[2/n] Merge CCP and copyprop - remove two copyprop passes

This patch removes copyprop passes run immediately after CCP.  This
uncovered that I failed to implement copyprop properly for PHI nodes
(due to the "clever" using UNDEFINED as initial value to meet PHI
args into and me not wanting to enable optimistic copy-prop just yet).

Fixed together with the pass removal.

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.

Richard.

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.

Index: gcc/tree-ssa-ccp.c
===================================================================
*** gcc/tree-ssa-ccp.c	(revision 222269)
--- gcc/tree-ssa-ccp.c	(working copy)
*************** set_lattice_value (tree var, ccp_prop_va
*** 539,547 ****
    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))))
      {
        /* ???  We would like to delay creation of INTEGER_CSTs from
  	 partially constants here.  */
--- 539,552 ----
    if (old_val->lattice_val != new_val.lattice_val
        || (new_val.lattice_val == CONSTANT
  	  && (TREE_CODE (new_val.value) != TREE_CODE (old_val->value)
  	      || (TREE_CODE (new_val.value) == INTEGER_CST
! 		  && (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.  */
*************** get_value_for_expr (tree expr, bool for_
*** 623,628 ****
--- 628,642 ----
  	  && 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))
*************** static enum ssa_prop_result
*** 1068,1074 ****
  ccp_visit_phi_node (gphi *phi)
  {
    unsigned i;
!   ccp_prop_value_t *old_val, new_val;
  
    if (dump_file && (dump_flags & TDF_DETAILS))
      {
--- 1082,1088 ----
  ccp_visit_phi_node (gphi *phi)
  {
    unsigned i;
!   ccp_prop_value_t new_val;
  
    if (dump_file && (dump_flags & TDF_DETAILS))
      {
*************** ccp_visit_phi_node (gphi *phi)
*** 1076,1100 ****
        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 ();
!     }
  
    for (i = 0; i < gimple_phi_num_args (phi); i++)
      {
        /* Compute the meet operator over all the PHI arguments flowing
--- 1090,1100 ----
        print_gimple_stmt (dump_file, phi, 0, dump_flags);
      }
  
!   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
*************** ccp_visit_phi_node (gphi *phi)
*** 1116,1122 ****
  	  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 (dump_file && (dump_flags & TDF_DETAILS))
  	    {
--- 1116,1128 ----
  	  tree arg = gimple_phi_arg (phi, i)->def;
  	  ccp_prop_value_t arg_val = get_value_for_expr (arg, false);
  
! 	  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))
  	    {