Hello!
This patch includes part of [1] that trivially renumbers a return
value, so the follow-up part of a patch that fixes aliasing issues can
be much smaller and more focused.
2016-01-08 Uros Bizjak <ubiz...@gmail.com>
* symtab.c (symtab_node::equal_address_to): Return -1 instead of 2
if we can't determine address equivalence.
* alias.c (compare_base_decl): Update for changed return value of
symtab_node::equal_address_to.
Bootstrapped and regression tested on alpha-linux-gnu.
OK for mainline?
[1] https://gcc.gnu.org/ml/gcc-patches/2015-12/msg02198.html
Uros.
Index: alias.c
===================================================================
--- alias.c (revision 232142)
+++ alias.c (working copy)
@@ -2053,8 +2053,6 @@ compare_base_decls (tree base1, tree base2)
return 0;
ret = node1->equal_address_to (node2, true);
- if (ret == 2)
- return -1;
return ret;
}
Index: symtab.c
===================================================================
--- symtab.c (revision 232142)
+++ symtab.c (working copy)
@@ -1877,7 +1877,7 @@ symtab_node::nonzero_address ()
/* Return 0 if symbol is known to have different address than S2,
Return 1 if symbol is known to have same address as S2,
- return 2 otherwise.
+ return -1 otherwise.
If MEMORY_ACCESSED is true, assume that both memory pointer to THIS
and S2 is going to be accessed. This eliminates the situations when
@@ -1941,7 +1941,7 @@ symtab_node::equal_address_to (symtab_node *s2, bo
/* If both symbols may resolve to NULL, we can not really prove them
different. */
if (!memory_accessed && !nonzero_address () && !s2->nonzero_address ())
- return 2;
+ return -1;
/* Except for NULL, functions and variables never overlap. */
if (TREE_CODE (decl) != TREE_CODE (s2->decl))
@@ -1949,7 +1949,7 @@ symtab_node::equal_address_to (symtab_node *s2, bo
/* If one of the symbols is unresolved alias, punt. */
if (rs1->alias || rs2->alias)
- return 2;
+ return -1;
/* If we have a non-interposale definition of at least one of the symbols
and the other symbol is different, we know other unit can not interpose
@@ -1976,7 +1976,7 @@ symtab_node::equal_address_to (symtab_node *s2, bo
We probably should be consistent and use this fact here, too, but for
the moment return false only when we are called from the alias oracle. */
- return memory_accessed && rs1 != rs2 ? 0 : 2;
+ return memory_accessed && rs1 != rs2 ? 0 : -1;
}
/* Worker for call_for_symbol_and_aliases. */
