From: Andrew Pinski <apinski@marvell.com>
Date: Sat, 23 Oct 2021 19:24:43 +0000 (+0000)
Subject: Fix PR 102908: wrongly removing null pointer loads
X-Git-Tag: basepoints/gcc-13~3652
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7518e4c2f0758daac5d650d400565cf49ac3c8c5;p=thirdparty%2Fgcc.git

Fix PR 102908: wrongly removing null pointer loads

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.
---

diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c
index 372e0691ae63..1281e67489c0 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;