[PATCH] Fix PR66793

[Richard Biener]

The following fixes path-isolation to properly split the block
if it inserts a trap after a stmt ending a BB (in this case a noreturn 
stmt).

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.

Richard.

2015-07-08  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/66793
        * gimple-ssa-isolate-paths.c (insert_trap_and_remove_trailing_statemen):
        Properly split the block after stmts ending it.

        * gcc.dg/torture/pr66793.c: New testcase.

Index: gcc/gimple-ssa-isolate-paths.c
===================================================================
--- gcc/gimple-ssa-isolate-paths.c      (revision 225534)
+++ gcc/gimple-ssa-isolate-paths.c      (working copy)
@@ -103,7 +103,14 @@ insert_trap_and_remove_trailing_statemen
   if (walk_stmt_load_store_ops (stmt, (void *)op,
                                check_loadstore,
                                check_loadstore))
-    gsi_insert_after (si_p, seq, GSI_NEW_STMT);
+    {
+      gsi_insert_after (si_p, seq, GSI_NEW_STMT);
+      if (stmt_ends_bb_p (stmt))
+       {
+         split_block (gimple_bb (stmt), stmt);
+         return;
+       }
+    }
   else
     gsi_insert_before (si_p, seq, GSI_NEW_STMT);
 
Index: gcc/testsuite/gcc.dg/torture/pr66793.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr66793.c      (revision 0)
+++ gcc/testsuite/gcc.dg/torture/pr66793.c      (working copy)
@@ -0,0 +1,26 @@
+/* { dg-do link } */
+
+int a, b, c; 
+
+struct S0
+{
+  int f1;
+} *d; 
+
+void
+fn1 (struct S0 p)
+{
+  for (p.f1 = 0; p.f1 < 1; p.f1++)
+    c = a && b ? a && b : 1; 
+  for (; c;)
+    ;
+}
+
+int
+main ()
+{
+  struct S0 **f = &d;
+  d = 0; 
+  fn1 (**f); 
+  return 0;
+}