re PR tree-optimization/87168 (ICE on valid code at -Os and above on…

re PR tree-optimization/87168 (ICE on valid code at -Os and above on x86_64-linux-gnu: verify_ssa failed)

2018-08-31  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/87168
	* tree-ssa-sccvn.c (SSA_VAL): Add visited output parameter.
	(rpo_elim::eliminate_avail): When OP was not visited it must
	be available.

	* gcc.dg/torture/pr87168.c: New testcase.

From-SVN: r264021

gcc/ChangeLog

+2018-08-31  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/87168
+	* tree-ssa-sccvn.c (SSA_VAL): Add visited output parameter.
+	(rpo_elim::eliminate_avail): When OP was not visited it must
+	be available.
+
 2018-08-31  David Malcolm  <dmalcolm@redhat.com>
 
 	* tree-vrp.c (copy_value_range): Convert param "from" from

gcc/testsuite/ChangeLog

+2018-08-31  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/87168
+	* gcc.dg/torture/pr87168.c: New testcase.
+
 2018-08-31  Vlad Lazar  <vlad.lazar@arm.com>
 
 	* gcc.target/aarch64/scalar_intrinsics.c (test_vnegd_s64): New.

gcc/testsuite/gcc.dg/torture/pr87168.c

+/* { dg-do compile } */
+
+int a, b, c, d, e, f, *g;
+
+int main ()
+{ 
+  unsigned i;
+  while (b)
+    { 
+      int j, m;
+L1:
+      f = j;
+L2:
+      if (i && e)
+	{ 
+	  i = f;
+	  goto L2;
+	}
+      j = f;
+      if (a)
+	goto L3;
+      for (m = 0; m < 2; m++)
+	if (d)
+	  goto L1;
+      goto L2;
+L3:
+      (&j != g) | c;
+    }
+  return 0;
+}

gcc/tree-ssa-sccvn.c

@@ -456,9 +456,11 @@ VN_INFO (tree name)
 /* Return the SSA value of X.  */
 
 inline tree
-SSA_VAL (tree x)
+SSA_VAL (tree x, bool *visited = NULL)
 {
   vn_ssa_aux_t tem = vn_ssa_aux_hash->find_with_hash (x, SSA_NAME_VERSION (x));
+  if (visited)
+    *visited = tem && tem->visited;
   return tem && tem->visited ? tem->valnum : x;
 }
 
@@ -5681,7 +5683,12 @@ rpo_elim::~rpo_elim ()
 tree
 rpo_elim::eliminate_avail (basic_block bb, tree op)
 {
-  tree valnum = SSA_VAL (op);
+  bool visited;
+  tree valnum = SSA_VAL (op, &visited);
+  /* If we didn't visit OP then it must be defined outside of the
+     region we process and also dominate it.  So it is available.  */
+  if (!visited)
+    return op;
   if (TREE_CODE (valnum) == SSA_NAME)
     {
       if (SSA_NAME_IS_DEFAULT_DEF (valnum))