Hi,
Chromium LTO build ICEs on bogus get_binfo_at_offset call. This is caused by
updating pasto bug in update_jump_functions_after_inlining.
While looking for it I noticed we have other issues here. In particular, when
combining -fno-devirtualize and -fdevirtualize units, we get all jump fuctions
as type preserved. This is because detect_type_change returns false when it
decides detection is not needed. It really should return true. Otherwise we will
end up propagating invalid types through the -fno-devirtualize function and
produce
wrong code at LTO.
I also added some sanity checking to jump functions while hunting the bug that
uncovered another problem in compute_complex_assign_jump_func and
compute_complex_ancestor_jump_func that are still confusing type of parameter
(that is pointer) to type of object passed by reference.
I also made us to not save the type to ipa_set_ancestor_jf when type is not
preserved, since it will never be used for enything useful.
ipa_get_jf_ancestor_result
uses to build it the updated address, but we can safely use pointer_type_node,
because it will be converted at the substitution time anyway.
Bootstrapped/regtested x86_64-linux, will commit it tomorrow after some furhter
testing
and unless Martin stops me ;)
Honza
* ipa-cp.c (ipa_get_jf_ancestor_result): Allow type to be NULL.
* ipa-prop.c (ipa_set_jf_known_type): Do not set anyting when
we do not devirtualize.
(ipa_set_ancestor_jf): Likewise; do not record type when we do not
devirtualize.
(detect_type_change): Signalize type change when giving up on
detection.
(compute_complex_assign_jump_func): Fix call of ipa_set_ancestor_jf.
(compute_complex_ancestor_jump_func): Likewise.
(update_jump_functions_after_inlining): Fix combining of PASS_THROUGH
and KNOWN_TYPE.
Index: ipa-cp.c
===================================================================
--- ipa-cp.c (revision 207817)
+++ ipa-cp.c (working copy)
@@ -798,7 +798,9 @@ ipa_get_jf_ancestor_result (struct ipa_j
tree t = TREE_OPERAND (input, 0);
t = build_ref_for_offset (EXPR_LOCATION (t), t,
ipa_get_jf_ancestor_offset (jfunc),
- ipa_get_jf_ancestor_type (jfunc), NULL, false);
+ ipa_get_jf_ancestor_type (jfunc)
+ ? ipa_get_jf_ancestor_type (jfunc)
+ : ptr_type_node, NULL, false);
return build_fold_addr_expr (t);
}
else
Index: ipa-prop.c
===================================================================
--- ipa-prop.c (revision 207817)
+++ ipa-prop.c (working copy)
@@ -393,6 +393,9 @@ ipa_set_jf_known_type (struct ipa_jump_f
{
gcc_assert (TREE_CODE (component_type) == RECORD_TYPE
&& TYPE_BINFO (component_type));
+ if (!flag_devirtualize)
+ return;
+ gcc_assert (BINFO_VTABLE (TYPE_BINFO (component_type)));
jfunc->type = IPA_JF_KNOWN_TYPE;
jfunc->value.known_type.offset = offset,
jfunc->value.known_type.base_type = base_type;
@@ -477,10 +480,16 @@ ipa_set_ancestor_jf (struct ipa_jump_fun
tree type, int formal_id, bool agg_preserved,
bool type_preserved)
{
+ if (!flag_devirtualize)
+ type_preserved = false;
+ gcc_assert (!type_preserved
+ || (TREE_CODE (type) == RECORD_TYPE
+ && TYPE_BINFO (type)
+ && BINFO_VTABLE (TYPE_BINFO (type))));
jfunc->type = IPA_JF_ANCESTOR;
jfunc->value.ancestor.formal_id = formal_id;
jfunc->value.ancestor.offset = offset;
- jfunc->value.ancestor.type = type;
+ jfunc->value.ancestor.type = type_preserved ? type : NULL;
jfunc->value.ancestor.agg_preserved = agg_preserved;
jfunc->value.ancestor.type_preserved = type_preserved;
}
@@ -686,7 +695,7 @@ detect_type_change (tree arg, tree base,
|| TREE_CODE (comp_type) != RECORD_TYPE
|| !TYPE_BINFO (comp_type)
|| !BINFO_VTABLE (TYPE_BINFO (comp_type)))
- return false;
+ return true;
/* C++ methods are not allowed to change THIS pointer unless they
are constructors or destructors. */
@@ -1103,7 +1112,7 @@ compute_complex_assign_jump_func (struct
bool type_p = !detect_type_change (op1, base, TREE_TYPE (param_type),
call, jfunc, offset);
if (type_p || jfunc->type == IPA_JF_UNKNOWN)
eg ipa_set_ancestor_jf (jfunc, offset, TREE_TYPE (op1), index,
+ ipa_set_ancestor_jf (jfunc, offset, TREE_TYPE (param_type), index,
parm_ref_data_pass_through_p (&parms_ainfo[index],
call, ssa), type_p);
}
@@ -1235,7 +1244,7 @@ compute_complex_ancestor_jump_func (stru
type_p = !detect_type_change (obj, expr, TREE_TYPE (param_type),
call, jfunc, offset);
if (type_p || jfunc->type == IPA_JF_UNKNOWN)
- ipa_set_ancestor_jf (jfunc, offset, TREE_TYPE (obj), index,
+ ipa_set_ancestor_jf (jfunc, offset, TREE_TYPE (param_type), index,
parm_ref_data_pass_through_p (&parms_ainfo[index],
call, parm), type_p);
}
@@ -2390,7 +2399,7 @@ update_jump_functions_after_inlining (st
ipa_set_jf_known_type (dst,
ipa_get_jf_known_type_offset (src),
ipa_get_jf_known_type_base_type
(src),
- ipa_get_jf_known_type_base_type
(src));
+ ipa_get_jf_known_type_component_type
(src));
else
dst->type = IPA_JF_UNKNOWN;
break;
