sel-sched: remove assert in merge_fences (PR 87273)

2019-04-01  Andrey Belevantsev  <abel@ispras.ru>

	PR rtl-optimization/87273
	* sel-sched-ir.c (merge_fences): Remove assert.

	* gcc.dg/pr87273.c: New test.

From-SVN: r270059

gcc/ChangeLog

+2019-04-01  Andrey Belevantsev  <abel@ispras.ru>
+
+	PR rtl-optimization/87273
+	* sel-sched-ir.c (merge_fences): Remove assert.
+
 2019-04-01  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/46590

gcc/sel-sched-ir.c

@@ -703,11 +703,6 @@ merge_fences (fence_t f, insn_t insn,
       else
         if (candidate->src == BLOCK_FOR_INSN (last_scheduled_insn))
           {
-            /* Would be weird if same insn is successor of several fallthrough
-               edges.  */
-            gcc_assert (BLOCK_FOR_INSN (insn)->prev_bb
-                        != BLOCK_FOR_INSN (last_scheduled_insn_old));
-
             state_free (FENCE_STATE (f));
             FENCE_STATE (f) = state;
 

gcc/testsuite/ChangeLog

+2019-04-01  Andrey Belevantsev  <abel@ispras.ru>
+
+	PR rtl-optimization/87273
+	* gcc.dg/pr87273.c: New test.
+
 2019-04-01  Martin Liska  <mliska@suse.cz>
 
 	PR driver/89861

gcc/testsuite/gcc.dg/pr87273.c

+/* { dg-do compile { target powerpc*-*-* ia64-*-* i?86-*-* x86_64-*-* } } */
+/* { dg-options "-Os -fschedule-insns -fsel-sched-pipelining -fselective-scheduling -fno-ssa-phiopt -fno-tree-loop-im" } */
+/* { dg-additional-options "-march=core2" { target i?86-*-* x86_64-*-* } } */
+
+int sd;
+
+void
+w5 (int n4)
+{
+  long int *vq = (long int *) &n4;
+
+  while (n4 < 1)
+    {
+      int ks;
+
+      ks = !!(n4 + 1) ? ((++sd) == *vq) : 0;
+      if (ks == 1 / *vq)
+        *vq *= sd;
+    }
+}