https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102347
--- Comment #9 from Kewen Lin <linkw at gcc dot gnu.org> --- (In reply to Peter Bergner from comment #7) > (In reply to Martin Liška from comment #6) > > Quickly looking at the rs6000 code, it fails here: > > > > #1 0x0000000011a0993c in rs6000_invalid_builtin > > (fncode=MMA_BUILTIN_DISASSEMBLE_ACC_INTERNAL) at > > ../../gcc/config/rs6000/rs6000-call.c:11643 > > #2 0x0000000011a13134 in rs6000_builtin_decl (code=1603, initialize_p=true) > > at ../../gcc/config/rs6000/rs6000-call.c:13870 > > #3 0x00000000115c3900 in unpack_ts_function_decl_value_fields > > (bp=0x3fffffffe2f0, expr=0x3fffaf195700) at ../../gcc/tree-streamer-in.c:361 > > #4 0x00000000115c4790 in streamer_read_tree_bitfields (ib=0x3fffffffe6a0, > > data_in=0x132d1910, expr=0x3fffaf195700) at ../../gcc/tree-streamer-in.c:528 > > #5 0x0000000010deaa28 in lto_read_tree_1 (ib=0x3fffffffe6a0, > > data_in=0x132d1910, expr=0x3fffaf195700) at ../../gcc/lto-streamer-in.c:1697 > > > > which relies on rs6000_builtin_mask. Note the mask is set here: > > rs6000_builtin_mask = rs6000_builtin_mask_calculate (); > > > > where rs6000_builtin_mask_calculate is based on TARGET_* values. > > Is that really the issue though? In a non-lto compile, > handle_pragma_target() ends up calling rs6000_option_override_internal which > sets the TARGET_* flags for the function given the pragma options. Where > does LTO do that? I think I see lto read in the default options that were > set on the command line, but where and when does LTO set the options defined > by the pragma? Are they even streamed out to the fat obj file? They could > be there, but I'm not seeing it. I guess the problem here is this bif checking is so early, it's when we make up the bif function_decl tree_node, at that time the context is still the one with default option. I may be wrong, what I understood is that the target_option is streamed out as part of its associated function decl into decls section, when streaming in the decls section, the decls are constructed (including function decls with target_option and bif decls), the bif validity checking happen here. But function decls with target_option will be used for setting current function later when lto starts to process cgraph_node one by one. IIUC, fat obj file should not affect since it's mainly to control normal non-lto sections generated or not.
