[LLVMdev] x86 unwind support[MESSAGE NOT SCANNED]

Duncan Sands
Mon, 20 Jul 2009 16:18:29 -0000

Hi Mark,

> You are confusing stopping the unwinding at *some* levels or at *all*
> levels.
> Eg.
> invoke
>   call
>    call
>     invoke
>      call
>       call
>        unwind

the dwarf unwinder only stops and runs user code at the invokes.
It does restore registers and so forth at every stack frame.
This is extra work done at unwind time that reduces the cost of
making invoke calls by avoiding the need to save a bunch of
context.

Ciao,

Duncan.