> Given the description the code looks fine. It would be nice to see
> more of a _why_ in the commit message. I'm guessing this is either
> something related to signal handling, or debugging... I don't see why
> this would be needed for functional correctness.
>
The issue is how we generate a function prologue when we use
fno-omit-frame-pointer, for example:
[snip]
mov_s fp,sp ; frame pointer is set here
[snip]
st r1,[fp,-24] ; frame pointer is used here
[snip]
sub_s sp,sp,0x20 ; stack pointer adjusted
So we can easily see that any interrupt between the `st` and `sub` instruction
will lead to faulty code as the interrupt routine will use a faulty sp
register, and, potentially, overwriting the value stored by 'st' instruction.
Thus, adding a scheduler barrier will force the compiler to emit the `sub`
instruction before the store one.
Thanks,
Claudiu
