varpool.c (dump_varpool_node): Dump write-only flag.
* varpool.c (dump_varpool_node): Dump write-only flag.
* lto-cgraph.c (lto_output_varpool_node, input_varpool_node): Stream
write-only flag.
* tree-cfg.c (execute_fixup_cfg): Remove statements setting write-only variables.
* gcc.c-torture/execute/
20101011-1.c: Update testcase.
* gcc.dg/ira-shrinkwrap-prep-1.c: Update testcase.
* gcc.dg/tree-ssa/writeonly.c: New testcase.
* gcc.dg/tree-ssa/ssa-dse-6.c: Update testcase.
* gcc.dg/tree-ssa/pr21559.c: Update testcase.
* gcc.dg/debug/pr35154.c: Update testcase.
* gcc.target/i386/vectorize1.c: Update testcase.
* ipa.c (process_references): New function.
(set_readonly_bit): New function.
(set_writeonly_bit): New function.
(clear_addressable_bit): New function.
(ipa_discover_readonly_nonaddressable_var): Mark write only variables; fix
handling of aliases.
* cgraph.h (struct varpool_node): Add writeonly flag.
From-SVN: r210522