gcc/fortran/convert.c

   1 /* Data type conversion
   2    Copyright (C) 1987-2017 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 "fold-const.h"
  30 #include "convert.h"
  31
  32 #include "gfortran.h"
  33 #include "trans.h"
  34 #include "trans-types.h"
  35
  36 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
  37    or validate its data type for a GIMPLE `if' or `while' statement.
  38
  39    The resulting type should always be `logical_type_node'.  */
  40
  41 static tree
  42 truthvalue_conversion (tree expr)
  43 {
  44   switch (TREE_CODE (TREE_TYPE (expr)))
  45     {
  46     case BOOLEAN_TYPE:
  47       if (TREE_TYPE (expr) == logical_type_node)
  48         return expr;
  49       else if (COMPARISON_CLASS_P (expr))
  50         {
  51           TREE_TYPE (expr) = logical_type_node;
  52           return expr;
  53         }
  54       else if (TREE_CODE (expr) == NOP_EXPR)
  55         return fold_build1_loc (input_location, NOP_EXPR,
  56                                 logical_type_node,
  57                                 TREE_OPERAND (expr, 0));
  58       else
  59         return fold_build1_loc (input_location, NOP_EXPR,
  60                                 logical_type_node,
  61                                 expr);
  62
  63     case INTEGER_TYPE:
  64       if (TREE_CODE (expr) == INTEGER_CST)
  65         return integer_zerop (expr) ? logical_false_node
  66           : logical_true_node;
  67       else
  68         return fold_build2_loc (input_location, NE_EXPR,
  69                                 logical_type_node,
  70                                 expr, build_int_cst (TREE_TYPE (expr), 0));
  71
  72     default:
  73       gcc_unreachable ();
  74     }
  75 }
  76
  77 /* Create an expression whose value is that of EXPR,
  78    converted to type TYPE.  The TREE_TYPE of the value
  79    is always TYPE.  This function implements all reasonable
  80    conversions; callers should filter out those that are
  81    not permitted by the language being compiled.  */
  82
  83 tree
  84 convert (tree type, tree expr)
  85 {
  86   tree e = expr;
  87   enum tree_code code;
  88
  89   if (type == TREE_TYPE (expr))
  90     return expr;
  91
  92   if (TREE_CODE (type) == ERROR_MARK
  93       || TREE_CODE (expr) == ERROR_MARK
  94       || TREE_CODE (TREE_TYPE (expr)) == ERROR_MARK)
  95     return expr;
  96
  97   gcc_checking_assert (TREE_CODE (TREE_TYPE (expr)) != VOID_TYPE);
  98
  99   if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr)))
 100     return fold_build1_loc (input_location, NOP_EXPR, type, expr);
 101
 102   code = TREE_CODE (type);
 103   if (code == VOID_TYPE)
 104     return fold_build1_loc (input_location, CONVERT_EXPR, type, e);
 105   if (code == BOOLEAN_TYPE)
 106     return fold_build1_loc (input_location, NOP_EXPR, type,
 107                             truthvalue_conversion (e));
 108   if (code == INTEGER_TYPE)
 109     return fold (convert_to_integer (type, e));
 110   if (code == POINTER_TYPE || code == REFERENCE_TYPE)
 111     return fold (convert_to_pointer (type, e));
 112   if (code == REAL_TYPE)
 113     return fold (convert_to_real (type, e));
 114   if (code == COMPLEX_TYPE)
 115     return fold (convert_to_complex (type, e));
 116   if (code == VECTOR_TYPE)
 117     return fold (convert_to_vector (type, e));
 118
 119   gcc_unreachable ();
 120 }
 121