Hi Mike, > why does it work without -std ? Then gcc uses it's best guess based on extension (.S). > shouldnt it either pass or fail regardless of -std ? No. If you use -std, then gcc is using the specified standard, not it's best guess. As to which C standard -std defaults to... I don't know. Without testing, my guess would be -std is an undocumented shortcut for -std=c99 (for gcc), and -std=c++98 (for g++), but maybe -std is a shortcut for -ansi. HTH, --Eljay
