N.B. the "Volatile?" column is specific to the Windows calling conventions. Under the Sys V calling conventions (i.e. what the world outside of Redmond uses), R

N.B. the "Volatile?" column is specific to the Windows calling conventions. Under the Sys V calling conventions (i.e. what the world outside of Redmond uses), RDI and RSI are volatile (and used for passing the first two integer arguments).