On Wed, Mar 23, 2011 at 4:14 PM, Richard Guenther <rguent...@suse.de> wrote:
>
> This fixes VOP renaming in IPA split (well, or rather adds to its
> crudeness). We really need to rename the reaching VDEF of the
> exit of the SESE region we kill, as that VDEF will be released
> when removing the definitions basic-block. What we really would
> want to do is replace that SESE region with the call using the
> reaching VDEF of its entry and the reaching VDEF of its exit
> as virtual operands. But the current code is somewhat twisted
> so I got lost and the following is what also works for me.
>
> Bootstrapped and tested on x86_64-unknown-linux-gnu.
>
> Honza, I fail to see the exact constraints on the region we
> outline, so you might want to provide a better fix?
Honza? Ping?
Thanks,
Richard.
> Thanks,
> Richard.
>
> 2011-03-23 Richard Guenther <rguent...@suse.de>
>
> PR tree-optimization/48193
> * ipa-slit.c (split_function): Properly rename the reaching
> VDEF.
>
> Index: gcc/ipa-split.c
> ===================================================================
> --- gcc/ipa-split.c (revision 171352)
> +++ gcc/ipa-split.c (working copy)
> @@ -169,8 +169,9 @@ static void
> dump_split_point (FILE * file, struct split_point *current)
> {
> fprintf (file,
> - "Split point at BB %i header time:%i header size: %i"
> - " split time: %i split size: %i\n bbs: ",
> + "Split point at BB %i\n"
> + " header time: %i header size: %i\n"
> + " split time: %i split size: %i\n bbs: ",
> current->entry_bb->index, current->header_time,
> current->header_size, current->split_time, current->split_size);
> dump_bitmap (file, current->split_bbs);
> @@ -1036,12 +1037,13 @@ split_function (struct split_point *spli
>
> /* If RETURN_BB has virtual operand PHIs, they must be removed and the
> virtual operand marked for renaming as we change the CFG in a way that
> - tree-inline is not able to compensate for.
> + tree-inline is not able to compensate for.
>
> Note this can happen whether or not we have a return value. If we have
> a return value, then RETURN_BB may have PHIs for real operands too. */
> if (return_bb != EXIT_BLOCK_PTR)
> {
> + bool phi_p = false;
> for (gsi = gsi_start_phis (return_bb); !gsi_end_p (gsi);)
> {
> gimple stmt = gsi_stmt (gsi);
> @@ -1052,7 +1054,28 @@ split_function (struct split_point *spli
> }
> mark_virtual_phi_result_for_renaming (stmt);
> remove_phi_node (&gsi, true);
> + phi_p = true;
> }
> + /* In reality we have to rename the reaching definition of the
> + virtual operand at return_bb as we will eventually release it
> + when we remove the code region we outlined.
> + So we have to rename all immediate virtual uses of that region
> + if we didn't see a PHI definition yet. */
> + /* ??? In real reality we want to set the reaching vdef of the
> + entry of the SESE region as the vuse of the call and the reaching
> + vdef of the exit of the SESE region as the vdef of the call. */
> + if (!phi_p)
> + for (gsi = gsi_start_bb (return_bb); !gsi_end_p (gsi); gsi_next
> (&gsi))
> + {
> + gimple stmt = gsi_stmt (gsi);
> + if (gimple_vuse (stmt))
> + {
> + gimple_set_vuse (stmt, NULL_TREE);
> + update_stmt (stmt);
> + }
> + if (gimple_vdef (stmt))
> + break;
> + }
> }
>
> /* Now create the actual clone. */
>
