re PR tree-optimization/88533 (Higher performance penalty of array-bounds checking for sparse-matrix vector multiply)

2018-12-19  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/88533
	Revert
	2018-04-30  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/28364
	PR tree-optimization/85275
	* tree-ssa-loop-ch.c (ch_base::copy_headers): Stop after
	copying first exit test.

	* gcc.dg/tree-ssa/ssa-dom-thread-7.c: Adjust.

	* tree-ssa-loop-ch.c: Include tree-phinodes.h and
	ssa-iterators.h.
	(should_duplicate_loop_header_p): Track whether stmt compute
	loop invariants or values based on IVs.  Apart from the
	original loop header only duplicate blocks with exit tests
	that are based on IVs or invariants.

	* gcc.dg/tree-ssa/copy-headers-6.c: New testcase.
	* gcc.dg/tree-ssa/copy-headers-7.c: Likewise.
	* gcc.dg/tree-ssa/ivopt_mult_1.c: Un-XFAIL.
	* gcc.dg/tree-ssa/ivopt_mult_2.c: Likewise.

From-SVN: r267262