2016-07-12  Steven Bosscher  <steven@gcc.gnu.org>
	Richard Biener  <rguenther@suse.de>

	PR tree-optimization/23286
	PR tree-optimization/70159
	* doc/invoke.texi: Document -fcode-hoisting.
	* common.opt (fcode-hoisting): New flag.
	* opts.c (default_options_table): Enable -fcode-hoisting at -O2+.
	* tree-ssa-pre.c (pre_stats): Add hoist_insert.
	(do_regular_insertion): Rename to ...
	(do_pre_regular_insertion): ... this and amend general comments
	on insertion strathegy.
	(do_partial_partial_insertion): Rename to ...
	(do_pre_partial_partial_insertion): ... this.
	(do_hoist_insertion): New function.
	(insert_aux): Take flags on whether to do PRE and/or hoist insertion
	and call do_hoist_insertion properly.
	(insert): Adjust.
	(pass_pre::gate): Enable also if -fcode-hoisting is enabled.
	(pass_pre::execute): Register hoist_insert stats.

	* gcc.dg/tree-ssa/ssa-pre-11.c: Disable code hosting.
	* gcc.dg/tree-ssa/ssa-pre-27.c: Likewise.
	* gcc.dg/tree-ssa/ssa-pre-28.c: Likewise.
	* gcc.dg/tree-ssa/ssa-pre-2.c: Likewise.
	* gcc.dg/tree-ssa/pr35286.c: Likewise.
	* gcc.dg/tree-ssa/pr35287.c: Likewise.
	* gcc.dg/hoist-register-pressure-1.c: Likewise.
	* gcc.dg/hoist-register-pressure-2.c: Likewise.
	* gcc.dg/hoist-register-pressure-3.c: Likewise.
	* gcc.dg/pr51879-12.c: Likewise.
	* gcc.dg/strlenopt-9.c: Likewise.
	* gcc.dg/tree-ssa/pr47392.c: Likewise.
	* gcc.dg/tree-ssa/pr68619-4.c: Likewise.
	* gcc.dg/tree-ssa/split-path-5.c: Likewise.
	* gcc.dg/tree-ssa/slsr-35.c: Likewise.
	* gcc.dg/tree-ssa/slsr-36.c: Likewise.
	* gcc.dg/tree-ssa/loadpre3.c: Adjust so hosting doesn't apply.
	* gcc.dg/tree-ssa/pr43491.c: Scan optimized dump for desired result.
	* gcc.dg/tree-ssa/ssa-pre-31.c: Adjust expected outcome for hoisting.
	* gcc.dg/tree-ssa/ssa-hoist-1.c: New testcase.
	* gcc.dg/tree-ssa/ssa-hoist-2.c: New testcase.
	* gcc.dg/tree-ssa/ssa-hoist-3.c: New testcase.
	* gcc.dg/tree-ssa/ssa-hoist-4.c: New testcase.
	* gcc.dg/tree-ssa/ssa-hoist-5.c: New testcase.
	* gcc.dg/tree-ssa/ssa-hoist-6.c: New testcase.
	* gfortran.dg/pr43984.f90: Adjust expected outcome.

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

From-SVN: r238242