Hi!
On Thu, May 21, 2020 at 03:29:49PM +0200, Martin Liška wrote:
> Adding Segher to CC, he can help us.
Oh dear. Are you sure?
> On 5/21/20 2:51 PM, Martin Liška wrote:
> >Back to this I noticed that ppc64le target build is broken due to:
> >insn-emit.o -MMD -MP -MF ./.deps/insn-emit.TPo insn-emit.c
> >/home/marxin/Programming/gcc/gcc/config/rs6000/vector.md:357:11: error:
> >vcondv4sfv4sf cannot FAIL
> > 357 | FAIL;
Is it new that vcond cannot FAIL? Because we have done that for years.
Since this breaks bootstrap on a primary target, please revert the patch
until it is sorted.
> >which is caused by the 4 added optabs:
> >
> >+DEF_INTERNAL_OPTAB_FN (VCOND, 0, vcond, vec_cond)
> >+DEF_INTERNAL_OPTAB_FN (VCONDU, 0, vcondu, vec_condu)
> >+DEF_INTERNAL_OPTAB_FN (VCONDEQ, 0, vcondeq, vec_condeq)
> >+DEF_INTERNAL_OPTAB_FN (VCOND_MASK, 0, vcond_mask, vec_cond_mask)
> >looking at the generator:
> >I get there due to:
> >
> >B- │516 if (find_optab (&p, XSTR (expand,
> >0)))│
> > │517
> > { │
> > │518 gcc_assert (p.op <
> > NUM_OPTABS); │
> > │519 if
> > (nofail_optabs[p.op]) │
> > │520 can_fail_p =
> > false; │
> > │521
> > } │
> >
> >
> >#define DEF_INTERNAL_OPTAB_FN(NAME, FLAGS, OPTAB, TYPE) \
> > nofail_optabs[OPTAB##_optab] = true;
So yes it is new. Please fix :-(
> >Any hint what's bad? Note that x86_64-linux-gnu is fine.
> >Do I miss a target hook?
There is a new IFN that requires the existing optabs to never fail. But
they *do* sometimes fail. That is what I understand from this anyway,
please correct if needed :-)
We can make the rs6000 patterns never FAIL if that is a good idea (I am
not convinced however), but this should be documented, and all existing
targets need to be checked.
In general it is not pleasant at all to have patterns that cannot FAIL,
it makes writing a (new) port much harder, and there can be cases where
there is no sane code at all that can be generated for some cases, etc.
Segher
