re PR tree-optimization/91756 (g++.dg/lto/alias-3 FAILs)

2019-09-16  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/91756
	PR tree-optimization/87132
	* tree-ssa-alias.h (enum translate_flags): New.
	(get_continuation_for_phi): Use it instead of simple bool flag.
	(walk_non_aliased_vuses): Likewise.
	* tree-ssa-alias.c (maybe_skip_until): Adjust.
	(get_continuation_for_phi): When looking across backedges only
	disallow valueization.
	(walk_non_aliased_vuses): Adjust.
	* tree-ssa-sccvn.c (vn_reference_lookup_3): Avoid valueization
	if requested.

	* gcc.dg/tree-ssa/ssa-fre-81.c: New testcase.

From-SVN: r275747

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 41cf9267c95dd265352d1ea909942a5455a6d754..49b7902e3a853feab65de30531624597014b06ab 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,17 @@
+2019-09-16  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/91756
+       PR tree-optimization/87132
+       * tree-ssa-alias.h (enum translate_flags): New.
+       (get_continuation_for_phi): Use it instead of simple bool flag.
+       (walk_non_aliased_vuses): Likewise.
+       * tree-ssa-alias.c (maybe_skip_until): Adjust.
+       (get_continuation_for_phi): When looking across backedges only
+       disallow valueization.
+       (walk_non_aliased_vuses): Adjust.
+       * tree-ssa-sccvn.c (vn_reference_lookup_3): Avoid valueization
+       if requested.
+
 2019-09-14  Kewen Lin  <linkw@gcc.gnu.org>
 
        PR middle-end/80791

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 6a5ba09391e63d415de2d36144187466e3eeaf94..b893ed0d462a697acf30e270db77ab8e76a449f2 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2019-09-16  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/91756
+       PR tree-optimization/87132
+       * gcc.dg/tree-ssa/ssa-fre-81.c: New testcase.
+
 2019-09-15  Marek Polacek  <polacek@redhat.com>
 
        PR c++/91740 - ICE with constexpr call and ?: in ARRAY_REF.

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-81.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-81.c
new file mode 100644 (file)
index 0000000..e88f666
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-81.c
@@ -0,0 +1,29 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-fre1-details" } */
+
+struct a
+{
+  int foo,bar;
+};
+struct b
+{
+  struct a a[10];
+};
+struct b b, *bptr=&b, *bptr2=&b;
+int j;
+int i;
+int n=1;
+
+int
+main ()
+{
+  int jj=j;
+  bptr2->a[jj].bar = 0;
+  for (int i=0; i<n; i++)
+    bptr->a[i].foo=1;
+  if (!__builtin_constant_p (bptr2->a[jj].bar == 0))
+    __builtin_abort ();
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump "Replaced __builtin_constant_p \\\(\[^)\]*\\\) with 1" "fre1" } } */

diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index dd2a43e1409014766aeac0bd49c096099d2a4cf0..52cda38c2aaad5778a48e3652b5711e27da629f2 100644 (file)
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -3150,7 +3150,8 @@ static bool
 maybe_skip_until (gimple *phi, tree &target, basic_block target_bb,
                  ao_ref *ref, tree vuse, bool tbaa_p, unsigned int &limit,
                  bitmap *visited, bool abort_on_visited,
-                 void *(*translate)(ao_ref *, tree, void *, bool *),
+                 void *(*translate)(ao_ref *, tree, void *, translate_flags *),
+                 translate_flags disambiguate_only,
                  void *data)
 {
   basic_block bb = gimple_bb (phi);
@@ -3185,7 +3186,7 @@ maybe_skip_until (gimple *phi, tree &target, basic_block target_bb,
            return !abort_on_visited;
          vuse = get_continuation_for_phi (def_stmt, ref, tbaa_p, limit,
                                           visited, abort_on_visited,
-                                          translate, data);
+                                          translate, data, disambiguate_only);
          if (!vuse)
            return false;
          continue;
@@ -3200,9 +3201,9 @@ maybe_skip_until (gimple *phi, tree &target, basic_block target_bb,
          --limit;
          if (stmt_may_clobber_ref_p_1 (def_stmt, ref, tbaa_p))
            {
-             bool disambiguate_only = true;
+             translate_flags tf = disambiguate_only;
              if (translate
-                 && (*translate) (ref, vuse, data, &disambiguate_only) == NULL)
+                 && (*translate) (ref, vuse, data, &tf) == NULL)
                ;
              else
                return false;
@@ -3233,8 +3234,10 @@ tree
 get_continuation_for_phi (gimple *phi, ao_ref *ref, bool tbaa_p,
                          unsigned int &limit, bitmap *visited,
                          bool abort_on_visited,
-                         void *(*translate)(ao_ref *, tree, void *, bool *),
-                         void *data)
+                         void *(*translate)(ao_ref *, tree, void *,
+                                            translate_flags *),
+                         void *data,
+                         translate_flags disambiguate_only)
 {
   unsigned nargs = gimple_phi_num_args (phi);
 
@@ -3276,13 +3279,15 @@ get_continuation_for_phi (gimple *phi, ao_ref *ref, bool tbaa_p,
       else if (! maybe_skip_until (phi, arg0, dom, ref, arg1, tbaa_p,
                                   limit, visited,
                                   abort_on_visited,
-                                  /* Do not translate when walking over
+                                  translate,
+                                  /* Do not valueize when walking over
                                      backedges.  */
                                   dominated_by_p
                                     (CDI_DOMINATORS,
                                      gimple_bb (SSA_NAME_DEF_STMT (arg1)),
                                      phi_bb)
-                                  ? NULL : translate, data))
+                                  ? TR_DISAMBIGUATE
+                                  : disambiguate_only, data))
        return NULL_TREE;
     }
 
@@ -3320,7 +3325,8 @@ get_continuation_for_phi (gimple *phi, ao_ref *ref, bool tbaa_p,
 void *
 walk_non_aliased_vuses (ao_ref *ref, tree vuse, bool tbaa_p,
                        void *(*walker)(ao_ref *, tree, void *),
-                       void *(*translate)(ao_ref *, tree, void *, bool *),
+                       void *(*translate)(ao_ref *, tree, void *,
+                                          translate_flags *),
                        tree (*valueize)(tree),
                        unsigned &limit, void *data)
 {
@@ -3373,7 +3379,7 @@ walk_non_aliased_vuses (ao_ref *ref, tree vuse, bool tbaa_p,
            {
              if (!translate)
                break;
-             bool disambiguate_only = false;
+             translate_flags disambiguate_only = TR_TRANSLATE;
              res = (*translate) (ref, vuse, data, &disambiguate_only);
              /* Failed lookup and translation.  */
              if (res == (void *)-1)
@@ -3385,7 +3391,7 @@ walk_non_aliased_vuses (ao_ref *ref, tree vuse, bool tbaa_p,
              else if (res != NULL)
                break;
              /* Translation succeeded, continue walking.  */
-             translated = translated || !disambiguate_only;
+             translated = translated || disambiguate_only == TR_TRANSLATE;
            }
          vuse = gimple_vuse (def_stmt);
        }

diff --git a/gcc/tree-ssa-alias.h b/gcc/tree-ssa-alias.h
index c7c6020efc03aee6ae51e6a2584e7ff7c19be289..6d72c2fcdc2791a68bd51fe4d83c7e09dfe14b87 100644 (file)
--- a/gcc/tree-ssa-alias.h
+++ b/gcc/tree-ssa-alias.h
@@ -132,13 +132,18 @@ extern bool call_may_clobber_ref_p (gcall *, tree);
 extern bool call_may_clobber_ref_p_1 (gcall *, ao_ref *);
 extern bool stmt_kills_ref_p (gimple *, tree);
 extern bool stmt_kills_ref_p (gimple *, ao_ref *);
+enum translate_flags
+  { TR_TRANSLATE, TR_VALUEIZE_AND_DISAMBIGUATE, TR_DISAMBIGUATE };
 extern tree get_continuation_for_phi (gimple *, ao_ref *, bool,
                                      unsigned int &, bitmap *, bool,
-                                     void *(*)(ao_ref *, tree, void *, bool *),
-                                     void *);
+                                     void *(*)(ao_ref *, tree, void *,
+                                               translate_flags *),
+                                     void *, translate_flags
+                                       = TR_VALUEIZE_AND_DISAMBIGUATE);
 extern void *walk_non_aliased_vuses (ao_ref *, tree, bool,
                                     void *(*)(ao_ref *, tree, void *),
-                                    void *(*)(ao_ref *, tree, void *, bool *),
+                                    void *(*)(ao_ref *, tree, void *,
+                                              translate_flags *),
                                     tree (*)(tree), unsigned &, void *);
 extern int walk_aliased_vdefs (ao_ref *, tree,
                               bool (*)(ao_ref *, tree, void *),

diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index f5d75bdfc99f59fff45cce082f3d93561ab72cc6..c29e2de61acdf69dbf6af4594d9b8c8569044a52 100644 (file)
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -2189,7 +2189,7 @@ adjust_offsets_for_equal_base_address (tree base1, poly_int64 *offset1,
 
 static void *
 vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
-                      bool *disambiguate_only)
+                      translate_flags *disambiguate_only)
 {
   vn_walk_cb_data *data = (vn_walk_cb_data *)data_;
   vn_reference_t vr = data->vr;
@@ -2210,8 +2210,11 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
       lhs_ops.truncate (0);
       basic_block saved_rpo_bb = vn_context_bb;
       vn_context_bb = gimple_bb (def_stmt);
-      copy_reference_ops_from_ref (lhs, &lhs_ops);
-      lhs_ops = valueize_refs_1 (lhs_ops, &valueized_anything, true);
+      if (*disambiguate_only <= TR_VALUEIZE_AND_DISAMBIGUATE)
+       {
+         copy_reference_ops_from_ref (lhs, &lhs_ops);
+         lhs_ops = valueize_refs_1 (lhs_ops, &valueized_anything, true);
+       }
       vn_context_bb = saved_rpo_bb;
       if (valueized_anything)
        {
@@ -2221,7 +2224,7 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
          if (lhs_ref_ok
              && !refs_may_alias_p_1 (ref, &lhs_ref, data->tbaa_p))
            {
-             *disambiguate_only = true;
+             *disambiguate_only = TR_VALUEIZE_AND_DISAMBIGUATE;
              return NULL;
            }
        }
@@ -2248,7 +2251,9 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
            }
          if (!refs_may_alias_p_1 (&data->orig_ref, lref, data->tbaa_p))
            {
-             *disambiguate_only = true;
+             *disambiguate_only = (valueized_anything
+                                   ? TR_VALUEIZE_AND_DISAMBIGUATE
+                                   : TR_DISAMBIGUATE);
              return NULL;
            }
        }
@@ -2290,7 +2295,8 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
            }
        }
     }
-  else if (gimple_call_builtin_p (def_stmt, BUILT_IN_NORMAL)
+  else if (*disambiguate_only <= TR_VALUEIZE_AND_DISAMBIGUATE
+          && gimple_call_builtin_p (def_stmt, BUILT_IN_NORMAL)
           && gimple_call_num_args (def_stmt) <= 4)
     {
       /* For builtin calls valueize its arguments and call the
@@ -2319,7 +2325,7 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
            gimple_call_set_arg (def_stmt, i, oldargs[i]);
          if (!res)
            {
-             *disambiguate_only = true;
+             *disambiguate_only = TR_VALUEIZE_AND_DISAMBIGUATE;
              return NULL;
            }
        }
@@ -2327,7 +2333,7 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
 
   /* If we are looking for redundant stores do not create new hashtable
      entries from aliasing defs with made up alias-sets.  */
-  if (*disambiguate_only || !data->tbaa_p)
+  if (*disambiguate_only > TR_TRANSLATE || !data->tbaa_p)
     return (void *)-1;
 
   /* If we cannot constrain the size of the reference we cannot