This does away with enabling -ffinite-loops at -O2+ for all languages
and instead enables it selectively for C++ only.
It also makes -ffinite-loops loop-private at CFG construction time
fixing correctness issues with inlining.
2020-04-02 Richard Biener <rguenther@suse.de>
PR c/94392
* c-opts.c (c_common_post_options): Enable -ffinite-loops
for -O2 and C++11 or newer.
* common.opt (ffinite-loops): Initialize to zero.
* opts.c (default_options_table): Remove OPT_ffinite_loops
entry.
* cfgloop.h (loop::finite_p): New member.
* cfgloopmanip.c (copy_loop_info): Copy finite_p.
* ipa-icf-gimple.c (func_checker::compare_loops): Compare
finite_p.
* lto-streamer-in.c (input_cfg): Stream finite_p.
* lto-streamer-out.c (output_cfg): Likewise.
* tree-cfg.c (replace_loop_annotate): Initialize finite_p
from flag_finite_loops at CFG build time.
* tree-ssa-loop-niter.c (finite_loop_p): Check the loops
finite_p flag instead of flag_finite_loops.
* doc/invoke.texi (ffinite-loops): Adjust documentation of
default setting.
* gcc.dg/torture/pr94392.c: New testcase.
