re PR tree-optimization/65053 (PostgreSQL miscompilation)

PR tree-optimization/65053
	* tree-ssa-phiopt.c (value_replacement): When moving assign before
	cond, either reset VR on lhs or set it to phi result VR.

	* gcc.c-torture/execute/pr65053-1.c: New test.
	* gcc.c-torture/execute/pr65053-2.c: New test.

From-SVN: r220700

gcc/ChangeLog

@@ -1,3 +1,9 @@
+2015-02-13  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/65053
+	* tree-ssa-phiopt.c (value_replacement): When moving assign before
+	cond, either reset VR on lhs or set it to phi result VR.
+
 2015-02-13  Jeff Law  <law@redhat.com>
 
 	PR tree-optimization/64823

gcc/testsuite/ChangeLog

@@ -1,3 +1,9 @@
+2015-02-13  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/65053
+	* gcc.c-torture/execute/pr65053-1.c: New test.
+	* gcc.c-torture/execute/pr65053-2.c: New test.
+
 2015-02-13  Marek Polacek  <polacek@redhat.com>
 
 	PR c/65050

gcc/testsuite/gcc.c-torture/execute/pr65053-1.c

@@ -0,0 +1,32 @@
+/* PR tree-optimization/65053 */
+
+int i;
+
+__attribute__ ((noinline, noclone))
+unsigned int foo (void)
+{
+  return 0;
+}
+
+int
+main ()
+{
+  unsigned int u = -1;
+  if (u == -1)
+    {
+      unsigned int n = foo ();
+      if (n > 0)
+	u = n - 1;
+    }
+
+  while (u != -1)
+    {
+      asm ("" : "+g" (u));
+      u = -1;
+      i = 1;
+    }
+
+  if (i)
+    __builtin_abort ();
+  return 0;
+}

gcc/testsuite/gcc.c-torture/execute/pr65053-2.c

@@ -0,0 +1,27 @@
+/* PR tree-optimization/65053 */
+
+int i;
+unsigned int x;
+
+int
+main ()
+{
+  asm volatile ("" : "+g" (x));
+  unsigned int n = x;
+  unsigned int u = 32;
+  if (n >= 32)
+    __builtin_abort ();
+  if (n != 0)
+    u = n + 32;
+
+  while (u != 32)
+    {
+      asm ("" : : "g" (u));
+      u = 32;
+      i = 1;
+    }
+
+  if (i)
+    __builtin_abort ();
+  return 0;
+}

gcc/tree-ssa-phiopt.c

@@ -917,6 +917,31 @@ value_replacement (basic_block cond_bb, basic_block middle_bb,
 	      && absorbing_element_p (code_def, cond_rhs))))
     {
       gsi = gsi_for_stmt (cond);
+      if (INTEGRAL_TYPE_P (TREE_TYPE (lhs)))
+	{
+	  /* Moving ASSIGN might change VR of lhs, e.g. when moving u_6
+	     def-stmt in:
+	     if (n_5 != 0)
+	       goto <bb 3>;
+	     else
+	       goto <bb 4>;
+
+	     <bb 3>:
+	     # RANGE [0, 4294967294]
+	     u_6 = n_5 + 4294967295;
+
+	     <bb 4>:
+	     # u_3 = PHI <u_6(3), 4294967295(2)>  */
+	  SSA_NAME_RANGE_INFO (lhs) = NULL;
+	  SSA_NAME_ANTI_RANGE_P (lhs) = 0;
+	  /* If available, we can use VR of phi result at least.  */
+	  tree phires = gimple_phi_result (phi);
+	  struct range_info_def *phires_range_info
+	    = SSA_NAME_RANGE_INFO (phires);
+	  if (phires_range_info)
+	    duplicate_ssa_name_range_info (lhs, SSA_NAME_RANGE_TYPE (phires),
+					   phires_range_info);
+	}
       gimple_stmt_iterator gsi_from = gsi_for_stmt (assign);
       gsi_move_before (&gsi_from, &gsi);
       replace_phi_edge_with_variable (cond_bb, e1, phi, lhs);