https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96939
--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:57e113cf7c94a682c29566cb3e0e85955904fd35 commit r11-3104-g57e113cf7c94a682c29566cb3e0e85955904fd35 Author: Jakub Jelinek <ja...@redhat.com> Date: Thu Sep 10 17:39:00 2020 +0200 arm: Fix up arm_override_options_after_change [PR96939] As mentioned in the PR, the testcase fails to link, because when set_cfun is being called on the crc function, arm_override_options_after_change is called from set_cfun -> invoke_set_current_function_hook: /* Change optimization options if needed. */ if (optimization_current_node != opts) { optimization_current_node = opts; cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts)); } and at that point target_option_default_node actually matches even the current state of options, so this means armv7 (or whatever) arch is set as arm_active_target, then targetm.set_current_function (fndecl); is called later in that function, which because the crc function's DECL_FUNCTION_SPECIFIC_TARGET is different from the current one will do: cl_target_option_restore (&global_options, TREE_TARGET_OPTION (new_tree)); which calls arm_option_restore and sets arm_active_target to armv8-a+crc (so far so good). Later arm_set_current_function calls: save_restore_target_globals (new_tree); which in this case calls: /* Call target_reinit and save the state for TARGET_GLOBALS. */ TREE_TARGET_GLOBALS (new_tree) = save_target_globals_default_opts (); which because optimization_current_node != optimization_default_node (the testcase is LTO, so all functions have their DECL_FUNCTION_SPECIFIC_TARGET and TREE_OPTIMIZATION nodes) will call: cl_optimization_restore (&global_options, TREE_OPTIMIZATION (optimization_default_node)); and cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts)); The problem is that these call arm_override_options_after_change again, and that one uses the target_option_default_node as what to set the arm_active_target to (i.e. back to armv7 or whatever, but not to the armv8-a+crc that should be the active target for the crc function). That means we then error on the builtin call in that function. Now, the targetm.override_options_after_change hook is called always at the end of cl_optimization_restore, i.e. when we change the Optimization marked generic options. So it seems unnecessary to call arm_configure_build_target at that point (nothing it depends on changed), and additionally incorrect (because it uses the target_option_default_node, rather than the current set of options; we'd need to revert https://gcc.gnu.org/legacy-ml/gcc-patches/2016-12/msg01390.html otherwise so that it works again with global_options otherwise). The options that arm_configure_build_target cares about will change only during option parsing (which is where it is called already), or during arm_set_current_function, where it is done during the cl_target_option_restore. Now, arm_override_options_after_change_1 wants to adjust the str_align_functions, which depends on the current Optimization options (e.g. optimize_size and flag_align_options and str_align_functions) as well as the target options target_flags, so IMHO needs to be called both when the Optimization options (possibly) change, i.e. from the targetm.override_options_after_change hook, and from when the target options change (set_current_function hook). 2020-09-10 Jakub Jelinek <ja...@redhat.com> PR target/96939 * config/arm/arm.c (arm_override_options_after_change): Don't call arm_configure_build_target here. (arm_set_current_function): Call arm_override_options_after_change_1 at the end. * gcc.target/arm/lto/pr96939_0.c: New test. * gcc.target/arm/lto/pr96939_1.c: New file.
