https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107303
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |jakub at gcc dot gnu.org
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
So, cp_build_modify_expr calls stabilize_expr on UNARY_PLUS_EXPR of a
TARGET_EXPR.
stabilize_expr wraps it into (another) TARGET_EXPR, puts the TARGET_EXPR as an
initialization statement and returns the TARGET_EXPR_SLOT.
With the TARGET_EXPR_SLOT being used in places other than the
TARGET_EXPR_{SLOT,INITIAL} the r13-2978 change doesn't look correct, because
it replaces the outer TARGET_EXPR with the inner one, but the slot of the outer
might be used elsewhere.
Now, maybe with the nested TARGET_EXPR case we never use the inner
TARGET_EXPR's slot outside of the outer TARGET_EXPR, if that is the case,
perhaps we could still do the optimization, but keep the outer TARGET_EXPR
rather than inner, strip the inner TARGET_EXPR from outer TARGET_EXPR's
initializer and replace all occurrences of the inner slot with the outer slot?
