https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93674
--- Comment #2 from Gábor Buella <gbuella at gmail dot com> --- (In reply to Andrew Pinski from comment #1) > -fstrict-enums > Allow the compiler to optimize using the assumption that a value of > enumerated type can only be one of the values of the enumeration (as defined > in the C++ standard; basically, a value that can be represented in the > minimum number of bits needed to represent all the enumerators). This > assumption may not be valid if the program uses a cast to convert an > arbitrary integer value to the enumerated type. > > ---- CUT --- > I assume that means since there is no negative numbers in the enum, that > means you might get undefined behavior if j is negative ... Look at the code, j is never negative when the cast is applied. You can easily verify it by printing the e.g. values.
