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