re PR tree-optimization/81303 (410.bwaves regression caused by r249919)

re PR tree-optimization/81303 (410.bwaves regression caused by r249919)

	PR tree-optimization/81303
	* Makefile.in (gimple-loop-interchange.o): New object file.
	* common.opt (floop-interchange): Reuse the option from graphite.
	* doc/invoke.texi (-floop-interchange): Ditto.  New document for
	-floop-interchange and mention it for -O3.
	* opts.c (default_options_table): Enable -floop-interchange at -O3.
	* gimple-loop-interchange.cc: New file.
	* params.def (PARAM_LOOP_INTERCHANGE_MAX_NUM_STMTS): New parameter.
	(PARAM_LOOP_INTERCHANGE_STRIDE_RATIO): New parameter.
	* passes.def (pass_linterchange): New pass.
	* timevar.def (TV_LINTERCHANGE): New time var.
	* tree-pass.h (make_pass_linterchange): New declaration.
	* tree-ssa-loop-ivcanon.c (create_canonical_iv): Change to external
	interchange.  Record IV before/after increment in new parameters.
	* tree-ssa-loop-ivopts.h (create_canonical_iv): New declaration.
	* tree-vect-loop.c (vect_is_simple_reduction): Factor out reduction
	path check into...
	(check_reduction_path): ...New function here.
	* tree-vectorizer.h (check_reduction_path): New declaration.

	gcc/testsuite
	* gcc.dg/tree-ssa/loop-interchange-1.c: New test.
	* gcc.dg/tree-ssa/loop-interchange-1b.c: New test.
	* gcc.dg/tree-ssa/loop-interchange-2.c: New test.
	* gcc.dg/tree-ssa/loop-interchange-3.c: New test.
	* gcc.dg/tree-ssa/loop-interchange-4.c: New test.
	* gcc.dg/tree-ssa/loop-interchange-5.c: New test.
	* gcc.dg/tree-ssa/loop-interchange-6.c: New test.
	* gcc.dg/tree-ssa/loop-interchange-7.c: New test.
	* gcc.dg/tree-ssa/loop-interchange-8.c: New test.
	* gcc.dg/tree-ssa/loop-interchange-9.c: New test.
	* gcc.dg/tree-ssa/loop-interchange-10.c: New test.
	* gcc.dg/tree-ssa/loop-interchange-11.c: New test.
	* gcc.dg/tree-ssa/loop-interchange-12.c: New test.
	* gcc.dg/tree-ssa/loop-interchange-13.c: New test.

Co-Authored-By: Richard Biener <rguenther@suse.de>
From-SVN: r255472