gcc/tree-dfa.h

   1 /* Header file for tree data flow functions.
   2    Copyright (C) 2013-2014 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 #ifndef GCC_TREE_DFA_H
  21 #define GCC_TREE_DFA_H
  22
  23 extern void renumber_gimple_stmt_uids (void);
  24 extern void renumber_gimple_stmt_uids_in_blocks (basic_block *, int);
  25 extern void dump_variable (FILE *, tree);
  26 extern void debug_variable (tree);
  27 extern void dump_dfa_stats (FILE *);
  28 extern void debug_dfa_stats (void);
  29 extern tree ssa_default_def (struct function *, tree);
  30 extern void set_ssa_default_def (struct function *, tree, tree);
  31 extern tree get_or_create_ssa_default_def (struct function *, tree);
  32 extern tree get_ref_base_and_extent (tree, HOST_WIDE_INT *,
  33                                      HOST_WIDE_INT *, HOST_WIDE_INT *);
  34 extern tree get_addr_base_and_unit_offset (tree, HOST_WIDE_INT *);
  35 extern bool stmt_references_abnormal_ssa_name (gimple);
  36 extern void dump_enumerated_decls (FILE *, int);
  37
  38 /* Returns the base object and a constant BITS_PER_UNIT offset in *POFFSET that
  39    denotes the starting address of the memory access EXP.
  40    Returns NULL_TREE if the offset is not constant or any component
  41    is not BITS_PER_UNIT-aligned.
  42    VALUEIZE if non-NULL is used to valueize SSA names.  It should return
  43    its argument or a constant if the argument is known to be constant.  */
  44 /* ??? This is a static inline here to avoid the overhead of the indirect calls
  45    to VALUEIZE.  But is this overhead really that significant?  And should we
  46    perhaps just rely on WHOPR to specialize the function?  */
  47
  48 static inline tree
  49 get_addr_base_and_unit_offset_1 (tree exp, HOST_WIDE_INT *poffset,
  50                                  tree (*valueize) (tree))
  51 {
  52   HOST_WIDE_INT byte_offset = 0;
  53
  54   /* Compute cumulative byte-offset for nested component-refs and array-refs,
  55      and find the ultimate containing object.  */
  56   while (1)
  57     {
  58       switch (TREE_CODE (exp))
  59         {
  60         case BIT_FIELD_REF:
  61           {
  62             HOST_WIDE_INT this_off = TREE_INT_CST_LOW (TREE_OPERAND (exp, 2));
  63             if (this_off % BITS_PER_UNIT)
  64               return NULL_TREE;
  65             byte_offset += this_off / BITS_PER_UNIT;
  66           }
  67           break;
  68
  69         case COMPONENT_REF:
  70           {
  71             tree field = TREE_OPERAND (exp, 1);
  72             tree this_offset = component_ref_field_offset (exp);
  73             HOST_WIDE_INT hthis_offset;
  74
  75             if (!this_offset
  76                 || TREE_CODE (this_offset) != INTEGER_CST
  77                 || (TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (field))
  78                     % BITS_PER_UNIT))
  79               return NULL_TREE;
  80
  81             hthis_offset = TREE_INT_CST_LOW (this_offset);
  82             hthis_offset += (TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (field))
  83                              / BITS_PER_UNIT);
  84             byte_offset += hthis_offset;
  85           }
  86           break;
  87
  88         case ARRAY_REF:
  89         case ARRAY_RANGE_REF:
  90           {
  91             tree index = TREE_OPERAND (exp, 1);
  92             tree low_bound, unit_size;
  93
  94             if (valueize
  95                 && TREE_CODE (index) == SSA_NAME)
  96               index = (*valueize) (index);
  97
  98             /* If the resulting bit-offset is constant, track it.  */
  99             if (TREE_CODE (index) == INTEGER_CST
 100                 && (low_bound = array_ref_low_bound (exp),
 101                     TREE_CODE (low_bound) == INTEGER_CST)
 102                 && (unit_size = array_ref_element_size (exp),
 103                     TREE_CODE (unit_size) == INTEGER_CST))
 104               {
 105                 double_int doffset
 106                   = (TREE_INT_CST (index) - TREE_INT_CST (low_bound))
 107                     .sext (TYPE_PRECISION (TREE_TYPE (index)));
 108                 doffset *= tree_to_double_int (unit_size);
 109                 byte_offset += doffset.to_shwi ();
 110               }
 111             else
 112               return NULL_TREE;
 113           }
 114           break;
 115
 116         case REALPART_EXPR:
 117           break;
 118
 119         case IMAGPART_EXPR:
 120           byte_offset += TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (exp)));
 121           break;
 122
 123         case VIEW_CONVERT_EXPR:
 124           break;
 125
 126         case MEM_REF:
 127           {
 128             tree base = TREE_OPERAND (exp, 0);
 129             if (valueize
 130                 && TREE_CODE (base) == SSA_NAME)
 131               base = (*valueize) (base);
 132
 133             /* Hand back the decl for MEM[&decl, off].  */
 134             if (TREE_CODE (base) == ADDR_EXPR)
 135               {
 136                 if (!integer_zerop (TREE_OPERAND (exp, 1)))
 137                   {
 138                     double_int off = mem_ref_offset (exp);
 139                     gcc_assert (off.high == -1 || off.high == 0);
 140                     byte_offset += off.to_shwi ();
 141                   }
 142                 exp = TREE_OPERAND (base, 0);
 143               }
 144             goto done;
 145           }
 146
 147         case TARGET_MEM_REF:
 148           {
 149             tree base = TREE_OPERAND (exp, 0);
 150             if (valueize
 151                 && TREE_CODE (base) == SSA_NAME)
 152               base = (*valueize) (base);
 153
 154             /* Hand back the decl for MEM[&decl, off].  */
 155             if (TREE_CODE (base) == ADDR_EXPR)
 156               {
 157                 if (TMR_INDEX (exp) || TMR_INDEX2 (exp))
 158                   return NULL_TREE;
 159                 if (!integer_zerop (TMR_OFFSET (exp)))
 160                   {
 161                     double_int off = mem_ref_offset (exp);
 162                     gcc_assert (off.high == -1 || off.high == 0);
 163                     byte_offset += off.to_shwi ();
 164                   }
 165                 exp = TREE_OPERAND (base, 0);
 166               }
 167             goto done;
 168           }
 169
 170         default:
 171           goto done;
 172         }
 173
 174       exp = TREE_OPERAND (exp, 0);
 175     }
 176 done:
 177
 178   *poffset = byte_offset;
 179   return exp;
 180 }
 181
 182
 183
 184 #endif /* GCC_TREE_DFA_H */