Avoid hash table lookups between requesting an insert and storing the
inserted value in avail_exprs_stack. Lookups before the insert is
completed could fail to find double-hashed elements.
Regstrapped on x86_64-linux-gnu. Ok to install?
for gcc/ChangeLog
* tree-ssa-scopedtables.cc
(avail_exprs_stack::lookup_avail_expr): Finish hash table
insertion before further lookups.
---
gcc/tree-ssa-scopedtables.cc | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/gcc/tree-ssa-scopedtables.cc b/gcc/tree-ssa-scopedtables.cc
index 6d203ef89ecef..3e6e129e7d5d3 100644
--- a/gcc/tree-ssa-scopedtables.cc
+++ b/gcc/tree-ssa-scopedtables.cc
@@ -259,11 +259,6 @@ avail_exprs_stack::lookup_avail_expr (gimple *stmt, bool
insert, bool tbaa_p,
}
else if (*slot == NULL)
{
- /* If we did not find the expression in the hash table, we may still
- be able to produce a result for some expressions. */
- tree retval = avail_exprs_stack::simplify_binary_operation (stmt,
- element);
-
/* We have, in effect, allocated *SLOT for ELEMENT at this point.
We must initialize *SLOT to a real entry, even if we found a
way to prove ELEMENT was a constant after not finding ELEMENT
@@ -277,6 +272,11 @@ avail_exprs_stack::lookup_avail_expr (gimple *stmt, bool
insert, bool tbaa_p,
class expr_hash_elt *element2 = new expr_hash_elt (element);
*slot = element2;
+ /* If we did not find the expression in the hash table, we may still
+ be able to produce a result for some expressions. */
+ tree retval = avail_exprs_stack::simplify_binary_operation (stmt,
+ element);
+
record_expr (element2, NULL, '2');
return retval;
}
--
Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/
Free Software Activist GNU Toolchain Engineer
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but very few check the facts. Ask me about <https://stallmansupport.org>
