On Sat, Jan 27, 2024 at 6:09 AM Jakub Jelinek <ja...@redhat.com> wrote:
>
> On Sat, Jan 27, 2024 at 05:52:34AM -0800, H.J. Lu wrote:
> > @@ -3391,7 +3392,9 @@ ix86_set_func_type (tree fndecl)
> > function is marked as noreturn in the IR output, which leads the
> > incompatible attribute error in LTO1. */
> > bool has_no_callee_saved_registers
> > - = (((TREE_NOTHROW (fndecl) || !flag_exceptions)
> > + = ((optimize
> > + && !optimize_debug
>
> Shouldn't that be opt_for_fn (fndecl, optimize) and ditto for
> optimize_debug?
> I mean, aren't the options not restored yet when this function is called
> (i.e. remain in whatever state they were in the previous function or
> global state)?
store_parm_decls is called when parsing a function. store_parm_decls
calls allocate_struct_function which calls
invoke_set_current_function_hook (fndecl);
which has
/* Change optimization options if needed. */
if (optimization_current_node != opts)
{
optimization_current_node = opts;
cl_optimization_restore (&global_options, &global_options_set,
TREE_OPTIMIZATION (opts));
}
targetm.set_current_function (fndecl);
which calls ix86_set_current_function after global_options
has been updated. ix86_set_func_type is called from
ix86_set_current_function.
I don't see an issue with optimize and optimize_debug here.
> Also, shouldn't the lookup_attribute ("noreturn" check be the first one?
> I mean, noreturn functions are quite rare and so checking all the other
I will fix it and updated one testcase with
__attribute__((noreturn, optimize("-Og")))
> conditions upon each set_cfun could waste too much compile time.
>
> Also, why check "noreturn" attribute rather than
> TREE_THIS_VOLATILE (fndecl)?
>
The comments above this code has
NB: Don't use TREE_THIS_VOLATILE to check if this is a noreturn
function. The local-pure-const pass turns an interrupt function
into a noreturn function by setting TREE_THIS_VOLATILE. Normally
the local-pure-const pass is run after ix86_set_func_type is called.
When the local-pure-const pass is enabled for LTO, the interrupt
function is marked as noreturn in the IR output, which leads the
incompatible attribute error in LTO1.
Thanks.
--
H.J.
