scop_plus.cc

   1 /*
   2  * Copyright 2011 Leiden University. All rights reserved.
   3  * Copyright 2013 Ecole Normale Superieure. All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  *    1. Redistributions of source code must retain the above copyright
  10  *       notice, this list of conditions and the following disclaimer.
  11  *
  12  *    2. Redistributions in binary form must reproduce the above
  13  *       copyright notice, this list of conditions and the following
  14  *       disclaimer in the documentation and/or other materials provided
  15  *       with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY LEIDEN UNIVERSITY ''AS IS'' AND ANY
  18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  20  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL LEIDEN UNIVERSITY OR
  21  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  22  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  23  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
  24  * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  27  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  *
  29  * The views and conclusions contained in the software and documentation
  30  * are those of the authors and should not be interpreted as
  31  * representing official policies, either expressed or implied, of
  32  * Leiden University.
  33  */
  34
  35 #include <set>
  36 #include <vector>
  37
  38 #include "clang.h"
  39 #include "expr.h"
  40 #include "id.h"
  41 #include "scop_plus.h"
  42 #include "tree.h"
  43
  44 using namespace std;
  45 using namespace clang;
  46
  47 /* Add the sequence of nested arrays of structures "ancestors"
  48  * to "arrays".  The final element in the sequence may be a leaf
  49  * and may therefore refer to a primitive type rather than a record type.
  50  *
  51  * Futhermore, if the innermost array in the sequence is an array of structures
  52  * then recursively call collect_sub_arrays for all subfields of this
  53  * structure.
  54  */
  55 static void collect_sub_arrays(ValueDecl *decl, vector<ValueDecl *> ancestors,
  56         array_desc_set &arrays)
  57 {
  58         QualType type = decl->getType();
  59         RecordDecl *record;
  60         RecordDecl::field_iterator it;
  61
  62         arrays.insert(ancestors);
  63
  64         type = pet_clang_base_type(type);
  65
  66         if (!type->isRecordType())
  67                 return;
  68
  69         record = pet_clang_record_decl(type);
  70
  71         for (it = record->field_begin(); it != record->field_end(); ++it) {
  72                 FieldDecl *field = *it;
  73                 bool anonymous = field->isAnonymousStructOrUnion();
  74
  75                 if (!anonymous)
  76                         ancestors.push_back(field);
  77                 collect_sub_arrays(field, ancestors, arrays);
  78                 if (!anonymous)
  79                         ancestors.pop_back();
  80         }
  81 }
  82
  83 /* Extract one or more sequences of declarations from the access expression
  84  * "expr" and them to "arrays".
  85  *
  86  * If "expr" represents an array access, then the extracted sequence
  87  * contains a single element corresponding to the array declaration.
  88  * Otherwise, if "expr" represents a member access, then the extracted
  89  * sequences contain an element for the outer array of structures and
  90  * for each nested array or scalar.  One such sequence is (recursively)
  91  * added for each member of the accessed outer array.
  92  *
  93  * If the array being accessed has a NULL ValueDecl, then it
  94  * is a virtual scalar.  We don't need to collect such scalars
  95  * because they are added to the scop of the statement writing
  96  * to the scalar.
  97  */
  98 static void access_collect_arrays(__isl_keep pet_expr *expr,
  99         array_desc_set &arrays)
 100 {
 101         isl_id *id;
 102         isl_space *space;
 103         ValueDecl *decl;
 104         vector<ValueDecl *> ancestors;
 105
 106         if (pet_expr_is_affine(expr))
 107                 return;
 108
 109         space = pet_expr_access_get_data_space(expr);
 110
 111         while (space && isl_space_is_wrapping(space))
 112                 space = isl_space_domain(isl_space_unwrap(space));
 113
 114         id = isl_space_get_tuple_id(space, isl_dim_set);
 115         isl_space_free(space);
 116         if (!id)
 117                 return;
 118
 119         decl = pet_id_get_decl(id);
 120         isl_id_free(id);
 121
 122         if (!decl)
 123                 return;
 124
 125         ancestors.push_back(decl);
 126         collect_sub_arrays(decl, ancestors, arrays);
 127 }
 128
 129 static void expr_collect_arrays(__isl_keep pet_expr *expr,
 130         array_desc_set &arrays)
 131 {
 132         int n;
 133
 134         if (!expr)
 135                 return;
 136
 137         n = pet_expr_get_n_arg(expr);
 138         for (int i = 0; i < n; ++i) {
 139                 pet_expr *arg;
 140
 141                 arg = pet_expr_get_arg(expr, i);
 142                 expr_collect_arrays(arg, arrays);
 143                 pet_expr_free(arg);
 144         }
 145
 146         if (pet_expr_get_type(expr) == pet_expr_access)
 147                 access_collect_arrays(expr, arrays);
 148 }
 149
 150 /* Wrapper around access_collect_arrays for use as a callback function
 151  * to pet_tree_foreach_access_expr.
 152  */
 153 static int access_collect_wrap(__isl_keep pet_expr *expr, void *user)
 154 {
 155         array_desc_set *arrays = (array_desc_set *) user;
 156
 157         access_collect_arrays(expr, *arrays);
 158
 159         return 0;
 160 }
 161
 162 static void stmt_collect_arrays(struct pet_stmt *stmt,
 163         array_desc_set &arrays)
 164 {
 165         if (!stmt)
 166                 return;
 167
 168         for (int i = 0; i < stmt->n_arg; ++i)
 169                 expr_collect_arrays(stmt->args[i], arrays);
 170
 171         pet_tree_foreach_access_expr(stmt->body, &access_collect_wrap, &arrays);
 172 }
 173
 174 /* Collect the set of all accessed arrays (or scalars) in "scop",
 175  * except those that already appear in scop->arrays,
 176  * and put them in "arrays".
 177  *
 178  * Each accessed array is represented by a sequence of nested
 179  * array declarations, one for the outer array of structures
 180  * and one for each member access.
 181  *
 182  * The arrays that already appear in scop->arrays are assumed
 183  * to be simple arrays, represented by a sequence of a single element.
 184  */
 185 void pet_scop_collect_arrays(struct pet_scop *scop,
 186         array_desc_set &arrays)
 187 {
 188         if (!scop)
 189                 return;
 190
 191         for (int i = 0; i < scop->n_stmt; ++i)
 192                 stmt_collect_arrays(scop->stmts[i], arrays);
 193
 194         for (int i = 0; i < scop->n_array; ++i) {
 195                 ValueDecl *decl;
 196                 vector<ValueDecl *> ancestors;
 197
 198                 isl_id *id = isl_set_get_tuple_id(scop->arrays[i]->extent);
 199                 decl = pet_id_get_decl(id);
 200                 isl_id_free(id);
 201
 202                 if (!decl)
 203                         continue;
 204
 205                 ancestors.push_back(decl);
 206
 207                 arrays.erase(ancestors);
 208         }
 209 }