backport: [multiple changes]

backport: [multiple changes]

2019-08-02  Richard Biener  <rguenther@suse.de>

	Backport from mainline
	2019-07-31  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/91178
	* tree-ssa-sccvn.c (vn_reference_maybe_forwprop_address):
	Use tail-recursion.

	* gcc.dg/torture/pr91178-2.c: New testcase.

	2019-07-17  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/91178
	* tree-ssa.c (release_defs_bitset): Iterate from higher to
	lower SSA names to avoid quadratic behavior in the common case.
	* tree-data-ref.c (split_constant_offset): Add limit argument
	and pass it down.  Initialize it from PARAM_SSA_NAME_DEF_CHAIN_LIMIT.
	(split_constant_offset_1): Add limit argument and use it to
	limit SSA def walking.  Optimize the common plus/minus case.

	* gcc.dg/torture/pr91178.c: New testcase.

	2019-07-12  Martin Sebor  <msebor@redhat.com>

	* doc/invoke.texi (ssa-name-def-chain-limit): Document new --param.
	* params.def (PARAM_SSA_NAME_DEF_CHAIN_LIMIT): Add new --param.
	* tree-vrp.c (vrp_prop::check_mem_ref): Use
	PARAM_SSA_NAME_DEF_CHAIN_LIMIT.

	* gcc.dg/Warray-bounds-43.c: New test.

From-SVN: r274000