On Fri, 9 Feb 2024, Jakub Jelinek wrote:
> Hi!
>
> Due to -fnon-call-exceptions the bitint lowering adds new EH edges
> in various places, so that the EH edge points from handling (e.g. load or
> store) of each of the limbs. The problem is that the EH edge destination
> as shown in the testcase can have some PHIs. If it is just a virtual
> PHI, no big deal, the pass uses TODO_update_ssa_only_virtuals, but if
> it has other PHIs, I think we need to copy the values from the preexisting
> corresponding EH edge (which is from the original stmt to the EH pad)
> to the newly added EH edge, so that the PHI arguments are the same rather
> than missing (which ICEs during checking at the end of the pass).
>
> This patch adds a function to do that and uses it whenever adding EH edges.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
Thanks,
Richard.
> 2024-02-09 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/113818
> * gimple-lower-bitint.cc (add_eh_edge): New function.
> (bitint_large_huge::handle_load,
> bitint_large_huge::lower_mergeable_stmt,
> bitint_large_huge::lower_muldiv_stmt): Use it.
>
> * gcc.dg/bitint-89.c: New test.
>
> --- gcc/gimple-lower-bitint.cc.jj 2024-02-08 14:33:36.033220098 +0100
> +++ gcc/gimple-lower-bitint.cc 2024-02-08 17:29:38.182386934 +0100
> @@ -1681,6 +1681,27 @@ bitint_large_huge::handle_cast (tree lhs
> return NULL_TREE;
> }
>
> +/* Add a new EH edge from SRC to EH_EDGE->dest, where EH_EDGE
> + is an older EH edge, and except for virtual PHIs duplicate the
> + PHI argument from the EH_EDGE to the new EH edge. */
> +
> +static void
> +add_eh_edge (basic_block src, edge eh_edge)
> +{
> + edge e = make_edge (src, eh_edge->dest, EDGE_EH);
> + e->probability = profile_probability::very_unlikely ();
> + for (gphi_iterator gsi = gsi_start_phis (eh_edge->dest);
> + !gsi_end_p (gsi); gsi_next (&gsi))
> + {
> + gphi *phi = gsi.phi ();
> + tree lhs = gimple_phi_result (phi);
> + if (virtual_operand_p (lhs))
> + continue;
> + const phi_arg_d *arg = gimple_phi_arg (phi, eh_edge->dest_idx);
> + add_phi_arg (phi, arg->def, e, arg->locus);
> + }
> +}
> +
> /* Helper function for handle_stmt method, handle a load from memory. */
>
> tree
> @@ -1756,8 +1777,7 @@ bitint_large_huge::handle_load (gimple *
> if (eh_edge)
> {
> edge e = split_block (gsi_bb (m_gsi), g);
> - make_edge (e->src, eh_edge->dest, EDGE_EH)->probability
> - = profile_probability::very_unlikely ();
> + add_eh_edge (e->src, eh_edge);
> m_gsi = gsi_after_labels (e->dest);
> if (gsi_bb (save_gsi) == e->src)
> {
> @@ -1876,8 +1896,7 @@ bitint_large_huge::handle_load (gimple *
> {
> edge e = split_block (gsi_bb (m_gsi), g);
> m_gsi = gsi_after_labels (e->dest);
> - make_edge (e->src, eh_edge->dest, EDGE_EH)->probability
> - = profile_probability::very_unlikely ();
> + add_eh_edge (e->src, eh_edge);
> }
> }
> if (conditional)
> @@ -1934,8 +1953,7 @@ normal_load:
> {
> edge e = split_block (gsi_bb (m_gsi), g);
> m_gsi = gsi_after_labels (e->dest);
> - make_edge (e->src, eh_edge->dest, EDGE_EH)->probability
> - = profile_probability::very_unlikely ();
> + add_eh_edge (e->src, eh_edge);
> }
> if (tree_fits_uhwi_p (idx))
> {
> @@ -2554,8 +2572,8 @@ bitint_large_huge::lower_mergeable_stmt
> {
> edge e = split_block (gsi_bb (m_gsi), g);
> m_gsi = gsi_after_labels (e->dest);
> - make_edge (e->src, eh_pad, EDGE_EH)->probability
> - = profile_probability::very_unlikely ();
> + add_eh_edge (e->src,
> + find_edge (gimple_bb (stmt), eh_pad));
> }
> }
> if (kind == bitint_prec_large)
> @@ -2633,8 +2651,8 @@ bitint_large_huge::lower_mergeable_stmt
> {
> edge e = split_block (gsi_bb (m_gsi), g);
> m_gsi = gsi_after_labels (e->dest);
> - make_edge (e->src, eh_pad, EDGE_EH)->probability
> - = profile_probability::very_unlikely ();
> + add_eh_edge (e->src,
> + find_edge (gimple_bb (stmt), eh_pad));
> }
> }
> if (new_bb)
> @@ -2777,8 +2795,7 @@ bitint_large_huge::lower_mergeable_stmt
> {
> edge e = split_block (gsi_bb (m_gsi), g);
> m_gsi = gsi_after_labels (e->dest);
> - make_edge (e->src, eh_pad, EDGE_EH)->probability
> - = profile_probability::very_unlikely ();
> + add_eh_edge (e->src, find_edge (gimple_bb (stmt), eh_pad));
> }
> }
> if (kind == bitint_prec_huge && i == (bo_bit != 0))
> @@ -2822,8 +2839,7 @@ bitint_large_huge::lower_mergeable_stmt
> {
> edge e = split_block (gsi_bb (m_gsi), g);
> m_gsi = gsi_after_labels (e->dest);
> - make_edge (e->src, eh_pad, EDGE_EH)->probability
> - = profile_probability::very_unlikely ();
> + add_eh_edge (e->src, find_edge (gimple_bb (stmt), eh_pad));
> }
> }
> }
> @@ -3479,8 +3495,7 @@ bitint_large_huge::lower_muldiv_stmt (tr
> {
> edge e2 = split_block (gsi_bb (m_gsi), g);
> m_gsi = gsi_after_labels (e2->dest);
> - make_edge (e2->src, e1->dest, EDGE_EH)->probability
> - = profile_probability::very_unlikely ();
> + add_eh_edge (e2->src, e1);
> }
> }
> }
> --- gcc/testsuite/gcc.dg/bitint-89.c.jj 2024-02-08 17:35:01.693881442
> +0100
> +++ gcc/testsuite/gcc.dg/bitint-89.c 2024-02-08 17:34:39.555189760 +0100
> @@ -0,0 +1,22 @@
> +/* PR tree-optimization/113818 */
> +/* { dg-do compile { target bitint } } */
> +/* { dg-options "-Os -fnon-call-exceptions -finstrument-functions-once" } */
> +
> +int c, i;
> +void bar (int *);
> +
> +#if __BITINT_MAXWIDTH__ >= 129
> +_BitInt(129) *a;
> +#else
> +_BitInt(63) *a;
> +#endif
> +
> +void
> +foo (void)
> +{
> + if (c)
> + return;
> + int q;
> + a[i] = 0;
> + bar (&q);
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
