re PR tree-optimization/36400 (points-to results wrong)

2008-06-27  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/36400
	PR tree-optimization/36373
	PR tree-optimization/36344
	* tree-ssa-structalias.c (var_escaped, escaped_tree, escaped_id,
	var_nonlocal, nonlocal_tree, nonlocal_id): New globals
	(update_alias_info): Remove call clobbering code.
	(make_constraint_to): New helper function.
	(make_escape_constraint): Likewise.
	(handle_rhs_call): Use it on all pointer containing arguments.
	Also mark the static chain escaped.
	(handle_lhs_call): Make constraints from NONLOCAL and ESCAPED
	instead of ANYTHING.
	(make_constraint_from): New helper split out from ...
	(make_constraint_from_anything): ... here.
	(find_func_aliases): Add constraints for escape sites.
	(intra_create_variable_infos): Make constraints from NONLOCAL
	for parameters.
	(find_what_p_points_to): Interpret NONLOCAL and ESCAPED the same
	as ANYTHING.
	(clobber_what_p_points_to): Remove.
	(clobber_what_escaped): New function.
	(init_base_vars): Init NONLOCAL and ESCAPED.
	(do_sd_constraint): Do not propagate the solution from ESCAPED
	but use ESCAPED as a placeholder.
	(solve_graph): Likewise.
	* tree-flow.h (clobber_what_p_points_to): Remove.
	(clobber_what_escaped): Declare.
	* tree-ssa-alias.c (set_initial_properties): Call it.
	Remove code clobbering escaped pointers.

	* gcc.dg/torture/pr36373-1.c: New testcase.
	* gcc.dg/torture/pr36373-2.c: Likewise.
	* gcc.dg/torture/pr36373-3.c: Likewise.
	* gcc.dg/torture/pr36373-4.c: Likewise.
	* gcc.dg/torture/pr36373-5.c: Likewise.
	* gcc.dg/torture/pr36373-6.c: Likewise.
	* gcc.dg/torture/pr36373-7.c: Likewise.
	* gcc.dg/torture/pr36373-8.c: Likewise.
	* gcc.dg/torture/pr36373-9.c: Likewise.
	* gcc.dg/torture/pr36373-10.c: Likewise.
	* gcc.dg/torture/pr36400.c: Likewise.
	* gcc.c-torture/execute/pta-field-1.c: Likewise.
	* gcc.c-torture/execute/pta-field-2.c: Likewise.
	* gcc.dg/tree-ssa/loadpre8.c: Remove XFAIL.
	* gcc.dg/tree-ssa/pr24287.c: XFAIL.

From-SVN: r137197

1 files changed, 12 insertions, 12 deletions

diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index 748ff31..7c24739 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -537,6 +537,12 @@ set_initial_properties (struct alias_info *ai)
 	}
     }
 
+  if (!clobber_what_escaped ())
+    {
+      any_pt_anything = true;
+      pt_anything_mask |= ESCAPE_TO_CALL;
+    }
+
   for (i = 0; VEC_iterate (tree, ai->processed_ptrs, i, ptr); i++)
     {
       struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr);
@@ -557,18 +563,6 @@ set_initial_properties (struct alias_info *ai)
 
 	  if (tag)
 	    mark_call_clobbered (tag, pi->escape_mask);
-
-	  /* Defer to points-to analysis if possible, otherwise
-	     clobber all addressable variables.  Parameters cannot
-	     point to local memory though.
-	     ???  Properly tracking which pointers point to non-local
-	     memory only would make a big difference here.  */
-	  if (!clobber_what_p_points_to (ptr)
-	      && !(pi->escape_mask & ESCAPE_IS_PARM))
-	    {
-	      any_pt_anything = true;
-	      pt_anything_mask |= pi->escape_mask;
-	    }
 	}
 
       /* If the name tag is call clobbered, so is the symbol tag
@@ -2906,6 +2900,12 @@ is_escape_site (tree stmt)
       if (TREE_CODE (lhs) == SSA_NAME)
 	return NO_ESCAPE;
 
+      /* If the LHS is a non-global decl, it isn't a non-local memory store.
+	 If the LHS escapes, the RHS escape is dealt with in the PTA solver.  */
+      if (DECL_P (lhs)
+	  && !is_global_var (lhs))
+	return NO_ESCAPE;
+
       /* FIXME: LHS is not an SSA_NAME.  Even if it's an assignment to a
 	 local variables we cannot be sure if it will escape, because we
 	 don't have information about objects not in SSA form.  Need to