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 "scop_plus.h"
  41 #include "tree.h"
  42
  43 using namespace std;
  44 using namespace clang;
  45
  46 /* And the sequence of nested arrays of structures "ancestors"
  47  * to "arrays".  The final element in the sequence may be a leaf
  48  * and may therefore refer to a primitive type rather than a record type.
  49  *
  50  * Futhermore, if the innermost array in the sequence is an array of structures
  51  * then recursively call collect_sub_arrays for all subfields of this
  52  * structure.
  53  */
  54 static void collect_sub_arrays(ValueDecl *decl, vector<ValueDecl *> ancestors,
  55         array_desc_set &arrays)
  56 {
  57         QualType type = decl->getType();
  58         RecordDecl *record;
  59         RecordDecl::field_iterator it;
  60
  61         arrays.insert(ancestors);
  62
  63         type = pet_clang_base_type(type);
  64
  65         if (!type->isRecordType())
  66                 return;
  67
  68         record = pet_clang_record_decl(type);
  69
  70         for (it = record->field_begin(); it != record->field_end(); ++it) {
  71                 FieldDecl *field = *it;
  72                 bool anonymous = field->isAnonymousStructOrUnion();
  73
  74                 if (!anonymous)
  75                         ancestors.push_back(field);
  76                 collect_sub_arrays(field, ancestors, arrays);
  77                 if (!anonymous)
  78                         ancestors.pop_back();
  79         }
  80 }
  81
  82 /* Extract one or more sequences of declarations from the access expression
  83  * "expr" and them to "arrays".
  84  *
  85  * If "expr" represents an array access, then the extracted sequence
  86  * contains a single element corresponding to the array declaration.
  87  * Otherwise, if "expr" represents a member access, then the extracted
  88  * sequences contain an element for the outer array of structures and
  89  * for each nested array or scalar.  One such sequence is (recursively)
  90  * added for each member of the accessed outer array.
  91  *
  92  * If the array being accessed has a NULL ValueDecl, then it
  93  * is a virtual scalar.  We don't need to collect such scalars
  94  * because they are added to the scop of the statement writing
  95  * to the scalar.
  96  */
  97 static void access_collect_arrays(__isl_keep pet_expr *expr,
  98         array_desc_set &arrays)
  99 {
 100         isl_id *id;
 101         isl_space *space;
 102         ValueDecl *decl;
 103         vector<ValueDecl *> ancestors;
 104
 105         if (pet_expr_is_affine(expr))
 106                 return;
 107
 108         space = pet_expr_access_get_data_space(expr);
 109
 110         while (space && isl_space_is_wrapping(space))
 111                 space = isl_space_domain(isl_space_unwrap(space));
 112
 113         id = isl_space_get_tuple_id(space, isl_dim_set);
 114         isl_space_free(space);
 115         if (!id)
 116                 return;
 117
 118         decl = (ValueDecl *)isl_id_get_user(id);
 119         isl_id_free(id);
 120
 121         if (!decl)
 122                 return;
 123
 124         ancestors.push_back(decl);
 125         collect_sub_arrays(decl, ancestors, arrays);
 126 }
 127
 128 static void expr_collect_arrays(__isl_keep pet_expr *expr,
 129         array_desc_set &arrays)
 130 {
 131         int n;
 132
 133         if (!expr)
 134                 return;
 135
 136         n = pet_expr_get_n_arg(expr);
 137         for (int i = 0; i < n; ++i) {
 138                 pet_expr *arg;
 139
 140                 arg = pet_expr_get_arg(expr, i);
 141                 expr_collect_arrays(arg, arrays);
 142                 pet_expr_free(arg);
 143         }
 144
 145         if (pet_expr_get_type(expr) == pet_expr_access)
 146                 access_collect_arrays(expr, arrays);
 147 }
 148
 149 /* Wrapper around access_collect_arrays for use as a callback function
 150  * to pet_tree_foreach_access_expr.
 151  */
 152 static int access_collect_wrap(__isl_keep pet_expr *expr, void *user)
 153 {
 154         array_desc_set *arrays = (array_desc_set *) user;
 155
 156         access_collect_arrays(expr, *arrays);
 157
 158         return 0;
 159 }
 160
 161 static void stmt_collect_arrays(struct pet_stmt *stmt,
 162         array_desc_set &arrays)
 163 {
 164         if (!stmt)
 165                 return;
 166
 167         for (int i = 0; i < stmt->n_arg; ++i)
 168                 expr_collect_arrays(stmt->args[i], arrays);
 169
 170         pet_tree_foreach_access_expr(stmt->body, &access_collect_wrap, &arrays);
 171 }
 172
 173 /* Collect the set of all accessed arrays (or scalars) in "scop",
 174  * except those that already appear in scop->arrays,
 175  * and put them in "arrays".
 176  *
 177  * Each accessed array is represented by a sequence of nested
 178  * array declarations, one for the outer array of structures
 179  * and one for each member access.
 180  *
 181  * The arrays that already appear in scop->arrays are assumed
 182  * to be simple arrays, represented by a sequence of a single element.
 183  */
 184 void pet_scop_collect_arrays(struct pet_scop *scop,
 185         array_desc_set &arrays)
 186 {
 187         if (!scop)
 188                 return;
 189
 190         for (int i = 0; i < scop->n_stmt; ++i)
 191                 stmt_collect_arrays(scop->stmts[i], arrays);
 192
 193         for (int i = 0; i < scop->n_array; ++i) {
 194                 ValueDecl *decl;
 195                 vector<ValueDecl *> ancestors;
 196
 197                 isl_id *id = isl_set_get_tuple_id(scop->arrays[i]->extent);
 198                 decl = (ValueDecl *)isl_id_get_user(id);
 199                 isl_id_free(id);
 200
 201                 if (!decl)
 202                         continue;
 203
 204                 ancestors.push_back(decl);
 205
 206                 arrays.erase(ancestors);
 207         }
 208 }