re PR debug/90733 (ICE in simplify_subreg, at simplify-rtx.c:6440)

	PR debug/90733
	* var-tracking.c (vt_expand_loc_callback): Don't create raw subregs
	with VOIDmode inner operands.

	* gcc.dg/pr90733.c: New test.

From-SVN: r271952

gcc/ChangeLog

+2019-06-05  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/90733
+	* var-tracking.c (vt_expand_loc_callback): Don't create raw subregs
+	with VOIDmode inner operands.
+
 2019-06-05  Richard Biener  <rguenther@suse.de>
 
 	PR middle-end/90726

gcc/testsuite/ChangeLog

+2019-06-05  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/90733
+	* gcc.dg/pr90733.c: New test.
+
 2019-06-05  Richard Biener  <rguenther@suse.de>
 
 	PR middle-end/90726

gcc/testsuite/gcc.dg/pr90733.c

+/* PR debug/90733 */
+/* { dg-do compile } */
+/* { dg-options "-g -O2 -w" } */
+
+struct S { unsigned a : 1; };
+union U { struct S b; _Complex unsigned c; };
+
+union U
+foo (union U d)
+{
+  union U e = d;
+  return e;
+}
+
+int
+bar (void)
+{
+  union U x, y;
+  x.c = x.b.a;
+  y = foo (x);
+  return x.c != y.c;
+}

gcc/var-tracking.c

@@ -8491,7 +8491,7 @@ vt_expand_loc_callback (rtx x, bitmap regs,
 
       /* Invalid SUBREGs are ok in debug info.  ??? We could try
 	 alternate expansions for the VALUE as well.  */
-      if (!result)
+      if (!result && GET_MODE (subreg) != VOIDmode)
 	result = gen_rtx_raw_SUBREG (GET_MODE (x), subreg, SUBREG_BYTE (x));
 
       return result;