re PR middle-end/81832 (ICE in expand_LOOP_DIST_ALIAS, at internal-fn.c:2273)

	PR tree-optimization/81832
	* tree-ssa-loop-ch.c (should_duplicate_loop_header_p): Don't
	copy loop header which has IFN_LOOP_DIST_ALIAS call.

	gcc/testsuite
	* gcc.dg/tree-ssa/pr81832.c: New test.

From-SVN: r251123

gcc/ChangeLog

+2017-08-16  Bin Cheng  <bin.cheng@arm.com>
+
+	PR tree-optimization/81832
+	* tree-ssa-loop-ch.c (should_duplicate_loop_header_p): Don't
+	copy loop header which has IFN_LOOP_DIST_ALIAS call.
+
 2017-08-16  Marek Polacek  <polacek@redhat.com>
 
 	PR middle/81695

gcc/testsuite/ChangeLog

+2017-08-16  Bin Cheng  <bin.cheng@arm.com>
+
+	PR tree-optimization/81832
+	* gcc.dg/tree-ssa/pr81832.c: New test.
+
 2017-08-16  Richard Sandiford  <richard.sandiford@linaro.org>
 
 	PR tree-optimization/81835

gcc/testsuite/gcc.dg/tree-ssa/pr81832.c

+/* { dg-do compile } */
+/* { dg-options "-O3" } */
+
+int a, b, *c;
+void d(void)
+{
+    int **e;
+    for(;;)
+        for(int f = 1; f <= 6; f++)
+        {
+            b = 0;
+            if(a)
+g:
+                while(a++);
+            if (**e);
+            else
+            {
+                *c = a;
+                goto g;
+            }
+        }
+}

gcc/tree-ssa-loop-ch.c

@@ -119,7 +119,10 @@ should_duplicate_loop_header_p (basic_block header, struct loop *loop,
 	continue;
 
       if (gimple_code (last) == GIMPLE_CALL
-	  && !gimple_inexpensive_call_p (as_a <gcall *> (last)))
+	  && (!gimple_inexpensive_call_p (as_a <gcall *> (last))
+	      /* IFN_LOOP_DIST_ALIAS means that inner loop is distributed
+		 at current loop's header.  Don't copy in this case.  */
+	      || gimple_call_internal_p (last, IFN_LOOP_DIST_ALIAS)))
 	{
 	  if (dump_file && (dump_flags & TDF_DETAILS))
 	    fprintf (dump_file,