re PR debug/83666 (ICE: SIGFPE with -O2 -g --param=sccvn-max-scc-size=10)

	PR debug/83666
	* cfgexpand.c (expand_dbeug_expr) <case BIT_FIELD_REF>: Punt if mode
	is BLKmode and bitpos not zero or mode change is needed.

	* gcc.dg/pr83666.c: New test.

From-SVN: r256232

gcc/ChangeLog

+2018-01-04  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/83666
+	* cfgexpand.c (expand_dbeug_expr) <case BIT_FIELD_REF>: Punt if mode
+	is BLKmode and bitpos not zero or mode change is needed.
+
 2018-01-04  Richard Sandiford  <richard.sandiford@linaro.org>
 
 	PR target/83675

gcc/cfgexpand.c

@@ -4560,7 +4560,7 @@ expand_debug_expr (tree exp)
 	if (maybe_lt (bitpos, 0))
           return NULL;
 
-	if (GET_MODE (op0) == BLKmode)
+	if (GET_MODE (op0) == BLKmode || mode == BLKmode)
 	  return NULL;
 
 	poly_int64 bytepos;

gcc/testsuite/ChangeLog

+2018-01-04  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/83666
+	* gcc.dg/pr83666.c: New test.
+
 2018-01-04  Uros Bizjak  <ubizjak@gmail.com>
 
 	PR target/83628

gcc/testsuite/gcc.dg/pr83666.c

+/* PR debug/83666 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -g --param=sccvn-max-scc-size=10 -Wno-psabi" } */
+
+typedef int __attribute__ ((vector_size (64))) V;
+
+int c, d;
+short e;
+V g;
+
+V
+bar (void)
+{
+  g[1] = d;
+  do
+    {
+      e += c;
+      g = g > 0;
+    }
+  while (g[1]);
+  return g;
+}
+
+void
+foo (void)
+{
+  int x = bar ()[3];
+}