gcc/fortran/convert.c

   1 /* Data type conversion
   2    Copyright (C) 1987-2014 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 "tree.h"
  29 #include "convert.h"
  30
  31 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
  32    or validate its data type for a GIMPLE `if' or `while' statement.
  33
  34    The resulting type should always be `boolean_type_node'.  */
  35
  36 static tree
  37 truthvalue_conversion (tree expr)
  38 {
  39   switch (TREE_CODE (TREE_TYPE (expr)))
  40     {
  41     case BOOLEAN_TYPE:
  42       if (TREE_TYPE (expr) == boolean_type_node)
  43         return expr;
  44       else if (COMPARISON_CLASS_P (expr))
  45         {
  46           TREE_TYPE (expr) = boolean_type_node;
  47           return expr;
  48         }
  49       else if (TREE_CODE (expr) == NOP_EXPR)
  50         return fold_build1_loc (input_location, NOP_EXPR,
  51                             boolean_type_node, TREE_OPERAND (expr, 0));
  52       else
  53         return fold_build1_loc (input_location, NOP_EXPR, boolean_type_node,
  54                                 expr);
  55
  56     case INTEGER_TYPE:
  57       if (TREE_CODE (expr) == INTEGER_CST)
  58         return integer_zerop (expr) ? boolean_false_node : boolean_true_node;
  59       else
  60         return fold_build2_loc (input_location, NE_EXPR, boolean_type_node,
  61                                 expr, build_int_cst (TREE_TYPE (expr), 0));
  62
  63     default:
  64       gcc_unreachable ();
  65     }
  66 }
  67
  68 /* Create an expression whose value is that of EXPR,
  69    converted to type TYPE.  The TREE_TYPE of the value
  70    is always TYPE.  This function implements all reasonable
  71    conversions; callers should filter out those that are
  72    not permitted by the language being compiled.  */
  73
  74 tree
  75 convert (tree type, tree expr)
  76 {
  77   tree e = expr;
  78   enum tree_code code;
  79
  80   if (type == TREE_TYPE (expr))
  81     return expr;
  82
  83   if (TREE_CODE (type) == ERROR_MARK
  84       || TREE_CODE (expr) == ERROR_MARK
  85       || TREE_CODE (TREE_TYPE (expr)) == ERROR_MARK)
  86     return expr;
  87
  88   gcc_checking_assert (TREE_CODE (TREE_TYPE (expr)) != VOID_TYPE);
  89
  90   if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr)))
  91     return fold_build1_loc (input_location, NOP_EXPR, type, expr);
  92
  93   code = TREE_CODE (type);
  94   if (code == VOID_TYPE)
  95     return fold_build1_loc (input_location, CONVERT_EXPR, type, e);
  96   if (code == BOOLEAN_TYPE)
  97     return fold_build1_loc (input_location, NOP_EXPR, type,
  98                             truthvalue_conversion (e));
  99   if (code == INTEGER_TYPE)
 100     return fold (convert_to_integer (type, e));
 101   if (code == POINTER_TYPE || code == REFERENCE_TYPE)
 102     return fold (convert_to_pointer (type, e));
 103   if (code == REAL_TYPE)
 104     return fold (convert_to_real (type, e));
 105   if (code == COMPLEX_TYPE)
 106     return fold (convert_to_complex (type, e));
 107   if (code == VECTOR_TYPE)
 108     return fold (convert_to_vector (type, e));
 109
 110   gcc_unreachable ();
 111 }
 112