revert: re PR tree-optimization/41488 (IVOpts cannot coalesce multiple induction...

	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.

From-SVN: r205880

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index fe57c5d..c581a97 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,17 @@
+2013-12-11  Bin Cheng  <bin.cheng@arm.com>
+
+       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.
+
 2013-12-10   H.J. Lu  <hongjiu.lu@intel.com>
 
        PR target/59458

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 5477f3f..02da360 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2013-12-11  Bin Cheng  <bin.cheng@arm.com>
+
+       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.
+
 2013-12-10  Janus Weil  <janus@gcc.gnu.org>
 
        PR fortran/35831

diff --git a/gcc/testsuite/gcc.dg/pr41488.c b/gcc/testsuite/gcc.dg/pr41488.c
deleted file mode 100644 (file)
index c4bc428..0000000
--- a/gcc/testsuite/gcc.dg/pr41488.c
+++ /dev/null
@@ -1,18 +0,0 @@
-/* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-sccp-scev" } */
-
-struct struct_t
-{
-  int* data;
-};
-
-void foo (struct struct_t* sp, int start, int end)
-{
-  int i;
-
-  for (i = 0; i+start < end; i++)
-    sp->data[i+start] = 0;
-}
-
-/* { dg-final { scan-tree-dump-times "Simplify PEELED_CHREC into POLYNOMIAL_CHREC" 1 "sccp" } } */
-/* { dg-final { cleanup-tree-dump "sccp" } } */

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/scev-7.c b/gcc/testsuite/gcc.dg/tree-ssa/scev-7.c
deleted file mode 100644 (file)
index d6ceb20..0000000
--- a/gcc/testsuite/gcc.dg/tree-ssa/scev-7.c
+++ /dev/null
@@ -1,18 +0,0 @@
-/* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-sccp-scev" } */
-
-struct struct_t
-{
-  int* data;
-};
-
-void foo (struct struct_t* sp, int start, int end)
-{
-  int i;
-
-  for (i = 1000; i+start > end; i--)
-    sp->data[i+start] = 0;
-}
-
-/* { dg-final { scan-tree-dump-times "Simplify PEELED_CHREC into POLYNOMIAL_CHREC" 1 "sccp" } } */
-/* { dg-final { cleanup-tree-dump "sccp" } } */

diff --git a/gcc/tree-scalar-evolution.c b/gcc/tree-scalar-evolution.c
index f114653..59e44cb 100644 (file)
--- 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,
 }
 
 \f
-/* 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

diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index 8d2dfc5..fb3ceb9 100644 (file)
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -2526,19 +2526,11 @@ add_old_iv_candidates (struct ivopts_data *data, struct iv *iv)
       /* Additionally record the possibility of leaving the original iv
         untouched.  */
       def = PHI_ARG_DEF_FROM_EDGE (phi, loop_latch_edge (data->current_loop));
-      /* Don't add candidate if it's from another PHI node because
-         it's an affine iv appearing in the form of PEELED_CHREC.  */
-      phi = SSA_NAME_DEF_STMT (def);
-      if (gimple_code (phi) != GIMPLE_PHI)
-       {
-         cand = add_candidate_1 (data,
-                                 iv->base, iv->step, true, IP_ORIGINAL, NULL,
-                                 SSA_NAME_DEF_STMT (def));
-         cand->var_before = iv->ssa_name;
-         cand->var_after = def;
-       }
-      else
-       gcc_assert (gimple_bb (phi) == data->current_loop->header);
+      cand = add_candidate_1 (data,
+                             iv->base, iv->step, true, IP_ORIGINAL, NULL,
+                             SSA_NAME_DEF_STMT (def));
+      cand->var_before = iv->ssa_name;
+      cand->var_after = def;
     }
 }