diff options
Diffstat (limited to 'gcc/tree-ssa-structalias.c')
| -rw-r--r-- | gcc/tree-ssa-structalias.c | 53 |
1 files changed, 47 insertions, 6 deletions
diff --git a/gcc/tree-ssa-structalias.c b/gcc/tree-ssa-structalias.c index 923bdb7..5f323ce 100644 --- a/gcc/tree-ssa-structalias.c +++ b/gcc/tree-ssa-structalias.c @@ -4032,7 +4032,8 @@ intra_create_variable_infos (void) { tree t; - /* For each incoming argument arg, ARG = &ANYTHING */ + /* For each incoming argument arg, ARG = &ANYTHING or a dummy variable if + flag_argument_noalias > 1. */ for (t = DECL_ARGUMENTS (current_function_decl); t; t = TREE_CHAIN (t)) { struct constraint_expr lhs; @@ -4041,11 +4042,43 @@ intra_create_variable_infos (void) lhs.offset = 0; lhs.type = SCALAR; lhs.var = create_variable_info_for (t, alias_get_name (t)); - - for (p = get_varinfo (lhs.var); p; p = p->next) - make_constraint_to_anything (p); - } + /* With flag_argument_noalias greater than one means that the incomming + argument cannot alias anything except for itself so create a HEAP + variable. */ + if (POINTER_TYPE_P (TREE_TYPE (t)) + && flag_argument_noalias > 1) + { + varinfo_t vi; + struct constraint_expr rhs; + tree heapvar = heapvar_lookup (t); + unsigned int id; + if (heapvar == NULL_TREE) + { + heapvar = create_tmp_var_raw (TREE_TYPE (TREE_TYPE (t)), "PARM_NOALIAS"); + DECL_EXTERNAL (heapvar) = 1; + add_referenced_tmp_var (heapvar); + heapvar_insert (t, heapvar); + } + id = create_variable_info_for (heapvar, + alias_get_name (heapvar)); + vi = get_varinfo (id); + vi->is_artificial_var = 1; + vi->is_heap_var = 1; + rhs.var = id; + rhs.type = ADDRESSOF; + rhs.offset = 0; + for (p = get_varinfo (lhs.var); p; p = p->next) + { + struct constraint_expr temp = lhs; + temp.var = p->id; + process_constraint (new_constraint (temp, rhs)); + } + } + else + for (p = get_varinfo (lhs.var); p; p = p->next) + make_constraint_to_anything (p); + } } /* Set bits in INTO corresponding to the variable uids in solution set @@ -4105,11 +4138,19 @@ bool find_what_p_points_to (tree p) { unsigned int id = 0; + tree lookup_p = p; if (!have_alias_info) return false; - if (lookup_id_for_tree (p, &id)) + /* For parameters, get at the points-to set for the actual parm + decl. */ + if (TREE_CODE (p) == SSA_NAME + && TREE_CODE (SSA_NAME_VAR (p)) == PARM_DECL + && default_def (SSA_NAME_VAR (p)) == p) + lookup_p = SSA_NAME_VAR (p); + + if (lookup_id_for_tree (lookup_p, &id)) { varinfo_t vi = get_varinfo (id); |