* tree-ssa-reassoc.c (undistribute_ops_list): Use create_tmp_reg.
	(can_reassociate_p): Use FLOAT_TYPE_P.
	* tree-vectorizer.h (vect_is_simple_reduction): Rename to ...
	(vect_force_simple_reduction): ... this.
	* tree-parloops.c (gather_scalar_reductions): Use 
	vect_force_simple_reduction.
	* tree-vect-loop.c (vect_is_simple_reduction_1): Rename from
	vect_is_simple_reduction, add modify argument, if true rewrite
	"a-b" into "a+(-b)".
	(vect_is_simple_reduction, vect_force_simple_reduction): New
	functions.
	(vect_analyze_scalar_cycles_1): Use vect_force_simple_reduction.

testsuite/
	* gcc.dg/vect/fast-math-vect-reduc-8.c: New test.

From-SVN: r159226