> So sth like
>
> Index: gcc/lto-streamer-out.c
> ===================================================================
> --- gcc/lto-streamer-out.c (revision 238039)
> +++ gcc/lto-streamer-out.c (working copy)
> @@ -996,7 +996,7 @@ hash_tree (struct streamer_tree_cache_d
> else
> hstate.add_flag (TREE_NO_WARNING (t));
> hstate.add_flag (TREE_NOTHROW (t));
> - hstate.add_flag (TREE_STATIC (t));
> + //hstate.add_flag (TREE_STATIC (t));
> hstate.add_flag (TREE_PROTECTED (t));
> hstate.add_flag (TREE_DEPRECATED (t));
> if (code != TREE_BINFO)
> @@ -1050,7 +1050,7 @@ hash_tree (struct streamer_tree_cache_d
> hstate.add_flag (DECL_ARTIFICIAL (t));
> hstate.add_flag (DECL_USER_ALIGN (t));
> hstate.add_flag (DECL_PRESERVE_P (t));
> - hstate.add_flag (DECL_EXTERNAL (t));
> + //hstate.add_flag (DECL_EXTERNAL (t));
> hstate.add_flag (DECL_GIMPLE_REG_P (t));
> hstate.commit_flag ();
> hstate.add_int (DECL_ALIGN (t));
> Index: gcc/lto/lto.c
> ===================================================================
> --- gcc/lto/lto.c (revision 238039)
> +++ gcc/lto/lto.c (working copy)
> @@ -1263,7 +1263,8 @@ compare_tree_sccs_1 (tree t1, tree t2, t
> tree t1_ = (E1), t2_ = (E2); \
> if (t1_ != t2_ \
> && (!t1_ || !t2_ \
> - || !TREE_VISITED (t2_) \
> + || (!TREE_VISITED (t2_) \
> + && !same_decls (t1_, t2_)) \
>
> || (!TREE_ASM_WRITTEN (t2_) \
>
> && !compare_tree_sccs_1 (t1_, t2_, map)))) \
> return false; \
>
> plus the magic new function same_decls which would check if the trees are
> var/function decls with the same assembler name. The function can't use
> the cgraph as that is not yet read in unfortunately - I still think we
> should do that so we can see the prevailing nodes early.
OK, thanks for the hint, the attached patch where the call to same_decls is
placed differently works on the testcase (modulo the gigi change I posted
earlier today) but not on the original code... It looks like the hash value
computed in lto-streamer-out.c is stricter than the hash value computed for
canonical types, I'm trying to pinpoint the difference.
* lto-streamer-out.c (hash_tree): Do not add the TREE_STATIC and
DECL_EXTERNAL flags for variable or function declarations.
lto/
* lto.c (same_global_decl_p): New predicate.
(compare_tree_sccs_1): Use it in the comparison of pointer fields.
(walk_simple_constant_arithmetic): New function.
(LTO_SET_PREVAIL): Use it to fix up DECL nodes in simple expressions.
--
Eric BotcazouIndex: lto-streamer-out.c
===================================================================
--- lto-streamer-out.c (revision 238156)
+++ lto-streamer-out.c (working copy)
@@ -996,7 +996,9 @@ hash_tree (struct streamer_tree_cache_d
else
hstate.add_flag (TREE_NO_WARNING (t));
hstate.add_flag (TREE_NOTHROW (t));
- hstate.add_flag (TREE_STATIC (t));
+ /* We want to unify DECL nodes in pointer fields of global types. */
+ if (!(VAR_OR_FUNCTION_DECL_P (t)))
+ hstate.add_flag (TREE_STATIC (t));
hstate.add_flag (TREE_PROTECTED (t));
hstate.add_flag (TREE_DEPRECATED (t));
if (code != TREE_BINFO)
@@ -1050,7 +1052,9 @@ hash_tree (struct streamer_tree_cache_d
hstate.add_flag (DECL_ARTIFICIAL (t));
hstate.add_flag (DECL_USER_ALIGN (t));
hstate.add_flag (DECL_PRESERVE_P (t));
- hstate.add_flag (DECL_EXTERNAL (t));
+ /* We want to unify DECL nodes in pointer fields of global types. */
+ if (!(VAR_OR_FUNCTION_DECL_P (t)))
+ hstate.add_flag (DECL_EXTERNAL (t));
hstate.add_flag (DECL_GIMPLE_REG_P (t));
hstate.commit_flag ();
hstate.add_int (DECL_ALIGN (t));
Index: lto/lto.c
===================================================================
--- lto/lto.c (revision 238156)
+++ lto/lto.c (working copy)
@@ -970,6 +970,27 @@ static unsigned long num_sccs_merged;
static unsigned long num_scc_compares;
static unsigned long num_scc_compare_collisions;
+/* Return true if T1 and T2 represent the same global declaration.
+
+ We need to unify declaration nodes in pointer fields of global types
+ so as to unify the types themselves before the declarations are merged. */
+
+static inline bool
+same_global_decl_p (tree t1, tree t2)
+{
+ if (TREE_CODE (t1) != TREE_CODE (t2) || !VAR_OR_FUNCTION_DECL_P (t1))
+ return false;
+
+ if (!(TREE_PUBLIC (t1) || DECL_EXTERNAL (t1)))
+ return false;
+
+ if (!(TREE_PUBLIC (t2) || DECL_EXTERNAL (t2)))
+ return false;
+
+ return symbol_table::assembler_names_equal_p
+ (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (t1)),
+ IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (t2)));
+}
/* Compare the two entries T1 and T2 of two SCCs that are possibly equal,
recursing through in-SCC tree edges. Returns true if the SCCs entered
@@ -1262,6 +1283,7 @@ compare_tree_sccs_1 (tree t1, tree t2, t
do { \
tree t1_ = (E1), t2_ = (E2); \
if (t1_ != t2_ \
+ && !(t1_ && t2_ && same_global_decl_p (t1_, t2_)) \
&& (!t1_ || !t2_ \
|| !TREE_VISITED (t2_) \
|| (!TREE_ASM_WRITTEN (t2_) \
@@ -2506,15 +2528,55 @@ lto_wpa_write_files (void)
timevar_pop (TV_WHOPR_WPA_IO);
}
+/* Look inside *EXPR into simple arithmetic operations involving constants.
+ Return the address of the outermost non-arithmetic or non-constant node.
+ This should be equivalent to tree.c:skip_simple_constant_arithmetic. */
+
+static tree *
+walk_simple_constant_arithmetic (tree *expr)
+{
+ while (TREE_CODE (*expr) == NON_LVALUE_EXPR)
+ expr = &TREE_OPERAND (*expr, 0);
+
+ while (true)
+ {
+ if (UNARY_CLASS_P (*expr))
+ expr = &TREE_OPERAND (*expr, 0);
+ else if (BINARY_CLASS_P (*expr))
+ {
+ if (TREE_CONSTANT (TREE_OPERAND (*expr, 1)))
+ expr = &TREE_OPERAND (*expr, 0);
+ else if (TREE_CONSTANT (TREE_OPERAND (*expr, 0)))
+ expr = &TREE_OPERAND (*expr, 1);
+ else
+ break;
+ }
+ else
+ break;
+ }
+
+ return expr;
+}
-/* If TT is a variable or function decl replace it with its
- prevailing variant. */
+/* If TT is a variable or function decl or a simple expression containing one,
+ replace the occurrence with its prevailing variant. This should be able to
+ deal with all the expressions attached to _DECL and _TYPE nodes which were
+ streamed into the GIMPLE IR. */
#define LTO_SET_PREVAIL(tt) \
do {\
+ tree *loc; \
if ((tt) && VAR_OR_FUNCTION_DECL_P (tt) \
&& (TREE_PUBLIC (tt) || DECL_EXTERNAL (tt))) \
{ \
- tt = lto_symtab_prevailing_decl (tt); \
+ tt = lto_symtab_prevailing_decl (tt); \
+ fixed = true; \
+ } \
+ else if ((tt) && EXPR_P (tt) \
+ && (loc = walk_simple_constant_arithmetic (&tt)) \
+ && VAR_OR_FUNCTION_DECL_P (*loc) \
+ && (TREE_PUBLIC (*loc) || DECL_EXTERNAL (*loc))) \
+ { \
+ *loc = lto_symtab_prevailing_decl (*loc); \
fixed = true; \
} \
} while (0)
