re PR tree-optimization/38964 (TBAA side-effects of C++ new still missing)

2009-05-22  Richard Guenther  <rguenther@suse.de>

	PR middle-end/38964
	* alias.c (write_dependence_p): Do not use TBAA for answering
	anti-dependence or output-dependence.
	* tree-ssa-structalias.c (set_uids_in_ptset): Remove TBAA pruning
	code.
	(emit_pointer_definition): Remove.
	(emit_alias_warning): Likewise.
	(find_what_var_points_to): Remove TBAA pruning code.
	(find_what_p_points_to): Likewise.  Do not warn about strict-aliasing
	violations.
	(compute_points_to_sets): Remove code computing the set of
	dereferenced pointers.
	* tree-data-ref.c (dr_may_alias_p): Properly use the split
	oracle for querying anti and output dependencies.
	* tree-ssa-alias.c (refs_may_alias_p_1): Add argument specifying
	if TBAA may be applied.
	(refs_anti_dependent_p): New function.
	(refs_output_dependent_p): Likewise.
	* tree-ssa-alias.h (refs_anti_dependent_p): Declare.
	(refs_output_dependent_p): Likewise.

	* doc/tree-ssa.texi (Memory model): New section.

	testsuite/
	* g++.dg/warn/Wstrict-aliasing-float-ref-int-obj.C: XFAIL.
	* gcc.dg/Wstrict-aliasing-converted-assigned.c: Likewise.
	* gcc.dg/Wstrict-aliasing-float-ptr-int-obj.c: Likewise.

	* doc/c-tree.texi (CHANGE_DYNAMIC_TYPE_EXPR): Remove.
	* doc/gimple.texi (GIMPLE_CHANGE_DYNAMIC_TYPE): Remove.

	* cfgexpand.c (expand_gimple_basic_block): Do not handle
	GIMPLE_CHANGE_DYNAMIC_TYPE or CHANGE_DYNAMIC_TYPE_EXPR.
	* expr.c (expand_expr_real_1): Likewise.
	* gimple-low.c (lower_stmt): Likewise.
	* gimple-pretty-print.c (dump_gimple_stmt): Likewise.
	(dump_gimple_cdt): Remove.
	* gimple.c (gss_for_code): Do not handle GIMPLE_CHANGE_DYNAMIC_TYPE.
	(gimple_size): Likewise.
	(walk_gimple_op): Likewise.
	(is_gimple_stmt): Likewise.
	(walk_stmt_load_store_addr_ops): Likewise.
	(gimple_build_cdt): Remove.
	* gimple.def (GIMPLE_CHANGE_DYNAMIC_TYPE): Remove.
	* gimple.h (gimple_cdt_new_type): Remove.
	(gimple_cdt_new_type_ptr): Likewise.
	(gimple_cdt_set_new_type): Likewise.
	(gimple_cdt_location): Likewise.
	(gimple_cdt_location_ptr): Likewise.
	(gimple_cdt_set_location): Likewise.
	* gimplify.c (gimplify_expr): Do not handle CHANGE_DYNAMIC_TYPE_EXPR.
	* tree-cfg.c (remove_useless_stmts_1): Do not handle
	GIMPLE_CHANGE_DYNAMIC_TYPE.
	(verify_types_in_gimple_stmt): Likewise.
	* tree-inline.c (estimate_num_insns): Likewise.
	(expand_call_inline): Do not copy DECL_NO_TBAA_P.
	(copy_decl_to_var): Likewise.
	(copy_result_decl_to_var): Likewise.
	* tree-pretty-print.c (dump_generic_node): Do not handle
	CHANGE_DYNAMIC_TYPE_EXPR.
	* tree-ssa-dce.c (mark_stmt_if_obviously_necessary): Likewise.
	* tree-ssa-operands.c (get_expr_operands): Likewise.
	* tree-ssa-structalias.c (struct variable_info): Remove
	no_tbaa_pruning member.
	(new_var_info): Do not set it based on DECL_NO_TBAA_P.
	(unify_nodes): Do not copy it.
	(find_func_aliases): Do not handle GIMPLE_CHANGE_DYNAMIC_TYPE.
	(dump_solution_for_var): Do not dump no_tbaa_pruning state.
	(set_uids_in_ptset): Do not check it.
	(find_what_var_points_to): Likewise.
	(compute_tbaa_pruning): Remove.
	(compute_points_to_sets): Do not call it.
	* tree.c (walk_tree_1): Do not handle CHANGE_DYNAMIC_TYPE_EXPR.
	* tree.def (CHANGE_DYNAMIC_TYPE_EXPR): Remove.
	* tree.h (CHANGE_DYNAMIC_TYPE_NEW_TYPE): Remove.
	(CHANGE_DYNAMIC_TYPE_LOCATION): Likewise.
	(DECL_NO_TBAA_P): Likewise.
	(struct tree_decl_common): Move no_tbaa_flag to unused flags section.
	* omp-low.c (copy_var_decl): Do not copy DECL_NO_TBAA_P.
	(expand_omp_atomic_pipeline): Do not set it.
	* print-tree.c (print_node): Do not dump it.
	* tree-ssa-copyrename.c (copy_rename_partition_coalesce): Remove
	redundant check.

	cp/
	* init.c (avoid_placement_new_aliasing): Remove.
	(build_new_1): Do not call it.

From-SVN: r147805

1 files changed, 38 insertions, 11 deletions

diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index 8982280..ef360ea 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -155,10 +155,13 @@ ptr_deref_may_alias_global_p (tree ptr)
   if (!pi)
     return true;
 
+  /* ???  This does not use TBAA to prune globals ptr may not access.  */
   return pt_solution_includes_global (&pi->pt);
 }
 
-/* Return true if dereferencing PTR may alias DECL.  */
+/* Return true if dereferencing PTR may alias DECL.
+   The caller is responsible for applying TBAA to see if PTR
+   may access DECL at all.  */
 
 static bool
 ptr_deref_may_alias_decl_p (tree ptr, tree decl)
@@ -190,7 +193,9 @@ ptr_deref_may_alias_decl_p (tree ptr, tree decl)
   return pt_solution_includes (&pi->pt, decl);
 }
 
-/* Return true if dereferenced PTR1 and PTR2 may alias.  */
+/* Return true if dereferenced PTR1 and PTR2 may alias.
+   The caller is responsible for applying TBAA to see if accesses
+   through PTR1 and PTR2 may conflict at all.  */
 
 static bool
 ptr_derefs_may_alias_p (tree ptr1, tree ptr2)
@@ -222,6 +227,8 @@ ptr_derefs_may_alias_p (tree ptr1, tree ptr2)
   if (!pi1 || !pi2)
     return true;
 
+  /* ???  This does not use TBAA to prune decls from the intersection
+     that not both pointers may access.  */
   return pt_solutions_intersect (&pi1->pt, &pi2->pt);
 }
 
@@ -653,13 +660,14 @@ indirect_refs_may_alias_p (tree ref1, tree ptr1,
 /* Return true, if the two memory references REF1 and REF2 may alias.  */
 
 static bool
-refs_may_alias_p_1 (tree ref1, tree ref2)
+refs_may_alias_p_1 (tree ref1, tree ref2, bool tbaa_p)
 {
   tree base1, base2;
   HOST_WIDE_INT offset1 = 0, offset2 = 0;
   HOST_WIDE_INT size1 = -1, size2 = -1;
   HOST_WIDE_INT max_size1 = -1, max_size2 = -1;
   bool var1_p, var2_p, ind1_p, ind2_p;
+  alias_set_type set;
 
   gcc_assert ((SSA_VAR_P (ref1)
 	       || handled_component_p (ref1)
@@ -694,7 +702,8 @@ refs_may_alias_p_1 (tree ref1, tree ref2)
 				  base2, offset2, max_size2);
 
   /* First defer to TBAA if possible.  */
-  if (flag_strict_aliasing
+  if (tbaa_p
+      && flag_strict_aliasing
       && !alias_sets_conflict_p (get_alias_set (ref1), get_alias_set (ref2)))
     return false;
 
@@ -708,21 +717,22 @@ refs_may_alias_p_1 (tree ref1, tree ref2)
   /* Dispatch to the pointer-vs-decl or pointer-vs-pointer disambiguators.  */
   ind1_p = INDIRECT_REF_P (base1);
   ind2_p = INDIRECT_REF_P (base2);
+  set = tbaa_p ? -1 : 0;
   if (var1_p && ind2_p)
     return indirect_ref_may_alias_decl_p (ref2, TREE_OPERAND (base2, 0),
-					  offset2, max_size2, -1,
+					  offset2, max_size2, set,
 					  ref1, base1,
-					  offset1, max_size1, -1);
+					  offset1, max_size1, set);
   else if (ind1_p && var2_p)
     return indirect_ref_may_alias_decl_p (ref1, TREE_OPERAND (base1, 0),
-					  offset1, max_size1, -1,
+					  offset1, max_size1, set,
 					  ref2, base2,
-					  offset2, max_size2, -1);
+					  offset2, max_size2, set);
   else if (ind1_p && ind2_p)
     return indirect_refs_may_alias_p (ref1, TREE_OPERAND (base1, 0),
-				      offset1, max_size1, -1,
+				      offset1, max_size1, set,
 				      ref2, TREE_OPERAND (base2, 0),
-				      offset2, max_size2, -1);
+				      offset2, max_size2, set);
 
   gcc_unreachable ();
 }
@@ -730,7 +740,7 @@ refs_may_alias_p_1 (tree ref1, tree ref2)
 bool
 refs_may_alias_p (tree ref1, tree ref2)
 {
-  bool res = refs_may_alias_p_1 (ref1, ref2);
+  bool res = refs_may_alias_p_1 (ref1, ref2, true);
   if (res)
     ++alias_stats.refs_may_alias_p_may_alias;
   else
@@ -738,6 +748,23 @@ refs_may_alias_p (tree ref1, tree ref2)
   return res;
 }
 
+/* Returns true if there is a anti-dependence for the STORE that
+   executes after the LOAD.  */
+
+bool
+refs_anti_dependent_p (tree load, tree store)
+{
+  return refs_may_alias_p_1 (load, store, false);
+}
+
+/* Returns true if there is a output dependence for the stores
+   STORE1 and STORE2.  */
+
+bool
+refs_output_dependent_p (tree store1, tree store2)
+{
+  return refs_may_alias_p_1 (store1, store2, false);
+}
 
 /* If the call CALL may use the memory reference REF return true,
    otherwise return false.  */