[PATCH] ira: volatile asm's are not moveable (PR82602)

[Segher Boessenkool]

On Wed, Oct 18, 2017 at 11:10:48AM +0000, Bernd Edlinger wrote:
> A memory clobber would also make rtx_moveable_p return false,
> thru the following case:
> 
>     case MEM:
>       if (type == OP_IN && MEM_READONLY_P (x))
>         return rtx_moveable_p (&XEXP (x, 0), OP_IN);
>       return false;
> 
> ...
> 
>     case CLOBBER:
>       return rtx_moveable_p (&SET_DEST (x), OP_OUT);
> 
> 
> because that memory clobber is in a parallel statement
> together with the ASM_OUTPUT.
> 
> Right?

Yes, that looks correct.  And a memory clobber of course _should_ make
the insn non-moveable as well -- it's an unknown side effect all by
itself :-)


Segher