2009-09-09 Richard Guenther <rguenther@suse.de>

	PR tree-optimization/41101
	* tree-ssa-pre.c (maximal_set): Remove.
	(compute_antic_aux): Treat the maximal set as implicitly all ones.
	Defer all blocks we didn't visit at least one successor.
	(add_to_exp_gen): Do not add to the maximal set.
	(make_values_for_phi): Likewise.
	(compute_avail): Likewise.
	(init_pre): Do not allocate the maximal set.
	(execute_pre): Do not dump it.

	* gcc.c-torture/compile/pr41101.c: New testcase.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@151561 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index dc1ad37..1035493 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+2009-09-09  Richard Guenther  <rguenther@suse.de>
+
+       PR tree-optimization/41101
+       * tree-ssa-pre.c (maximal_set): Remove.
+       (compute_antic_aux): Treat the maximal set as implicitly all ones.
+       Defer all blocks we didn't visit at least one successor.
+       (add_to_exp_gen): Do not add to the maximal set.
+       (make_values_for_phi): Likewise.
+       (compute_avail): Likewise.
+       (init_pre): Do not allocate the maximal set.
+       (execute_pre): Do not dump it.
+
 2009-09-09  Martin Jambor  <mjambor@suse.cz>
 
        * tree-cfg.c (verify_gimple_phi): Check that gimple_phi_result is

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 7b17043..b8aa756 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,10 @@
 2009-09-09  Richard Guenther  <rguenther@suse.de>
 
+       PR tree-optimization/41101
+       * gcc.c-torture/compile/pr41101.c: New testcase.
+
+2009-09-09  Richard Guenther  <rguenther@suse.de>
+
        PR middle-end/41317
        * gcc.c-torture/execute/pr41317.c: New testcase.
        * gcc.dg/tree-ssa/forwprop-11.c: XFAIL.

diff --git a/gcc/testsuite/gcc.c-torture/compile/pr41101.c b/gcc/testsuite/gcc.c-torture/compile/pr41101.c
new file mode 100644 (file)
index 0000000..8d21a00
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr41101.c
@@ -0,0 +1,19 @@
+int func(int);
+
+void
+bug(int* x, int* y, unsigned long int N)
+{
+  unsigned long int i;
+  int* t;
+
+  while (1)
+    {
+      for (i=1; i<=N; i++)
+       {
+         y[i] = func(x[i] - x[1]);
+         if (y[i])
+           return;
+       }
+      t=x; x=y; y=t;
+    }
+}

diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index 7a0533e..267aeb5 100644 (file)
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -401,10 +401,6 @@ typedef struct bb_bitmap_sets
 #define BB_DEFERRED(BB) ((bb_value_sets_t) ((BB)->aux))->deferred
 
 
-/* Maximal set of values, used to initialize the ANTIC problem, which
-   is an intersection problem.  */
-static bitmap_set_t maximal_set;
-
 /* Basic block list in postorder.  */
 static int *postorder;
 
@@ -2201,49 +2197,45 @@ compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge)
     {
       VEC(basic_block, heap) * worklist;
       size_t i;
-      basic_block bprime, first;
+      basic_block bprime, first = NULL;
 
       worklist = VEC_alloc (basic_block, heap, EDGE_COUNT (block->succs));
       FOR_EACH_EDGE (e, ei, block->succs)
-       VEC_quick_push (basic_block, worklist, e->dest);
-      first = VEC_index (basic_block, worklist, 0);
-
-      if (phi_nodes (first))
        {
-         bitmap_set_t from = ANTIC_IN (first);
-
-         if (!BB_VISITED (first))
-           from = maximal_set;
-         phi_translate_set (ANTIC_OUT, from, block, first);
+         if (!first
+             && BB_VISITED (e->dest))
+           first = e->dest;
+         else if (BB_VISITED (e->dest))
+           VEC_quick_push (basic_block, worklist, e->dest);
        }
-      else
+
+      /* Of multiple successors we have to have visited one already.  */
+      if (!first)
        {
-         if (!BB_VISITED (first))
-           bitmap_set_copy (ANTIC_OUT, maximal_set);
-         else
-           bitmap_set_copy (ANTIC_OUT, ANTIC_IN (first));
+         SET_BIT (changed_blocks, block->index);
+         BB_VISITED (block) = 0;
+         BB_DEFERRED (block) = 1;
+         changed = true;
+         VEC_free (basic_block, heap, worklist);
+         goto maybe_dump_sets;
        }
 
-      for (i = 1; VEC_iterate (basic_block, worklist, i, bprime); i++)
+      if (phi_nodes (first))
+       phi_translate_set (ANTIC_OUT, ANTIC_IN (first), block, first);
+      else
+       bitmap_set_copy (ANTIC_OUT, ANTIC_IN (first));
+
+      for (i = 0; VEC_iterate (basic_block, worklist, i, bprime); i++)
        {
          if (phi_nodes (bprime))
            {
              bitmap_set_t tmp = bitmap_set_new ();
-             bitmap_set_t from = ANTIC_IN (bprime);
-
-             if (!BB_VISITED (bprime))
-               from = maximal_set;
-             phi_translate_set (tmp, from, block, bprime);
+             phi_translate_set (tmp, ANTIC_IN (bprime), block, bprime);
              bitmap_set_and (ANTIC_OUT, tmp);
              bitmap_set_free (tmp);
            }
          else
-           {
-             if (!BB_VISITED (bprime))
-               bitmap_set_and (ANTIC_OUT, maximal_set);
-             else
-               bitmap_set_and (ANTIC_OUT, ANTIC_IN (bprime));
-           }
+           bitmap_set_and (ANTIC_OUT, ANTIC_IN (bprime));
        }
       VEC_free (basic_block, heap, worklist);
     }
@@ -3711,7 +3703,6 @@ add_to_exp_gen (basic_block block, tree op)
        return;
       result = get_or_alloc_expr_for_name (op);
       bitmap_value_insert_into_set (EXP_GEN (block), result);
-      bitmap_value_insert_into_set (maximal_set, result);
     }
 }
 
@@ -3740,7 +3731,6 @@ make_values_for_phi (gimple phi, basic_block block)
                {
                  e = get_or_alloc_expr_for_name (arg);
                  add_to_value (get_expr_value_id (e), e);
-                 bitmap_value_insert_into_set (maximal_set, e);
                }
            }
        }
@@ -3781,10 +3771,7 @@ compute_avail (void)
       e = get_or_alloc_expr_for_name (name);
       add_to_value (get_expr_value_id (e), e);
       if (!in_fre)
-       {
-         bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR), e);
-         bitmap_value_insert_into_set (maximal_set, e);
-       }
+       bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR), e);
       bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR), e);
     }
 
@@ -3888,11 +3875,7 @@ compute_avail (void)
                get_or_alloc_expression_id (result);
                add_to_value (get_expr_value_id (result), result);
                if (!in_fre)
-                 {
-                   bitmap_value_insert_into_set (EXP_GEN (block),
-                                                 result);
-                   bitmap_value_insert_into_set (maximal_set, result);
-                 }
+                 bitmap_value_insert_into_set (EXP_GEN (block), result);
                continue;
              }
 
@@ -3974,10 +3957,7 @@ compute_avail (void)
                get_or_alloc_expression_id (result);
                add_to_value (get_expr_value_id (result), result);
                if (!in_fre)
-                 {
-                   bitmap_value_insert_into_set (EXP_GEN (block), result);
-                   bitmap_value_insert_into_set (maximal_set, result);
-                 }
+                 bitmap_value_insert_into_set (EXP_GEN (block), result);
 
                continue;
              }
@@ -4515,7 +4495,6 @@ init_pre (bool do_fre)
       TMP_GEN (bb) = bitmap_set_new ();
       AVAIL_OUT (bb) = bitmap_set_new ();
     }
-  maximal_set = in_fre ? NULL : bitmap_set_new ();
 
   need_eh_cleanup = BITMAP_ALLOC (NULL);
 }
@@ -4601,8 +4580,6 @@ execute_pre (bool do_fre ATTRIBUTE_UNUSED)
          print_bitmap_set (dump_file, TMP_GEN (bb), "tmp_gen", bb->index);
          print_bitmap_set (dump_file, AVAIL_OUT (bb), "avail_out", bb->index);
        }
-
-      print_bitmap_set (dump_file, maximal_set, "maximal", 0);
     }
 
   /* Insert can get quite slow on an incredibly large number of basic