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| author | Eric Botcazou <ebotcazou@adacore.com> | 2025-03-19 08:55:04 +0100 |
|---|---|---|
| committer | Eric Botcazou <ebotcazou@adacore.com> | 2025-03-19 08:56:51 +0100 |
| commit | 3a59a1e1bbc7c16477902149d200ce2d3d6c8df5 (patch) | |
| tree | e99199d1bf6d872ce31ba5498a3558cc2a7f3cff /gcc/ada/gcc-interface | |
| parent | 1636e85270d918a84d57bb521c22c42abf42a47c (diff) | |
| download | gcc-3a59a1e1bbc7c16477902149d200ce2d3d6c8df5.zip gcc-3a59a1e1bbc7c16477902149d200ce2d3d6c8df5.tar.gz gcc-3a59a1e1bbc7c16477902149d200ce2d3d6c8df5.tar.bz2 | |
Fix misoptimization at -O2 in LTO mode
This is a regression in recent releases. The problem is that the IPA mod/ref
pass looks through the (nominal) type of a pointer-to-discriminated-type
parameter in a call to a subprogram in order to see the (actual) type used
for the dereferences of the parameter in the callee, which is a
pointer-to-constrained-subtype.
Historically the discriminated type is marked with the may_alias attribute
because of the symmetric effect for the argument in the caller, so we mark
the constrained subtype with the attribute now for the sake of the callee.
gcc/ada/
* gcc-interface/decl.cc (gnat_to_gnu_entity) <E_Record_Subtype>: Set
the may_alias attribute if a specific GCC type is built.
Diffstat (limited to 'gcc/ada/gcc-interface')
| -rw-r--r-- | gcc/ada/gcc-interface/decl.cc | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/gcc/ada/gcc-interface/decl.cc b/gcc/ada/gcc-interface/decl.cc index 1854c58..1694b4e 100644 --- a/gcc/ada/gcc-interface/decl.cc +++ b/gcc/ada/gcc-interface/decl.cc @@ -3651,6 +3651,14 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition) TYPE_PACKED (gnu_type) = TYPE_PACKED (gnu_base_type); TYPE_REVERSE_STORAGE_ORDER (gnu_type) = Reverse_Storage_Order (gnat_entity); + + /* Do the same for subtypes as for the base type, since pointers + to them may symmetrically also point to the latter. */ + prepend_one_attribute + (&attr_list, ATTR_MACHINE_ATTRIBUTE, + get_identifier ("may_alias"), NULL_TREE, + gnat_entity); + process_attributes (&gnu_type, &attr_list, true, gnat_entity); /* Set the size, alignment and alias set of the type to match |