Just came across this article and found it very useful.
In fact, the whole blog seems very useful and I shall be dipping in further. Seems it's been referenced a couple of time in other threads (yes, I did search).
It concentrates on GNU ARM Embedded - so details may not (all) be directly relevant here ... ?
Indeed, but this outsider glanced through the list and -flto is a bad one. I recall many threads here in AVRland that have lto in them.
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