re PR middle-end/86122 (ICE in useless_type_conversion_p, at gimple-expr.c:87)

	PR middle-end/86122
	* match.pd ((A +- CST1) +- CST2): Punt if last resort
	unsigned_type_for returns NULL.

	* gcc.c-torture/compile/pr86122.c: New test.

From-SVN: r261606

gcc/ChangeLog

 2018-06-14  Jakub Jelinek  <jakub@redhat.com>
 
+	PR middle-end/86122
+	* match.pd ((A +- CST1) +- CST2): Punt if last resort
+	unsigned_type_for returns NULL.
+
 	PR target/85945
 	* lower-subreg.c (find_decomposable_subregs): Don't decompose float
 	subregs of multi-word pseudos unless the float mode has word size.

gcc/match.pd

@@ -1771,10 +1771,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 	   (neg_inner_op @0 { wide_int_to_tree (type, wi::to_wide (cst)); })
 	   /* Last resort, use some unsigned type.  */
 	   (with { tree utype = unsigned_type_for (type); }
-	    (view_convert (inner_op
-			   (view_convert:utype @0)
-			   (view_convert:utype
-			    { drop_tree_overflow (cst); })))))))))))))
+	    (if (utype)
+	     (view_convert (inner_op
+			    (view_convert:utype @0)
+			    (view_convert:utype
+			     { drop_tree_overflow (cst); }))))))))))))))
 
   /* (CST1 - A) +- CST2 -> CST3 - A  */
   (for outer_op (plus minus)

gcc/testsuite/ChangeLog

 2018-06-14  Jakub Jelinek  <jakub@redhat.com>
 
+	PR middle-end/86122
+	* gcc.c-torture/compile/pr86122.c: New test.
+
 	P0624R2 - Default constructible and assignable stateless lambdas
 	* g++.dg/cpp2a/lambda1.C: New test.
 	* g++.dg/cpp0x/lambda/lambda-ice2.C: Adjust expected diagnostics

gcc/testsuite/gcc.c-torture/compile/pr86122.c

+/* PR middle-end/86122 */
+
+_Complex int
+foo (_Complex int x)
+{
+  x += __INT_MAX__;
+  x += 1;
+  return x;
+}
+
+_Complex int
+bar (_Complex int x)
+{
+  x += 1;
+  x += __INT_MAX__;
+  return x;
+}