2015-09-29 Richard Biener <rguenther@suse.de>

	PR tree-optimization/67170
	* tree-ssa-alias.h (get_continuation_for_phi): Adjust
	the translate function pointer parameter to get the
	bool whether to disambiguate only by reference.
	(walk_non_aliased_vuses): Likewise.
	* tree-ssa-alias.c (maybe_skip_until): Adjust.
	(get_continuation_for_phi_1): Likewise.
	(get_continuation_for_phi): Likewise.
	(walk_non_aliased_vuses): Likewise.
	* tree-ssa-sccvn.c (const_parms): New bitmap.
	(vn_reference_lookup_3): Adjust for interface change.
	Disambiguate parameters pointing to readonly memory.
	(free_scc_vn): Free const_parms.
	(run_scc_vn): Initialize const_parms from a fn spec attribute.

	* gfortran.dg/pr67170.f90: New testcase.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@228244 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8fc37ce595165fa8e2fc0d59fbf6a365a88ea836..03f566c2cd96a0fda4f620dc8578dd844f20b8f8 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,20 @@
+2015-09-29  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/67170
+       * tree-ssa-alias.h (get_continuation_for_phi): Adjust
+       the translate function pointer parameter to get the
+       bool whether to disambiguate only by reference.
+       (walk_non_aliased_vuses): Likewise.
+       * tree-ssa-alias.c (maybe_skip_until): Adjust.
+       (get_continuation_for_phi_1): Likewise.
+       (get_continuation_for_phi): Likewise.
+       (walk_non_aliased_vuses): Likewise.
+       * tree-ssa-sccvn.c (const_parms): New bitmap.
+       (vn_reference_lookup_3): Adjust for interface change.
+       Disambiguate parameters pointing to readonly memory.
+       (free_scc_vn): Free const_parms.
+       (run_scc_vn): Initialize const_parms from a fn spec attribute.
+
 2015-09-29  Richard Biener  <rguenther@suse.de>
 
        PR tree-optimization/67741

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 6582172b5720bc02dfdf4bab86c8735657bd858c..335e00b3eab6c06cbc0b9f589b94bf4f2c8a027e 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-09-29  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/67170
+       * gfortran.dg/pr67170.f90: New testcase.
+
 2015-09-29  Richard Biener  <rguenther@suse.de>
 
        PR tree-optimization/67741

diff --git a/gcc/testsuite/gfortran.dg/pr67170.f90 b/gcc/testsuite/gfortran.dg/pr67170.f90
new file mode 100644 (file)
index 0000000..8023647
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr67170.f90
@@ -0,0 +1,31 @@
+! { dg-do compile }
+! { dg-options "-O -fdump-tree-fre1" }
+
+module test_module
+  integer, parameter :: r=10
+   integer :: data(r, r), block(r, r, r)
+  contains
+recursive subroutine foo(arg) 
+integer, intent(in) :: arg
+integer :: loop, x(r), y(r)
+
+   where(data(arg, :) /= 0)
+      x = data(arg, :)
+       y = l
+   elsewhere
+      x = 1
+      y = r
+   end where
+
+do loop = x(1), y(1)
+   if(block(arg, 1, loop) <= 0) cycle
+   block(arg, 1:4, loop) =  block(arg, 1:4, i1) + 1
+   call foo(arg + 2)     
+   block(arg, 1:4, loop) = block(arg, 1:4, i1) + 10
+end do
+end subroutine foo
+
+end module test_module
+end program
+
+! { dg-final { scan-tree-dump-times "= \\*arg_\[0-9\]+\\(D\\);" 1 "fre1" } }

diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index 5ff2275c079bd7ccf8029a5a65c8fcf3f68d5b11..3b8d5946d0e0a55beab5e45341e474b759e019eb 100644 (file)
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -2442,7 +2442,7 @@ static bool
 maybe_skip_until (gimple *phi, tree target, ao_ref *ref,
                  tree vuse, unsigned int *cnt, bitmap *visited,
                  bool abort_on_visited,
-                 void *(*translate)(ao_ref *, tree, void *, bool),
+                 void *(*translate)(ao_ref *, tree, void *, bool *),
                  void *data)
 {
   basic_block bb = gimple_bb (phi);
@@ -2477,8 +2477,9 @@ maybe_skip_until (gimple *phi, tree target, ao_ref *ref,
          ++*cnt;
          if (stmt_may_clobber_ref_p_1 (def_stmt, ref))
            {
+             bool disambiguate_only = true;
              if (translate
-                 && (*translate) (ref, vuse, data, true) == NULL)
+                 && (*translate) (ref, vuse, data, &disambiguate_only) == NULL)
                ;
              else
                return false;
@@ -2505,7 +2506,7 @@ static tree
 get_continuation_for_phi_1 (gimple *phi, tree arg0, tree arg1,
                            ao_ref *ref, unsigned int *cnt,
                            bitmap *visited, bool abort_on_visited,
-                           void *(*translate)(ao_ref *, tree, void *, bool),
+                           void *(*translate)(ao_ref *, tree, void *, bool *),
                            void *data)
 {
   gimple *def0 = SSA_NAME_DEF_STMT (arg0);
@@ -2547,13 +2548,14 @@ get_continuation_for_phi_1 (gimple *phi, tree arg0, tree arg1,
   else if ((common_vuse = gimple_vuse (def0))
           && common_vuse == gimple_vuse (def1))
     {
+      bool disambiguate_only = true;
       *cnt += 2;
       if ((!stmt_may_clobber_ref_p_1 (def0, ref)
           || (translate
-              && (*translate) (ref, arg0, data, true) == NULL))
+              && (*translate) (ref, arg0, data, &disambiguate_only) == NULL))
          && (!stmt_may_clobber_ref_p_1 (def1, ref)
              || (translate
-                 && (*translate) (ref, arg1, data, true) == NULL)))
+                 && (*translate) (ref, arg1, data, &disambiguate_only) == NULL)))
        return common_vuse;
     }
 
@@ -2571,7 +2573,7 @@ tree
 get_continuation_for_phi (gimple *phi, ao_ref *ref,
                          unsigned int *cnt, bitmap *visited,
                          bool abort_on_visited,
-                         void *(*translate)(ao_ref *, tree, void *, bool),
+                         void *(*translate)(ao_ref *, tree, void *, bool *),
                          void *data)
 {
   unsigned nargs = gimple_phi_num_args (phi);
@@ -2648,7 +2650,7 @@ get_continuation_for_phi (gimple *phi, ao_ref *ref,
 void *
 walk_non_aliased_vuses (ao_ref *ref, tree vuse,
                        void *(*walker)(ao_ref *, tree, unsigned int, void *),
-                       void *(*translate)(ao_ref *, tree, void *, bool),
+                       void *(*translate)(ao_ref *, tree, void *, bool *),
                        tree (*valueize)(tree),
                        void *data)
 {
@@ -2690,7 +2692,8 @@ walk_non_aliased_vuses (ao_ref *ref, tree vuse,
            {
              if (!translate)
                break;
-             res = (*translate) (ref, vuse, data, false);
+             bool disambiguate_only = false;
+             res = (*translate) (ref, vuse, data, &disambiguate_only);
              /* Failed lookup and translation.  */
              if (res == (void *)-1)
                {
@@ -2701,7 +2704,7 @@ walk_non_aliased_vuses (ao_ref *ref, tree vuse,
              else if (res != NULL)
                break;
              /* Translation succeeded, continue walking.  */
-             translated = true;
+             translated = translated || !disambiguate_only;
            }
          vuse = gimple_vuse (def_stmt);
        }

diff --git a/gcc/tree-ssa-alias.h b/gcc/tree-ssa-alias.h
index 67d9bcb17509dea5655848418a60fba01c147f4f..f328e244c42bf3031a55e8abcf903df7e1ee5252 100644 (file)
--- a/gcc/tree-ssa-alias.h
+++ b/gcc/tree-ssa-alias.h
@@ -118,12 +118,12 @@ extern bool stmt_kills_ref_p (gimple *, tree);
 extern bool stmt_kills_ref_p (gimple *, ao_ref *);
 extern tree get_continuation_for_phi (gimple *, ao_ref *,
                                      unsigned int *, bitmap *, bool,
-                                     void *(*)(ao_ref *, tree, void *, bool),
+                                     void *(*)(ao_ref *, tree, void *, bool *),
                                      void *);
 extern void *walk_non_aliased_vuses (ao_ref *, tree,
                                     void *(*)(ao_ref *, tree,
                                               unsigned int, void *),
-                                    void *(*)(ao_ref *, tree, void *, bool),
+                                    void *(*)(ao_ref *, tree, void *, bool *),
                                     tree (*)(tree),
                                     void *);
 extern unsigned int walk_aliased_vdefs (ao_ref *, tree,

diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index ce79842dd2bfb2078cc0a19a7d34c6340c30bc11..5b06d29f62205bf3e0c568169a1ec913d60b6ca7 100644 (file)
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -120,6 +120,7 @@ along with GCC; see the file COPYING3.  If not see
 static tree *last_vuse_ptr;
 static vn_lookup_kind vn_walk_kind;
 static vn_lookup_kind default_vn_walk_kind;
+bitmap const_parms;
 
 /* vn_nary_op hashtable helpers.  */
 
@@ -1656,21 +1657,35 @@ vn_reference_lookup_or_insert_for_pieces (tree vuse,
 /* Callback for walk_non_aliased_vuses.  Tries to perform a lookup
    from the statement defining VUSE and if not successful tries to
    translate *REFP and VR_ through an aggregate copy at the definition
-   of VUSE.  */
+   of VUSE.  If *DISAMBIGUATE_ONLY is true then do not perform translation
+   of *REF and *VR.  If only disambiguation was performed then
+   *DISAMBIGUATE_ONLY is set to true.  */
 
 static void *
 vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_,
-                      bool disambiguate_only)
+                      bool *disambiguate_only)
 {
   vn_reference_t vr = (vn_reference_t)vr_;
   gimple *def_stmt = SSA_NAME_DEF_STMT (vuse);
-  tree base;
+  tree base = ao_ref_base (ref);
   HOST_WIDE_INT offset, maxsize;
   static vec<vn_reference_op_s>
     lhs_ops = vNULL;
   ao_ref lhs_ref;
   bool lhs_ref_ok = false;
 
+  /* If the reference is based on a parameter that was determined as
+     pointing to readonly memory it doesn't change.  */
+  if (TREE_CODE (base) == MEM_REF
+      && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME
+      && SSA_NAME_IS_DEFAULT_DEF (TREE_OPERAND (base, 0))
+      && bitmap_bit_p (const_parms,
+                      SSA_NAME_VERSION (TREE_OPERAND (base, 0))))
+    {
+      *disambiguate_only = true;
+      return NULL;
+    }
+
   /* First try to disambiguate after value-replacing in the definitions LHS.  */
   if (is_gimple_assign (def_stmt))
     {
@@ -1687,7 +1702,10 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_,
                                                      TREE_TYPE (lhs), lhs_ops);
          if (lhs_ref_ok
              && !refs_may_alias_p_1 (ref, &lhs_ref, true))
-           return NULL;
+           {
+             *disambiguate_only = true;
+             return NULL;
+           }
        }
       else
        {
@@ -1723,14 +1741,16 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_,
          for (unsigned i = 0; i < gimple_call_num_args (def_stmt); ++i)
            gimple_call_set_arg (def_stmt, i, oldargs[i]);
          if (!res)
-           return NULL;
+           {
+             *disambiguate_only = true;
+             return NULL;
+           }
        }
     }
 
-  if (disambiguate_only)
+  if (*disambiguate_only)
     return (void *)-1;
 
-  base = ao_ref_base (ref);
   offset = ref->offset;
   maxsize = ref->max_size;
 
@@ -4342,6 +4362,8 @@ free_scc_vn (void)
   XDELETE (valid_info);
   free_vn_table (optimistic_info);
   XDELETE (optimistic_info);
+
+  BITMAP_FREE (const_parms);
 }
 
 /* Set *ID according to RESULT.  */
@@ -4677,6 +4699,29 @@ run_scc_vn (vn_lookup_kind default_vn_walk_kind_)
 
   init_scc_vn ();
 
+  /* Collect pointers we know point to readonly memory.  */
+  const_parms = BITMAP_ALLOC (NULL);
+  tree fnspec = lookup_attribute ("fn spec",
+                                 TYPE_ATTRIBUTES (TREE_TYPE (cfun->decl)));
+  if (fnspec)
+    {
+      fnspec = TREE_VALUE (TREE_VALUE (fnspec));
+      i = 1;
+      for (tree arg = DECL_ARGUMENTS (cfun->decl);
+          arg; arg = DECL_CHAIN (arg), ++i)
+       {
+         if (i >= (unsigned) TREE_STRING_LENGTH (fnspec))
+           break;
+         if (TREE_STRING_POINTER (fnspec)[i]  == 'R'
+             || TREE_STRING_POINTER (fnspec)[i] == 'r')
+           {
+             tree name = ssa_default_def (cfun, arg);
+             if (name)
+               bitmap_set_bit (const_parms, SSA_NAME_VERSION (name));
+           }
+       }
+    }
+
   /* Mark all edges as possibly executable.  */
   FOR_ALL_BB_FN (bb, cfun)
     {