tree-ssa-alias.c (ao_ref_init): New function.

2009-05-28  Richard Guenther  <rguenther@suse.de>

	* tree-ssa-alias.c (ao_ref_init): New function.
	(ao_ref_base): Likewise.
	(ao_ref_base_alias_set): Likewise.
	(ao_ref_alias_set): Likewise.
	(refs_may_alias_p_1): Change signature.
	(refs_may_alias_p): Adjust.
	(refs_anti_dependent_p): Likewise.
	(refs_output_dependent_p): Likewise.
	(call_may_clobber_ref_p_1): Change signature.
	(call_may_clobber_ref_p): Adjust.
	(stmt_may_clobber_ref_p_1): New function split out from ...
	(stmt_may_clobber_ref_p): ... here.
	(maybe_skip_until): Adjust signature.
	(get_continuation_for_phi): Likewise.
	(walk_non_aliased_vuses): Likewise.
	* tree-ssa-alias.h (struct ao_ref_s): New structure type.
	(ao_ref_init): Declare.
	(ao_ref_base): Likewise.
	(ao_ref_alias_set): Likewise.
	(stmt_may_clobber_ref_p_1): Likewise.
	(walk_non_aliased_vuses): Adjust.
	* tree-ssa-sccvn.c (ao_ref_init_from_vn_reference): New function.
	(get_ref_from_reference_ops): remove.
	(vn_reference_lookup_2): Adjust signature.
	(vn_reference_lookup_3): Do not re-build trees.  Handle unions.
	(vn_reference_lookup_pieces): Adjust signature, do not re-build
	trees.
	(vn_reference_lookup): Adjust.
	(vn_reference_insert): Likewise.
	(vn_reference_insert_pieces): Adjust signature.
	(visit_reference_op_call): Adjust.
	* tree-ssa-pre.c (get_expr_type): Simplify.
	(phi_translate_1): Adjust.
	(compute_avail): Likewise.
	(translate_vuse_through_block): Do not re-build trees.
	(value_dies_in_block_x): Likewise.
	* tree-ssa-sccvn.h (struct vn_reference_s): Add type and alias-set
	fields.
	(vn_reference_lookup_pieces): Adjust declaration.
	(vn_reference_insert_pieces): Likewise.

	* gcc.dg/tree-ssa/ssa-fre-26.c: New testcase.
	* gcc.c-torture/execute/20090527-1.c: Likewise.

From-SVN: r147953

gcc/ChangeLog

+2009-05-28  Richard Guenther  <rguenther@suse.de>
+
+	* tree-ssa-alias.c (ao_ref_init): New function.
+	(ao_ref_base): Likewise.
+	(ao_ref_base_alias_set): Likewise.
+	(ao_ref_alias_set): Likewise.
+	(refs_may_alias_p_1): Change signature.
+	(refs_may_alias_p): Adjust.
+	(refs_anti_dependent_p): Likewise.
+	(refs_output_dependent_p): Likewise.
+	(call_may_clobber_ref_p_1): Change signature.
+	(call_may_clobber_ref_p): Adjust.
+	(stmt_may_clobber_ref_p_1): New function split out from ...
+	(stmt_may_clobber_ref_p): ... here.
+	(maybe_skip_until): Adjust signature.
+	(get_continuation_for_phi): Likewise.
+	(walk_non_aliased_vuses): Likewise.
+	* tree-ssa-alias.h (struct ao_ref_s): New structure type.
+	(ao_ref_init): Declare.
+	(ao_ref_base): Likewise.
+	(ao_ref_alias_set): Likewise.
+	(stmt_may_clobber_ref_p_1): Likewise.
+	(walk_non_aliased_vuses): Adjust.
+	* tree-ssa-sccvn.c (ao_ref_init_from_vn_reference): New function.
+	(get_ref_from_reference_ops): remove.
+	(vn_reference_lookup_2): Adjust signature.
+	(vn_reference_lookup_3): Do not re-build trees.  Handle unions.
+	(vn_reference_lookup_pieces): Adjust signature, do not re-build
+	trees.
+	(vn_reference_lookup): Adjust.
+	(vn_reference_insert): Likewise.
+	(vn_reference_insert_pieces): Adjust signature.
+	(visit_reference_op_call): Adjust.
+	* tree-ssa-pre.c (get_expr_type): Simplify.
+	(phi_translate_1): Adjust.
+	(compute_avail): Likewise.
+	(translate_vuse_through_block): Do not re-build trees.
+	(value_dies_in_block_x): Likewise.
+	* tree-ssa-sccvn.h (struct vn_reference_s): Add type and alias-set
+	fields.
+	(vn_reference_lookup_pieces): Adjust declaration.
+	(vn_reference_insert_pieces): Likewise.
+
 2009-05-28  Benjamin Kosnik  <bkoz@redhat.com>
 
 	* tree-ssa-copy.c (replace_exp_1): Move op for warning-free use

gcc/testsuite/ChangeLog

+2009-05-28  Richard Guenther  <rguenther@suse.de>
+
+	* gcc.dg/tree-ssa/ssa-fre-26.c: New testcase.
+	* gcc.c-torture/execute/20090527-1.c: Likewise.
+
 2009-05-28  Dodji Seketeli  <dodji@redhat.com>
 
 	PR c++/39754

gcc/testsuite/gcc.c-torture/execute/20090527-1.c

+typedef enum { POSITION_ASIS, POSITION_UNSPECIFIED } unit_position;
+
+typedef enum { STATUS_UNKNOWN, STATUS_UNSPECIFIED } unit_status;
+
+typedef struct
+{
+  unit_position position;
+  unit_status status;
+} unit_flags;
+
+extern void abort (void);
+
+void
+new_unit (unit_flags * flags)
+{
+  if (flags->status == STATUS_UNSPECIFIED)
+    flags->status = STATUS_UNKNOWN;
+
+  if (flags->position == POSITION_UNSPECIFIED)
+    flags->position = POSITION_ASIS;
+
+  switch (flags->status)
+    {
+    case STATUS_UNKNOWN:
+      break;
+
+    default:
+      abort ();
+    }
+}
+
+int main()
+{
+  unit_flags f;
+  f.status = STATUS_UNSPECIFIED;
+  new_unit (&f);
+  return 0;
+}

gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-26.c

+/* { dg-do compile } */
+/* { dg-options "-O -fno-tree-sra -fdump-tree-fre-details" } */
+
+union U {
+  float f;
+  int i;
+};
+
+int foo (union U *p)
+{
+  union U u;
+  p->f = 0.0;
+  u = *p;
+  return u.i;
+}
+
+/* { dg-final { scan-tree-dump "Replaced u.i with 0 in" "fre" } } */
+/* { dg-final { cleanup-tree-dump "fre" } } */

gcc/tree-ssa-alias.h

@@ -74,7 +74,39 @@ struct GTY(()) pt_solution
 };
 
 
+/* Simplified and cached information about a memory reference tree.
+   Used by the alias-oracle internally and externally in alternate
+   interfaces.  */
+typedef struct ao_ref_s
+{
+  /* The original full memory reference tree or NULL_TREE if that is
+     not available.  */
+  tree ref;
+
+  /* The following fields are the decomposed reference as returned
+     by get_ref_base_and_extent.  */
+  /* The base object of the memory reference or NULL_TREE if all of
+     the following fields are not yet computed.  */
+  tree base;
+  /* The offset relative to the base.  */
+  HOST_WIDE_INT offset;
+  /* The size of the access.  */
+  HOST_WIDE_INT size;
+  /* The maximum possible extent of the access or -1 if unconstrained.  */
+  HOST_WIDE_INT max_size;
+
+  /* The alias set of the access or -1 if not yet computed.  */
+  alias_set_type ref_alias_set;
+
+  /* The alias set of the base object or -1 if not yet computed.  */
+  alias_set_type base_alias_set;
+} ao_ref;
+
+
 /* In tree-ssa-alias.c  */
+extern void ao_ref_init (ao_ref *, tree);
+extern tree ao_ref_base (ao_ref *);
+extern alias_set_type ao_ref_alias_set (ao_ref *);
 extern enum escape_type is_escape_site (gimple);
 extern bool ptr_deref_may_alias_global_p (tree);
 extern bool refs_may_alias_p (tree, tree);
@@ -82,9 +114,10 @@ extern bool refs_anti_dependent_p (tree, tree);
 extern bool refs_output_dependent_p (tree, tree);
 extern bool ref_maybe_used_by_stmt_p (gimple, tree);
 extern bool stmt_may_clobber_ref_p (gimple, tree);
-extern void *walk_non_aliased_vuses (tree, tree,
-				     void *(*)(tree, tree, void *),
-				     void *(*)(tree *, tree, void *), void *);
+extern bool stmt_may_clobber_ref_p_1 (gimple, ao_ref *);
+extern void *walk_non_aliased_vuses (ao_ref *, tree,
+				     void *(*)(ao_ref *, tree, void *),
+				     void *(*)(ao_ref *, tree, void *), void *);
 extern unsigned int walk_aliased_vdefs (tree, tree,
 					bool (*)(tree, tree, void *), void *,
 					bitmap *);

gcc/tree-ssa-pre.c

@@ -1252,12 +1252,12 @@ do_unary:
 
 static tree
 translate_vuse_through_block (VEC (vn_reference_op_s, heap) *operands,
-			      tree vuse,
+			      alias_set_type set, tree type, tree vuse,
 			      basic_block phiblock,
 			      basic_block block)
 {
   gimple phi = SSA_NAME_DEF_STMT (vuse);
-  tree ref;
+  ao_ref ref;
 
   if (gimple_bb (phi) != phiblock)
     return vuse;
@@ -1268,13 +1268,13 @@ translate_vuse_through_block (VEC (vn_reference_op_s, heap) *operands,
       return PHI_ARG_DEF (phi, e->dest_idx);
     }
 
-  if (!(ref = get_ref_from_reference_ops (operands)))
+  if (!ao_ref_init_from_vn_reference (&ref, set, type, operands))
     return NULL_TREE;
 
   /* Use the alias-oracle to find either the PHI node in this block,
      the first VUSE used in this block that is equivalent to vuse or
      the first VUSE which definition in this block kills the value.  */
-  while (!stmt_may_clobber_ref_p (phi, ref))
+  while (!stmt_may_clobber_ref_p_1 (phi, &ref))
     {
       vuse = gimple_vuse (phi);
       phi = SSA_NAME_DEF_STMT (vuse);
@@ -1317,23 +1317,7 @@ get_expr_type (const pre_expr e)
     case CONSTANT:
       return TREE_TYPE (PRE_EXPR_CONSTANT (e));
     case REFERENCE:
-      {
-	vn_reference_op_t vro;
-
-	gcc_assert (PRE_EXPR_REFERENCE (e)->operands);
-	vro = VEC_index (vn_reference_op_s,
-			 PRE_EXPR_REFERENCE (e)->operands,
-			 0);
-	/* We don't store type along with COMPONENT_REF because it is
-	   always the same as FIELD_DECL's type.  */
-	if (!vro->type)
-	  {
-	    gcc_assert (vro->opcode == COMPONENT_REF);
-	    return TREE_TYPE (vro->op0);
-	  }
-	return vro->type;
-      }
-
+      return PRE_EXPR_REFERENCE (e)->type;
     case NARY:
       return PRE_EXPR_NARY (e)->type;
     }
@@ -1661,6 +1645,7 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
 	if (vuse)
 	  {
 	    newvuse = translate_vuse_through_block (newoperands,
+						    ref->set, ref->type,
 						    vuse, phiblock, pred);
 	    if (newvuse == NULL_TREE)
 	      {
@@ -1675,7 +1660,8 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
 	    unsigned int new_val_id;
 	    pre_expr constant;
 
-	    tree result = vn_reference_lookup_pieces (newvuse,
+	    tree result = vn_reference_lookup_pieces (newvuse, ref->set,
+						      ref->type,
 						      newoperands,
 						      &newref, true);
 	    if (newref)
@@ -1706,7 +1692,8 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
 		new_val_id = get_next_value_id ();
 		VEC_safe_grow_cleared (bitmap_set_t, heap, value_expressions,
 				       get_max_value_id() + 1);
-		newref = vn_reference_insert_pieces (newvuse,
+		newref = vn_reference_insert_pieces (newvuse, ref->set,
+						     ref->type,
 						     newoperands,
 						     result, new_val_id);
 		newoperands = NULL;
@@ -1884,10 +1871,10 @@ value_dies_in_block_x (pre_expr expr, basic_block block)
   tree vuse = PRE_EXPR_REFERENCE (expr)->vuse;
   vn_reference_t refx = PRE_EXPR_REFERENCE (expr);
   gimple def;
-  tree ref = NULL_TREE;
   gimple_stmt_iterator gsi;
   unsigned id = get_expression_id (expr);
   bool res = false;
+  ao_ref ref;
 
   if (!vuse)
     return false;
@@ -1902,6 +1889,7 @@ value_dies_in_block_x (pre_expr expr, basic_block block)
      top of the basic block, a statement uses VUSE there can be no kill
      inbetween that use and the original statement that loaded {e, VUSE},
      so we can stop walking.  */
+  ref.base = NULL_TREE;
   for (gsi = gsi_start_bb (block); !gsi_end_p (gsi); gsi_next (&gsi))
     {
       tree def_vuse, def_vdef;
@@ -1924,16 +1912,15 @@ value_dies_in_block_x (pre_expr expr, basic_block block)
 	}
 
       /* Init ref only if we really need it.  */
-      if (ref == NULL_TREE)
+      if (ref.base == NULL_TREE
+	  && !ao_ref_init_from_vn_reference (&ref, refx->set, refx->type,
+					     refx->operands))
 	{
-	  if (!(ref = get_ref_from_reference_ops (refx->operands)))
-	    {
-	      res = true;
-	      break;
-	    }
+	  res = true;
+	  break;
 	}
       /* If the statement may clobber expr, it dies.  */
-      if (stmt_may_clobber_ref_p (def, ref))
+      if (stmt_may_clobber_ref_p_1 (def, &ref))
 	{
 	  res = true;
 	  break;
@@ -3793,7 +3780,8 @@ compute_avail (void)
 		  continue;
 
 		copy_reference_ops_from_call (stmt, &ops);
-		vn_reference_lookup_pieces (gimple_vuse (stmt),
+		vn_reference_lookup_pieces (gimple_vuse (stmt), 0,
+					    gimple_expr_type (stmt),
 					    ops, &ref, false);
 		VEC_free (vn_reference_op_s, heap, ops);
 		if (!ref)

gcc/tree-ssa-sccvn.h

@@ -92,6 +92,8 @@ typedef struct vn_reference_s
   unsigned int value_id;
   hashval_t hashcode;
   tree vuse;
+  alias_set_type set;
+  tree type;
   VEC (vn_reference_op_s, heap) *operands;
   tree result;
 } *vn_reference_t;
@@ -177,13 +179,14 @@ void vn_reference_fold_indirect (VEC (vn_reference_op_s, heap) **,
 				 unsigned int *);
 void copy_reference_ops_from_ref (tree, VEC(vn_reference_op_s, heap) **);
 void copy_reference_ops_from_call (gimple, VEC(vn_reference_op_s, heap) **);
-tree get_ref_from_reference_ops (VEC(vn_reference_op_s, heap) *ops);
-tree vn_reference_lookup_pieces (tree,
+bool ao_ref_init_from_vn_reference (ao_ref *, alias_set_type, tree,
+				    VEC (vn_reference_op_s, heap) *);
+tree vn_reference_lookup_pieces (tree, alias_set_type, tree,
 				 VEC (vn_reference_op_s, heap) *,
 				 vn_reference_t *, bool);
 tree vn_reference_lookup (tree, tree, bool, vn_reference_t *);
 vn_reference_t vn_reference_insert (tree, tree, tree);
-vn_reference_t vn_reference_insert_pieces (tree,
+vn_reference_t vn_reference_insert_pieces (tree, alias_set_type, tree,
 					   VEC (vn_reference_op_s, heap) *,
 					   tree, unsigned int);