From f469220df6185dee831686631c570245769887da Mon Sep 17 00:00:00 2001
From: Richard Biener <rguenther@suse.de>
Date: Thu, 25 Apr 2019 11:15:35 +0000
Subject: [PATCH] re PR middle-end/90194 (ICE in expand_debug_expr, at
 cfgexpand.c:5244)

2019-04-25  Richard Biener  <rguenther@suse.de>

	PR middle-end/90194
	* match.pd: Add pattern to simplify view-conversion of an
	empty constructor.

	* g++.dg/torture/pr90194.C: New testcase.

From-SVN: r270569
---
 gcc/ChangeLog                          |  6 ++++++
 gcc/match.pd                           |  7 +++++++
 gcc/testsuite/ChangeLog                |  5 +++++
 gcc/testsuite/g++.dg/torture/pr90194.C | 18 ++++++++++++++++++
 4 files changed, 36 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/torture/pr90194.C

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d4c5b31613c..2aeafe1d30c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2019-04-25  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/90194
+	* match.pd: Add pattern to simplify view-conversion of an
+	empty constructor.
+
 2019-04-24  Clement Chigot  <clement.chigot@atos.net>
 
 	* config/rs6000/aix71.h (SUBTARGET_OVERRIDE_OPTIONS): Disable
diff --git a/gcc/match.pd b/gcc/match.pd
index 0d82beab45b..039ddacfed1 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -2596,6 +2596,13 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 	       && TYPE_UNSIGNED (TREE_TYPE (@1)))))
    (view_convert @1)))
 
+/* Simplify a view-converted empty constructor.  */
+(simplify
+  (view_convert CONSTRUCTOR@0)
+  (if (TREE_CODE (@0) != SSA_NAME
+       && CONSTRUCTOR_NELTS (@0) == 0)
+   { build_zero_cst (type); }))
+
 /* Re-association barriers around constants and other re-association
    barriers can be removed.  */
 (simplify
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 115c22088ef..f1291f11c52 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2019-04-25  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/90194
+	* g++.dg/torture/pr90194.C: New testcase.
+
 2019-04-24  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/90236
diff --git a/gcc/testsuite/g++.dg/torture/pr90194.C b/gcc/testsuite/g++.dg/torture/pr90194.C
new file mode 100644
index 00000000000..f0c3a77db8a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr90194.C
@@ -0,0 +1,18 @@
+// { dg-do compile }
+// { dg-additional-options "-g" }
+
+struct cb {
+    int yr;
+};
+
+void *
+operator new (__SIZE_TYPE__, void *nq)
+{
+  return nq;
+}
+
+void
+af (int xn)
+{
+  new (&xn) cb { };
+}