[ARC] Do not emit ZOL in the presence of text jump tables.

Avoid emitting lp instruction when in its ZOL body we find a jump
table data in text section. One of the reason is the jump tables size
can be changed latter on, hence the total ZOL length may be wrongly
computed.

gcc/
xxxx-xx-xx  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc.c (hwloop_optimize): Bailout when detecting a
	jump table data in the text section.

From-SVN: r266067

gcc/ChangeLog

 2018-11-13  Claudiu Zissulescu  <claziss@synopsys.com>
 
+	* config/arc/arc.c (hwloop_optimize): Bailout when detecting a
+	jump table data in the text section.
+
+2018-11-13  Claudiu Zissulescu  <claziss@synopsys.com>
+
 	* config/arc/arc.c (arc_eh_return_address_location): Repurpose it
 	to fit the eh_return pattern.
 	* config/arc/arc.md (eh_return): Define.

gcc/config/arc/arc.c

@@ -7861,7 +7861,17 @@ hwloop_optimize (hwloop_info loop)
   for (insn = loop->start_label;
        insn && insn != loop->loop_end;
        insn = NEXT_INSN (insn))
-    length += NONDEBUG_INSN_P (insn) ? get_attr_length (insn) : 0;
+    {
+      length += NONDEBUG_INSN_P (insn) ? get_attr_length (insn) : 0;
+      if (JUMP_TABLES_IN_TEXT_SECTION
+	  && JUMP_TABLE_DATA_P (insn))
+	{
+	  if (dump_file)
+	    fprintf (dump_file, ";; loop %d has a jump table\n",
+		     loop->loop_no);
+	  return false;
+	}
+    }
 
   if (!insn)
     {