Check is_single_const in intersect_with_plats

2018-05-11  Martin Jambor  <mjambor@suse.cz>

	PR ipa/85655
	* ipa-cp.c (intersect_with_plats): Check that the lattice contains
	single const.

testsuite/
	* g++.dg/lto/pr85655_0.C: New test.

From-SVN: r260165

gcc/ChangeLog

+2018-05-11  Martin Jambor  <mjambor@suse.cz>
+
+	PR ipa/85655
+	* ipa-cp.c (intersect_with_plats): Check that the lattice contains
+	single const.
+
 2018-05-11  Richard Earnshaw  <rearnsha@arm.com>
 
 	PR target/85733

gcc/ipa-cp.c

@@ -4127,7 +4127,9 @@ intersect_with_plats (struct ipcp_param_lattices *plats,
 	  if (aglat->offset - offset == item->offset)
 	    {
 	      gcc_checking_assert (item->value);
-	      if (values_equal_for_ipcp_p (item->value, aglat->values->value))
+	      if (aglat->is_single_const ()
+		  && values_equal_for_ipcp_p (item->value,
+					      aglat->values->value))
 		found = true;
 	      break;
 	    }

gcc/testsuite/ChangeLog

+2018-05-11  Martin Jambor  <mjambor@suse.cz>
+
+	PR ipa/85655
+	* g++.dg/lto/pr85655_0.C: New test.
+
 2018-05-11  Sebastian Peryt  <sebastian.peryt@intel.com>
 
 	* gcc.target/i386/tpause-1.c: New test.

gcc/testsuite/g++.dg/lto/pr85655_0.C

+// { dg-lto-do link }
+// { dg-require-effective-target shared }
+// { dg-require-effective-target fpic }
+// { dg-lto-options {{-O2 -fPIC -shared -flto}} }
+
+int a;
+void b(...);
+void c(int);
+enum { d, e, f, g, h, i, j, k };
+class l {
+public:
+  int ac;
+  bool m;
+  l(char *);
+  int n();
+};
+struct o {
+  int ad;
+  o(int p = 0) : ad(p) {}
+};
+class C : public l {
+public:
+  char q;
+  C(o) : l(&q) { m |= ac & a ?: 9; }
+};
+class r : C {
+public:
+  char s;
+  r(o p, char) : C(p) {
+    if (n()) {
+      b(a, s, "");
+      c(5);
+    }
+  }
+};
+class t : C {
+public:
+  t(int) : C(d) {}
+};
+r ag('b', 0), ah(o(), 0), ai(e, 0), aj(f, 0), ak(g, 0), al(h, 0), am(k, 0),
+    an(i, 0), ao(j, 0);
+t ap(0);