gcc/cp/cp-cilkplus.c

   1 /* This file is part of the Intel(R) Cilk(TM) Plus support
   2    This file contains routines to handle Cilk Plus specific
   3    routines for the C++ Compiler.
   4    Copyright (C) 2013-2017 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 "cp-tree.h"
  27 #include "tree-iterator.h"
  28 #include "cilk.h"
  29 #include "c-family/c-common.h"
  30
  31 /* Return TRUE if T is a FUNCTION_DECL for a type-conversion operator.  */
  32
  33 static bool
  34 is_conversion_operator_function_decl_p (tree t)
  35 {
  36   if (TREE_CODE (t) != FUNCTION_DECL)
  37     return false;
  38
  39   return DECL_CONV_FN_P (t);
  40 }
  41
  42 /* Recursively traverse EXP to search for a CILK_SPAWN_STMT subtree.
  43    Return the CILK_SPAWN_STMT subtree if found; otherwise, the last subtree
  44    searched.  */
  45
  46 static tree
  47 find_spawn (tree exp)
  48 {
  49   /* Happens with C++ TARGET_EXPR.  */
  50   if (exp == NULL_TREE)
  51     return exp;
  52
  53   if (cilk_ignorable_spawn_rhs_op (exp))
  54     return find_spawn (TREE_OPERAND (exp, 0));
  55
  56   switch (TREE_CODE (exp))
  57     {
  58     case AGGR_INIT_EXPR:
  59       {
  60         /* Check for initialization via a constructor call that represents
  61            implicit conversion.  */
  62         if (AGGR_INIT_VIA_CTOR_P (exp) && aggr_init_expr_nargs (exp) == 2)
  63           return find_spawn (AGGR_INIT_EXPR_ARG (exp, 1));
  64
  65         /* Check for initialization via a call to a type-conversion
  66            operator.  */
  67         tree fn = AGGR_INIT_EXPR_FN (exp);
  68         if (TREE_CODE (fn) == ADDR_EXPR
  69             && is_conversion_operator_function_decl_p (TREE_OPERAND (fn, 0))
  70             && aggr_init_expr_nargs (exp) == 1)
  71           return find_spawn (AGGR_INIT_EXPR_ARG (exp, 0));
  72       }
  73       break;
  74
  75     case CALL_EXPR:
  76       {
  77         /* Check for a call to a type-conversion operator.  */
  78         tree fndecl = TREE_OPERAND (CALL_EXPR_FN (exp), 0);
  79         if (is_conversion_operator_function_decl_p (fndecl)
  80             && call_expr_nargs (exp) == 1)
  81           return find_spawn (CALL_EXPR_ARG (exp, 0));
  82       }
  83       break;
  84
  85     case TARGET_EXPR:
  86       return find_spawn (TARGET_EXPR_INITIAL (exp));
  87
  88     case CLEANUP_POINT_EXPR:
  89     case COMPOUND_EXPR:
  90     case EXPR_STMT:
  91       return find_spawn (TREE_OPERAND (exp, 0));
  92
  93     default:
  94       break;
  95     }
  96
  97     return exp;
  98 }
  99
 100 /* Return true if *EXP0 is a recognized form of spawn.  Recognized forms
 101    are, after conversion to void, a call expression at outer level or an
 102    assignment at outer level with the right hand side being a spawned call.
 103    In addition to this, it also unwraps the CILK_SPAWN_STMT cover from the
 104    CALL_EXPR that is being spawned.
 105
 106    Note that `=' in C++ may turn into a CALL_EXPR rather than a
 107    MODIFY_EXPR.  */
 108
 109 bool
 110 cilk_cp_detect_spawn_and_unwrap (tree *exp0)
 111 {
 112   tree exp = *exp0;
 113
 114   if (!TREE_SIDE_EFFECTS (exp))
 115     return false;
 116
 117   /* Strip off any conversion to void.  It does not affect whether spawn
 118      is supported here.  */
 119   if (TREE_CODE (exp) == CONVERT_EXPR && VOID_TYPE_P (TREE_TYPE (exp)))
 120     exp = TREE_OPERAND (exp, 0);
 121
 122   if (TREE_CODE (exp) == MODIFY_EXPR || TREE_CODE (exp) == INIT_EXPR)
 123     exp = TREE_OPERAND (exp, 1);
 124
 125   exp = find_spawn (exp);
 126   if (exp == NULL_TREE)
 127     return false;
 128
 129   /* Now we should have a CALL_EXPR with a CILK_SPAWN_STMT wrapper around
 130      it, or return false.  */
 131   return cilk_recognize_spawn (exp, exp0);
 132 }
 133
 134 /* Callback for cp_walk_tree to validate the body of a pragma simd loop
 135    or _cilk_for loop.
 136
 137    This function is passed in as a function pointer to walk_tree.  *TP is
 138    the current tree pointer, *WALK_SUBTREES is set to 0 by this function if
 139    recursing into TP's subtrees is unnecessary. *DATA is a bool variable that
 140    is set to false if an error has occurred.  */
 141
 142 static tree
 143 cpp_validate_cilk_plus_loop_aux (tree *tp, int *walk_subtrees, void *data)
 144 {
 145   bool *valid = (bool *) data;
 146
 147   if (!tp || !*tp)
 148     return NULL_TREE;
 149
 150   location_t loc = EXPR_LOCATION (*tp);
 151   if (TREE_CODE (*tp) == THROW_EXPR)
 152     {
 153       error_at (loc, "throw expressions are not allowed inside loops "
 154                 "marked with pragma simd");
 155       *walk_subtrees = 0;
 156       *valid = false;
 157     }
 158   else if (TREE_CODE (*tp) == TRY_BLOCK)
 159     {
 160       error_at (loc, "try statements are not allowed inside loops marked "
 161                 "with #pragma simd");
 162       *valid = false;
 163       *walk_subtrees = 0;
 164     }
 165   return NULL_TREE;
 166 }
 167
 168
 169 /* Walks through all the subtrees of BODY using walk_tree to make sure
 170    invalid statements/expressions are not found inside BODY.  Returns
 171    false if any invalid statements are found.  */
 172
 173 bool
 174 cpp_validate_cilk_plus_loop (tree body)
 175 {
 176   bool valid = true;
 177   cp_walk_tree (&body, cpp_validate_cilk_plus_loop_aux,
 178                 (void *) &valid, NULL);
 179   return valid;
 180 }
 181
 182 /* Sets the EXCEPTION bit (0x10) in the FRAME.flags field.  */
 183
 184 static tree
 185 set_cilk_except_flag (tree frame)
 186 {
 187   tree flags = cilk_dot (frame, CILK_TI_FRAME_FLAGS, 0);
 188
 189   flags = build2 (MODIFY_EXPR, void_type_node, flags,
 190                   build2 (BIT_IOR_EXPR, TREE_TYPE (flags), flags,
 191                           build_int_cst (TREE_TYPE (flags),
 192                                          CILK_FRAME_EXCEPTING)));
 193   return flags;
 194 }
 195
 196 /* Sets the frame.EXCEPT_DATA field to the head of the exception pointer.  */
 197
 198 static tree
 199 set_cilk_except_data (tree frame)
 200 {
 201   tree except_data = cilk_dot (frame, CILK_TI_FRAME_EXCEPTION, 0);
 202   tree uresume_fn = builtin_decl_implicit (BUILT_IN_EH_POINTER);
 203   tree ret_expr;
 204   uresume_fn  = build_call_expr (uresume_fn, 1,
 205                                  build_int_cst (integer_type_node, 0));
 206   ret_expr = build2 (MODIFY_EXPR, void_type_node, except_data, uresume_fn);
 207   return ret_expr;
 208 }
 209
 210 /* Installs BODY into function FNDECL with appropriate exception handling
 211    code.  WD holds information of wrapper function used to pass into the
 212    outlining function, cilk_outline.  */
 213
 214 void
 215 cilk_install_body_with_frame_cleanup (tree fndecl, tree orig_body, void *wd)
 216 {
 217   tree frame = make_cilk_frame (fndecl);
 218   tree dtor = create_cilk_function_exit (frame, false, false);
 219   add_local_decl (cfun, frame);
 220
 221   cfun->language = ggc_cleared_alloc<language_function> ();
 222
 223   location_t loc = EXPR_LOCATION (orig_body);
 224   tree list = alloc_stmt_list ();
 225   DECL_SAVED_TREE (fndecl) = list;
 226   tree body = alloc_stmt_list ();
 227   cilk_outline (fndecl, &orig_body, (struct wrapper_data *) wd);
 228   append_to_statement_list (orig_body, &body);
 229   if (flag_exceptions)
 230     {
 231       tree except_flag = set_cilk_except_flag (frame);
 232       tree except_data = set_cilk_except_data (frame);
 233       tree catch_list = alloc_stmt_list ();
 234       append_to_statement_list (except_flag, &catch_list);
 235       append_to_statement_list (except_data, &catch_list);
 236       body = create_try_catch_expr (body, catch_list);
 237     }
 238   append_to_statement_list (build_stmt (loc, TRY_FINALLY_EXPR, body, dtor),
 239                             &list);
 240 }