middle-end/94479 - fix gimplification of address

When gimplifying an address operand we may expose an indirect
ref via DECL_VALUE_EXPR for example.  This is dealt with in the
code already but it fails to consider that INDIRECT_REFs get
gimplified to MEM_REFs.

Fixed which makes the ICE observed on x86_64-netbsd go away.

2020-04-07  Richard Biener  <rguenther@suse.de>

	PR middle-end/94479
	* gimplify.c (gimplify_addr_expr): Also consider generated
	MEM_REFs.

	* gcc.dg/torture/pr94479.c: New testcase.

gcc/ChangeLog

+2020-04-07  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/94479
+	* gimplify.c (gimplify_addr_expr): Also consider generated
+	MEM_REFs.
+
 2020-04-07  Andre Vieira  <andre.simoesdiasvieira@arm.com>
 
 	* config/arm/arm_mve.h: Add C++ polymorphism and fix preserve MACROs.

gcc/gimplify.c

@@ -6181,7 +6181,9 @@ gimplify_addr_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
 
       /* For various reasons, the gimplification of the expression
 	 may have made a new INDIRECT_REF.  */
-      if (TREE_CODE (op0) == INDIRECT_REF)
+      if (TREE_CODE (op0) == INDIRECT_REF
+	  || (TREE_CODE (op0) == MEM_REF
+	      && integer_zerop (TREE_OPERAND (op0, 1))))
 	goto do_indirect_ref;
 
       mark_addressable (TREE_OPERAND (expr, 0));

gcc/testsuite/ChangeLog

+2020-04-07  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/94479
+	* gcc.dg/torture/pr94479.c: New testcase.
+
 2020-04-01  Fritz Reese  <foreese@gcc.gnu.org>
 
 	 PR fortran/93871

gcc/testsuite/gcc.dg/torture/pr94479.c

+/* { dg-do compile } */
+/* { dg-require-stack-check "specific" } */
+/* { dg-additional-options "-fstack-check -w" } */
+
+int a;
+struct b {
+    char c;
+    void *d;  
+};
+struct b e() {
+    struct b f[] = {{}, "", f, a};
+}