On Fri, Apr 11, 2014 at 05:19:59PM +0800, Zhenqiang Chen wrote:
> > Or, fix up the insane arm costs for ASM_OPERANDS:
> > case ASM_OPERANDS:
> > /* Just a guess. Cost one insn per input. */
> > *cost = COSTS_N_INSNS (ASM_OPERANDS_INPUT_LENGTH (x));
> > return true;
> > I don't think this heuristics is even close to reality most of the
> > time, more importantly, for no inputs, just outputs and clobbers it means
> > *cost = 0; and that is why ARM is supposedly the only target now where CSE
> > thinks it is worthwhile to break all inline asms without inputs appart.
>
> I will raise a patch to discuss it for ARM backend.
AFAIK Kyrill is already working on such a patch, but it was agreed to put
it into stage1 only and eventually backport for 4.9.1.
Jakub
