tree-ssa-loop-niter.c (number_of_iterations_popcount): If popcount argument is…

tree-ssa-loop-niter.c (number_of_iterations_popcount): If popcount argument is checked for zero before entering loop, avoid checking again.

gcc/ChangeLog:

2018-07-06  Kugan Vivekanandarajah  <kuganv@linaro.org>

	* tree-ssa-loop-niter.c (number_of_iterations_popcount): If popcount
	argument is checked for zero before entering loop, avoid checking again.

From-SVN: r262487

gcc/ChangeLog

 2018-07-06  Kugan Vivekanandarajah  <kuganv@linaro.org>
 
+	* tree-ssa-loop-niter.c (number_of_iterations_popcount): If popcount
+	argument is checked for zero before entering loop, avoid checking again.
+
+2018-07-06  Kugan Vivekanandarajah  <kuganv@linaro.org>
+
 	* gimplify.h (generic_expr_could_trap_p): Set as global function.
 	* gimplify.h (generic_expr_could_trap_p): Likwise.
 	* tree-scalar-evolution.c (expression_expensive_p): Handle COND_EXPR.

gcc/tree-ssa-loop-niter.c

@@ -2596,10 +2596,15 @@ number_of_iterations_popcount (loop_p loop, edge exit,
 
   niter->niter = iter;
   niter->assumptions = boolean_true_node;
+
   if (adjust)
-    niter->may_be_zero = fold_build2 (EQ_EXPR, boolean_type_node, src,
+    {
+      tree may_be_zero = fold_build2 (EQ_EXPR, boolean_type_node, src,
 				      build_zero_cst
 				      (TREE_TYPE (src)));
+      niter->may_be_zero =
+	simplify_using_initial_conditions (loop, may_be_zero);
+    }
   else
     niter->may_be_zero = boolean_false_node;