2018-05-16 Richard Biener <rguenther@suse.de>
* params.def (PARAM_DSE_MAX_ALIAS_QUERIES_PER_STORE): New param.
* doc/invoke.texi (dse-max-alias-queries-per-store): Document.
* tree-ssa-dse.c: Include tree-ssa-loop.h.
(check_name): New callback.
(dse_classify_store): Track cycles via a visited bitmap of PHI
defs and simplify handling of in-loop and across loop dead stores
and properly fail for loop-variant refs. Handle byte-tracking with
multiple defs. Use PARAM_DSE_MAX_ALIAS_QUERIES_PER_STORE for
limiting the walk.
* gcc.dg/tree-ssa/ssa-dse-32.c: New testcase.
* gcc.dg/tree-ssa/ssa-dse-33.c: Likewise.
* gcc.dg/uninit-pr81897-2.c: Use -fno-tree-dse.
From-SVN: r260288
