From: Jakub Jelinek <jakub@redhat.com>
Date: Mon, 3 May 2021 10:03:02 +0000 (+0200)
Subject: tree-ssa-dse: Fix up go.test/test/fixedbugs/issue16095.go miscompilation [PR100382]
X-Git-Tag: basepoints/gcc-13~7935
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=80bbb7ff83d81544b09820428bdd7db9f50fe362;p=thirdparty%2Fgcc.git

tree-ssa-dse: Fix up go.test/test/fixedbugs/issue16095.go miscompilation [PR100382]

The new DCE code inside of tree DSE removes in -fnon-call-exceptions
go code a load from NULL pointer the testcase relies on throwing an
exception and so the test hangs.

The following patch just repeats a check that e.g. tree-ssa-dce.c
uses to prevent this.

2021-05-03  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/100382
	* tree-ssa-dse.c: Include tree-eh.h.
	(dse_dom_walker::before_dom_children): Don't remove stmts if
	stmt_unremovable_because_of_non_call_eh_p is true.
---

diff --git a/gcc/tree-ssa-dse.c b/gcc/tree-ssa-dse.c
index aecf6ab8c46c..76929fa03c7a 100644
--- a/gcc/tree-ssa-dse.c
+++ b/gcc/tree-ssa-dse.c
@@ -39,6 +39,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "builtins.h"
 #include "gimple-fold.h"
 #include "gimplify.h"
+#include "tree-eh.h"
 
 /* This file implements dead store elimination.
 
@@ -1193,7 +1194,8 @@ dse_dom_walker::before_dom_children (basic_block bb)
 	  /* When we remove dead stores make sure to also delete trivially
 	     dead SSA defs.  */
 	  if (has_zero_uses (DEF_FROM_PTR (def_p))
-	      && !gimple_has_side_effects (stmt))
+	      && !gimple_has_side_effects (stmt)
+	      && !stmt_unremovable_because_of_non_call_eh_p (cfun, stmt))
 	    {
 	      if (dump_file && (dump_flags & TDF_DETAILS))
 		{