From 2326627eb19d8c21251fd60479f1a190621c475b Mon Sep 17 00:00:00 2001
From: Richard Biener <rguenther@suse.de>
Date: Tue, 4 May 2021 09:18:11 +0200
Subject: [PATCH] tree-optimization/100398 - avoid DSE of control flow stmt
The following makes sure to preserve control altering stmts
when removing trivially dead stmts in DSE.
2021-05-04 Richard Biener <rguenther@suse.de>
PR tree-optimization/100398
* tree-ssa-dse.c (pass_dse::execute): Preserve control
altering stmts.
* gcc.dg/torture/pr100398.c: New testcase.
---
gcc/testsuite/gcc.dg/torture/pr100398.c | 13 +++++++++++++
gcc/tree-ssa-dse.c | 1 +
2 files changed, 14 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/torture/pr100398.c
diff --git a/gcc/testsuite/gcc.dg/torture/pr100398.c b/gcc/testsuite/gcc.dg/torture/pr100398.c
new file mode 100644
index 000000000000..41eaddee27e4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr100398.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+
+int
+test5_limit (void)
+{
+ int addr;
+
+ asm goto ("" : "+r" (addr) : : : t_err);
+ return 0;
+
+ t_err:
+ return 1;
+}
diff --git a/gcc/tree-ssa-dse.c b/gcc/tree-ssa-dse.c
index dfa6d3147270..d7cf74770285 100644
--- a/gcc/tree-ssa-dse.c
+++ b/gcc/tree-ssa-dse.c
@@ -1219,6 +1219,7 @@ pass_dse::execute (function *fun)
dead SSA defs. */
if (has_zero_uses (DEF_FROM_PTR (def_p))
&& !gimple_has_side_effects (stmt)
+ && !is_ctrl_altering_stmt (stmt)
&& !stmt_unremovable_because_of_non_call_eh_p (cfun, stmt))
{
if (dump_file && (dump_flags & TDF_DETAILS))
--
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