end Expand_Vax_Comparison;
 225
 226    ---------------------------
 227    -- Expand_Vax_Conversion --
 228    ---------------------------
 229
 230    procedure Expand_Vax_Conversion (N : Node_Id) is
 231       Loc   : constant Source_Ptr := Sloc (N);
 232       Expr  : constant Node_Id    := Expression (N);
 233       S_Typ : constant Entity_Id  := Base_Type (Etype (Expr));
 234       T_Typ : constant Entity_Id  := Base_Type (Etype (N));
 235
 236       CallS : RE_Id;
 237       CallT : RE_Id;
 238       Func  : RE_Id;
 239
 240       function Call_Type (T : Entity_Id; Otyp : Entity_Id) return RE_Id;
 241       --  Given one of the two types T, determines the coresponding call
 242       --  type, i.e. the type to be used for the call (or the result of
 243       --  the call). The actual operand is converted to (or from) this type.
 244       --  Otyp is the other type, which is useful in figuring out the result.
 245       --  The result returned is the RE_Id value for the type entity.
 246
 247       function Equivalent_Integer_Type (T : Entity_Id) return Entity_Id;
 248       --  Find the predefined integer type that has the same size as the
 249       --  fixed-point type T, for use in fixed/float conversions.
 250
 251       ---------------
 252       -- Call_Type --
 253       ---------------
 254
 255       function Call_Type (T : Entity_Id; Otyp : Entity_Id) return RE_Id is
 256       begin
 257          --  Vax float formats
 258
 259          if Vax_Float (T) then
 260             if Digits_Value (T) = VAXFF_Digits then
 261                return RE_F;
 262
 263             elsif Digits_Value (T) = VAXGF_Digits then
 264                return RE_G;
 265
 266             --  For D_Float, leave it as D float if the other operand is
 267             --  G_Float, since this is the one conversion that is properly
 268             --  supported for D_Float, but otherwise, use G_Float.
 269
 270             else pragma Assert (Digits_Value (T) = VAXDF_Digits);
 271
 272                if Vax_Float (Otyp)
 273                  and then Digits_Value (Otyp) = VAXGF_Digits
 274                then
 275                   return RE_D;
 276                else
 277                   return RE_G;
 278                end if;
 279             end if;
 280
 281          --  For all discrete types, use 64-bit integer
 282
 283          elsif Is_Discrete_Type (T) then
 284             return RE_Q;
 285
 286          --  For all real types (other than Vax float format), we use the
 287          --  IEEE float-type which corresponds in length to the other type
 288          --  (which is Vax Float).
 289
 290          else pragma Assert (Is_Real_Type (T));
 291
 292             if Digits_Value (Otyp) = VAXFF_Digits then
 293                return RE_S;
 294             else
 295                return RE_T;
 296             end if;
 297          end if;
 298       end Call_Type;
 299
 300       function Equivalent_Integer_Type (T : Entity_Id) return Entity_Id is
 301       begin
 302          if Esize (T) = Esize (Standard_Long_Long_Integer) then
 303             return Standard_Long_Long_Integer;
 304
 305          elsif Esize (T) = Esize (Standard_Long_Integer) then
 306             return  Standard_Long_Integer;
 307
 308          else
 309             return Standard_Integer;
 310          end if;
 311       end Equivalent_Integer_Type;
 312
 313
 314    --  Start of processing for Expand_Vax_Conversion;
 315
 316    begin
 317       --  If input and output are the same Vax type, we change the
 318       --  conversion to be an unchecked conversion and that's it.
 319
 320       if Vax_Float (S_Typ) and then Vax_Float (T_Typ)
 321         and then Digits_Value (S_Typ) = Digits_Value (T_Typ)
 322       then
 323          Rewrite (N,
 324            Unchecked_Convert_To (T_Typ, Expr));
 325
 326
 327       elsif Is_Fixed_Point_Type (S_Typ) then
 328
 329          --  convert the scaled integer value to the target type, and multiply
 330          --  by 'Small of type.
 331
 332          Rewrite (N,
 333             Make_Op_Multiply (Loc,
 334               Left_Opnd =>
 335                 Make_Type_Conversion (Loc,
 336                   Subtype_Mark => New_Occurrence_Of (T_Typ, Loc),
 337                   Expression   =>
 338                     Unchecked_Convert_To (
 339                       Equivalent_Integer_Type (S_Typ), Expr)),
 340               Right_Opnd =>
 341                 Make_Real_Literal (Loc, Realval => Small_Value (S_Typ))));
 342
 343       elsif Is_Fixed_Point_Type (T_Typ) then
 344
 345          --  multiply value by 'small of type, and convert to the corresponding
 346          --  integer type.
 347
 348          Rewrite (N,
 349            Unchecked_Convert_To (T_Typ,
 350              Make_Type_Conversion (Loc,
 351                Subtype_Mark =>
 352                  New_Occurrence_Of (Equivalent_Integer_Type (T_Typ), Loc),
 353                Expression =>
 354                  Make_Op_Multiply (Loc,
 355                    Left_Opnd => Expr,
 356                    Right_Opnd =>
 357                      Make_Real_Literal (Loc,
 358                        Realval => Ureal_1 / Small_Value (T_Typ))))));
 359
 360       --  All other cases.
 361
 362       else
 363          --  Compute types for call
 364
 365          CallS := Call_Type (S_Typ, T_Typ);
 366          CallT := Call_Type (T_Typ, S_Typ);
 367
 368          --  Get function and its types
 369
 370          if CallS = RE_D and then CallT = RE_G then
 371             Func := RE_D_To_G;
 372
 373          elsif CallS = RE_G and then CallT = RE_D then
 374             Func := RE_G_To_D;
 375
 376          elsif CallS = RE_G and then CallT = RE_F then
 377             Func := RE_G_To_F;
 378
 379          elsif CallS = RE_F and then CallT = RE_G then
 380             Func := RE_F_To_G;
 381
 382          elsif CallS = RE_F and then CallT = RE_S then
 383             Func := RE_F_To_S;
 384
 385          elsif CallS = RE_S and then CallT = RE_F then
 386             Func := RE_S_To_F;
 387
 388          elsif CallS = RE_G and then CallT = RE_T then
 389             Func := RE_G_To_T;
 390
 391          elsif CallS = RE_T and then CallT = RE_G then
 392             Func := RE_T_To_G;
 393
 394          elsif CallS = RE_F and then CallT = RE_Q then
 395             Func := RE_F_To_Q;
 396
 397          elsif CallS = RE_Q and then CallT = RE_F then
 398             Func := RE_Q_To_F;
 399
 400          elsif CallS = RE_G and then CallT = RE_Q then
 401             Func := RE_G_To_Q;
 402
 403          else pragma Assert (CallS = RE_Q and then CallT = RE_G);
 404             Func := RE_Q_To_G;
 405          end if;
 406
 407          Rewrite (N,
 408            Convert_To (T_Typ,
 409              Make_Function_Call (Loc,
 410                Name => New_Occurrence_Of (RTE (Func), Loc),
 411                Parameter_Associations => New_List (
 412                  Convert_To (RTE (CallS), Expr)))));
 413       end if;
 414
 415       Analyze_And_Resolve (N, T_Typ, Suppress => All_Checks);
 416    end Expand_Vax_Conversion;
 417
 418    -----------------------------
 419    -- Expand_Vax_Real_Literal --
 420    -----------------------------
 421
 422    procedure Expand_Vax_Real_Literal (N : Node_Id) is
 423       Loc  : constant Source_Ptr := Sloc (N);
 424       Typ  : constant Entity_Id  := Etype (N);
 425       Btyp : constant Entity_Id  := Base_Type (Typ);
 426       Stat : constant Boolean    := Is_Static_Expression (N);
 427       Nod  : Node_Id;
 428
 429       RE_Source : RE_Id;
 430       RE_Target : RE_Id;
 431       RE_Fncall : RE_Id;
 432       --  Entities for source, target and function call in conversion
 433
 434    begin
 435       --  We do not know how to convert Vax format real literals, so what
 436       --  we do is to convert these to be IEEE literals, and introduce the
 437       --  necessary conversion operation.
 438
 439       if Vax_Float (Btyp) then
 440          --  What we want to construct here is
 441
 442          --    x!(y_to_z (1.0E0))
 443
 444          --  where
 445
 446          --    x is the base type of the literal (Btyp)
 447
 448          --    y_to_z is
 449
 450          --      s_to_f for F_Float
 451          --      t_to_g for G_Float
 452          --      t_to_d for D_Float
 453
 454          --  The literal is typed as S (for F_Float) or T otherwise
 455
 456          --  We do all our own construction, analysis, and expansion here,
 457          --  since things are at too low a level to use Analyze or Expand
 458          --  to get this built (we get circularities and other strange
 459          --  problems if we try!)
 460
 461          if Digits_Value (Btyp) = VAXFF_Digits then
 462             RE_Source := RE_S;
 463             RE_Target := RE_F;
 464             RE_Fncall := RE_S_To_F;
 465
 466          elsif Digits_Value (Btyp) = VAXDF_Digits then
 467             RE_Source := RE_T;
 468             RE_Target := RE_D;
 469             RE_Fncall := RE_T_To_D;
 470
 471          else pragma Assert (Digits_Value (Btyp) = VAXGF_Digits);
 472             RE_Source := RE_T;
 473             RE_Target := RE_G;
 474             RE_Fncall := RE_T_To_G;
 475          end if;
 476
 477          Nod := Relocate_Node (N);
 478
 479          Set_Etype (Nod, RTE (RE_Source));
 480          Set_Analyzed (Nod, True);
 481
 482          Nod :=
 483            Make_Function_Call (Loc,
 484              Name => New_Occurrence_Of (RTE (RE_Fncall), Loc),
 485              Parameter_Associations => New_List (Nod));
 486
 487          Set_Etype (Nod, RTE (RE_Target));
 488          Set_Analyzed (Nod, True);
 489
 490          Nod :=
 491            Make_Unchecked_Type_Conversion (Loc,
 492              Subtype_Mark => New_Occurrence_Of (Typ, Loc),
 493              Expression   => Nod);
 494
 495          Set_Etype (Nod, Typ);
 496          Set_Analyzed (Nod, True);
 497          Rewrite (N, Nod);
 498
 499          --  This odd expression is still a static expression. Note that
 500          --  the routine Sem_Eval.Expr_Value_R understands this.
 501
 502          Set_Is_Static_Expression (N, Stat);
 503       end if;
 504    end Expand_Vax_Real_Literal;
 505
 506 end Exp_VFpt;