Hi,
ipa_find_agg_cst_for_param can leave from_global_constant as it is
when it returns NULL. It's user ipa_get_indirect_edge_target_1 then
reads that uninitialized value when it tests whether it should NULLify
the result itself, which was caught by valgrind.
Fixed by the patch below, which checks whether
ipa_find_agg_cst_for_param returned non-NULL before loading
from_global_constant. I decided to address it here rather than in
ipa_find_agg_cst_for_param because that would require a check that
from_global_constant in not NULL there and because it is consistent
with how by_ref is returned in other functions in ipa-prop.
Bootstrapped and tested on x86_64-linux, I will go ahead and commit it
as obvious.
Martin
2016-05-23 Martin Jambor <mjam...@suse.cz>
PR ipa/71234
* ipa-cp.c (ipa_get_indirect_edge_target_1): Only check value of
from_global_constant if t is not NULL.
---
gcc/ipa-cp.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/gcc/ipa-cp.c b/gcc/ipa-cp.c
index 8caa973..4b7f6bb 100644
--- a/gcc/ipa-cp.c
+++ b/gcc/ipa-cp.c
@@ -2027,7 +2027,8 @@ ipa_get_indirect_edge_target_1 (struct cgraph_edge *ie,
ie->indirect_info->offset,
ie->indirect_info->by_ref,
&from_global_constant);
- if (!from_global_constant
+ if (t
+ && !from_global_constant
&& !ie->indirect_info->guaranteed_unmodified)
t = NULL_TREE;
}
--
2.8.2
