From 0f3f0e4e97a0d564f87cbd8a7dfdaf9be3665fe3 Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Mon, 1 Jan 2018 00:52:01 +0100
Subject: [PATCH] re PR rtl-optimization/83608 (ICE in convert_move, at
 expr.c:229 in GIMPLE store merging pass)

	PR middle-end/83608
	* expr.c (store_expr_with_bounds): Use simplify_gen_subreg instead of
	convert_modes if target mode has the right side, but different mode
	class.

	* g++.dg/opt/pr83608.C: New test.

From-SVN: r256053
---
 gcc/ChangeLog                      |  5 +++++
 gcc/expr.c                         | 17 +++++++++++++++--
 gcc/testsuite/ChangeLog            |  3 +++
 gcc/testsuite/g++.dg/opt/pr83608.C | 28 ++++++++++++++++++++++++++++
 4 files changed, 51 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/opt/pr83608.C

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 98073e8f942..a0c9bf86bb5 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,10 @@
 2018-01-01  Jakub Jelinek  <jakub@redhat.com>
 
+	PR middle-end/83608
+	* expr.c (store_expr_with_bounds): Use simplify_gen_subreg instead of
+	convert_modes if target mode has the right side, but different mode
+	class.
+
 	PR middle-end/83609
 	* expr.c (expand_assignment): Fix up a typo in simplify_gen_subreg
 	last argument when extracting from CONCAT.  If either from_real or
diff --git a/gcc/expr.c b/gcc/expr.c
index 0a735762e51..bae853c00cc 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -5638,8 +5638,21 @@ store_expr_with_bounds (tree exp, rtx target, int call_param_p,
   if (CONSTANT_P (temp) && GET_MODE (temp) == VOIDmode
       && TREE_CODE (exp) != ERROR_MARK
       && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
-    temp = convert_modes (GET_MODE (target), TYPE_MODE (TREE_TYPE (exp)),
-			  temp, TYPE_UNSIGNED (TREE_TYPE (exp)));
+    {
+      if (GET_MODE_CLASS (GET_MODE (target))
+	  != GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (exp)))
+	  && GET_MODE_BITSIZE (GET_MODE (target))
+	     == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (exp))))
+	{
+	  rtx t = simplify_gen_subreg (GET_MODE (target), temp,
+				       TYPE_MODE (TREE_TYPE (exp)), 0);
+	  if (t)
+	    temp = t;
+	}
+      if (GET_MODE (temp) == VOIDmode)
+	temp = convert_modes (GET_MODE (target), TYPE_MODE (TREE_TYPE (exp)),
+			      temp, TYPE_UNSIGNED (TREE_TYPE (exp)));
+    }
 
   /* If value was not generated in the target, store it there.
      Convert the value to TARGET's type first if necessary and emit the
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 59c9543de5f..8b5c062e1f0 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2018-01-01  Jakub Jelinek  <jakub@redhat.com>
 
+	PR middle-end/83608
+	* g++.dg/opt/pr83608.C: New test.
+
 	PR middle-end/83609
 	* gcc.dg/pr83609.c: New test.
 	* g++.dg/opt/pr83609.C: New test.
diff --git a/gcc/testsuite/g++.dg/opt/pr83608.C b/gcc/testsuite/g++.dg/opt/pr83608.C
new file mode 100644
index 00000000000..555e5877e75
--- /dev/null
+++ b/gcc/testsuite/g++.dg/opt/pr83608.C
@@ -0,0 +1,28 @@
+// PR middle-end/83608
+// { dg-do compile }
+// { dg-options "-O2" }
+
+template <typename> class B;
+template <> struct B<float>
+{
+  float foo () { return __real__ b; }
+  _Complex double b;
+};
+
+void bar (int);
+
+template <class T>
+void
+baz ()
+{
+  B<T> h;
+  T *a = (T *) &h;
+  a[0] = a[1] = 6;
+  h.foo () ? void () : bar (7);
+}
+
+int
+main ()
+{
+  baz<float> ();
+}
-- 
2.30.2