http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34940
--- Comment #9 from Jan Hubicka <hubicka at ucw dot cz> 2010-11-10 22:35:46 UTC --- The inline heuristics should take that into account. But at the moment io block simply always prevent inlining function with IO into function without IO. We consider function with more than 256 bytes of stack frame to have large frame and those are. Why it needs that much of stack space at first place?