re PR tree-optimization/61221 (ICE on valid code at -O1 and above on x86_64-linux-gnu)

2014-05-20  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/61221
	* tree-ssa-pre.c (el_to_update): Remove.
	(eliminate_dom_walker::before_dom_children): Handle released
	VDEFs by value-numbering them to the associated VUSE.  Update
	stmt immediately for substituted call address.
	(eliminate): Remove delayed stmt updating code.
	* tree-ssa-sccvn.c (vuse_ssa_val): New function valueizing
	possibly late re-numbered vuses.
	(vn_reference_lookup_2): Adjust.
	(vn_reference_lookup_pieces): Likewise.
	(vn_reference_lookup): Likewise.

From-SVN: r210633

3 files changed, 51 insertions, 13 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 16c7f51..26142ba 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,19 @@
 2014-05-20  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/61221
+	* tree-ssa-pre.c (el_to_update): Remove.
+	(eliminate_dom_walker::before_dom_children): Handle released
+	VDEFs by value-numbering them to the associated VUSE.  Update
+	stmt immediately for substituted call address.
+	(eliminate): Remove delayed stmt updating code.
+	* tree-ssa-sccvn.c (vuse_ssa_val): New function valueizing
+	possibly late re-numbered vuses.
+	(vn_reference_lookup_2): Adjust.
+	(vn_reference_lookup_pieces): Likewise.
+	(vn_reference_lookup): Likewise.
+
+2014-05-20  Richard Biener  <rguenther@suse.de>
+
 	* config.gcc: Remove need_64bit_hwint.
 	* configure.ac: Do not define NEED_64BIT_HOST_WIDE_INT.
 	* hwint.h: Do not check NEED_64BIT_HOST_WIDE_INT but assume
diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index e487d28..2929d4d 100644
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -3915,7 +3915,6 @@ compute_avail (void)
 
 /* Local state for the eliminate domwalk.  */
 static vec<gimple> el_to_remove;
-static vec<gimple> el_to_update;
 static unsigned int el_todo;
 static vec<tree> el_avail;
 static vec<tree> el_avail_stack;
@@ -4155,9 +4154,14 @@ eliminate_dom_walker::before_dom_children (basic_block b)
 		  print_gimple_stmt (dump_file, stmt, 0, 0);
 		}
 	      pre_stats.eliminations++;
+
+	      tree vdef = gimple_vdef (stmt);
+	      tree vuse = gimple_vuse (stmt);
 	      propagate_tree_value_into_stmt (&gsi, sprime);
 	      stmt = gsi_stmt (gsi);
 	      update_stmt (stmt);
+	      if (vdef != gimple_vdef (stmt))
+		VN_INFO (vdef)->valnum = vuse;
 
 	      /* If we removed EH side-effects from the statement, clean
 		 its EH information.  */
@@ -4255,9 +4259,14 @@ eliminate_dom_walker::before_dom_children (basic_block b)
 		sprime = fold_convert (gimple_expr_type (stmt), sprime);
 
 	      pre_stats.eliminations++;
+
+	      tree vdef = gimple_vdef (stmt);
+	      tree vuse = gimple_vuse (stmt);
 	      propagate_tree_value_into_stmt (&gsi, sprime);
 	      stmt = gsi_stmt (gsi);
 	      update_stmt (stmt);
+	      if (vdef != gimple_vdef (stmt))
+		VN_INFO (vdef)->valnum = vuse;
 
 	      /* If we removed EH side-effects from the statement, clean
 		 its EH information.  */
@@ -4371,7 +4380,11 @@ eliminate_dom_walker::before_dom_children (basic_block b)
 		}
 
 	      gimple_call_set_fn (stmt, fn);
-	      el_to_update.safe_push (stmt);
+	      tree vdef = gimple_vdef (stmt);
+	      tree vuse = gimple_vuse (stmt);
+	      update_stmt (stmt);
+	      if (vdef != gimple_vdef (stmt))
+		VN_INFO (vdef)->valnum = vuse;
 
 	      /* When changing a call into a noreturn call, cfg cleanup
 		 is needed to fix up the noreturn call.  */
@@ -4430,7 +4443,6 @@ eliminate (void)
   need_ab_cleanup = BITMAP_ALLOC (NULL);
 
   el_to_remove.create (0);
-  el_to_update.create (0);
   el_todo = 0;
   el_avail.create (0);
   el_avail_stack.create (0);
@@ -4482,13 +4494,6 @@ eliminate (void)
     }
   el_to_remove.release ();
 
-  /* We cannot update call statements with virtual operands during
-     SSA walk.  This might remove them which in turn makes our
-     VN lattice invalid.  */
-  FOR_EACH_VEC_ELT (el_to_update, i, stmt)
-    update_stmt (stmt);
-  el_to_update.release ();
-
   return el_todo;
 }
 
diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index fc00682..73362f8 100644
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -318,6 +318,25 @@ static int *rpo_numbers;
 
 #define SSA_VAL(x) (VN_INFO ((x))->valnum)
 
+/* Return the SSA value of the VUSE x, supporting released VDEFs
+   during elimination which will value-number the VDEF to the
+   associated VUSE (but not substitute in the whole lattice).  */
+
+static inline tree
+vuse_ssa_val (tree x)
+{
+  if (!x)
+    return NULL_TREE;
+
+  do
+    {
+      x = SSA_VAL (x);
+    }
+  while (SSA_NAME_IN_FREE_LIST (x));
+
+  return x;
+}
+
 /* This represents the top of the VN lattice, which is the universal
    value.  */
 
@@ -1495,7 +1514,7 @@ vn_reference_lookup_2 (ao_ref *op ATTRIBUTE_UNUSED, tree vuse,
   /* Fixup vuse and hash.  */
   if (vr->vuse)
     vr->hashcode = vr->hashcode - SSA_NAME_VERSION (vr->vuse);
-  vr->vuse = SSA_VAL (vuse);
+  vr->vuse = vuse_ssa_val (vuse);
   if (vr->vuse)
     vr->hashcode = vr->hashcode + SSA_NAME_VERSION (vr->vuse);
 
@@ -2035,7 +2054,7 @@ vn_reference_lookup_pieces (tree vuse, alias_set_type set, tree type,
     vnresult = &tmp;
   *vnresult = NULL;
 
-  vr1.vuse = vuse ? SSA_VAL (vuse) : NULL_TREE;
+  vr1.vuse = vuse_ssa_val (vuse);
   shared_lookup_references.truncate (0);
   shared_lookup_references.safe_grow (operands.length ());
   memcpy (shared_lookup_references.address (),
@@ -2090,7 +2109,7 @@ vn_reference_lookup (tree op, tree vuse, vn_lookup_kind kind,
   if (vnresult)
     *vnresult = NULL;
 
-  vr1.vuse = vuse ? SSA_VAL (vuse) : NULL_TREE;
+  vr1.vuse = vuse_ssa_val (vuse);
   vr1.operands = operands
     = valueize_shared_reference_ops_from_ref (op, &valuezied_anything);
   vr1.type = TREE_TYPE (op);