If the index of a constructor_elt is a FIELD_DECL, the CONSTRUCTOR is already reshaped, so we can save time and memory by returning immediately.
Tested x86_64-pc-linux-gnu, applying to trunk. gcc/cp/ChangeLog: * decl.cc (reshape_init): Shortcut already-reshaped init. (reshape_init_class): Assert not getting one here. --- gcc/cp/decl.cc | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc index c9110db796a..0fa758ff214 100644 --- a/gcc/cp/decl.cc +++ b/gcc/cp/decl.cc @@ -6631,7 +6631,9 @@ reshape_init_class (tree type, reshape_iter *d, bool first_initializer_p, if (TREE_CODE (d->cur->index) == FIELD_DECL) { - /* We already reshaped this. */ + /* We already reshaped this; we should have returned early from + reshape_init. */ + gcc_checking_assert (false); if (field != d->cur->index) { if (tree id = DECL_NAME (d->cur->index)) @@ -7068,6 +7070,10 @@ reshape_init (tree type, tree init, tsubst_flags_t complain) if (vec_safe_is_empty (v)) return init; + if ((*v)[0].index && TREE_CODE ((*v)[0].index) == FIELD_DECL) + /* Already reshaped. */ + return init; + /* Brace elision is not performed for a CONSTRUCTOR representing parenthesized aggregate initialization. */ if (CONSTRUCTOR_IS_PAREN_INIT (init)) base-commit: c2e846b539bb932d7f68f7e6b3e401c361cc3bf3 -- 2.27.0