gcc/fortran/convert.c

   1 /* Data type conversion
   2    Copyright (C) 1987-2015 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20
  21 /* This file contains the functions for converting expressions to
  22    different data types for the translation of the gfortran internal
  23    representation to GIMPLE.  The only entry point is `convert'.  */
  24
  25 #include "config.h"
  26 #include "system.h"
  27 #include "coretypes.h"
  28 #include "hash-set.h"
  29 #include "vec.h"
  30 #include "input.h"
  31 #include "alias.h"
  32 #include "symtab.h"
  33 #include "options.h"
  34 #include "inchash.h"
  35 #include "tree.h"
  36 #include "fold-const.h"
  37 #include "convert.h"
  38
  39 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
  40    or validate its data type for a GIMPLE `if' or `while' statement.
  41
  42    The resulting type should always be `boolean_type_node'.  */
  43
  44 static tree
  45 truthvalue_conversion (tree expr)
  46 {
  47   switch (TREE_CODE (TREE_TYPE (expr)))
  48     {
  49     case BOOLEAN_TYPE:
  50       if (TREE_TYPE (expr) == boolean_type_node)
  51         return expr;
  52       else if (COMPARISON_CLASS_P (expr))
  53         {
  54           TREE_TYPE (expr) = boolean_type_node;
  55           return expr;
  56         }
  57       else if (TREE_CODE (expr) == NOP_EXPR)
  58         return fold_build1_loc (input_location, NOP_EXPR,
  59                             boolean_type_node, TREE_OPERAND (expr, 0));
  60       else
  61         return fold_build1_loc (input_location, NOP_EXPR, boolean_type_node,
  62                                 expr);
  63
  64     case INTEGER_TYPE:
  65       if (TREE_CODE (expr) == INTEGER_CST)
  66         return integer_zerop (expr) ? boolean_false_node : boolean_true_node;
  67       else
  68         return fold_build2_loc (input_location, NE_EXPR, boolean_type_node,
  69                                 expr, build_int_cst (TREE_TYPE (expr), 0));
  70
  71     default:
  72       gcc_unreachable ();
  73     }
  74 }
  75
  76 /* Create an expression whose value is that of EXPR,
  77    converted to type TYPE.  The TREE_TYPE of the value
  78    is always TYPE.  This function implements all reasonable
  79    conversions; callers should filter out those that are
  80    not permitted by the language being compiled.  */
  81
  82 tree
  83 convert (tree type, tree expr)
  84 {
  85   tree e = expr;
  86   enum tree_code code;
  87
  88   if (type == TREE_TYPE (expr))
  89     return expr;
  90
  91   if (TREE_CODE (type) == ERROR_MARK
  92       || TREE_CODE (expr) == ERROR_MARK
  93       || TREE_CODE (TREE_TYPE (expr)) == ERROR_MARK)
  94     return expr;
  95
  96   gcc_checking_assert (TREE_CODE (TREE_TYPE (expr)) != VOID_TYPE);
  97
  98   if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr)))
  99     return fold_build1_loc (input_location, NOP_EXPR, type, expr);
 100
 101   code = TREE_CODE (type);
 102   if (code == VOID_TYPE)
 103     return fold_build1_loc (input_location, CONVERT_EXPR, type, e);
 104   if (code == BOOLEAN_TYPE)
 105     return fold_build1_loc (input_location, NOP_EXPR, type,
 106                             truthvalue_conversion (e));
 107   if (code == INTEGER_TYPE)
 108     return fold (convert_to_integer (type, e));
 109   if (code == POINTER_TYPE || code == REFERENCE_TYPE)
 110     return fold (convert_to_pointer (type, e));
 111   if (code == REAL_TYPE)
 112     return fold (convert_to_real (type, e));
 113   if (code == COMPLEX_TYPE)
 114     return fold (convert_to_complex (type, e));
 115   if (code == VECTOR_TYPE)
 116     return fold (convert_to_vector (type, e));
 117
 118   gcc_unreachable ();
 119 }
 120