Enable musttail tail conversion even when not optimizing

Enable the tailcall optimization for non optimizing builds,
but in this case only checks calls that have the musttail attribute set.
This makes musttail work without optimization.

This is done with a new late musttail pass that is only active when
not optimizing. The new pass relies on tree-cfg to discover musttails.
This avoids a ~0.8% compiler run time penalty at -O0.

gcc/ChangeLog:

	PR c/83324
	* function.h (struct function): Add has_musttail.
	* lto-streamer-in.cc (input_struct_function_base): Stream
	has_musttail.
	* lto-streamer-out.cc (output_struct_function_base): Dito.
	* passes.def (pass_musttail): Add.
	* tree-cfg.cc (notice_special_calls): Record has_musttail.
	(clear_special_calls): Clear has_musttail.
	* tree-pass.h (make_pass_musttail): Add.
	* tree-tailcall.cc (find_tail_calls): Handle only_musttail
	argument.
	(tree_optimize_tail_calls_1): Pass on only_musttail.
	(execute_tail_calls): Pass only_musttail as false.
	(class pass_musttail): Add.
	(make_pass_musttail): Add.

0 files changed, 0 insertions, 0 deletions