https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83133
--- Comment #8 from Uroš Bizjak <ubizjak at gmail dot com> --- (In reply to jos...@codesourcery.com from comment #5) > Both 32-bit and 64-bit ABIs make the values of flags in EFLAGS (other than > DF) undefined on function entry and return. Thus, a function can never > assume anything about the value of OF unless it has executed an > instruction known to set/clear it and has not called any other functions > since then. In the testcase, there is nothing that violates ABI. It all happens in "g" that passes calculated result to a function. Selected function depends on flags, calculated from the subtraction, and wrong function gets selected when overflow happens.
