On Mon, Feb 18, 2013 at 9:06 PM, Martin Jambor <mjam...@suse.cz> wrote:
> Hi,
>
> after much pondering about PR 55334 I came to conclusion that no nice
> fix to the regression could be introduced in stage4. So for the sake
> of the SPEC 200 benchmark I decided to cripple IPA-CP on restrict
> pointers to arrays so that the restrict-ness of the memory references
> which need to be vectorized is not lost.
>
> I have tried various less aggressive tricks like only propagating the
> one constant address that heuristics decided was profitable and not
> all the others that came from the same calling contexts (and were
> restrict) but then inlining came along and finished the deed with the
> same consequences as IPA-CP had.
>
> That only reinforced my feeling that the patch below is a spec hack
> and that we ought to find a better way of preserving the restrict-ness
> across IPA optimizations. Therefore I will keep the bug open and
> revert this patch after 4.8 is branched and stage1 opens.
>
> Meanwhile, this passes bootstrap and testsuite on x86_64-linux. OK
> for trunk?
>
> Thanks,
>
> Martin
>
>
> 2013-02-07 Martin Jambor <mjam...@suse.cz>
>
> PR tree-optimization/55334
> * ipa-cp.c (initialize_node_lattices): Disable IPA-CP through and to
> restricted pointers to arrays.
>
> Index: src/gcc/ipa-cp.c
> ===================================================================
> --- src.orig/gcc/ipa-cp.c
> +++ src/gcc/ipa-cp.c
> @@ -730,6 +730,22 @@ initialize_node_lattices (struct cgraph_
> cgraph_node_name (node), node->uid,
> disable ? "BOTTOM" : "VARIABLE");
> }
> + if (!disable)
> + for (i = 0; i < ipa_get_param_count (info) ; i++)
> + {
> + struct ipcp_param_lattices *plats = ipa_get_parm_lattices (info, i);
> + tree t = TREE_TYPE (ipa_get_param(info, i));
> +
> + if (TYPE_RESTRICT (t) && POINTER_TYPE_P (t)
You want to first test for POINTER_TYPE_P and then for TYPE_RESTRICT.
> + && TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE)
With only testing for ARRAY_TYPE here you will still IPA-CP array
descriptors, right? Those are RECORD_TYPE, the parameter being
DECL_BY_REFERENCE. So I'd try instead
&& DECL_BY_REFERENCE (ipa_get_parm (info, i))
which leads me to the question - what is ipa_get_parm (info, i) returning?
Is it the lattice _value_? Or is it the PARM_DECL of the callee (which is
the only important piece of information!)?
Thanks,
Richard.
> + {
> + set_lattice_to_bottom (&plats->itself);
> + if (dump_file && (dump_flags & TDF_DETAILS)
> + && !node->alias && !node->thunk.thunk_p)
> + fprintf (dump_file, "Going to ignore param %i of of %s/%i.\n",
> + i, cgraph_node_name (node), node->uid);
> + }
> + }
>
> for (ie = node->indirect_calls; ie; ie = ie->next_callee)
> if (ie->indirect_info->polymorphic)
>
