cselim: Extend to check non-trapping for more references [PR89430]
If there is a dominating store, a store to the same reference can not be
trapped. But previously, it only supports such check on MEM_REFs.
So this patch extends it to support ARRAY_REFs and COMPONENT_REFs.
This patch also supports a special case: if there is a dominating load of
local variable without address escape, a store is not trapped, as local
stack is always writable. Other loads are ignored for simplicity, as they
don't help to check if a store can be trapped (the memory may be read-only).
gcc/ChangeLog:
PR tree-optimization/89430
* tree-ssa-phiopt.c
(struct name_to_bb): Rename to ref_to_bb; add a new field exp;
remove ssa_name_ver, store, offset fields.
(struct ssa_names_hasher): Rename to refs_hasher; update functions.
(class nontrapping_dom_walker): Rename m_seen_ssa_names to m_seen_refs.
(nontrapping_dom_walker::add_or_mark_expr): Extend to support ARRAY_REFs
and COMPONENT_REFs.
gcc/testsuite/ChangeLog:
PR tree-optimization/89430
* gcc.dg/tree-ssa/pr89430-1.c: Remove xfail.
* gcc.dg/tree-ssa/pr89430-2.c: Remove xfail.
* gcc.dg/tree-ssa/pr89430-5.c: Remove xfail.
* gcc.dg/tree-ssa/pr89430-6.c: Remove xfail.
* gcc.dg/tree-ssa/pr89430-7-comp-ref.c: New test.
* gcc.dg/tree-ssa/pr89430-8-mem-ref-size.c: New test.
* gcc.dg/tree-ssa/ssa-pre-17.c: Add -fno-tree-cselim.