https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91287
--- Comment #28 from Xiong Hu XS Luo <luoxhu at cn dot ibm.com> --- (In reply to Richard Biener from comment #24) > Btw, this is controlled by symtab_node::output_to_lto_symbol_table_p which > has > > /* FIXME: Builtins corresponding to real functions probably should have > symbol table entries. */ > if (TREE_CODE (decl) == FUNCTION_DECL && fndecl_built_in_p (decl)) > return false; > > we could try to do sth like > > if (TREE_CODE (decl) == FUNCTION_DECL > && (fndecl_built_in_p (decl, BUILT_IN_MD) > || (fndecl_built_in_p (decl, BUILT_IN_NORMAL) > && !associated_internal_fn (decl)))) > return false; > > but that would still leave us with too many undefineds I guess > (gcc_unreachable for one). > > We do not currently track builtins that do have a library implementation > (whether that it is used in the end is another thing, but less important). > > What we definitely can do is put a whitelist above like via the following > which also catches the case of definitions of builtins. > > Index: gcc/symtab.c > =================================================================== > --- gcc/symtab.c (revision 273968) > +++ gcc/symtab.c (working copy) > @@ -2375,10 +2375,24 @@ symtab_node::output_to_lto_symbol_table_ > first place. */ > if (VAR_P (decl) && DECL_HARD_REGISTER (decl)) > return false; > + > /* FIXME: Builtins corresponding to real functions probably should have > symbol table entries. */ > - if (TREE_CODE (decl) == FUNCTION_DECL && fndecl_built_in_p (decl)) > - return false; > + if (TREE_CODE (decl) == FUNCTION_DECL > + && !definition > + && fndecl_built_in_p (decl)) > + { > + if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL) > + switch (DECL_FUNCTION_CODE (decl)) > + { > + CASE_FLT_FN (BUILT_IN_ATAN2): > + CASE_FLT_FN (BUILT_IN_SIN): > + return true; > + default: > + break; > + } > + return false; > + } > > /* We have real symbol that should be in symbol table. However try to > trim > down the refernces to libraries bit more because linker will otherwise Hi Richard, no undefineds generated with below code, what's your opinion about the updated code, please? Thanks. diff --git a/gcc/lto-streamer-out.c b/gcc/lto-streamer-out.c index 47a9143ae26..9d42a57b4b6 100644 --- a/gcc/lto-streamer-out.c +++ b/gcc/lto-streamer-out.c @@ -2644,7 +2644,10 @@ write_symbol (struct streamer_tree_cache_d *cache, gcc_checking_assert (TREE_PUBLIC (t) && (TREE_CODE (t) != FUNCTION_DECL - || !fndecl_built_in_p (t)) + || !fndecl_built_in_p (t, BUILT_IN_MD)) + && (TREE_CODE (t) != FUNCTION_DECL + || !fndecl_built_in_p (t, BUILT_IN_NORMAL) + || associated_internal_fn (t) != IFN_LAST) && !DECL_ABSTRACT_P (t) && (!VAR_P (t) || !DECL_HARD_REGISTER (t))); diff --git a/gcc/symtab.c b/gcc/symtab.c index 63e2820eb93..ce74589b291 100644 --- a/gcc/symtab.c +++ b/gcc/symtab.c @@ -2377,7 +2377,10 @@ symtab_node::output_to_lto_symbol_table_p (void) return false; /* FIXME: Builtins corresponding to real functions probably should have symbol table entries. */ - if (TREE_CODE (decl) == FUNCTION_DECL && fndecl_built_in_p (decl)) + if (TREE_CODE (decl) == FUNCTION_DECL + && (fndecl_built_in_p (decl, BUILT_IN_MD) + || (fndecl_built_in_p (decl, BUILT_IN_NORMAL) + && IFN_LAST == associated_internal_fn (decl)))) return false; /* We have real symbol that should be in symbol table. However try to trim