2016-01-15 Richard Biener <rguenther@suse.de>

	PR tree-optimization/69117
	* tree-ssa-sccvn.h (struct vn_ssa_aux): Add info member.
	* tree-ssa-sccvn.c (set_ssa_val_to): Save and adjust SSA name info
	of the leader conservatively.
	(free_scc_vn): Restore original SSA name infos.

	* gcc.dg/torture/pr69117.c: New testcase.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@232401 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6f9c6a5f90673f84bfbae315b91d11e670ac0c2b..410c893ee61d39a840460efa83f3fca33038965c 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2016-01-15  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/69117
+       * tree-ssa-sccvn.h (struct vn_ssa_aux): Add info member.
+       * tree-ssa-sccvn.c (set_ssa_val_to): Save and adjust SSA name info
+       of the leader conservatively.
+       (free_scc_vn): Restore original SSA name infos.
+
 2016-01-14  Jeff Law  <law@redhat.com>
 
        PR tree-optimization/69270

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 250f55f7043f66f7b540c145f47e5072b114a211..52f5b1e643858af7b151d7d789201c6f57caa1ba 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-01-15  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/69117
+       * gcc.dg/torture/pr69117.c: New testcase.
+
 2015-01-14  Ryan Burn  <contact@rnburn.com>
 
        PR c++/69048

diff --git a/gcc/testsuite/gcc.dg/torture/pr69117.c b/gcc/testsuite/gcc.dg/torture/pr69117.c
new file mode 100644 (file)
index 0000000..fbf82c1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr69117.c
@@ -0,0 +1,23 @@
+/* { dg-do run } */
+/* { dg-additional-options "-fstrict-aliasing" } */
+
+int a, c, *d = &c, **e = &d, *g = &a;
+static int ***b, **f = &d;
+
+int
+main ()
+{
+  **f = 0;
+  int ****h = 0;
+  if (c) 
+    {
+      *h = &e; 
+      ***b = 0;
+    }
+  *e = g;
+
+  if (d != &a)
+    __builtin_abort ();
+
+  return 0;
+}

diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index 669d0b1e8a00aeee0c03dc80ef49edfd17947501..a6ee501892b1d38bdffab9f3940ff8c15d52b462 100644 (file)
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -3037,6 +3037,73 @@ set_ssa_val_to (tree from, tree to)
               == get_addr_base_and_unit_offset (TREE_OPERAND (to, 0), &toff))
           && coff == toff))
     {
+      /* If we equate two SSA names we have to make the side-band info
+         of the leader conservative (and remember whatever original value
+        was present).  */
+      if (TREE_CODE (to) == SSA_NAME)
+       {
+         if (INTEGRAL_TYPE_P (TREE_TYPE (to))
+             && SSA_NAME_RANGE_INFO (to))
+           {
+             if (SSA_NAME_IS_DEFAULT_DEF (to)
+                 || dominated_by_p (CDI_DOMINATORS,
+                                    gimple_bb (SSA_NAME_DEF_STMT (from)),
+                                    gimple_bb (SSA_NAME_DEF_STMT (to))))
+               /* Keep the info from the dominator.  */
+               ;
+             else if (SSA_NAME_IS_DEFAULT_DEF (from)
+                      || dominated_by_p (CDI_DOMINATORS,
+                                         gimple_bb (SSA_NAME_DEF_STMT (to)),
+                                         gimple_bb (SSA_NAME_DEF_STMT (from))))
+               {
+                 /* Save old info.  */
+                 if (! VN_INFO (to)->info.range_info)
+                   VN_INFO (to)->info.range_info = SSA_NAME_RANGE_INFO (to);
+                 /* Use that from the dominator.  */
+                 SSA_NAME_RANGE_INFO (to) = SSA_NAME_RANGE_INFO (from);
+               }
+             else
+               {
+                 /* Save old info.  */
+                 if (! VN_INFO (to)->info.range_info)
+                   VN_INFO (to)->info.range_info = SSA_NAME_RANGE_INFO (to);
+                 /* Rather than allocating memory and unioning the info
+                    just clear it.  */
+                 SSA_NAME_RANGE_INFO (to) = NULL;
+               }
+           }
+         else if (POINTER_TYPE_P (TREE_TYPE (to))
+                  && SSA_NAME_PTR_INFO (to))
+           {
+             if (SSA_NAME_IS_DEFAULT_DEF (to)
+                 || dominated_by_p (CDI_DOMINATORS,
+                                    gimple_bb (SSA_NAME_DEF_STMT (from)),
+                                    gimple_bb (SSA_NAME_DEF_STMT (to))))
+               /* Keep the info from the dominator.  */
+               ;
+             else if (SSA_NAME_IS_DEFAULT_DEF (from)
+                      || dominated_by_p (CDI_DOMINATORS,
+                                         gimple_bb (SSA_NAME_DEF_STMT (to)),
+                                         gimple_bb (SSA_NAME_DEF_STMT (from))))
+               {
+                 /* Save old info.  */
+                 if (! VN_INFO (to)->info.ptr_info)
+                   VN_INFO (to)->info.ptr_info = SSA_NAME_PTR_INFO (to);
+                 /* Use that from the dominator.  */
+                 SSA_NAME_PTR_INFO (to) = SSA_NAME_PTR_INFO (from);
+               }
+             else
+               {
+                 /* Save old info.  */
+                 if (! VN_INFO (to)->info.ptr_info)
+                   VN_INFO (to)->info.ptr_info = SSA_NAME_PTR_INFO (to);
+                 /* Rather than allocating memory and unioning the info
+                    just clear it.  */
+                 SSA_NAME_PTR_INFO (to) = NULL;
+               }
+           }
+       }
+
       VN_INFO (from)->valnum = to;
       if (dump_file && (dump_flags & TDF_DETAILS))
        fprintf (dump_file, " (changed)\n");
@@ -4152,9 +4219,17 @@ free_scc_vn (void)
     {
       tree name = ssa_name (i);
       if (name
-         && has_VN_INFO (name)
-         && VN_INFO (name)->needs_insertion)
-       release_ssa_name (name);
+         && has_VN_INFO (name))
+       {
+         if (VN_INFO (name)->needs_insertion)
+           release_ssa_name (name);
+         else if (POINTER_TYPE_P (TREE_TYPE (name))
+                  && VN_INFO (name)->info.ptr_info)
+           SSA_NAME_PTR_INFO (name) = VN_INFO (name)->info.ptr_info;
+         else if (INTEGRAL_TYPE_P (TREE_TYPE (name))
+                  && VN_INFO (name)->info.range_info)
+           SSA_NAME_RANGE_INFO (name) = VN_INFO (name)->info.range_info;
+       }
     }
   obstack_free (&vn_ssa_aux_obstack, NULL);
   vn_ssa_aux_table.release ();

diff --git a/gcc/tree-ssa-sccvn.h b/gcc/tree-ssa-sccvn.h
index 04339ac96522ae07422e7513dc2b2d55968d5463..d94bc1c095055999be97fde8a6db9b40908f3acb 100644 (file)
--- a/gcc/tree-ssa-sccvn.h
+++ b/gcc/tree-ssa-sccvn.h
@@ -169,6 +169,9 @@ typedef struct vn_ssa_aux
   /* Statements to insert if needs_insertion is true.  */
   gimple_seq expr;
 
+  /* Saved SSA name info.  */
+  tree_ssa_name::ssa_name_info_type info;
+
   /* Unique identifier that all expressions with the same value have. */
   unsigned int value_id;