passes.def: Remove copy propagation passes run directly after CCP.

2015-04-23  Richard Biener  <rguenther@suse.de>

	* passes.def: Remove copy propagation passes run directly after CCP.
	* tree-ssa-ccp.c (get_value_for_expr): Fall back to a COPY for
	SSA names.
	(ccp_visit_phi_node): Rework to handle first executable edge
	specially.

From-SVN: r222360

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c56113e1dd6b769089687a9e04fa800017a227f7..6e2742837c0d22adea3d236aa44e73052e4ff698 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2015-04-23  Richard Biener  <rguenther@suse.de>
+
+       * passes.def: Remove copy propagation passes run directly after CCP.
+       * tree-ssa-ccp.c (get_value_for_expr): Fall back to a COPY for
+       SSA names.
+       (ccp_visit_phi_node): Rework to handle first executable edge
+       specially.
+
 2015-04-23  Matthew Wahab  <matthew.wahab@arm.com>
 
        * config/arm/arm.h (LEGITIMIZE_RELOAD_ADDRESS): Remove.

diff --git a/gcc/passes.def b/gcc/passes.def
index 4c20cdf0dfce1153f2855baf1498a5a084df1678..6dce1419de12c32b3466ffe78b6c1276e6504a62 100644 (file)
--- a/gcc/passes.def
+++ b/gcc/passes.def
@@ -159,7 +159,6 @@ along with GCC; see the file COPYING3.  If not see
       NEXT_PASS (pass_ccp);
       /* After CCP we rewrite no longer addressed locals into SSA
         form if possible.  */
-      NEXT_PASS (pass_copy_prop);
       NEXT_PASS (pass_complete_unrolli);
       NEXT_PASS (pass_phiprop);
       NEXT_PASS (pass_forwprop);
@@ -211,7 +210,6 @@ along with GCC; see the file COPYING3.  If not see
       NEXT_PASS (pass_ccp);
       /* After CCP we rewrite no longer addressed locals into SSA
         form if possible.  */
-      NEXT_PASS (pass_copy_prop);
       NEXT_PASS (pass_cse_sincos);
       NEXT_PASS (pass_optimize_bswap);
       NEXT_PASS (pass_split_crit_edges);

diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c
index 1d7cafeb80790a6eac17ac5e58c144aa00e5797d..b14c12d8b187f7c3ff275488fac9eea1bfc02d14 100644 (file)
--- a/gcc/tree-ssa-ccp.c
+++ b/gcc/tree-ssa-ccp.c
@@ -539,9 +539,14 @@ set_lattice_value (tree var, ccp_prop_value_t new_val)
   if (old_val->lattice_val != new_val.lattice_val
       || (new_val.lattice_val == CONSTANT
          && (TREE_CODE (new_val.value) != TREE_CODE (old_val->value)
-             || simple_cst_equal (new_val.value, old_val->value) != 1
              || (TREE_CODE (new_val.value) == INTEGER_CST
-                 && new_val.mask != old_val->mask))))
+                 && (new_val.mask != old_val->mask
+                     || (wi::bit_and_not (wi::to_widest (old_val->value),
+                                          new_val.mask)
+                         != wi::bit_and_not (wi::to_widest (new_val.value),
+                                             new_val.mask))))
+             || (TREE_CODE (new_val.value) != INTEGER_CST
+                 && !operand_equal_p (new_val.value, old_val->value, 0)))))
     {
       /* ???  We would like to delay creation of INTEGER_CSTs from
         partially constants here.  */
@@ -623,6 +628,15 @@ get_value_for_expr (tree expr, bool for_bits_p)
          && val.lattice_val == CONSTANT
          && TREE_CODE (val.value) == ADDR_EXPR)
        val = get_value_from_alignment (val.value);
+      /* Fall back to a copy value.  */
+      if (!for_bits_p
+         && val.lattice_val == VARYING
+         && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (expr))
+       {
+         val.lattice_val = CONSTANT;
+         val.value = expr;
+         val.mask = -1;
+       }
     }
   else if (is_gimple_min_invariant (expr)
           && (!for_bits_p || TREE_CODE (expr) != ADDR_EXPR))
@@ -1068,7 +1082,7 @@ static enum ssa_prop_result
 ccp_visit_phi_node (gphi *phi)
 {
   unsigned i;
-  ccp_prop_value_t *old_val, new_val;
+  ccp_prop_value_t new_val;
 
   if (dump_file && (dump_flags & TDF_DETAILS))
     {
@@ -1076,25 +1090,11 @@ ccp_visit_phi_node (gphi *phi)
       print_gimple_stmt (dump_file, phi, 0, dump_flags);
     }
 
-  old_val = get_value (gimple_phi_result (phi));
-  switch (old_val->lattice_val)
-    {
-    case VARYING:
-      return SSA_PROP_VARYING;
-
-    case CONSTANT:
-      new_val = *old_val;
-      break;
-
-    case UNDEFINED:
-      new_val.lattice_val = UNDEFINED;
-      new_val.value = NULL_TREE;
-      break;
-
-    default:
-      gcc_unreachable ();
-    }
+  new_val.lattice_val = UNDEFINED;
+  new_val.value = NULL_TREE;
+  new_val.mask = 0;
 
+  bool first = true;
   for (i = 0; i < gimple_phi_num_args (phi); i++)
     {
       /* Compute the meet operator over all the PHI arguments flowing
@@ -1116,7 +1116,13 @@ ccp_visit_phi_node (gphi *phi)
          tree arg = gimple_phi_arg (phi, i)->def;
          ccp_prop_value_t arg_val = get_value_for_expr (arg, false);
 
-         ccp_lattice_meet (gimple_bb (phi), &new_val, &arg_val);
+         if (first)
+           {
+             new_val = arg_val;
+             first = false;
+           }
+         else
+           ccp_lattice_meet (gimple_bb (phi), &new_val, &arg_val);
 
          if (dump_file && (dump_flags & TDF_DETAILS))
            {