Fix PR 102908: wrongly removing null pointer loads
Commit Message
From: Andrew Pinski <apinski@marvell.com>
Just like PR 100382, here we have a DCE removing a
null pointer load which is needed still.
In this case, execute_fixup_cfg removes a store (correctly)
and then removes the null load (incorrectly) due to
not checking stmt_unremovable_because_of_non_call_eh_p.
This patch adds the check in the similar way as the patch
to fix PR 100382 did.
gcc/ChangeLog:
* tree-ssa-dce.c (simple_dce_from_worklist):
Check stmt_unremovable_because_of_non_call_eh_p also
before removing the statement.
---
gcc/tree-ssa-dce.c | 5 +++++
1 file changed, 5 insertions(+)
Comments
On Sun, Oct 24, 2021 at 11:28 AM apinski--- via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> From: Andrew Pinski <apinski@marvell.com>
>
> Just like PR 100382, here we have a DCE removing a
> null pointer load which is needed still.
> In this case, execute_fixup_cfg removes a store (correctly)
> and then removes the null load (incorrectly) due to
> not checking stmt_unremovable_because_of_non_call_eh_p.
> This patch adds the check in the similar way as the patch
> to fix PR 100382 did.
OK.
Thanks,
Richard.
> gcc/ChangeLog:
>
> * tree-ssa-dce.c (simple_dce_from_worklist):
> Check stmt_unremovable_because_of_non_call_eh_p also
> before removing the statement.
> ---
> gcc/tree-ssa-dce.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c
> index 372e0691ae6..1281e67489c 100644
> --- a/gcc/tree-ssa-dce.c
> +++ b/gcc/tree-ssa-dce.c
> @@ -1828,6 +1828,11 @@ simple_dce_from_worklist (bitmap worklist)
> if (gimple_has_side_effects (t))
> continue;
>
> + /* Don't remove statements that are needed for non-call
> + eh to work. */
> + if (stmt_unremovable_because_of_non_call_eh_p (cfun, t))
> + continue;
> +
> /* Add uses to the worklist. */
> ssa_op_iter iter;
> use_operand_p use_p;
> --
> 2.17.1
>
@@ -1828,6 +1828,11 @@ simple_dce_from_worklist (bitmap worklist)
if (gimple_has_side_effects (t))
continue;
+ /* Don't remove statements that are needed for non-call
+ eh to work. */
+ if (stmt_unremovable_because_of_non_call_eh_p (cfun, t))
+ continue;
+
/* Add uses to the worklist. */
ssa_op_iter iter;
use_operand_p use_p;