On Thu, 8 Oct 2020, Jan Hubicka wrote:
> Hi,
> as discussed on IRC, I am testing the attached patch to disable TBAA for
> some uses of call_may_clobber_ref_p.
>
> OK if testing passes?
OK.
Thanks,
Richard.
> Honza
>
> gcc/ChangeLog:
>
> 2020-10-08 Jan Hubicka <hubi...@ucw.cz>
>
> * tree-nrv.c (dest_safe_for_nrv_p): Disable tbaa in
> call_may_clobber_ref_p and ref_maybe_used_by_stmt_p.
> * tree-tailcall.c (find_tail_calls): Likewise.
> * tree-ssa-alias.c (call_may_clobber_ref_p): Add tbaa_p parameter.
> * tree-ssa-alias.h (call_may_clobber_ref_p): Update prototype.
> * tree-ssa-sccvn.c (vn_reference_lookup_3): Pass data->tbaa_p
> to call_may_clobber_ref_p_1.
>
> diff --git a/gcc/tree-nrv.c b/gcc/tree-nrv.c
> index 9d17a104f34..df757f70e71 100644
> --- a/gcc/tree-nrv.c
> +++ b/gcc/tree-nrv.c
> @@ -315,8 +315,8 @@ dest_safe_for_nrv_p (gcall *call)
> if (TREE_CODE (dest) == SSA_NAME)
> return true;
>
> - if (call_may_clobber_ref_p (call, dest)
> - || ref_maybe_used_by_stmt_p (call, dest))
> + if (call_may_clobber_ref_p (call, dest, false)
> + || ref_maybe_used_by_stmt_p (call, dest, false))
> return false;
>
> return true;
> diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
> index 97255987e79..ac7e020c5e2 100644
> --- a/gcc/tree-ssa-alias.c
> +++ b/gcc/tree-ssa-alias.c
> @@ -3320,12 +3320,12 @@ call_may_clobber_ref_p_1 (gcall *call, ao_ref *ref,
> bool tbaa_p)
> return true, otherwise return false. */
>
> bool
> -call_may_clobber_ref_p (gcall *call, tree ref)
> +call_may_clobber_ref_p (gcall *call, tree ref, bool tbaa_p)
> {
> bool res;
> ao_ref r;
> ao_ref_init (&r, ref);
> - res = call_may_clobber_ref_p_1 (call, &r, true);
> + res = call_may_clobber_ref_p_1 (call, &r, tbaa_p);
> if (res)
> ++alias_stats.call_may_clobber_ref_p_may_alias;
> else
> diff --git a/gcc/tree-ssa-alias.h b/gcc/tree-ssa-alias.h
> index 1dd02c0ea62..1561ead2941 100644
> --- a/gcc/tree-ssa-alias.h
> +++ b/gcc/tree-ssa-alias.h
> @@ -128,7 +128,7 @@ extern bool ref_maybe_used_by_stmt_p (gimple *, ao_ref *,
> bool = true);
> extern bool stmt_may_clobber_global_p (gimple *);
> extern bool stmt_may_clobber_ref_p (gimple *, tree, bool = true);
> extern bool stmt_may_clobber_ref_p_1 (gimple *, ao_ref *, bool = true);
> -extern bool call_may_clobber_ref_p (gcall *, tree);
> +extern bool call_may_clobber_ref_p (gcall *, tree, bool = true);
> extern bool call_may_clobber_ref_p_1 (gcall *, ao_ref *, bool = true);
> extern bool stmt_kills_ref_p (gimple *, tree);
> extern bool stmt_kills_ref_p (gimple *, ao_ref *);
> diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
> index 014b7bdfd01..c139adb6130 100644
> --- a/gcc/tree-ssa-sccvn.c
> +++ b/gcc/tree-ssa-sccvn.c
> @@ -2586,7 +2586,7 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void
> *data_,
> if (valueized_anything)
> {
> bool res = call_may_clobber_ref_p_1 (as_a <gcall *> (def_stmt),
> - ref);
> + ref, data->tbaa_p);
> for (unsigned i = 0; i < gimple_call_num_args (def_stmt); ++i)
> gimple_call_set_arg (def_stmt, i, oldargs[i]);
> if (!res)
> diff --git a/gcc/tree-tailcall.c b/gcc/tree-tailcall.c
> index d81e9213460..44643bef5f1 100644
> --- a/gcc/tree-tailcall.c
> +++ b/gcc/tree-tailcall.c
> @@ -523,7 +523,7 @@ find_tail_calls (basic_block bb, struct tailcall **ret)
> tree result_decl = DECL_RESULT (cfun->decl);
> if (result_decl
> && may_be_aliased (result_decl)
> - && ref_maybe_used_by_stmt_p (call, result_decl))
> + && ref_maybe_used_by_stmt_p (call, result_decl, false))
> return;
>
> /* We found the call, check whether it is suitable. */
> @@ -597,8 +597,8 @@ find_tail_calls (basic_block bb, struct tailcall **ret)
> if (TREE_CODE (var) != PARM_DECL
> && auto_var_in_fn_p (var, cfun->decl)
> && may_be_aliased (var)
> - && (ref_maybe_used_by_stmt_p (call, var)
> - || call_may_clobber_ref_p (call, var)))
> + && (ref_maybe_used_by_stmt_p (call, var, false)
> + || call_may_clobber_ref_p (call, var, false)))
> {
> if (!VAR_P (var))
> {
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imend
