array.c

   1 /*
   2  * Copyright 2011      Leiden University. All rights reserved.
   3  * Copyright 2012-2014 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 <string.h>
  36
  37 #include "array.h"
  38
  39 /* Given a partial index expression "base" and an extra index "index",
  40  * append the extra index to "base" and return the result.
  41  * Additionally, add the constraints that the extra index is non-negative.
  42  * If "index" represent a member access, i.e., if its range is a wrapped
  43  * relation, then we recursively extend the range of this nested relation.
  44  *
  45  * The inputs "base" and "index", as well as the result, all have
  46  * an anonymous zero-dimensional domain.
  47  */
  48 __isl_give isl_multi_pw_aff *pet_array_subscript(
  49         __isl_take isl_multi_pw_aff *base, __isl_take isl_pw_aff *index)
  50 {
  51         isl_id *id;
  52         isl_set *domain;
  53         isl_multi_pw_aff *access;
  54         int member_access;
  55
  56         member_access = isl_multi_pw_aff_range_is_wrapping(base);
  57         if (member_access < 0)
  58                 goto error;
  59         if (member_access) {
  60                 isl_multi_pw_aff *domain, *range;
  61                 isl_id *id;
  62
  63                 id = isl_multi_pw_aff_get_tuple_id(base, isl_dim_out);
  64                 domain = isl_multi_pw_aff_copy(base);
  65                 domain = isl_multi_pw_aff_range_factor_domain(domain);
  66                 range = isl_multi_pw_aff_range_factor_range(base);
  67                 range = pet_array_subscript(range, index);
  68                 access = isl_multi_pw_aff_range_product(domain, range);
  69                 access = isl_multi_pw_aff_set_tuple_id(access, isl_dim_out, id);
  70                 return access;
  71         }
  72
  73         id = isl_multi_pw_aff_get_tuple_id(base, isl_dim_set);
  74         domain = isl_pw_aff_nonneg_set(isl_pw_aff_copy(index));
  75         index = isl_pw_aff_intersect_domain(index, domain);
  76         access = isl_multi_pw_aff_from_pw_aff(index);
  77         access = isl_multi_pw_aff_flat_range_product(base, access);
  78         access = isl_multi_pw_aff_set_tuple_id(access, isl_dim_set, id);
  79
  80         return access;
  81 error:
  82         isl_multi_pw_aff_free(base);
  83         isl_pw_aff_free(index);
  84         return NULL;
  85 }
  86
  87 /* Construct a name for a member access by concatenating the name
  88  * of the array of structures and the member, separated by an underscore.
  89  *
  90  * The caller is responsible for freeing the result.
  91  */
  92 char *pet_array_member_access_name(isl_ctx *ctx, const char *base,
  93         const char *field)
  94 {
  95         int len;
  96         char *name;
  97
  98         len = strlen(base) + 1 + strlen(field);
  99         name = isl_alloc_array(ctx, char, len + 1);
 100         if (!name)
 101                 return NULL;
 102         snprintf(name, len + 1, "%s_%s", base, field);
 103
 104         return name;
 105 }
 106
 107 /* Given an index expression "base" for an element of an array of structures
 108  * and an expression "field" for the field member being accessed, construct
 109  * an index expression for an access to that member of the given structure.
 110  * In particular, take the range product of "base" and "field" and
 111  * attach a name to the result.
 112  */
 113 __isl_give isl_multi_pw_aff *pet_array_member(
 114         __isl_take isl_multi_pw_aff *base, __isl_take isl_multi_pw_aff *field)
 115 {
 116         isl_ctx *ctx;
 117         isl_multi_pw_aff *access;
 118         const char *base_name, *field_name;
 119         char *name;
 120
 121         ctx = isl_multi_pw_aff_get_ctx(base);
 122
 123         base_name = isl_multi_pw_aff_get_tuple_name(base, isl_dim_out);
 124         field_name = isl_multi_pw_aff_get_tuple_name(field, isl_dim_out);
 125         name = pet_array_member_access_name(ctx, base_name, field_name);
 126
 127         access = isl_multi_pw_aff_range_product(base, field);
 128
 129         access = isl_multi_pw_aff_set_tuple_name(access, isl_dim_out, name);
 130         free(name);
 131
 132         return access;
 133 }