Avoid changing type in the type_hash_canon hash
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Commit Message
When building a type and type_hash_canon returns an existing type
avoid changing it, in particular its TYPE_CANONICAL.
Bootstrapped and tested on x86_64-unknown-linux-gnu for all languages.
OK for trunk?
Thanks,
Richard.
PR middle-end/114931
* tree.cc (build_array_type_1): Return early when type_hash_canon
returned an older existing type.
(build_function_type): Likewise.
(build_method_type_directly): Likewise.
(build_offset_type): Likewise.
---
gcc/tree.cc | 12 ++++++++++++
1 file changed, 12 insertions(+)
Comments
On Fri, May 03, 2024 at 12:58:55PM +0200, Richard Biener wrote:
> When building a type and type_hash_canon returns an existing type
> avoid changing it, in particular its TYPE_CANONICAL.
>
> Bootstrapped and tested on x86_64-unknown-linux-gnu for all languages.
>
> OK for trunk?
>
> Thanks,
> Richard.
>
> PR middle-end/114931
> * tree.cc (build_array_type_1): Return early when type_hash_canon
> returned an older existing type.
> (build_function_type): Likewise.
> (build_method_type_directly): Likewise.
> (build_offset_type): Likewise.
LGTM, thanks.
Jakub
@@ -7352,7 +7352,10 @@ build_array_type_1 (tree elt_type, tree index_type, bool typeless_storage,
if (shared)
{
hashval_t hash = type_hash_canon_hash (t);
+ tree probe_type = t;
t = type_hash_canon (hash, t);
+ if (t != probe_type)
+ return t;
}
if (TYPE_CANONICAL (t) == t && set_canonical)
@@ -7509,7 +7512,10 @@ build_function_type (tree value_type, tree arg_types,
/* If we already have such a type, use the old one. */
hashval_t hash = type_hash_canon_hash (t);
+ tree probe_type = t;
t = type_hash_canon (hash, t);
+ if (t != probe_type)
+ return t;
/* Set up the canonical type. */
any_structural_p = TYPE_STRUCTURAL_EQUALITY_P (value_type);
@@ -7663,7 +7669,10 @@ build_method_type_directly (tree basetype,
/* If we already have such a type, use the old one. */
hashval_t hash = type_hash_canon_hash (t);
+ tree probe_type = t;
t = type_hash_canon (hash, t);
+ if (t != probe_type)
+ return t;
/* Set up the canonical type. */
any_structural_p
@@ -7720,7 +7729,10 @@ build_offset_type (tree basetype, tree type)
/* If we already have such a type, use the old one. */
hashval_t hash = type_hash_canon_hash (t);
+ tree probe_type = t;
t = type_hash_canon (hash, t);
+ if (t != probe_type)
+ return t;
if (!COMPLETE_TYPE_P (t))
layout_type (t);