re PR tree-optimization/64853 (wrong code at -Os and above on x86_64-linux-gnu)

2015-01-29  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/64853
	* tree-vrp.c (vrp_valueize_1): Do not return anything if the
	stmt will get simulated again.
	* tree-ssa-ccp.c (valueize_op_1): Likewise.

	* gcc.dg/torture/pr64853.c: New testcase.

From-SVN: r220247

gcc/ChangeLog

+2015-01-29  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/64853
+	* tree-vrp.c (vrp_valueize_1): Do not return anything if the
+	stmt will get simulated again.
+	* tree-ssa-ccp.c (valueize_op_1): Likewise.
+
 2015-01-29  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	* config/arm/arm.c (arm_emit_multi_reg_pop): Simplify definition of

gcc/testsuite/ChangeLog

 2015-01-29  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/64853
+	* gcc.dg/torture/pr64853.c: New testcase.
+
+2015-01-29  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/64844
 	* gcc.dg/vect/pr64844.c: New testcase.
 

gcc/testsuite/gcc.dg/torture/pr64853.c

+/* { dg-do run } */
+
+struct S
+{
+  int f1;
+};
+
+static struct S a = { 1 };
+char b;
+static unsigned char *c = &b;
+int d, e, f;
+
+int
+fn1 (int p)
+{
+  return 0 ? 0 : p - 1;
+}
+
+static int
+fn2 (struct S p)
+{
+  int g = 200;
+  for (e = 4; e; e = fn1 (e))
+    {
+      for (; d; d++)
+	;
+      *c &= p.f1 & g;
+      g = --*c;
+      if (f)
+	return 0;
+    }
+  return 0;
+}
+
+int
+main ()
+{
+  fn2 (a);
+
+  if (b != 0) 
+    __builtin_abort (); 
+
+  return 0;
+}

gcc/tree-ssa-ccp.c

@@ -1141,15 +1141,15 @@ valueize_op_1 (tree op)
 {
   if (TREE_CODE (op) == SSA_NAME)
     {
-      tree tem = get_constant_value (op);
-      if (tem)
-	return tem;
       /* If the definition may be simulated again we cannot follow
          this SSA edge as the SSA propagator does not necessarily
 	 re-visit the use.  */
       gimple def_stmt = SSA_NAME_DEF_STMT (op);
       if (prop_simulate_again_p (def_stmt))
 	return NULL_TREE;
+      tree tem = get_constant_value (op);
+      if (tem)
+	return tem;
     }
   return op;
 }

gcc/tree-vrp.c

@@ -7092,15 +7092,15 @@ vrp_valueize_1 (tree name)
 {
   if (TREE_CODE (name) == SSA_NAME)
     {
-      value_range_t *vr = get_value_range (name);
-      if (range_int_cst_singleton_p (vr))
-	return vr->min;
       /* If the definition may be simulated again we cannot follow
          this SSA edge as the SSA propagator does not necessarily
 	 re-visit the use.  */
       gimple def_stmt = SSA_NAME_DEF_STMT (name);
       if (prop_simulate_again_p (def_stmt))
 	return NULL_TREE;
+      value_range_t *vr = get_value_range (name);
+      if (range_int_cst_singleton_p (vr))
+	return vr->min;
     }
   return name;
 }