gcc/c-family/c-cilkplus.c

   1 /* This file contains routines to construct and validate Cilk Plus
   2    constructs within the C and C++ front ends.
   3
   4    Copyright (C) 2013  Free Software Foundation, Inc.
   5    Contributed by Aldy Hernandez <aldyh@redhat.com>.
   6
   7 This file is part of GCC.
   8
   9 GCC is free software; you can redistribute it and/or modify it
  10 under the terms of the GNU General Public License as published by
  11 the Free Software Foundation; either version 3, or (at your option)
  12 any later version.
  13
  14 GCC is distributed in the hope that it will be useful, but
  15 WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17 General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GCC; see the file COPYING3.  If not see
  21 <http://www.gnu.org/licenses/>.  */
  22
  23 #include "config.h"
  24 #include "system.h"
  25 #include "coretypes.h"
  26 #include "tree.h"
  27 #include "c-common.h"
  28
  29 /* Validate the body of a _Cilk_for construct or a <#pragma simd> for
  30    loop.
  31
  32    Returns true if there were no errors, false otherwise.  */
  33
  34 bool
  35 c_check_cilk_loop (location_t loc, tree decl)
  36 {
  37   if (TREE_THIS_VOLATILE (decl))
  38     {
  39       error_at (loc, "iteration variable cannot be volatile");
  40       return false;
  41     }
  42   return true;
  43 }
  44
  45 /* Validate and emit code for <#pragma simd> clauses.  */
  46
  47 tree
  48 c_finish_cilk_clauses (tree clauses)
  49 {
  50   for (tree c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
  51     {
  52       tree prev = clauses;
  53
  54       /* If a variable appears in a linear clause it cannot appear in
  55          any other OMP clause.  */
  56       if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LINEAR)
  57         for (tree c2 = clauses; c2; c2 = OMP_CLAUSE_CHAIN (c2))
  58           {
  59             if (c == c2)
  60               continue;
  61             enum omp_clause_code code = OMP_CLAUSE_CODE (c2);
  62
  63             switch (code)
  64               {
  65               case OMP_CLAUSE_LINEAR:
  66               case OMP_CLAUSE_PRIVATE:
  67               case OMP_CLAUSE_FIRSTPRIVATE:
  68               case OMP_CLAUSE_LASTPRIVATE:
  69               case OMP_CLAUSE_REDUCTION:
  70                 break;
  71
  72               case OMP_CLAUSE_SAFELEN:
  73                 goto next;
  74
  75               default:
  76                 gcc_unreachable ();
  77               }
  78
  79             if (OMP_CLAUSE_DECL (c) == OMP_CLAUSE_DECL (c2))
  80               {
  81                 error_at (OMP_CLAUSE_LOCATION (c2),
  82                           "variable appears in more than one clause");
  83                 inform (OMP_CLAUSE_LOCATION (c),
  84                         "other clause defined here");
  85                 // Remove problematic clauses.
  86                 OMP_CLAUSE_CHAIN (prev) = OMP_CLAUSE_CHAIN (c2);
  87               }
  88           next:
  89             prev = c2;
  90           }
  91     }
  92   return clauses;
  93 }