re PR tree-optimization/30965 (Fails to tree-combine conditions in COND_EXPRs)

re PR tree-optimization/30965 (Fails to tree-combine conditions in COND_EXPRs)

2007-04-27  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/30965
	PR tree-optimization/30978
	* Makefile.in (tree-ssa-forwprop.o): Depend on $(FLAGS_H).
        * tree-ssa-forwprop.c (forward_propagate_into_cond_1): Remove.
        (find_equivalent_equality_comparison): Likewise.
        (simplify_cond): Likewise.
        (get_prop_source_stmt): New helper.
        (get_prop_dest_stmt): Likewise.
	(can_propagate_from): Likewise.
	(remove_prop_source_from_use): Likewise.
        (combine_cond_expr_cond): Likewise.
        (forward_propagate_comparison): New function.
        (forward_propagate_into_cond): Rewrite to use fold for
        tree combining.
	(tree_ssa_forward_propagate_single_use_vars): Call
	forward_propagate_comparison to propagate comparisons.

	* gcc.dg/tree-ssa/pr30978.c: New testcase.
	* gcc.dg/tree-ssa/bool-3.c: Remove XFAIL, explain why.
	* gcc.dg/tree-ssa/ssa-fre-4.c: Use char instead of bool
	* gcc.dg/strict-overflow-5.c: Adjust tree dump scanning.

From-SVN: r124217