re PR tree-optimization/61518 (wrong code (by tree vectorizer) at -O3 on x86_64-linux-gnu)

        PR tree-optimization/61518
gcc/
        * tree-if-conv.c (is_cond_scalar_reduction): Add missed check that
        reduction var is used in reduction stmt or phi-function only.

gcc/testsuite/
        * gcc.dg/torture/pr61518.c: New test.

From-SVN: r211780

gcc/ChangeLog

+2014-06-18  Yuri Rumyantsev  <ysrumyan@gmail.com>
+
+	PR tree-optimization/61518
+	* tree-if-conv.c (is_cond_scalar_reduction): Add missed check that
+	reduction var is used in reduction stmt or phi-function only.
+
 2014-06-18  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	* config/arm/arm_neon.h (vadd_f32): Change #ifdef to __FAST_MATH.

gcc/testsuite/ChangeLog

+2014-06-18  Yuri Rumyantsev  <ysrumyan@gmail.com>
+
+	PR tree-optimization/61518
+	* gcc.dg/torture/pr61518.c: New test.
+
 2014-06-18  Thomas Preud'homme  <thomas.preudhomme@arm.com>
 
 	PR tree-optimization/61517

gcc/testsuite/gcc.dg/torture/pr61518.c

+/* { dg-do run } */
+
+int a, b, c[1], d, e, f;
+
+void
+fn1 ()
+{
+  for (; d < 1; d++)
+    {
+      if (b)
+	{
+	  a = e++ && f;
+	  b = f;
+	}
+      c[b] = 0;
+    }
+}
+
+int
+main ()
+{
+  fn1 ();
+
+  if (e != 0)
+    __builtin_abort ();
+
+  return 0;
+}
+

gcc/tree-if-conv.c

@@ -1409,6 +1409,8 @@ is_cond_scalar_reduction (gimple phi, gimple *reduc,
   enum tree_code reduction_op;
   struct loop *loop = gimple_bb (phi)->loop_father;
   edge latch_e = loop_latch_edge (loop);
+  imm_use_iterator imm_iter;
+  use_operand_p use_p;
 
   arg_0 = PHI_ARG_DEF (phi, 0);
   arg_1 = PHI_ARG_DEF (phi, 1);
@@ -1465,6 +1467,18 @@ is_cond_scalar_reduction (gimple phi, gimple *reduc,
   else if (r_op1 != PHI_RESULT (header_phi))
     return false;
 
+  /* Check that R_OP1 is used in reduction stmt or in PHI only.  */
+  FOR_EACH_IMM_USE_FAST (use_p, imm_iter, r_op1)
+    {
+      gimple use_stmt = USE_STMT (use_p);
+      if (is_gimple_debug (use_stmt))
+	continue;
+      if (use_stmt == stmt)
+	continue;
+      if (gimple_code (use_stmt) != GIMPLE_PHI)
+	return false;
+    }
+
   *op0 = r_op1; *op1 = r_op2;
   *reduc = stmt;
   return true;