Reverted:

	2013-12-10  Bin Cheng  <bin.cheng@arm.com>
	PR tree-optimization/41488
	* tree-ssa-loop-ivopts.c (add_old_iv_candidates): Don't add cand
	for PEELED_CHREC kind IV.
	* tree-scalar-evolution.c: Include necessary header files.
	(peeled_chrec_map, simplify_peeled_chrec): New.
	(analyze_evolution_in_loop): New static variable.
	Call simplify_peeled_chrec.
	(scev_initialize): Initialize peeled_chrec_map.
	(scev_reset, scev_finalize): Reset and release peeled_chrec_map.

	Reverted:
	2013-12-10  Bin Cheng  <bin.cheng@arm.com>
	PR tree-optimization/41488
	* gcc.dg/tree-ssa/scev-7.c: New test.
	* gcc.dg/pr41488.c: New test.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@205880 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 1 insertions, 89 deletions

diff --git a/gcc/tree-scalar-evolution.c b/gcc/tree-scalar-evolution.c
index f114653a5fa..59e44cbb9c9 100644
--- a/gcc/tree-scalar-evolution.c
+++ b/gcc/tree-scalar-evolution.c
@@ -280,8 +280,6 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-ssa.h"
 #include "cfgloop.h"
 #include "tree-chrec.h"
-#include "pointer-set.h"
-#include "tree-affine.h"
 #include "tree-scalar-evolution.h"
 #include "dumpfile.h"
 #include "params.h"
@@ -1382,66 +1380,6 @@ follow_ssa_edge (struct loop *loop, gimple def, gimple halting_phi,
 }
 
 
-/* Pointer map used when simplifying PEELED_CHREC into POLYNOMIAL_CHREC.  */
-static pointer_map_t *peeled_chrec_map;
-
-/* Simplify PEELED_CHREC represented by (init_cond, arg) in LOOP.
-   Handle below case and return the corresponding POLYNOMIAL_CHREC:
-
-   # i_17 = PHI <i_13(5), 0(3)>
-   # _20 = PHI <_5(5), start_4(D)(3)>
-   ...
-   i_13 = i_17 + 1;
-   _5 = start_4(D) + i_13;
-
-   Though variable _20 appears as a PEELED_CHREC in the form of
-   (start_4, _5)_LOOP, it's a POLYNOMIAL_CHREC like {start_4, 1}_LOOP.
-
-   See PR41488.  */
-
-static tree
-simplify_peeled_chrec (struct loop *loop, tree arg, tree init_cond)
-{
-  aff_tree aff1, aff2;
-  tree ev, left, right, type, step_val;
-
-  ev = instantiate_parameters (loop, analyze_scalar_evolution (loop, arg));
-  if (ev == NULL_TREE || TREE_CODE (ev) != POLYNOMIAL_CHREC)
-    return chrec_dont_know;
-
-  left = CHREC_LEFT (ev);
-  right = CHREC_RIGHT (ev);
-  type = TREE_TYPE (left);
-  step_val = chrec_fold_plus (type, init_cond, right);
-
-  /* Transform (init, {left, right}_LOOP)_LOOP to {init, right}_LOOP
-     if "left" equals to "init + right".  */
-  if (operand_equal_p (left, step_val, 0))
-    {
-      if (dump_file && (dump_flags & TDF_SCEV))
-	fprintf (dump_file, "Simplify PEELED_CHREC into POLYNOMIAL_CHREC.\n");
-
-      return build_polynomial_chrec (loop->num, init_cond, right);
-    }
-
-  /* Try harder to check if they are equal.  */
-  tree_to_aff_combination_expand (left, type, &aff1, &peeled_chrec_map);
-  tree_to_aff_combination_expand (step_val, type, &aff2, &peeled_chrec_map);
-  aff_combination_scale (&aff2, double_int_minus_one);
-  aff_combination_add (&aff1, &aff2);
-  left = fold_convert (type, aff_combination_to_tree (&aff1));
-
-  /* Transform (init, {left, right}_LOOP)_LOOP to {init, right}_LOOP
-     if "left" equals to "init + right".  */
-  if (operand_equal_p (left, integer_zero_node, 0))
-    {
-      if (dump_file && (dump_flags & TDF_SCEV))
-	fprintf (dump_file, "Simplify PEELED_CHREC into POLYNOMIAL_CHREC.\n");
-
-      return build_polynomial_chrec (loop->num, init_cond, right);
-    }
-  return chrec_dont_know;
-}
 
 /* Given a LOOP_PHI_NODE, this function determines the evolution
    function from LOOP_PHI_NODE to LOOP_PHI_NODE in the loop.  */
@@ -1454,7 +1392,6 @@ analyze_evolution_in_loop (gimple loop_phi_node,
   tree evolution_function = chrec_not_analyzed_yet;
   struct loop *loop = loop_containing_stmt (loop_phi_node);
   basic_block bb;
-  static bool simplify_peeled_chrec_p = true;
 
   if (dump_file && (dump_flags & TDF_SCEV))
     {
@@ -1505,19 +1442,7 @@ analyze_evolution_in_loop (gimple loop_phi_node,
 	 all the other iterations it has the value of ARG.
 	 For the moment, PEELED_CHREC nodes are not built.  */
       if (res != t_true)
-	{
-	  ev_fn = chrec_dont_know;
-	  /* Try to recognize POLYNOMIAL_CHREC which appears in
-	     the form of PEELED_CHREC, but guard the process with
-	     a bool variable to keep the analyzer from infinite
-	     recurrence for real PEELED_RECs.  */
-	  if (simplify_peeled_chrec_p && TREE_CODE (arg) == SSA_NAME)
-	    {
-	      simplify_peeled_chrec_p = false;
-	      ev_fn = simplify_peeled_chrec (loop, arg, init_cond);
-	      simplify_peeled_chrec_p = true;
-	    }
-	}
+	ev_fn = chrec_dont_know;
 
       /* When there are multiple back edges of the loop (which in fact never
 	 happens currently, but nevertheless), merge their evolutions.  */
@@ -3161,8 +3086,6 @@ scev_initialize (void)
 
   initialize_scalar_evolutions_analyzer ();
 
-  peeled_chrec_map = pointer_map_create ();
-
   FOR_EACH_LOOP (loop, 0)
     {
       loop->nb_iterations = NULL_TREE;
@@ -3199,12 +3122,6 @@ scev_reset (void)
 
   scev_reset_htab ();
 
-  if (peeled_chrec_map)
-    {
-      pointer_map_destroy (peeled_chrec_map);
-      peeled_chrec_map = NULL;
-    }
-
   if (!current_loops)
     return;
 
@@ -3292,11 +3209,6 @@ scev_finalize (void)
     return;
   htab_delete (scalar_evolution_info);
   scalar_evolution_info = NULL;
-  if (peeled_chrec_map)
-    {
-      pointer_map_destroy (peeled_chrec_map);
-      peeled_chrec_map = NULL;
-    }
 }
 
 /* Returns true if the expression EXPR is considered to be too expensive