[PATCH] Fix typos in move_sese_region_to_fn

[PATCH] Fix typos in move_sese_region_to_fn

[Kewen.Lin]

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Hi,

This patch is to fix the typos in the move_sese_region_to_fn.
As mentioned here [1], I tried to debug the test case
gcc.dg/graphite/pr83359.c with trunk, but I found it didn't
go into the hunk guard with "if (moved_orig_loop_num)".  So
I switched to commit 555758de90074 (also reproduced the ICE
with 555758de90074~ to ensure my used command step is correct),
I noticed the compilation of the test case only covers the
hunk

	else
	  {
	    moved_orig_loop_num[dloop->orig_loop_num] = -1;
	    dloop->orig_loop_num = 0;
	  }

it doesn't touch the hunk

	if ((*larray)[dloop->orig_loop_num] != NULL
	    && get_loop (saved_cfun, dloop->orig_loop_num) == NULL)
	  {
	    if (moved_orig_loop_num[dloop->orig_loop_num] >= 0
		&& moved_orig_loop_num[dloop->orig_loop_num] < 2)
	      moved_orig_loop_num[dloop->orig_loop_num]++;
	    dloop->orig_loop_num = (*larray)[dloop->orig_loop_num]->num;
	  }

so the following hunk using dloop and guarded with 
"if (moved_orig_loop_num[orig_loop_num] == 2)" doesn't get executed.

It explains why the problem doesn't get exposed before.

By looking to the code using dloop, I think it's a copy/paste typo,
the assertion

	      gcc_assert ((*larray)[dloop->orig_loop_num] != NULL
			  && (get_loop (saved_cfun, dloop->orig_loop_num)
			      == NULL));

would like to ensure the condition in the previous
loop iterating is true, that is:

	if ((*larray)[dloop->orig_loop_num] != NULL
	    && get_loop (saved_cfun, dloop->orig_loop_num) == NULL)

But in that context, I think the expected original number has been
assigned to variable orig_loop_num by extracting from the arg0
of IFN_LOOP_DIST_ALIAS call.  So replace those ones.

Is it ok for trunk?

[1] https://gcc.gnu.org/pipermail/gcc-patches/2021-July/576367.html

BR,
Kewen
-----
gcc/ChangeLog:

	* tree-cfg.c (move_sese_region_to_fn): Fix typos on dloop.

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diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index 48ee8c011ab..9883eaaa9bf 100644
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -7747,9 +7747,8 @@ move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb,
 
   /* Fix up orig_loop_num.  If the block referenced in it has been moved
      to dest_cfun, update orig_loop_num field, otherwise clear it.  */
-  class loop *dloop = NULL;
   signed char *moved_orig_loop_num = NULL;
-  for (class loop *dloop : loops_list (dest_cfun, 0))
+  for (auto dloop : loops_list (dest_cfun, 0))
     if (dloop->orig_loop_num)
       {
 	if (moved_orig_loop_num == NULL)
@@ -7787,11 +7786,10 @@ move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb,
 	      /* If we have moved both loops with this orig_loop_num into
 		 dest_cfun and the LOOP_DIST_ALIAS call is being moved there
 		 too, update the first argument.  */
-	      gcc_assert ((*larray)[dloop->orig_loop_num] != NULL
-			  && (get_loop (saved_cfun, dloop->orig_loop_num)
-			      == NULL));
+	      gcc_assert ((*larray)[orig_loop_num] != NULL
+			  && (get_loop (saved_cfun, orig_loop_num) == NULL));
 	      tree t = build_int_cst (integer_type_node,
-				      (*larray)[dloop->orig_loop_num]->num);
+				      (*larray)[orig_loop_num]->num);
 	      gimple_call_set_arg (g, 0, t);
 	      update_stmt (g);
 	      /* Make sure the following loop will not update it.  */

Re: [PATCH] Fix typos in move_sese_region_to_fn

[Richard Biener]

On Fri, Jul 30, 2021 at 1:15 PM Kewen.Lin <linkw@linux.ibm.com> wrote:
>
> Hi,
>
> This patch is to fix the typos in the move_sese_region_to_fn.
> As mentioned here [1], I tried to debug the test case
> gcc.dg/graphite/pr83359.c with trunk, but I found it didn't
> go into the hunk guard with "if (moved_orig_loop_num)".  So
> I switched to commit 555758de90074 (also reproduced the ICE
> with 555758de90074~ to ensure my used command step is correct),
> I noticed the compilation of the test case only covers the
> hunk
>
>         else
>           {
>             moved_orig_loop_num[dloop->orig_loop_num] = -1;
>             dloop->orig_loop_num = 0;
>           }
>
> it doesn't touch the hunk
>
>         if ((*larray)[dloop->orig_loop_num] != NULL
>             && get_loop (saved_cfun, dloop->orig_loop_num) == NULL)
>           {
>             if (moved_orig_loop_num[dloop->orig_loop_num] >= 0
>                 && moved_orig_loop_num[dloop->orig_loop_num] < 2)
>               moved_orig_loop_num[dloop->orig_loop_num]++;
>             dloop->orig_loop_num = (*larray)[dloop->orig_loop_num]->num;
>           }
>
> so the following hunk using dloop and guarded with
> "if (moved_orig_loop_num[orig_loop_num] == 2)" doesn't get executed.
>
> It explains why the problem doesn't get exposed before.
>
> By looking to the code using dloop, I think it's a copy/paste typo,
> the assertion
>
>               gcc_assert ((*larray)[dloop->orig_loop_num] != NULL
>                           && (get_loop (saved_cfun, dloop->orig_loop_num)
>                               == NULL));
>
> would like to ensure the condition in the previous
> loop iterating is true, that is:
>
>         if ((*larray)[dloop->orig_loop_num] != NULL
>             && get_loop (saved_cfun, dloop->orig_loop_num) == NULL)
>
> But in that context, I think the expected original number has been
> assigned to variable orig_loop_num by extracting from the arg0
> of IFN_LOOP_DIST_ALIAS call.  So replace those ones.
>
> Is it ok for trunk?

OK.

Thanks,
Richard.

> [1] https://gcc.gnu.org/pipermail/gcc-patches/2021-July/576367.html
>
> BR,
> Kewen
> -----
> gcc/ChangeLog:
>
>         * tree-cfg.c (move_sese_region_to_fn): Fix typos on dloop.