On Mon, 22 Feb 2016, Jakub Jelinek wrote:
> On Mon, Feb 22, 2016 at 01:44:09PM +0100, Richard Biener wrote:
> > --- 1079,1086 ----
> > || !dominated_by_p (CDI_DOMINATORS,
> > loop->latch, gimple_bb (stmt)))
> > return;
> > + if (cgraph_node::get (cfun->decl)->aliases (BUILT_IN_MEMSET))
> > + return;
>
> Perhaps also punt here for:
> BUILT_IN_MEMSET_CHK
> BUILT_IN_TM_MEMSET
> BUILT_IN_BZERO
> ?
>
> > partition->kind = PKIND_MEMSET;
> > partition->main_dr = single_store;
> > partition->niter = nb_iter;
> > *************** classify_partition (loop_p loop, struct
> > *** 1135,1140 ****
> > --- 1138,1146 ----
> > }
> > free_dependence_relation (ddr);
> > loops.release ();
> > + if (cgraph_node::get (cfun->decl)->aliases (BUILT_IN_MEMCPY)
> > + || cgraph_node::get (cfun->decl)->aliases (BUILT_IN_MEMMOVE))
> > + return;
>
> And here for
> BUILT_IN_MEMCPY_CHK
> BUILT_IN_TM_MEMCPY
> BUILT_IN_TM_MEMCPY_RNWT
> BUILT_IN_TM_MEMCPY_RTWN
> BUILT_IN_MEMPCPY
> BUILT_IN_MEMPCPY_CHK
> BUILT_IN_MEMMOVE_CHK
> BUILT_IN_TM_MEMMOVE
> BUILT_IN_BCOPY
> ?
I'm going to wait for Honzas feedback. Testing all of the above
looks expensive - if those are implemented in terms of memcpy/memset
then hopefully in libc itself which hopefully always does local
calls.
It's not going to be an exhaustive check anyway, just a QOI one
covering those cases we've seen in the wild. Esp. as indirection
will break the detection (so does using asm(".alias XXX") which glibc
does).
Richard.
