From e63d76234d18cac731c4f3610d513bd8b39b5520 Mon Sep 17 00:00:00 2001
From: Richard Biener <rguenther@suse.de>
Date: Wed, 21 Jul 2021 09:14:24 +0200
Subject: [PATCH] c/101512 - fix missing address-taking in
 c_common_mark_addressable_vec

c_common_mark_addressable_vec fails to look through C_MAYBE_CONST_EXPR
in the case it isn't at the toplevel.

2021-07-21  Richard Biener  <rguenther@suse.de>

	PR c/101512
gcc/c-family/
	* c-common.c (c_common_mark_addressable_vec): Look through
	C_MAYBE_CONST_EXPR even if not at the toplevel.

gcc/testsuite/
	* gcc.dg/torture/pr101512.c: New testcase.
---
 gcc/c-family/c-common.c                 | 11 +++++++----
 gcc/testsuite/gcc.dg/torture/pr101512.c | 11 +++++++++++
 2 files changed, 18 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/torture/pr101512.c

diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index aacdfb46a02..21da679cd3c 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -6894,10 +6894,13 @@ complete_flexible_array_elts (tree init)
 void 
 c_common_mark_addressable_vec (tree t)
 {   
-  if (TREE_CODE (t) == C_MAYBE_CONST_EXPR)
-    t = C_MAYBE_CONST_EXPR_EXPR (t);
-  while (handled_component_p (t))
-    t = TREE_OPERAND (t, 0);
+  while (handled_component_p (t) || TREE_CODE (t) == C_MAYBE_CONST_EXPR)
+    {
+      if (TREE_CODE (t) == C_MAYBE_CONST_EXPR)
+	t = C_MAYBE_CONST_EXPR_EXPR (t);
+      else
+	t = TREE_OPERAND (t, 0);
+    }
   if (!VAR_P (t)
       && TREE_CODE (t) != PARM_DECL
       && TREE_CODE (t) != COMPOUND_LITERAL_EXPR)
diff --git a/gcc/testsuite/gcc.dg/torture/pr101512.c b/gcc/testsuite/gcc.dg/torture/pr101512.c
new file mode 100644
index 00000000000..a25da2aa0b5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr101512.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-w -Wno-psabi" } */
+
+int n();
+typedef unsigned long V __attribute__ ((vector_size (64)));
+V
+foo (int i, V v)
+{
+  i = ((V)(V){n()})[n()];
+  return v + i;
+}