haifa-sched: handle fallthru edge to EXIT block (PR 85899)

	PR rtl-optimization/85899
	* haifa-sched.c (find_fallthru_edge_from): Relax assert to account for
	fallthru edges leading to the exit block.

	* gcc.dg/pr85899.c: New test.

From-SVN: r269319

gcc/ChangeLog

+2019-03-01  Alexander Monakov  <amonakov@ispras.ru>
+
+	PR rtl-optimization/85899
+	* haifa-sched.c (find_fallthru_edge_from): Relax assert to account for
+	fallthru edges leading to the exit block.
+
 2019-03-01  Tamar Christina  <tamar.christina@arm.com>
 
 	PR target/89517

gcc/haifa-sched.c

@@ -8082,7 +8082,7 @@ find_fallthru_edge_from (basic_block pred)
 
       if (e)
 	{
-	  gcc_assert (e->dest == succ);
+	  gcc_assert (e->dest == succ || e->dest->index == EXIT_BLOCK);
 	  return e;
 	}
     }

gcc/testsuite/ChangeLog

+2019-03-01  Alexander Monakov  <amonakov@ispras.ru>
+
+	PR rtl-optimization/85899
+	* gcc.dg/pr85899.c: New test.
+
 2019-03-01  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/89537 - missing location for error with non-static member fn.

gcc/testsuite/gcc.dg/pr85899.c

+/* { dg-do compile { target powerpc*-*-* ia64-*-* i?86-*-* x86_64-*-* } } */
+/* { dg-options "-O2 -fschedule-insns -fselective-scheduling -funroll-loops -fno-gcse -fno-if-conversion -fno-ivopts" } */
+
+#define N 4096
+int cb[N];
+int cc[N];
+int cd[N];
+
+void init ()
+{
+  int i;
+  for (i = 0; i < N; ++i) {
+    cb[i] = 3 * i - 2048;
+    cc[i] = -5 * i + 93;
+    cd[i] = i % 2 ? 1 : -1;
+  }
+}