re PR tree-optimization/66101 (internal compiler error: in…

re PR tree-optimization/66101 (internal compiler error: in verify_loop_structure, at cfgloop.c:1662)

2015-05-12  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/66101
	* tree-ssa-dce.c (remove_dead_stmt): Properly mark loops for
	fixup if we turn a loop exit edge to a fallthru edge.

	* gcc.dg/torture/pr66101.c: New testcase.

From-SVN: r223065

gcc/ChangeLog

 2015-05-12  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/66101
+	* tree-ssa-dce.c (remove_dead_stmt): Properly mark loops for
+	fixup if we turn a loop exit edge to a fallthru edge.
+
+2015-05-12  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/37021
 	* tree-vectorizer.h (struct _slp_tree): Add two_operators flag.
 	(SLP_TREE_TWO_OPERATORS): New define.

gcc/testsuite/ChangeLog

 2015-05-12  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/66101
+	* gcc.dg/torture/pr66101.c: New testcase.
+
+2015-05-12  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/37021
 	* gcc.target/i386/vect-addsub.c: New testcase.
 

gcc/testsuite/gcc.dg/torture/pr66101.c

+/* { dg-do compile } */
+
+#include <setjmp.h>
+
+jmp_buf env;
+
+int a, c, d, e;
+
+int
+bar ()
+{
+  int b = *(long *) 7 == 5 ? : 0;
+  if (a || a > b)
+    longjmp (env, 0);
+  return 1;
+}
+
+void
+foo ()
+{
+  long f;
+  setjmp (env);
+  for (; d; c++)
+    switch (c)
+case 0:
+      {
+	f = bar () >> 1;
+	if (e)
+	  goto L;
+	if (bar () >> 1)
+	  goto L;
+      }
+L:
+    ;
+}

gcc/tree-ssa-dce.c

@@ -1149,7 +1149,12 @@ remove_dead_stmt (gimple_stmt_iterator *i, basic_block bb)
 	if (e != e2)
 	  {
 	    cfg_altered = true;
-            remove_edge (e2);
+	    /* If we made a BB unconditionally exit a loop then this
+	       transform alters the set of BBs in the loop.  Schedule
+	       a fixup.  */
+	    if (loop_exit_edge_p (bb->loop_father, e))
+	      loops_state_set (LOOPS_NEED_FIXUP);
+	    remove_edge (e2);
 	  }
 	else
 	  ei_next (&ei);