[4.9] Additional SLM tuning. Backport from trunk.

2014-11-24  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/55334
    * function.h (struct function): Add last_clique member.
    * tree-inline.c (remap_dependence_clique): New function.
    (remap_gimple_op_r): Remap dependence cliques in MEM_REFs.
    (copy_tree_body_r): Likewise.
    (copy_cfg_body): Free dependence map.
    (copy_gimple_seq_and_replace_locals): Likewise.
    * tree-pretty-print.c (dump_generic_node): Dump
    dependence info.
    * tree-ssa-alias.c (refs_may_alias_p_1): Use dependence info
    to answer alias query.
    * tree-ssa-structalias.c: Include tree-phinodes.h, ssa-iterators.h,
    tree-pretty-print.h and gimple-walk.h.
    (struct variable_info): Add is_restrict_var flag and ruid
    member.
    (new_var_info): Initialize is_restrict_var.
    (make_constraint_from_restrict): Likewise.
    (create_variable_info_for): Exclude restricts from global vars
    from new handling.
    (intra_create_variable_infos): But not those from parameters.
    (visit_loadstore): New function.
    (maybe_set_dependence_info): Likewise.
    (compute_dependence_clique): Likewise.
    (compute_may_aliases): Call compute_dependence_clique.
    * tree-data-ref.c (dr_analyze_indices): Copy dependence info
    to fake MEM_REF.
    (dr_may_alias_p): Use recorded dependence info to answer
    alias query.
    * tree-core.h (struct tree_base): Add clique, base struct in
    union.
    * tree.h (MR_DEPENDENCE_CLIQUE): New macro.
    (MR_DEPENDENCE_BASE): Likewise.
    * tree-inline.h (dependence_hasher): New hash-map kind.
    (struct copy_body_data): Add dependence_map pointer.
    * tree-streamer-in.c (unpack_value_fields): Stream dependence info.
    * tree-streamer-out.c (streamer_pack_tree_bitfields): Likewise.
    * gcc.dg/tree-ssa/restrict-5.c: New testcase.

Change-Id: I45c8d5eac758aea881a884c131f627cc916cbaf3
Signed-off-by: Andrew Senkevich <andrew.senkevich@intel.com>

1 files changed, 30 insertions, 1 deletions

diff --git a/gcc-4.9/gcc/tree-ssa-alias.c b/gcc-4.9/gcc/tree-ssa-alias.c
index de3fd0598..9a02de399 100644
--- a/gcc-4.9/gcc/tree-ssa-alias.c
+++ b/gcc-4.9/gcc/tree-ssa-alias.c
@@ -1405,7 +1405,36 @@ refs_may_alias_p_1 (ao_ref *ref1, ao_ref *ref2, bool tbaa_p)
 					  ao_ref_alias_set (ref1),
 					  ao_ref_base_alias_set (ref1),
 					  tbaa_p);
-  else if (ind1_p && ind2_p)
+
+  /* Handle restrict based accesses.
+     ???  ao_ref_base strips inner MEM_REF [&decl], recover from that
+     here.  */
+  tree rbase1 = base1;
+  tree rbase2 = base2;
+  if (var1_p)
+    {
+      rbase1 = ref1->ref;
+      if (rbase1)
+	while (handled_component_p (rbase1))
+	  rbase1 = TREE_OPERAND (rbase1, 0);
+    }
+  if (var2_p)
+    {
+      rbase2 = ref2->ref;
+      if (rbase2)
+	 while (handled_component_p (rbase2))
+	   rbase2 = TREE_OPERAND (rbase2, 0);
+    }
+  if (rbase1 && rbase2
+      && (TREE_CODE (base1) == MEM_REF || TREE_CODE (base1) == TARGET_MEM_REF)
+      && (TREE_CODE (base2) == MEM_REF || TREE_CODE (base2) == TARGET_MEM_REF)
+      /* If the accesses are in the same restrict clique... */
+      && MR_DEPENDENCE_CLIQUE (base1) == MR_DEPENDENCE_CLIQUE (base2)
+      /* But based on different pointers they do not alias.  */
+      && MR_DEPENDENCE_BASE (base1) != MR_DEPENDENCE_BASE (base2))
+    return false;
+
+  if (ind1_p && ind2_p)
     return indirect_refs_may_alias_p (ref1->ref, base1,
 				      offset1, max_size1,
 				      ao_ref_alias_set (ref1), -1,