https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64711
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2020-11-12
Status|UNCONFIRMED |NEW
Ever confirmed|0 |1
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
As Andrew says the reason is that C library builtins are marked nothrow which
currently implies "notrap" in the context of -fnon-call-exceptions. There's
no separate attribute for not trapping (or IPA discovery of this) but a
simple enough workaround only pessimizing -fnon-call-exceptions would be sth
like the following
diff --git a/gcc/tree-eh.c b/gcc/tree-eh.c
index c3314bbd78c..bcf6a7fb348 100644
--- a/gcc/tree-eh.c
+++ b/gcc/tree-eh.c
@@ -2902,6 +2902,12 @@ stmt_could_throw_p (function *fun, gimple *stmt)
return true;
case GIMPLE_CALL:
+ /* ??? We need to check whether the callee can throw non-call
+ exceptions or conservatively assume so if we cannot tell but
+ non-call exceptions are enabled. */
+ if (fun && fun->can_throw_non_call_exceptions
+ || flag_non_call_exceptions)
+ return true;
return !gimple_call_nothrow_p (as_a <gcall *> (stmt));
case GIMPLE_COND:
as the comments says the check isn't correct but it might work for simple
non-LTO cases. Anybody willing to try?
