predict.c (find_qualified_ssa_name): New

predict.c (find_qualified_ssa_name): New

2012-05-08  Dehao Chen  <dehao@google.com>
gcc/
	* predict.c (find_qualified_ssa_name): New
	(find_ssa_name_in_expr): New
	(find_ssa_name_in_assign_stmt): New
	(is_comparison_with_loop_invariant_p): New
	(is_bound_expr_similar): New
	(predict_iv_comparison): New
	(predict_loops): Add heuristic for loop-nested branches that compare an
	induction variable to a loop bound variable.
	* predict.def (PRED_LOOP_IV_COMPARE): New macro
testsuite/
	* gcc.dg/predict-1.c: Check if LOOP_IV_COMPARE static predict
	heuristic is working properly.
	* gcc.dg/predict-2.c: Likewise.
	* gcc/dg/predict-3.c: Likewise.
	* gcc/dg/predict-4.c: Likewise.
	* gcc/dg/predict-5.c: Likewise.
	* gcc/dg/predict-6.c: Likewise.

From-SVN: r187277