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Re: [PATCH] Fix -fcompare-debug failure during inlining (PR tree-optimization/44182, take 2)
On Mon, 31 May 2010, Jakub Jelinek wrote:
> On Mon, May 31, 2010 at 11:30:39AM +0200, Richard Guenther wrote:
> > But you could move them to the last succ instead of copying them
> > there. Btw - do debug stmts have a location? If so you probably
> > want to copy those too.
>
> I think debug stmts don't have location (and even if they would, 1)
> it is completely ignored during expansion and 2) block and location
> is copied over from stmt when stmt is passed as last argument to
> gimple_build_debug_bind).
>
> The following patch does the moving instead of copying when processing the
> last edge. Bootstrapped/regtested on x86_64-linux/i686-linux, ok for
> trunk/4.5?
Ok.
Thanks,
Richard.
> 2010-05-31 Jakub Jelinek <jakub@redhat.com>
>
> PR tree-optimization/44182
> * tree-inline.c (copy_edges_for_bb): Don't split bb if a stmt that
> newly needs to end a bb is followed by debug stmts, instead return
> true from the function at the end.
> (maybe_move_debug_stmts_to_successors): New function.
> (copy_cfg_body): Call it if copy_edges_for_bb returned true.
>
> * g++.dg/debug/pr44182.C: New test.
>
> --- gcc/tree-inline.c.jj 2010-05-31 14:48:56.000000000 +0200
> +++ gcc/tree-inline.c 2010-05-31 15:05:12.000000000 +0200
> @@ -1834,9 +1834,10 @@ update_ssa_across_abnormal_edges (basic_
>
> /* Copy edges from BB into its copy constructed earlier, scale profile
> accordingly. Edges will be taken care of later. Assume aux
> - pointers to point to the copies of each BB. */
> + pointers to point to the copies of each BB. Return true if any
> + debug stmts are left after a statement that must end the basic block. */
>
> -static void
> +static bool
> copy_edges_for_bb (basic_block bb, gcov_type count_scale, basic_block ret_bb)
> {
> basic_block new_bb = (basic_block) bb->aux;
> @@ -1844,6 +1845,7 @@ copy_edges_for_bb (basic_block bb, gcov_
> edge old_edge;
> gimple_stmt_iterator si;
> int flags;
> + bool need_debug_cleanup = false;
>
> /* Use the indices from the original blocks to create edges for the
> new ones. */
> @@ -1864,7 +1866,7 @@ copy_edges_for_bb (basic_block bb, gcov_
> }
>
> if (bb->index == ENTRY_BLOCK || bb->index == EXIT_BLOCK)
> - return;
> + return false;
>
> for (si = gsi_start_bb (new_bb); !gsi_end_p (si);)
> {
> @@ -1899,6 +1901,13 @@ copy_edges_for_bb (basic_block bb, gcov_
> if (can_throw || nonlocal_goto)
> {
> if (!gsi_end_p (si))
> + {
> + while (!gsi_end_p (si) && is_gimple_debug (gsi_stmt (si)))
> + gsi_next (&si);
> + if (gsi_end_p (si))
> + need_debug_cleanup = true;
> + }
> + if (!gsi_end_p (si))
> /* Note that bb's predecessor edges aren't necessarily
> right at this point; split_block doesn't care. */
> {
> @@ -1923,6 +1932,7 @@ copy_edges_for_bb (basic_block bb, gcov_
> update_ssa_across_abnormal_edges (gimple_bb (copy_stmt), ret_bb,
> can_throw, nonlocal_goto);
> }
> + return need_debug_cleanup;
> }
>
> /* Copy the PHIs. All blocks and edges are copied, some blocks
> @@ -2059,6 +2069,63 @@ initialize_cfun (tree new_fndecl, tree c
> pop_cfun ();
> }
>
> +/* Helper function for copy_cfg_body. Move debug stmts from the end
> + of NEW_BB to the beginning of successor basic blocks when needed. If the
> + successor has multiple predecessors, reset them, otherwise keep
> + their value. */
> +
> +static void
> +maybe_move_debug_stmts_to_successors (copy_body_data *id, basic_block new_bb)
> +{
> + edge e;
> + edge_iterator ei;
> + gimple_stmt_iterator si = gsi_last_nondebug_bb (new_bb);
> +
> + if (gsi_end_p (si)
> + || gsi_one_before_end_p (si)
> + || !(stmt_can_throw_internal (gsi_stmt (si))
> + || stmt_can_make_abnormal_goto (gsi_stmt (si))))
> + return;
> +
> + FOR_EACH_EDGE (e, ei, new_bb->succs)
> + {
> + gimple_stmt_iterator ssi = gsi_last_bb (new_bb);
> + gimple_stmt_iterator dsi = gsi_after_labels (e->dest);
> + while (is_gimple_debug (gsi_stmt (ssi)))
> + {
> + gimple stmt = gsi_stmt (ssi), new_stmt;
> + tree var;
> + tree value;
> +
> + /* For the last edge move the debug stmts instead of copying
> + them. */
> + if (ei_one_before_end_p (ei))
> + {
> + si = ssi;
> + gsi_prev (&ssi);
> + if (!single_pred_p (e->dest))
> + gimple_debug_bind_reset_value (stmt);
> + gsi_remove (&si, false);
> + gsi_insert_before (&dsi, stmt, GSI_SAME_STMT);
> + continue;
> + }
> +
> + var = gimple_debug_bind_get_var (stmt);
> + if (single_pred_p (e->dest))
> + {
> + value = gimple_debug_bind_get_value (stmt);
> + value = unshare_expr (value);
> + }
> + else
> + value = NULL_TREE;
> + new_stmt = gimple_build_debug_bind (var, value, stmt);
> + gsi_insert_before (&dsi, new_stmt, GSI_SAME_STMT);
> + VEC_safe_push (gimple, heap, id->debug_stmts, new_stmt);
> + gsi_prev (&ssi);
> + }
> + }
> +}
> +
> /* Make a copy of the body of FN so that it can be inserted inline in
> another function. Walks FN via CFG, returns new fndecl. */
>
> @@ -2072,6 +2139,7 @@ copy_cfg_body (copy_body_data * id, gcov
> struct function *cfun_to_copy;
> basic_block bb;
> tree new_fndecl = NULL;
> + bool need_debug_cleanup = false;
> gcov_type count_scale;
> int last;
>
> @@ -2112,7 +2180,7 @@ copy_cfg_body (copy_body_data * id, gcov
>
> /* Now that we've duplicated the blocks, duplicate their edges. */
> FOR_ALL_BB_FN (bb, cfun_to_copy)
> - copy_edges_for_bb (bb, count_scale, exit_block_map);
> + need_debug_cleanup |= copy_edges_for_bb (bb, count_scale, exit_block_map);
>
> if (gimple_in_ssa_p (cfun))
> FOR_ALL_BB_FN (bb, cfun_to_copy)
> @@ -2120,6 +2188,10 @@ copy_cfg_body (copy_body_data * id, gcov
>
> FOR_ALL_BB_FN (bb, cfun_to_copy)
> {
> + if (need_debug_cleanup
> + && bb->index != ENTRY_BLOCK
> + && bb->index != EXIT_BLOCK)
> + maybe_move_debug_stmts_to_successors (id, (basic_block) bb->aux);
> ((basic_block)bb->aux)->aux = NULL;
> bb->aux = NULL;
> }
> @@ -2127,7 +2199,11 @@ copy_cfg_body (copy_body_data * id, gcov
> /* Zero out AUX fields of newly created block during EH edge
> insertion. */
> for (; last < last_basic_block; last++)
> - BASIC_BLOCK (last)->aux = NULL;
> + {
> + if (need_debug_cleanup)
> + maybe_move_debug_stmts_to_successors (id, BASIC_BLOCK (last));
> + BASIC_BLOCK (last)->aux = NULL;
> + }
> entry_block_map->aux = NULL;
> exit_block_map->aux = NULL;
>
> --- gcc/testsuite/g++.dg/debug/pr44182.C.jj 2010-05-31 14:52:51.000000000 +0200
> +++ gcc/testsuite/g++.dg/debug/pr44182.C 2010-05-31 14:52:51.000000000 +0200
> @@ -0,0 +1,26 @@
> +// PR tree-optimization/44182
> +// { dg-do compile }
> +// { dg-options "-fcompare-debug" }
> +
> +struct S
> +{
> + int i;
> + S ();
> + ~S ();
> + void f1 ();
> + void f2 (S s)
> + {
> + f3 (s.i);
> + for (int j = 0; j < s.i; j++) f1 ();
> + }
> + void f3 (int j)
> + {
> + if (j > i) f1 ();
> + }
> +};
> +
> +void
> +f (S *x)
> +{
> + x->f2 (S ());
> +}
>
>
> Jakub
>
>
--
Richard Guenther <rguenther@suse.de>
Novell / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746 - GF: Markus Rex