[LLVMdev] x86 unwind support[MESSAGE NOT SCANNED]

Duncan Sands baldrick at free.fr
Mon Jul 20 09:18:29 PDT 2009


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.



More information about the llvm-dev mailing list