Revert "tree-optimization/120003 - missed jump threading"

This reverts commit 1a13684dfc7286139064f7d7341462c9995cbd1c.

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-thread-23.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-thread-23.c
deleted file mode 100644 (file)
index 930360a..0000000
--- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-thread-23.c
+++ /dev/null
@@ -1,19 +0,0 @@
-/* PR120003 */
-/* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-cddce3-details" } */
-
-extern _Bool g(int);
-
-_Bool f()
-{
-  _Bool retval = 0;
-  for(int i=0; i<1000000; ++i)
-    retval = retval || g(i);
-  return retval;
-}
-
-/* Jump threading after loop optimization should get the counting loop
-   separated from the loop until retval is true and CD-DCE elide it.
-   It's difficult to check for the fact that a true retval terminates
-   the loop so check CD-DCE eliminates one loop instead.  */
-/* { dg-final { scan-tree-dump "fix_loop_structure: removing loop" "cddce3" } } */

diff --git a/gcc/tree-ssa-threadbackward.cc b/gcc/tree-ssa-threadbackward.cc
index a573b8349bea8adde5d6a0f462733bf829241f7f..d4b3734304ddf5caf7380114017967c3b173772c 100644 (file)
--- a/gcc/tree-ssa-threadbackward.cc
+++ b/gcc/tree-ssa-threadbackward.cc
@@ -349,6 +349,9 @@ back_threader::find_paths_to_names (basic_block bb, bitmap interesting,
                                    unsigned overall_paths,
                                    back_threader_profitability &profit)
 {
+  if (m_visited_bbs.add (bb))
+    return;
+
   m_path.safe_push (bb);
 
   // Try to resolve the path without looking back.  Avoid resolving paths
@@ -374,8 +377,7 @@ back_threader::find_paths_to_names (basic_block bb, bitmap interesting,
   // Continue looking for ways to extend the path but limit the
   // search space along a branch
   else if ((overall_paths = overall_paths * EDGE_COUNT (bb->preds))
-          <= (unsigned)param_max_jump_thread_paths
-          && !m_visited_bbs.add (bb))
+          <= (unsigned)param_max_jump_thread_paths)
     {
       // For further greedy searching we want to remove interesting
       // names defined in BB but add ones on the PHI edges for the
@@ -487,7 +489,6 @@ back_threader::find_paths_to_names (basic_block bb, bitmap interesting,
         backtracking we have to restore it.  */
       for (int j : new_imports)
        bitmap_clear_bit (m_imports, j);
-      m_visited_bbs.remove (bb);
     }
   else if (dump_file && (dump_flags & TDF_DETAILS))
     fprintf (dump_file, "  FAIL: Search space limit %d reached.\n",
@@ -495,6 +496,7 @@ back_threader::find_paths_to_names (basic_block bb, bitmap interesting,
 
   // Reset things to their original state.
   m_path.pop ();
+  m_visited_bbs.remove (bb);
 }
 
 // Search backwards from BB looking for paths where the final