Hi!
This removes some dead and unreachable code in c_common_get_alias_set:
Because cc1 was recently changed to be only called with one file at a
time, the code after "if (num_in_fnames == 1) return -1;" is no longer
reachable, and can thus be removed.
Bootstrapped and reg-tested on x86_64-pc-linux-gnu.
Is it OK for trunk?
Thanks
Bernd.
2017-04-21 Bernd Edlinger <bernd.edlin...@hotmail.de>
* c-common.c (c_type_hasher): Remove.
(type_hash_table): Remove.
(c_common_get_alias_set): Remove unreachable code.
Index: gcc/c-family/c-common.c
===================================================================
--- gcc/c-family/c-common.c (Revision 247029)
+++ gcc/c-family/c-common.c (Arbeitskopie)
@@ -3508,67 +3508,6 @@ c_apply_type_quals_to_decl (int type_quals, tree d
}
}
-struct c_type_hasher : ggc_ptr_hash<tree_node>
-{
- static hashval_t hash (tree);
- static bool equal (tree, tree);
-};
-
-/* Hash function for the problem of multiple type definitions in
- different files. This must hash all types that will compare
- equal via comptypes to the same value. In practice it hashes
- on some of the simple stuff and leaves the details to comptypes. */
-
-hashval_t
-c_type_hasher::hash (tree t)
-{
- int n_elements;
- int shift, size;
- tree t2;
- switch (TREE_CODE (t))
- {
- /* For pointers, hash on pointee type plus some swizzling. */
- case POINTER_TYPE:
- return hash (TREE_TYPE (t)) ^ 0x3003003;
- /* Hash on number of elements and total size. */
- case ENUMERAL_TYPE:
- shift = 3;
- t2 = TYPE_VALUES (t);
- break;
- case RECORD_TYPE:
- shift = 0;
- t2 = TYPE_FIELDS (t);
- break;
- case QUAL_UNION_TYPE:
- shift = 1;
- t2 = TYPE_FIELDS (t);
- break;
- case UNION_TYPE:
- shift = 2;
- t2 = TYPE_FIELDS (t);
- break;
- default:
- gcc_unreachable ();
- }
- /* FIXME: We want to use a DECL_CHAIN iteration method here, but
- TYPE_VALUES of ENUMERAL_TYPEs is stored as a TREE_LIST. */
- n_elements = list_length (t2);
- /* We might have a VLA here. */
- if (TREE_CODE (TYPE_SIZE (t)) != INTEGER_CST)
- size = 0;
- else
- size = TREE_INT_CST_LOW (TYPE_SIZE (t));
- return ((size << 24) | (n_elements << shift));
-}
-
-bool
-c_type_hasher::equal (tree t1, tree t2)
-{
- return lang_hooks.types_compatible_p (t1, t2);
-}
-
-static GTY(()) hash_table<c_type_hasher> *type_hash_table;
-
/* Return the typed-based alias set for T, which may be an expression
or a type. Return -1 if we don't do anything special. */
@@ -3607,60 +3546,6 @@ c_common_get_alias_set (tree t)
return get_alias_set (t1);
}
- /* Handle the case of multiple type nodes referring to "the same" type,
- which occurs with IMA. These share an alias set. FIXME: Currently only
- C90 is handled. (In C99 type compatibility is not transitive, which
- complicates things mightily. The alias set splay trees can theoretically
- represent this, but insertion is tricky when you consider all the
- different orders things might arrive in.) */
-
- if (c_language != clk_c || flag_isoc99)
- return -1;
-
- /* Save time if there's only one input file. */
- if (num_in_fnames == 1)
- return -1;
-
- /* Pointers need special handling if they point to any type that
- needs special handling (below). */
- if (TREE_CODE (t) == POINTER_TYPE)
- {
- tree t2;
- /* Find bottom type under any nested POINTERs. */
- for (t2 = TREE_TYPE (t);
- TREE_CODE (t2) == POINTER_TYPE;
- t2 = TREE_TYPE (t2))
- ;
- if (!RECORD_OR_UNION_TYPE_P (t2)
- && TREE_CODE (t2) != ENUMERAL_TYPE)
- return -1;
- if (TYPE_SIZE (t2) == 0)
- return -1;
- }
- /* These are the only cases that need special handling. */
- if (!RECORD_OR_UNION_TYPE_P (t)
- && TREE_CODE (t) != ENUMERAL_TYPE
- && TREE_CODE (t) != POINTER_TYPE)
- return -1;
- /* Undefined? */
- if (TYPE_SIZE (t) == 0)
- return -1;
-
- /* Look up t in hash table. Only one of the compatible types within each
- alias set is recorded in the table. */
- if (!type_hash_table)
- type_hash_table = hash_table<c_type_hasher>::create_ggc (1021);
- tree *slot = type_hash_table->find_slot (t, INSERT);
- if (*slot != NULL)
- {
- TYPE_ALIAS_SET (t) = TYPE_ALIAS_SET ((tree)*slot);
- return TYPE_ALIAS_SET ((tree)*slot);
- }
- else
- /* Our caller will assign and record (in t) a new alias set; all we need
- to do is remember t in the hash table. */
- *slot = t;
-
return -1;
}
