6.6.1.31 -msmart-io [=0|1|2]

This option attempts to statically analyze format strings passed to printf, scanf and the ‘f’ and ‘v’ variations of these functions. Uses of nonfloating point format arguments will be converted to use an integer-only variation of the library functions.

-msmart-io=0 disables this option, while -msmart-io=2 causes the compiler to be optimistic and convert function calls with variable or unknown format arguments. -msmart-io=1 is the default and will only convert the literal values it can prove.