From 074ee8d9a91d7573c1e8774a22e4e08f923adb18 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Mon, 15 Nov 2021 17:37:10 -0800
Subject: [PATCH] Add a missing return when transforming atomic bit test and
 operations

When failing to transform equivalent, but slighly different cases of
atomic bit test and operations to their canonical forms, return
immediately.

gcc/

	PR middle-end/103268
	* tree-ssa-ccp.c (optimize_atomic_bit_test_and): Add a missing
	return.

gcc/testsuite/

	PR middle-end/103268
	* gcc.dg/pr103268-1.c: New test.
	* gcc.dg/pr103268-2.c: Likewise.
---
 gcc/testsuite/gcc.dg/pr103268-1.c | 10 ++++++++++
 gcc/testsuite/gcc.dg/pr103268-2.c | 12 ++++++++++++
 gcc/tree-ssa-ccp.c                |  2 ++
 3 files changed, 24 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/pr103268-1.c
 create mode 100644 gcc/testsuite/gcc.dg/pr103268-2.c

diff --git a/gcc/testsuite/gcc.dg/pr103268-1.c b/gcc/testsuite/gcc.dg/pr103268-1.c
new file mode 100644
index 00000000000..6d583d55d6d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr103268-1.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+extern int si;
+long
+test_types (void)
+{
+  unsigned int u2 = __atomic_fetch_xor (&si, 0, 5);
+  return u2;
+}
diff --git a/gcc/testsuite/gcc.dg/pr103268-2.c b/gcc/testsuite/gcc.dg/pr103268-2.c
new file mode 100644
index 00000000000..12283bb43d9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr103268-2.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+ 
+extern long pscc_a_2_3;
+extern int pscc_a_1_4;
+
+void
+pscc (void)
+{
+  pscc_a_1_4 = __sync_fetch_and_and (&pscc_a_2_3, 1);
+}
+
diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c
index 0666dc652d0..18d57729d8a 100644
--- a/gcc/tree-ssa-ccp.c
+++ b/gcc/tree-ssa-ccp.c
@@ -3638,6 +3638,8 @@ optimize_atomic_bit_test_and (gimple_stmt_iterator *gsip,
 	      use_stmt = use_nop_stmt;
 	    }
 	}
+      else
+	return;
 
       if (!bit)
 	{
-- 
2.47.3